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LI NI U

Tun th php lut v bo v mi trng, hot ng bo v mi trng ni chung v nh gi tc ng mi trng ni ring c trin khai rng khp trn ton quc. T nm 1994 n nay, hng nghn cc d n pht trin tin hnh nh gi tc ng mi trng (TM), bo co TM ca cc d n ny c thm nh v ph duyt bi cc B Trung ng v cc a phng cp tnh.

Thi gian qua, vi s tr gip ti chnh t Hp phn Kim sot nhim cc vng ng dn ngho thuc Chng trnh hp tc Vit Nam an Mch v mi trng giai on 2005-2010, Cc Thm nh v nh gi tc ng mi trng, Tng cc Mi trng, B Ti nguyn v Mi trng (trc y l V Thm nh v nh gi tc ng mi trng trc thuc B Ti nguyn v Mi trng) phi hp cng cc chuyn gia xy dng v ban hnh hng dn k thut lp bo co TM cho mt s loi hnh d n pht trin:

- H thng h tng k thut khu/cm cng nghip; - Bi chn lp cht thi rn sinh hot; - Trm x l nc thi th; - Nh my sn xut xi mng; - Nh my nhit in; - Nh my sn xut thp; - Nh my sn xut giy v bt giy Tuy nhin, theo Ph lc ban hnh km theo s 21/2008/N-CP ngy 28 thng 02 nm

2008 ca Chnh ph v sa i, b sung mt s iu ca Ngh nh s 80/2006/N-CP ngy 09 thng 8 nm 2006 ca Chnh ph v vic quy nh chi tit v hng dn thi hnh mt s iu ca Lut Bo v mi trng, s lng cc loi hnh d n thuc i tng phi lp bo co TM l rt ln, khong 162 loi.

S tay TM, c bin dch t cc ngun ti liu quc t v chnh l cho ph hp vi iu kin ca Vit Nam, gii thiu v nh gi tc ng mi trng cho cc d n pht trin theo cc nhm ngnh, lnh vc. S tay TM, bao gm 02 (hai) tp, cung cp cho cc nh qun l, cc chuyn gia, cc nh khoa hc hot ng trong lnh vc bo v mi trng cch nhn bit cc tc ng mi trng chnh; cc gii php, bin php gim thiu cc tc ng tiu cc ca cc nhm loi hnh d n km theo danh mc cc ti liu tham kho.

Cc Thm nh v nh gi tc ng mi trng xin c gii thiu S tay TM cho nhiu i tng khc nhau s dng trong qu trnh nh gi tc ng mi trng ca cc hot ng pht trin. Trong qu trnh p dng vo thc t, nu c kh khn, vng mt xin kp thi phn nh v Cc Thm nh v nh gi tc ng mi trng theo a ch:

Cc Thm nh v nh gi tc ng mi trng 83 Nguyn Ch Thanh, H Ni in thoi: 844-37734246

Fax: 844-37734916

Tp II: NNG NGHIP, KHAI THC M/NNG LNG,

THNG MI/CNG NGHIP

Hng dn xy dng nghin cu ton din v cc kha cnh mi trng ca d n

MC LC

LI NI U ................................................................................................................................. i

I. NNG NGHIP ........................................................................................................................ 18

1. Canh tc nng nghip ................................................................................................................ 18

1.1. Phm vi ............................................................................................................................... 18

1.2. Tc ng mi trng v cc phng php bo v ............................................................. 18

1.2.1. Cc tc ng mi trng ............................................................................................. 19

1.2.1.1. t ............................................................................................................................ 19

1.2.1.2. Nc. ........................................................................................................................ 20

1.2.1.3. Khng kh ................................................................................................................. 20

1.2.1.4. Sinh quyn ................................................................................................................ 20

1.2.2. Phng php bo v .................................................................................................... 21

1.2.2.1. iu kin chung ....................................................................................................... 21

1.2.2.2. Sinh thi nng tri .................................................................................................... 22

1.3. Nhng lu trong phn tch v nh gi ca cc tc ng mi trng ............................ 24

1.4. S tng tc vi cc khu vc khc .................................................................................... 26

1.5. Tm lc nh gi mi trng lin quan. .......................................................................... 26

1.6. Ti liu tham kho .............................................................................................................. 27

2. Bo v thc vt .......................................................................................................................... 31

2.1. Phm vi ............................................................................................................................... 31

2.2. Cc tc ng mi trng v bin php bo v ................................................................... 33

2.2.1. Tng quan v bo v thc vt ..................................................................................... 33

2.2.2. Cc phng php bo v thc vt c trng ............................................................... 34

2.2.2.1. Cc phng php vt l ............................................................................................ 34

2.2.2.2. Cc phng php ho hc ........................................................................................ 35

2.2.2.3. Cc phng php cng ngh sinh hc ...................................................................... 38

2.2.2.4. Cc bin php sinh hc ............................................................................................. 39

2.2.2.5. Cc phng php tng hp ...................................................................................... 39

2.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 40

2.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 40

2

2.5. Tm lc nh gi tc ng mi trng lin quan ............................................................ 41

2.6. Ti liu tham kho .............................................................................................................. 41

3. Lm nghip ................................................................................................................................ 46

3.1. Phm vi ............................................................................................................................... 46

3.1.1. Tng quan .................................................................................................................... 46

3.1.2. Cc lnh vc ................................................................................................................ 46

3.1.2.1. Qui hoch/sn xut sinh hc ..................................................................................... 46

3.1.2.2. Xc lp loi cy trng ............................................................................................... 47

3.1.2.3. S dng cy ci ........................................................................................................ 48

3.1.2.4. Cc k thut thu hoch ............................................................................................. 50


3.2.1. Cc tc ng c th ca tng lnh vc n mi trng ............................................. 53

3.2.2. Cc chin lc bo v c th theo lnh vc ............................................................... 53



3.4.1. Cc b sung ................................................................................................................. 56

3.4.2. Mi trng x hi ........................................................................................................ 57


3.6. Ti liu tham kho .............................................................................................................. 57

Ph lc: Gii thch mt s thut ng ......................................................................................... 61

4. Chn nui .................................................................................................................................. 63

4.1. Phm vi ............................................................................................................................... 63


4.2.1. Cc dng qun l chn nui ........................................................................................ 63

4.2.1.1. Ch s dng ng c ................................................................................................. 63

4.2.1.2. S dng ng c v c b sung thm thc n .......................................................... 65

4.2.1.3. Sn xut c kh ........................................................................................................ 65

4.2.1.4. Chung, tri .............................................................................................................. 66

4.2.2. Cc h thng chn nui ............................................................................................... 66

4.2.2.1. Tri nui sc vt (Ranches- M, Canada) ............................................................. 66

4.2.2.2. H thng ng c ..................................................................................................... 67

4.2.2.3. Chn nui qui m nh ........................................................................................... 69

4.2.4. Cc trang tri ln vi qu trnh chn nui thm canh (chn nui thng mi) .......... 71



3


4.6. Ti liu tham kho .................................................................................................................. 73

5. Dch v th y ............................................................................................................................. 75

5.1. Phm vi ............................................................................................................................... 75


5.2.1. Kim sot dch bnh .................................................................................................... 76

5.2.1.1. Khm v cha bnh .................................................................................................. 76

5.2.1.2. Phng bnh (prophylaxis) ........................................................................................ 76

5.2.1.3. Kim sot sinh vt trung gian (Vector control) ........................................................ 77

5.2.1.4. Kim sot dch bnh ................................................................................................. 79

5.2.1.5. Kim sot cc bnh c th ly lan sang ngi ......................................................... 79

5.2.2. Cc hot ng ti phng th nghim ............................................................................ 79

5.2.2.1. Chun on ti phng th nghim ............................................................................ 79

5.2.2.2. Sn xut vaccine ....................................................................................................... 80

5.2.2.3. Phn tch cht thi .................................................................................................... 80

5.2.3. Th tinh nhn to v cy phi ..................................................................................... 80

5.2.4. Kim tra thc phm ..................................................................................................... 80

5.2.4.1. Kim tra tht ............................................................................................................. 80

5.2.4.2. V sinh thc phm .................................................................................................... 80



5.6. Ti liu tham kho .............................................................................................................. 82

6. nh bt v nui trng thu sn ................................................................................................ 83

6.1. Phm vi ............................................................................................................................... 83


6.2.1. Cc tri nui c th cng qui m nh .......................................................................... 84

6.2.2. Nui trng thu sn qui m nh .................................................................................. 85

6.2.3. S dng cc h nhn to nui c v nui trng thu sn ....................................... 86

6.2.4. Ngh c trong khu vc 200 dm c quyn kinh t .................................................... 87

6.2.5. S dng rng ngp mn nui c v nui trng thu sn ........................................ 88




6.6. Ti liu tham kho .............................................................................................................. 91

7. Cng ngh/k thut nng nghip .............................................................................................. 93

4

7.1. Phm vi ............................................................................................................................... 93


7.2.1. Con ngi, h sinh thi v k thut nng nghip ........................................................ 93

7.2.1.1. Con ngi v k thut nng nghip ......................................................................... 93

7.2.1.2. H sinh thi v k thut nng nghip ...................................................................... 94

7.2.2. Tng quan v k thut nng nghip ............................................................................ 94

7.2.2.1. Cc ngun nng lng, h thng ng lc, nhin liu v cht bi trn ................... 94

7.2.2.2. Sn xut cc k thut ph tr ................................................................................... 95

7.2.3. Cc c th ca sn xut cy trng ............................................................................. 95

7.2.3.1. Cy cy ..................................................................................................................... 95

7.2.3.2. Gieo ht/trng cy,chm sc v bn phn ................................................................ 96

7.2.3.3. Thu hoch, p la, ch bin, bo qun v lu tr ................................................... 97

7.2.3.4. Cung cp v phn phi nc .................................................................................... 97

7.2.4. Cc c trng ca ngnh chn nui ............................................................................ 98




7.6. Ti liu tham kho .............................................................................................................. 99

8. Thu li ................................................................................................................................... 101

8.1. Phm vi ............................................................................................................................. 101

8.2. Cc tc ng mi trng v bin php bo v ................................................................. 101

8.2.1. Tc ng n cc thnh phn ca mi trng t nhin ............................................ 102

8.2.1.1. Cung cp, vn chuyn v phn phi nc .............................................................. 102

8.2.1.2. S dng v tiu thot nc ..................................................................................... 103

8.2.2. Cc tc ng kinh t-x hi gy bi qu trnh cp, vn chuyn, phn phi, s dng v tiu thot nc ..................................................................................................................... 104

8.2.2.1. Cc yu cu, nhn lc, thu nhp v phn phi ....................................................... 104

8.2.2.2. Sc kho ................................................................................................................. 105

8.2.2.3. Sinh k, nh v gii tr ......................................................................................... 105

8.2.2.4. Tp hun v cc quan h x hi ............................................................................ 106

8.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 106

8.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 107

8.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 107

8.6. Ti liu tham kho ............................................................................................................ 108

II. M V NNG LNG ....................................................................................................... 111

5

1. Thm d, kho st v khai thc cc ngun ti nguyn thin nhin ......................................... 111

1.1. Phm vi ............................................................................................................................. 111


1.2.1. Tip cn khu vc lm vic ........................................................................................ 112

1.2.1.1. Cc tuyn ng tip cn ....................................................................................... 112

1.2.1.2. Cc tuyn dng cp ................................................................................................ 112

1.2.2. Lp bn a hnh v a cht ................................................................................. 113

1.2.3. Tri v cc h thng h tr ........................................................................................ 113

1.2.4. a vt l ................................................................................................................... 113

1.2.4.1. K thut hng khng .............................................................................................. 113

1.2.4.2. Kho st a chn ................................................................................................... 113

1.2.4.3. Kho st a vt l khng dng a chn ............................................................... 113

1.2.4.4. Bn ph ging khoan .............................................................................................. 113

1.2.5. Kho st a cht thu vn ........................................................................................ 114

1.2.5.1. Bm th nghim di hn ......................................................................................... 114

1.2.5.2. Th nghim phun .................................................................................................... 114

1.2.5.3. Th nghim nh du .............................................................................................. 114

1.2.6. Cng tc thm d ....................................................................................................... 114

1.2.6.1. Cc h th nghim ................................................................................................. 114

1.2.6.2. Hm, ng l ........................................................................................................ 114

1.2.6.3. Khoan ..................................................................................................................... 115

1.2.6.4. Cht thi rn/qu trnh b .................................................................................. 115

1.2.7. Thu mu ..................................................................................................................... 116

1.2.7.1. Ly mu b mt ...................................................................................................... 116

1.2.7.2. Ly mu hi dng hc .......................................................................................... 116

1.2.8. Th nghim/phng th nghim ................................................................................... 116

1.2.8.1. Phn tch phng th nghim .................................................................................... 116

1.2.8.2. Th nghim tuyn, lm giu qung ......................................................................... 117




1.6. Ti liu tham kho ............................................................................................................ 118

2. Khai thc m l thin .......................................................................................................... 120

2.1. Phm vi ............................................................................................................................. 120


6

2.2.1. Cc h qu mi trng tim tng ca qu trnh khai thc l thin ............................ 121

2.2.1.1. Khai thc kh ......................................................................................................... 122

2.2.1.2. Khai thc t .......................................................................................................... 125

3. Khai thc ngm ........................................................................................................................ 127

3.1. Phm vi ............................................................................................................................. 127


3.2.1. Tc ng mi trng n tr lng v cc vng nguyn liu ln cn ...................... 128

3.2.1.1. Khai thc cc ngun ti nguyn ............................................................................. 128

3.2.1.2 S ph v cc kt cu .............................................................................................. 128

3.2.1.3. S ph v/chia r dng chy ca nc ngm ......................................................... 128

3.2.1.4. Thay i cht lng nc ngm ............................................................................. 128

3.2.2. Cc tc ng mi trng ca khai thc ngm ........................................................... 128

3.2.2.1. Khng kh/kh hu .................................................................................................. 128

3.2.2.2. Ting n .................................................................................................................. 129

3.2.2.3. Bi .......................................................................................................................... 130

3.2.2.4. Nc m ................................................................................................................. 130

3.2.3. Cc tc ng pha trn b mt ................................................................................... 130

3.2.3.1. Khng kh/kh hu .................................................................................................. 130

3.2.3.2. Nc ....................................................................................................................... 131

3.2.3.3. St ln .................................................................................................................... 131

3.2.3.4. X thi cht thi, nhu cu s dng t, cnh quan ................................................. 131

3.2.4. Cc h qu khc ca qu trnh khai thc ngm ......................................................... 132


3.3.1. Khng kh/kh hu ..................................................................................................... 132

3.3.2. Ting n ..................................................................................................................... 133

3.3.3. Bi ............................................................................................................................. 133

3.3.4. Nc .......................................................................................................................... 133

3.3.5. t ............................................................................................................................. 134



3.6. Ti liu tham kho ............................................................................................................ 135

4. X l v ch bin khong sn ................................................................................................. 139

4.1. Phm vi ............................................................................................................................. 139


4.2.1. X l .......................................................................................................................... 139

7

4.2.2. Tn vn, sng, nghin v phn loi ........................................................................... 140

4.2.3. Tch, tuyn ni .......................................................................................................... 140

4.2.4. Nung .......................................................................................................................... 143

4.2.5 X l, bo qun cc cht lm giu, ti trng trt................................................... 143




4.6. Ti liu tham kho ............................................................................................................ 146

5. Du m v kh thin nhin Khai thc, sn xut, x l, lu tr ............................................ 149

5.1. Phm vi ............................................................................................................................. 149


5.2.1. Khai thc ................................................................................................................... 149

5.2.1.1. Mi trng t nhin v sinh thi ............................................................................ 149

5.2.1.2. Mi trng x hi ................................................................................................... 151

5.2.1.3. Sc kho v an ton ............................................................................................... 151

5.2.2. Sn xut ..................................................................................................................... 151

5.2.2.1 Mi trng t nhin v sinh thi ............................................................................. 152

5.2.2.2. Kinh t, x hi ........................................................................................................ 152

5.2.2.3. Sc kho v an ton ............................................................................................... 152

5.2.3. X l v lu tr ......................................................................................................... 153

5.2.3.1. Mi trng t nhin ............................................................................................... 153

5.2.3.2. Sc kho v an ton ............................................................................................... 153




5.6. Ti liu tham kho ............................................................................................................ 154

6. Sn xut than cc (coke), kh ho than, sn xut v phn phi kh ..................................... 156

6.1. Phm vi ............................................................................................................................. 156


6.2.1 Cc tc ng mi trng ............................................................................................ 158

6.2.2. Cc bin php bo v ................................................................................................ 159


6.3.1. Tng quan .................................................................................................................. 162

6.3.2. Tm lc cc gi tr gii hn v tiu chun .............................................................. 162

6.3.3. nh gi tc ng mi trng ................................................................................... 166

8



6.6. Ti liu tham kho ............................................................................................................ 167

7. Cc trm nhit in ................................................................................................................. 169

7.1. Phm vi ............................................................................................................................. 169


7.2.1. Khng kh .................................................................................................................. 172

7.2.1.1. Kim sot bi ........................................................................................................ 173

7.2.1.2. Kh lu hunh...................................................................................................... 173

7.2.1.3. Kh NOx ............................................................................................................... 175

7.2.1.4. Hiu ng nh knh ................................................................................................ 175

7.2.1.5.Cc ngun pht thi dng din ............................................................................ 175

7.2.2.Nc ........................................................................................................................... 176

7.2.3.t v nc ngm ...................................................................................................... 177

7.2.4.Sc kho cng ng ................................................................................................... 179

7.2.5. Cnh quan .................................................................................................................. 179


7.3.1. Cc gii hn pht thi ................................................................................................ 180

7.3.2. Cc gii hn pht thi vo khng kh ........................................................................ 181

7.3.3. Quan trc/gim st mc nhim .......................................................................... 182

7.3.4. Gii hn x thi nc thi ......................................................................................... 183

7.3.5. Ting n ..................................................................................................................... 184



7.6. Ti liu tham kho ............................................................................................................ 186

7.7. Ph lc .............................................................................................................................. 190

8. Truyn ti v phn phi in ................................................................................................... 195

8.1. Phm vi ............................................................................................................................. 195


8.2.1. Cc h qu i vi mi trng .................................................................................. 195

8.2.2. Sc kho cng ng, an ton lao ng v ngn nga tai nn ................................... 197

8.2.3. Lm suy thoi cnh quan ........................................................................................... 198

8.2.4. Cc tc ng kinh t-x hi v vn ho-x hi ......................................................... 199

8.3. Cc lu trong phn tch v nh gi tc ng mi trng v tiu chun an ton ngh nghip ...................................................................................................................................... 199

9



8.6. Ti liu tham kho ............................................................................................................ 200

9. Cc ngun ti nguyn ti to nng lng ................................................................................ 203

9.1. Phm vi ............................................................................................................................. 203


9.2.1. Nng lng mt tri .................................................................................................. 204

9.2.2. Nng lng sinh khi ................................................................................................ 205

9.2.2.1. t .......................................................................................................................... 205

9.2.2.2. Kh ho .................................................................................................................. 206

9.2.2.3. Biogas ..................................................................................................................... 207

9.2.2.4. Nhin liu sinh hc ............................................................................................... 207

9.2.3. Nng lng gi .......................................................................................................... 208

9.2.4. Thu in ................................................................................................................... 209

9.2.5. Nng lng a nhit ................................................................................................. 209

9.3. Cc lu trong phn tch v nh gi tc ng mi trng ........................................ 210

9.4. S tng tc vi cc khu vc/lnh vc khc ................................................................ 210

9.6. Ti liu tham kho ........................................................................................................ 212

III. CNG NGHIP V THNG MI .................................................................................. 214

1. Phn bn ni-t (sn xut nguyn liu, amoni v ur - urea) ................................................... 214

1.1. Phm vi ............................................................................................................................. 214


1.2.1. Sn xut kh ammoniac tng hp (ASGP) ................................................................ 215

1.2.1.1. ASGP t cc thnh phn hydrocarbons nh ........................................................... 215

1.2.1.2. ASGP t du cn .................................................................................................... 216

1.2.1.3. ASGP t nhin liu rn .......................................................................................... 217

1.2.1.4. in phn nc v tch kh .................................................................................... 218

1.2.2. Lu tr ammoniac tng hp ...................................................................................... 218

1.2.3. Tng hp v to ht ur ............................................................................................. 219




1.6. Ti liu tham kho ............................................................................................................ 221

2. Cc loi phn bn ni-t (nguyn liu ban u v sn phm cui) .......................................... 223

2.1. Phm vi ............................................................................................................................. 223

10


2.2.1. Sn xut a-xt ni-t-ric .............................................................................................. 223

2.2.2. Sn xut a-xt sun-phua-rc ....................................................................................... 224

2.2.3. Sn xut amoni ni-t-rat ............................................................................................ 225

2.2.4. Sn xut ni-t-rat can-xi amoni .............................................................................. 225

2.2.5. Sun-pht amoni ........................................................................................................ 225

2.2.5.1. Sn phm t cc l luyn coke hoc kh ho than ................................................. 226

2.2.5.2. Sn xut t amoni v a-xt sun-phua-rc ................................................................ 226

2.2.5.3. Phn bn nit nh l sn phm ph ....................................................................... 226

2.2.5.4. Sn xut t thch cao, amoni v CO2 ..................................................................... 226

2.2.6 Sn xut ni-t-rt can-xi ............................................................................................. 227

2.2.7 Sn xut cc dung dch ni-t ...................................................................................... 227

2.2.8. Sn xut clo-rua amoni .............................................................................................. 227

2.2.9. Bi-cc-bo-nat amoni .................................................................................................. 228

2.2.10. Vn chuyn, lu tr v ng gi cc phn bn dng rn ........................................ 228




2.6. Ti liu tham kho ............................................................................................................ 230

3. Xi-mng, vi, thch cao .......................................................................................................... 232

3.1. Phm vi ............................................................................................................................. 232


3.2.1. Khng kh .................................................................................................................. 233

3.2.1.1. Kh thi ................................................................................................................... 233

3.2.1.2. Bi .......................................................................................................................... 234

3.2.2. Ting n ..................................................................................................................... 234

3.2.3. Nc .......................................................................................................................... 235

3.2.4. t ............................................................................................................................. 235

3.2.5. Mi trng lao ng .................................................................................................. 235

3.2.6. Cc h sinh thi ......................................................................................................... 236




3.6. Ti liu tham kho ............................................................................................................ 238

4. Gm s k ngh, dn dng v cng nghip ......................................................................... 240

11

4.1. Phm vi ............................................................................................................................. 240


4.2.1. Khng kh .................................................................................................................. 241

4.2.1.1. Kh thi ................................................................................................................... 241

4.2.1.2. Bi .......................................................................................................................... 242

4.2.2. Ting n ..................................................................................................................... 242

4.2.3. Nc .......................................................................................................................... 243

4.2.4. t ............................................................................................................................. 243

4.2.5. Ni lm vic .............................................................................................................. 244

4.2.6. Cc h sinh thi ......................................................................................................... 244




4.6. Ti liu tham kho ............................................................................................................ 248

5. Thy tinh ................................................................................................................................. 250

5.1. Phm vi ............................................................................................................................. 250


5.2.1. Khng kh .................................................................................................................. 251

5.2.2.1. Kh thi ................................................................................................................... 251

5.2.1.2. Bi .......................................................................................................................... 252

5.2.2. Ting n ..................................................................................................................... 253

5.2.3. Nc .......................................................................................................................... 253

5.2.4. t ............................................................................................................................. 254

5.2.5. Mi trng lao ng .................................................................................................. 254

5.2.6. Cc h sinh thi ......................................................................................................... 254




5.6. Ti liu tham kho ............................................................................................................ 259

6. Gang, thp ............................................................................................................................... 261

6.1. Phm vi ............................................................................................................................. 261


6.2.1. Nh my nung kt/to ht .......................................................................................... 262

6.2.2. L cao ........................................................................................................................ 263

6.2.3. Cc nh my kh trc tip ....................................................................................... 265

12

6.2.4. Sn xut thp th ...................................................................................................... 265

6.2.5. Sn xut thp hnh ..................................................................................................... 267

6.2.6. Cc hot ng c v rn .......................................................................................... 269




6.6. Ti liu tham kho ............................................................................................................ 273

7. Kim loi mu ........................................................................................................................... 278

7.1. Phm vi ............................................................................................................................. 278


7.2.1. Tch Aluminium ....................................................................................................... 278

7.2.2. Nu chy qung kim loi nng .................................................................................. 280

7.2.3. Cc nh my luyn th cp ....................................................................................... 283

7.2.4. Sn xut bn thnh phm ca kim loi mu .............................................................. 284




7.6. Ti liu tham kho ............................................................................................................ 287

8. C kh ch to v ng tu ...................................................................................................... 291

8.1. Phm vi ............................................................................................................................. 291


8.2.1. Cc dng nguy hi tim tang ca mt s hot ng .................................................. 292

8.2.1.1. Ct kim loi ............................................................................................................ 292

8.2.1.2. Lm sch v ty m bn thnh phm ..................................................................... 293

8.2.1.3. Sn .......................................................................................................................... 295

8.2.1.4. Xi m in .............................................................................................................. 296

8.2.1.5. Hn ......................................................................................................................... 296

8.2.1.6. Hn nhit cao ..................................................................................................... 298

8.2.1.7. Mi ......................................................................................................................... 298

8.2.2. Qu trnh cng ngh c kh v vn hnh ca cc xng c kh v xng ng tu (shipyards) ........................................................................................................................... 299

8.2.2.1. Kh thi ................................................................................................................... 300

8.2.2.2. Nc thi ................................................................................................................ 301

8.2.2.3. Cht thi rn ........................................................................................................... 303

8.2.2.4. t .......................................................................................................................... 303

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8.2.2.5. Ting n .................................................................................................................. 304


8.3.1 Khng kh ................................................................................................................... 306

8.3.2 Nc thi .................................................................................................................... 306

8.3.3 Cht thi rn ............................................................................................................... 306



8.6. Ti liu tham kho ............................................................................................................ 307

9. Nng cng nghip ................................................................................................................ 310

9.1. Phm vi ............................................................................................................................. 310


9.2.1. Tng quan v nng-cng nghip ............................................................................... 310

9.2.2. Mt s lnh vc chnh ................................................................................................ 311

9.2.2.1. Xay bt ng cc ...................................................................................................... 311

9.2.2.2. Ch bin tinh bt .................................................................................................... 311

9.2.2.3. Ch bin ht c du v tri cy .............................................................................. 311

9.2.2.4. Ch bin c ci ng v ma ng ..................................................................... 311

9.2.2.5. Ch bin rau qu ..................................................................................................... 312

9.2.2.6. B sa ..................................................................................................................... 312

9.2.2..7 Ch bin cc mt hng trung-cao cp v gia v ...................................................... 312

9.2.2.8 Chit/tch cht x t thc vt ................................................................................. 312

9.2.2.9. Thuc da ................................................................................................................. 313

9.2.3. Cc tc ng kinh t-x hi ....................................................................................... 313




9.6. Ti liu tham kho ............................................................................................................ 314

10. L sc sn v ch bin tht .................................................................................................... 315

10.1. Phm vi ........................................................................................................................... 315

10.2. Cc tc ng mi trng v bin php bo v ............................................................... 316

10.2.1. nhim nc .......................................................................................................... 316

10.2.2. nhim khng kh .................................................................................................. 318

10.2.3. Ting n ................................................................................................................... 320

10.2.4. Cht thi rn v cn ................................................................................................. 320

10.2.5. Nhit d ................................................................................................................... 320

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10.2.6. An ton cng nghip ............................................................................................... 321

10.2.7. Qui hoch v tr ........................................................................................................ 321

10.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 321

10.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 322

10.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 323

10.6. Ti liu tham kho .......................................................................................................... 323

11. Xay bt ng cc ..................................................................................................................... 325

11.1. Phm vi ........................................................................................................................... 325


11.2.1.Lu tr v x l ng cc .......................................................................................... 326

11.2.1.1. Cc silo ti cng khi vn chuyn v ni xay/nghin ............................................ 326

11.2.1.2. Nh kho ca cc hp tc x .................................................................................. 328

11.2.1.3. Lm sch ht ......................................................................................................... 329

11.2.1.4. Sy kh ................................................................................................................. 329

11.2.2. Xay bt (xay bt la m ) ........................................................................................ 330

11.2.3. Xay ht c v ........................................................................................................... 330

11.2.3.1. Xay la ................................................................................................................. 330

11.2.3.2. Tch v v ch bin la min (sorghum) v k (millet) ....................................... 331

11.2.3.3. Xay (u) ......................................................................................................... 332

11.2.4. Qui hoch v tr ........................................................................................................ 332

11.2.5. Nng lng t v (tru) thi .................................................................................... 332

11.2.6. Cc qu trnh ch bin cht thi c lm sch v sn phm sau khi xay ......... 333

11.2.7. X l bi .................................................................................................................. 333




11.6. Ti liu tham kho .......................................................................................................... 335

12. Cht bo v du thc vt ....................................................................................................... 337

12.1. Phm vi ........................................................................................................................... 337


12.2.1 Tim nng nguy hi ca cc cng on ch bin ..................................................... 338

12.2.2. Ch bin tri cy (qu c v -lu) ......................................................................... 339

12.2.3. Ch bin cc qu v ht c du ............................................................................... 340

12.2.3.1. Bo qun ............................................................................................................... 340

12.2.3.2. Lm sch v nghin .............................................................................................. 340

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12.2.3.3. n nh nguyn liu th ....................................................................................... 340

12.2.3.4. Qu trnh p .......................................................................................................... 341

12.2.3.5. Chit bng dung mi ............................................................................................ 341

12.2.3.6. Tinh luyn ............................................................................................................ 342


12.3.1. Khng kh ................................................................................................................ 344

12.3.2. Ting n ................................................................................................................... 344

12.3.3. Nc thi ................................................................................................................. 345

12.3.4. Cht thi .................................................................................................................. 347

12.3.5. t ........................................................................................................................... 347

12.3.6. La chn v tr ......................................................................................................... 347

12.3.7. Vn chuyn .............................................................................................................. 348



12.5.1. Tch du th ............................................................................................................ 348

12.5.2. Tinh luyn du ......................................................................................................... 349

12.6. Ti liu tham kho .......................................................................................................... 349

13. ng .................................................................................................................................... 352

13.1. Phm vi ........................................................................................................................... 352


13.2.1. Trng, thu hoch, bo qun v lm sch nguyn liu ............................................. 354

13.2.2. Ct, nghin nguyn liu th v chit ....................................................................... 355

13.2.3. Lm sch dung dch sau khi chit ........................................................................... 356

13.2.4. Bay hi, kt tinh v lm kh ng ........................................................................ 357

13.2.5. Ch bin cc sn phm ph ..................................................................................... 357

13.2.6. Nhu cu nng lng ................................................................................................ 358

13.2.7. Qun l nc ........................................................................................................... 358


13.3.1. Cc yu cu v gii hn pht thi ............................................................................ 360

13.3.2. Cng ngh gim thiu pht thi v quan trc pht thi ........................................... 362

13.3.3. Cc gi tr gii hn lin quan n bo v sc kho ................................................. 363



13.6. Ti liu tham kho .......................................................................................................... 365

14. n g, ca, ch bin g v cc sn phm t g .................................................................. 367

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14.1. Phm vi ........................................................................................................................... 367


14.2.1. Ch bin g bng c kh .......................................................................................... 367

14.2.2. Sn xut cc sn phm t g ................................................................................... 370




14.6. Ti liu tham kho .......................................................................................................... 373

15. Giy v bt giy .................................................................................................................... 377

15.1. Phm vi ........................................................................................................................... 377

15.1.1. Gii thiu/Thng tin chung/thut ng ..................................................................... 377

15.1.2. Sn xut bt giy ..................................................................................................... 377

15.1.2.1. Cc nguyn liu th .............................................................................................. 378

15.1.2.2. Cc sn phm v qu trnh sn xut ..................................................................... 378

15.1.3. Sn xut giy v ba ................................................................................................ 380

15.1.3.1. Cc vt liu dng si c bn, bt giy (nguyn liu th cho qu trnh sn xut giy v ba) .................................................................................................................................. 380

15.1.3.2. Cc sn phm v qu trnh sn xut ..................................................................... 380

15.1.4. Cc h thng my mc ph v ph tr .................................................................... 381


15.2.1. Phm vi: Nguyn liu th v ph tr ...................................................................... 381

15.2.1.1. Nguyn liu th dng si ...................................................................................... 381

15.2.1.2. Nc ..................................................................................................................... 382

15.2.1.3. Nng lng ........................................................................................................... 382

15.2.1.4. Ho cht v cc cht ph tr khc ........................................................................ 383

15.2.2. Cc dng thi t qu trnh sn xut giy v bt giy .............................................. 383

15.2.2.1. Cc dng thi lng ................................................................................................ 383

15.2.2.2. Cc dng thi vo khng kh ................................................................................ 384

15.2.2.3. Cht thi rn ......................................................................................................... 384

15.2.2.4. Ting n ................................................................................................................ 384


15.3.1. Cc dng thi lng ................................................................................................... 385

15.3.2. Cc dng thi vo khng kh ................................................................................... 385

15.3.3. Cht thi rn ............................................................................................................ 386

15.3.4. Ting n ................................................................................................................... 386

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15.4.1. Cc phm vi c trng ............................................................................................ 386

15.4.1.1. Nguyn liu th .................................................................................................... 386

15.4.1.2. Cc cht ph tr v ph gia .................................................................................. 388

15.4.2. Cc phm vi khng c trng ................................................................................. 389

16. Dt ......................................................................................................................................... 402

16.1. Phm vi ........................................................................................................................... 402

16.1.1. Thut ng ................................................................................................................ 402

16.1.2. Nguyn liu ............................................................................................................. 402

16.1.3. Cc qu trnh sn xut ............................................................................................. 402

16.1.3.1. n nh si (Fibre conditioning) .......................................................................... 402

16.1.3.2. Xe si (sn xut si) ............................................................................................. 402

16.1.3.3. Dt v dt kim ...................................................................................................... 403

16.1.3.4. Hon tt sn phm ................................................................................................ 403

16.1.4. Kch thc ca dt nhum ...................................................................................... 403

16.1.4.1. Ko si ................................................................................................................. 403

16.1.4.2. Dt thoi v dt kim ............................................................................................... 403

16.1.4.3. Hon tt sn phm ................................................................................................ 403

16.1.5. Cc vn lin quan n v tr ................................................................................ 403

16.2.1. n nh si .............................................................................................................. 404

16.2.2. Xe si v nh ng .................................................................................................. 404

16.2.3. Dt thoi v dt kim .................................................................................................. 404

16.2.4. Hon tt sn phm ................................................................................................... 405

16.2.4.1. nhim nc thi ................................................................................................ 405

16.2.4.2. Cc dng kh v hi thi ....................................................................................... 407

16.2.4.3. Ting n ................................................................................................................ 408

16.2.5. Cc tc ng mi trng chung .............................................................................. 408

16.3.1. Kim sot nhim khng kh ................................................................................. 409

16.3.2. Kim sot ting n ................................................................................................... 410

16.3.3. Kim sot nhim nc ......................................................................................... 410



16.6. Ti liu tham kho .......................................................................................................... 413

18

I. NNG NGHIP

1. Canh tc nng nghip

1.1. Phm vi

Cc thut ng sau thng c s dng v nh ngha ca chng nh sau:

- n canh (Single cropping) l ch canh tc mt loi cy trn mt mnh t c th, v d la. Nu trn mt mnh t m cc loi cy khc nhau c canh tc k tip nhau th cn c gi l lun canh (crop rotation).

- Xen (a) canh (Intercropping) l h thng c nhiu loi cy khc nhau c canh tc trn cng mt mnh t, v d nh kt hp trng sn (khoai m) vi ht k c (cowpeas).

- Cy thng nin (Annual crops) l thc vt c vng i trong mt nm, v d ng cc, cy h u, cc loi rau v thuc l.

- Cy lu nin (Perennial crops) l loi cy c vng i nhiu hn mt nm v thng ch trng hoc gieo ht mt ln, v d nh cy n tri, c ph, cacao, ch

- c canh (Monoculture) l ch trng mt loi cy c th trn mt vng t c th trong mt s chu k nht nh v d nh cy ma.

Trong trng hp sn xut g, nguyn liu th, thc n gia sc hoc thc vt dng sn xut cc vt dng xa x, canh tc nng nghip trn quan im khu vc - th hin mt dng tc ng ca con ngi n cn bng t t nhin.

Cc h thng canh tc truyn thng thng da trn a canh v nh hng tn ti. Cc dng vo bao gm phn bn v thuc bo v thc vt thng khng ph bin v s dng phm vi nh.

Ngc li, cc nng tri vi quy m ln thng dng c canh (ma, bng) hoc cy lu nin (c ph, ch, c ca). cc dng canh tc thng nh hng th trng v ph thuc vo cc dng ngoi vi.

Sn phm nng nghip thng c cc hot ng sau:

- Bo v cy trng. - K thut nng nghip v sc ko ng vt. - Thy li. - Chn v nhn ging. - Ci to t v bn phn. - Chm sc cy v dit c, thu hoch, x l sau thu hoch. - Chng v kim sot xi mn. Cy trng pht trin p ng cc nhu cu sn xut v kinh doanh. Chng cng c mt

vai tr trong vic bo v t, khng kh v nc.

Sn xut nng nghip l c thc hin trn cc nng tri, hu ht s sng lao ng l cc thnh vin trong gia nh, m bo s tn ti v thu nhp.

1.2. Tc ng mi trng v cc phng php bo v

Trong h sinh thi nng nghip, con ngi s tr thnh cc yu t chi phi h sinh thi (h sinh thi nh hng nhn to). cc h sinh thi nng nghip khc vi h sinh thi t nhin ch cc qu trnh iu tit t nhin c xp hng hai sau qu trnh kim sot ca con ngi.

19

Trong mi trng t nhin th thc vt l mt phn ca h sinh thi v ng vai tr quan trng trong vic bo v chng. Ty thuc vo phng thc canh tc, mt cch hin nhin, cng sut v tc ng qua li ca cc bin php canh tc s lm tng cc tc ng mi trng c th. Cc tc ng ny c th lm gim tnh a dng sinh hc, lm thay i cu trc t v gy nhim t, nc v khng kh (thuc bo v thc vt, cc loi mui l kt qu ca qu trnh ti v bn phn, Nitorat). Cc h sinh thi t nhin cng cng vi cc chc nng khc nhau c thay th bi s dng t nhn to km a dng hn.

Vic gia tng s dng cc sn phm cng nghip (phn bn, thuc bo v thc vt, nng lng) v cc k thut canh tc khng ph hp dn ti s nhim nc sinh hot bi phn bn v thuc bo v thc vt cng nh xi mn t, sa mc ha v thoi ha gen.

1.2.1. Cc tc ng mi trng

1.2.1.1. t

t l nn tng cho canh tc nng nghip v chc nng quan trng trong vic m bo s tn ti ca loi ngi.

Bo v t l yu t cn thit nu mi trng sng ca con ngi c duy tr bn vng kh nng cung cp thc phm cht lng cao cho con ngi.

Cc c hi thay i cc iu kin ch o ti mt v tr c th l c gii hn. Cc gii php canh tc do vy phi c iu tit bi cc iu kin t nhin ti khu vc .

Xi mn hay cn c gi l s dch chuyn t bi gi v nc l hu qu ln nht ca vic canh tc nng nghip c bit l vng nhit i.

Mc xi mn ph thuc vo loi cy trng v phng thc canh tc. gim thiu xi mn cn m vo mt t c che ph quanh nm. Trong trng hp c canh v n canh th ri ro xi mn s ln hn trong thi k u ca thc vt (v d ng, cy h u), khi mt cy thp v cc bin php tr c th ang mnh. i vi cy thng nin nh cy ng cc, thn c v ly ht i hi cy t thng xuyn v gy nn cc tc ng xu ti cu trc t dn n xi mn.

Cc cy lu nin nh cy n qu thng ngn cn qu trnh xi mn t khi tn, n cung cp lp che ph bn v c tc ng tch cc n cu trc t.

Tnh xi mn ca t cn ph thuc vo c trng vt l ca n. Ct mn v cc ht bo mn d b di chuyn trong khi d cc thnh phn v st th c tnh chng xi mn cao. Cc thng phn mn lm tng tnh n nh ca cu trc t cng nh kh nng gi nc c tc dng ngn cn kh nng xi mn.

Cc bin php quan trng chng xi mn gm:

- m bo che ph t tt (a canh, gieo chm). - "storeyed" canh tc kt hp vi cy c tn v cc cy bi. - Chia vng t canh tc thnh cc mnh nh v to cc vng ph gi i vi hng gi

ch o.

- Trnh tp trung gia sc hoc c cc bin php ngn cn sinh n ca gia sc ti cc vng mi gieo ht (xem tm tt mi trng v nui gia cm).

p dng cc bin php c gii nng trong bin php cy t v thu hoch s lm cho t b nn, cc rnh v cc vng ly, c bit trong trng hp t trong vng nhit i c cu trc yu. iu ny c th c nhng hiu qu bt li ca vic cho gim dng nc r qua v s cp kh

20

cho h thc vt v ng vt trong t cng nh i vi cy trng. c gii ha cng c th dn ti s thay i ca vic phn chia lao ng gia nam gii v n gii.

Mc du thng xuyn cy cy trng trt s c tc dng kch thch hiu qu hot ng ca cc vi sinh vt v v vy cng b sung thm cht dinh dng, n gy ra cc iu khng thun li trong vng nhit i:

- Cht mn b thi ra s lm tng nhit . - H ng vt t b nh hng bi s hnh thnh cc cht mn mi. y mnh sn xut n canh s lm h hi mt phm vi rng ln v vic chm sc cn

thit phi s dng thuc tr su hi. a thuc tr su hi vo t s gy ra nhng tc ng ti h ng vt v thc vt t.

Cht hu c c mt vai tr ln trong ng thi ca t trong vng nhit i. N d tr nc, cung cp mi trng sng cho sinh vt t, tng cng cu trc bn vng ca t, v l ni cung cp v lu tr cht dinh dng. Ngoi cc chc nng cha ng cc cht dinh dng l cc cht hu c thc hin chc nng sng quan trng, th t trong vng nhit i t khi cha ng cht dinh dng cht lng cao v gn cc khong cht trong t. S dng cc khong cht lm mu m t v vy ph thuc vo s cn i v n nh cc cht hu c trong t. Nu s lng cc cht lm mu m t c s dng khng cn i vi cc cht hu c trong t, th n gy ra mt mi nguy him cho nc ngm khi thm vo lp t su hn. S dng qu nhiu cc cht lm mu m t th l nguyn nhn h hi h sinh thi v thit hi v kinh t.

Ri ro ca vic mt dinh dng khng cn bng l rt ln trong trng hp n canh v c canh. V d nh trong trng hp trng ng, c ca, cy ly c, cy ly thn. Ni m mt s loi thc vt pht trin a canh hoc h thng cy trng lun phin th r ro tr nn nh hn, nh l s p ng i hi nhu cu cht dinh dng khc nhau. Nh vy, dng trng cy kt hp vi s khc nhau v n su ca r cy (nng, cn) v nhu cu cht dinh dng khc nhau (cao, thp), s cnh tranh cc cht dinh dng, nc v nh sng gim i ng k.

1.2.1.2. Nc.

Xi mn nh cp trn c th dn ti ph dng ha cc ngun nc tip nhn cc cht dinh dng t qu trnh xi mn, v d nh phn lng, nitrat, v c th b nhim bi d lng thuc bo v thc vt

1.2.1.3. Khng kh

Kh hu nhng vng a canh v cc loi cy c nhiu tng th tt hn, ni mt cch khc cn bng hn so vi vng trng cy thng nin, n canh hay c canh. Tc gi thp hn, do vy s tt hn cho cc loi thc vt nhy cm vi gi (v d nh chui).

nhim khng kh cng c th gy ra do vic s dng ha cht bo v thc vt. S bay hi ammonia trong qu trnh s dng phn bn rn v lng l khng ng k. Di iu kin nhit i (nhit cao, kh nng hp ph trn b mt ca t thp), c th ln n 80% tng lng nit b bay hi.

nhim khng kh v bu kh quyn l kt qu ca s thi kh t qu trnh s dng cc my mc, trong k thut ct v t, v vic t cc sn phm thc vt d tha, nh vy vic thi cc kh nh CH4 v NOx t qu trnh chn nui cc by n gia sc ln v canh tc la nc. Cc yu t trn ng mt phn trong hu qu gy nn hiu ng nh knh.

1.2.1.4. Sinh quyn

Ri ro ca s mt cc loi v thay i mt cn bng trong cc loi th tng t l vi cng canh tc. Kim sot du canh quan st cc giai on khng canh tc cn thit s xm ln t

21

nht trong iu kin mi trng t nhin ca vng khng ch mt cp vng b xa sch trn c s chn la. iu ny khng ch l bo tn cc khu rng, c bit l rng ma nhit i v cc ngun ti nguyn t chng, m cn bo v ngi dn rng, h thng c nhng hiu bit v s dng nhng th cy c kh nng cha bnh v mi tng quan sinh thi trong mi trng sng ca h.

Phng php canh tc cc v ma, mi lin h vi cc my mc, cc dng ha cht v phng php kim sot c di l nguyn nhn lm cho cc cy hoang d pht trin chim ch, dn n gim s lng cc loi.

Trong cc vng ty thuc vo cc thi k hn hn, vi quy m trng trt ln loi cy rng trong mt s h thng c canh th thng tng nguy c chy rng. Ngoi ra cc cht dinh dng v nc b mt, nhng iu ny cng c th l kt qu ca s tiu dit khng mong mun ca cc loi c v cc loi cy khng khng c c s chy.

Thay th v ph hy cc loi thc vt s dn ti s lm gim tnh a dng sinh hc. M rng phm vi s dng ca rng nhit i cng l nguyn nhn lm gim tnh a dng loi ng vt. V d trong trng hp ca cc loi linh trng v cc loi chim.

H sinh thi t nhin c nhng nh hng bt li khng nhng bi nhu cu t bt u cho sn phm nng nghip m cn bt u b phn chia ra (v d nh cc tuyn ng giao thng), cng vi kh nng c th mt tnh n nh ca t.

S dng t cho sn xut nng nghip thng dn ti lm gim din tch rng, h sinh thi kh, h sinh thi nc v l nguyn nhn lm cho phong cnh n iu, v d nh hu qu ca s gii phng mt bng, tiu nc, san mt bng v thy li.

Bng cch so snh vi h thc vt t nhin, sn xut nng nghip ph hy mi trng sng v lm gim tnh a dng trong vng. Tiu chun ha cc sn phm cho th trng v duy tr ni ging c cc im ring bit (v d nh l sn lng, hnh dng, mu sc) gp phn lm gim tnh a dng a phng (suy thi gen).

1.2.2. Phng php bo v

1.2.2.1. iu kin chung

Trong phm tr rng sn xut nng nghip b nh hng bi cc yu t c bn; n khng ch lin quan ti kh hu m c yu t quc gia (v d nh l phng php s hu t) hoc yu t quc t (quan h kinh t).

C rt nhiu vng kh hu v thc vt mang tnh nhy cm cao vi s can thip ca con ngi, cc hot ng ny tng ph hoi thm thc vt sau:

- Ph rng ma nhit i chu th Amazon ly g cht lng cao. - Ct v t gii phng mt bng bi cc vng t nng nghip Nigeria, ni chuyn

i sang trng trt c nh khng cn cho php t c c hi c ti sinh.

- Pht trin n gia sc qu mc trong vng Sahel l kt qu tp trung mt lng ln gia cm v chng n ht thm thc vt vn tha tht ti y.

Cc hu qu l thm ha, khng nhng ch xy ra vng nhit i m t m c i vi vng c lng ma t hn. Hu nh khng c thm thc vt no c th che ph,v vy thnh phn ca t s b thay i sau t nm; vai tr quan trng y l s tng kh nng phn hy cc cht hu c trong t v vi vic th vic b sung cc cht hu c mi l gim n mc ti thiu.

Trong phm vi nn kinh t th gii, gi tr thng mi cho cc quc gia quan tm l tnh trng n nh. l cc quc gia trn c gia tng chi ph nng lng v thng phm.

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Chnh sch nng nghip quc t hin nay khng c g m bo cn i pht trin sn xut nng nghip.

Tc gia tng dn s nhanh chng ng ngha vi din tch t nng nghip s gim xung v nh vy t ai li tr nn b s dng mnh m hn. Cc trang tri M La tinh ngy nay c kch thc trung bnh ch khong 2,7ha; v Chu phi trung bnh khong 1,3 ha, trong khi tng ng vi hnh thi ca chu th t hn 1ha. Nh vy, 10% s ngi sng nh vo nng nghip v Chu Phi, 25% Trung ng v 30% M La tinh khng c g. Hai phn ba trong s h c din tch t rt nh khng th vn v k thut u t nh thc tr su bnh, thuc dit c v khong cht lm mu m t.

Nh trn, t ai ngy cng thiu, h thng nng nghip chuyn i t du canh du c sang bn du canh v cui cng lp nng tri c nh. Qu trnh ny c hnh thnh chu , trong khi phn ln chu Phi v M Latinh vn ang ang c thc hin. Thay i thnh cc nng tri c nh c ngha l khng c cc vng t b hoang nh cc giai on trc (rng, bi cy, ng c) m cho php ci to t; vng t mu m b suy gim v cui cng cn li mt mc thp ch cho mt sn lng nh. S thiu ht t ai nn bt buc s dng cc vng t nghing, dc nn c nguy c xi mn v v vy gp phn lm suy gim mi trng.

Tnh quan trng ca cy trng cng c nhng thay i. Trong cc vng m t v cn nhit i trng khoai m, cy la min, v ng b st gim nng sut, trong khi cc v ma nh sn v khoai lang tr nn quan trng hn. Hai loi cy cp trn th cho sn phm ma v tng i tt ngay c trn cc vng t ngho, nhng trng n chnh l nguyn nhn t tr nn b bc mu mt cch nhanh chng.

Trong rt nhiu quc gia, va tng cng cng tc nng nghip v va qu trnh cng nghip ha th c nhiu tc ng xu ln mi trng. S ng nc, mn ha v bi p l nguyn nhn t qu trnh ct xn cc cng trnh thy li - thng th to ra mt chi ph ln mt kh nng mu m ca t sau mt vi nm, dn ti lm gim sn lng ng k. Du vt tn ti bn ca cc loi thuc tr su ngy cng tng trong ngun nc mt v nc ngm. Mt thp k va qua s lng ngi b nhim thuc tr su tng cao, trong khong thi gian cng tng ng k s lng loi khng thuc tr su bnh do s dng chng qu thng xuyn.

Cc yu t miu t y c thng tm thy khi c s n lc ang c thc hin nng cao sn lng, qu trnh hin i ha sn xut nng nghip mt cch thng thng. Tuy nhin, cc vn khng ch l hu qu ca cc d n sn xut quy m ln m n cn c gy ra bi qu trnh tch ly ca hng lot cc hot ng ca cc d n quy m nh.

Hin nay, cc chi ph mi trng thc t khng hoc c tc ng rt t t cc quan im qun l trn cc trang tri, ni m khng khuyn khch bo tn cc ngun ti nguyn thin nhin hay nng cao hiu qu mt cch bn vng.

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