crop productivity index cpi soil root shoot

CROP PRODUCTIVITY INDEXCPI

SOIL ROOT SHOOT

CROP YIELD

Tanah yg padat menghambat pertumbuhan akar (kanan)

Sumber: http://www.dpi.nsw.gov.au/agriculture/resources/soils/structure/compaction

Pemadatan tanah mempengaruhi

pertumbuhan tanaman. There are not enough pores or spaces in compacted soil to allow unrestricted root

movement, infiltration, drainage or air circulation.

The restricted roots are often unable to take up

sufficient water or nutrients from the soil.

Pertumbuhan tanaman terhambat dan hasilnya lebih rendah , terutama

selama periode kekeringan.

Lapisan Tanah padat tidak dapat

ditembus oleh akar tanaman

Effect of solution pH on soybean root growth (Sanzonowicz et al., 1998).

Sumber: http://courses.soil.ncsu.edu/ssc541de/units/ch3/main3_4.html

pH larutan media tumbuh berpengaruh

terhadap pertumbuhan

pemanjangan akar kedelai.

Pemanjangan akar utama dan akar-akar

cabang meningkat eksponensial dengan

meningkatnya pH media tumbuhnya.

Influence of solution Al3+ on corn root growth at tasseling in two North Carolina Ultisols (Jallah and Smyth, 1998).


Peningkatan konsentrasi Al dalam larutan

tanah menghambat pertumbuhan panjang akar

tanaman jagung.

Influence of exchangeable Al3+ on corn root growth in Oxisols and Ultisols (Gonzalez-Erico et al., 1979; Jallah and Smyth, 1998).


Peningkatan kejenuhan Al dalam tanah

mengakibatkan hambatan

pertumbuhan panjang akar

tanaman, khususnya

pada kejenuhan Al di

atas 30%.

Influence of solution Ca from different sources on increasing root growth in wheat grown in a Ca deficient Oxisol.


Pada tanah-tanah masam yang kaya Al3+ tukar, efek

toksisitas Al dapat dikurangi atau dicegah

dengan jalan meningkatkan konsnetrasi Ca2+ dalam larutan tanah. For example, Ritchie et al. (1983) added 0.1 cmol Ca2+

kg-1 to an Oxisol containing only 0.02 cmol Ca2+ kg-1, observing a 50%

increase in wheat root growth, independent of Ca

source

Efek Ca terhadap panjang akar utama tunggang tanaman

kedelai

(Sanzonowicz et al., 1998b).


Root Growth and Development2001 Peter Graham and Deborah Allan

Sumber: http://www.soils.umn.edu/academics/classes/soil5611/content/RootGrowth_Development/index.htm

Bagian-bagian akar tanaman, mulai dari bulu akar, epidermis, korteks, hingga

pembuluh Xilem.



Bagian-bagian akar: Penampang longitudinal

i. MERISTEM UJUNG1. cell division 2. hormone (PGR) synthesis ii. TUDUNG AKAR1. geotropic response (senses gravity) also light 2. protection of apical meristem 3. facilitates penetration 4. synthesis and release of hormones

iii. ZONE PEMANJANGAN DAN DIFERENSIASI

iv. ZONE BULU AKAR1. 5-10 mm di belakang ujung akar2. Panjang, densitas dan umur bulu akar3. Bertahan hidup beberapa hari4. Dipengaruhi oleh hormon dan suplai hara

v. Pembentukan akar laeral dan pertumbuhan nya



Faktor-faktor yg mempengaruhi pertumbuhan akar

1. Hormon-hormon dari tumbuhan dan mikroba tanah2. Unsur hara - Concept of compensatory growth-phloem unloading

increases where nutrients, water, etc. available.3. Air tanah - Loss of turgor required for cell elongation4. Mechanical impedance - Can't enter pores less than root tip diameter in

width5. Temperature - Optimum 20-25 degrees Celcius6. Aeration - Need 10-15% oxygen in the soil gas phase7. Calcium - Need at least about 15% of total cations8. Organic compounds - Some high molecular weight enhance root initiation

and elongation. Some low mw cpds at high conc can inhibit9. Microorganism - Inoculation usually inhibits root growth and root hair

formation, but some can stimulate by nutrient mobilizatioin, nitrogen fixatioin and synthesis of PGRs (hormones)



Sistem akar tanaman kapri (Pisum arvense) yg

menunjukkan pertumbuhan akar yg lebat (proliferasi akar) akibat penempatan

pupuk P dan K 5 cm di samping benih dan 7-5 cm di

bawah permukaan tanah

(Cooke, 1954).



Modifikasi bentuk akar tanaman barley (Hordeum vulgare) yg

diakibatkan oleh suplai nitrat (1-0 mM) di bagian tengah dari

salah satu sumbu akar; sedangkan di bagian lainnya

konsentrasi nitrat hanya 1/100 nya.

Photograph taken 15 days after treatment (Drew and Saker,

1975).



Tipe-tipe Sistem Akar TanamanA - Shallow, spreading fibrous root system. B - fibrous root system penetrating the soil evenly

from 1 to 1.5 m. c - tap root system, in which main primary root penetrates soil 2.5 m or more. D - fibrous root system developed from adventilous roots growing at lower nodes of stem. E -

tap root system in carrot (Daucus carota).



Sistem akar tanaman di daerah Prairie berumput-

pendek, setelah berlangsungnya periode

tahun dg surah hujan rata-rata (Hays, Kansas).

Al - Allionis lineraris, Ap - Aristida purpurea, Aps - Ambrosia psilostachya, Bd - Buchloe dactyloides, Bg - Bouteloua gracilis, Kg - Kuhnia glutinosa, Lj - Lygodesmia juncea, Mc - Malvastrun coccineum, Pt - Psoralia tenuiflora, Sm - Solidago mollis, Ss - Sideranthus spinulosus.



Sistem akar tanaman di

suatu daerah setelah

berlangsungnya periode

tahun kering.



Efek jumlah curah-hujan thd

kedalaman perakaran tanaman

gandum winter. (Tekstur tanah

Lempung berpasir halus

hingga Lempung berdebu di

daerah Great Plains)



Laju pemanjangan akar tanaman kacangtanah

dan kapas sebagai fungsi dari kekuatan

tanah (resistensi

penetrasi akar).



Sistem akar tanaman barley muda yang

tumbuh di lapangan pada tanah-tanah yang bobot isi (BI)

nya berbeda (Kiri ) BI = 1.35 g cm -3;

(kanan) BI = 1.50 g cm -3.



Efek suhu-tanah di zone perakaran

terhadap morfologi akar

kentang dan pertumbuhan

batang kecambah kentang

(Sattelmacher et al., 1990)



Pengaruh pH larutan hara

terhadap pemanjangan akar Lupinus

angustifolius dan Pisum sativum selama periode tumbuh 60 jam

(Tang et al., 1992)



Efek ratio molaritas Ca/Total

kation dalam larutan tanah

terhadap pertumbuhan akar tanaman

kapas.



Efek pengapuran subsoil masam (pH 4.6) thd pemanjangan akar tanaman kapas *

% massa tanah (subsoil )yg dikapur **

Jarak antara lapisan yg dikapur (cm) Panjang akar relatif

Tidka terbatas - 32

10 4.5 38

20 4.0 57

40 3.0 57

60 2.0 70

100 - 100

*Based on Pearson et al. (1973)**Application of the same dose, but differently distributed



Aspects of the rhizosphere that may

influence the arrival of ions at the absorptive surface of the root.

The extent of the unstirred layer that surrounds roots in solution culture is

indicated.

Dalam lapisan ini, konsentrasi ion-ion

dapat dnagat berbeda dengan konsentrasinya

dalam larutan keseluruhan .

. Quercus ilex root growth in response to heterogeneous conditions of soil bulk density and soil NH4-N content

Elena Cubera, Gerardo Moreno, Alejandro Solla.Soil and Tillage Research. Volume 103, Issue 1, April 2009, Pages 16–22

Sumber: http://www.sciencedirect.com/science/article/pii/S0167198708001724

Variation of fine root densities with depth

of Quercus ilex seedlings grown in soil with different

doses of NH4: control, 0.1, 0.25,

and 1 g NH4 L−1 soil.

Sebagian besar akar-akar halus tumbuh

dalam topsoil .

SHOOT-ROOT RELATIONSHIP


Physiological mechanisms of crop responses to soil compaction. The thickness of the lines reflect qualitatively the importance attributed to

each of the three major pathways. Pathway 1 involves direct root perception of soil hardness, and root

signals inducing reduction in shoot growth. Pathway 2 involves a strong, reinforcing loop of reduced shoot and root growth which is

mediated by impairment of the ability of root systems and canopies to capture resources.

Pathway 3 involves reductions in the efficiency in the use of resources, as exemplified by radiation-use efficiency (RUE) and transpiration

efficiency (TE).

Crop responses to compacted soil: capture and efficiency in the use of water and radiation

Víctor O. Sadras, Garry J. O’Leary, David K. Roget. Field Crops Research. Volume 91, Issues 2–3, 14 February 2005, Pages 131–148.

SHOOT-ROOT RELATIONSHIP


crop productivity index cpi soil root shoot

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