agriculture pollution notes by muhammad fahad ansari 12ieem14

1- Define Eutrophication, 6 stages of Eutrophication

process and stages of Eutrophication?

Definitions

Eutrophication - "Eutrophication is defined as an increase in the rate of supply

of organic matter in an ecosystem.” - Nixon, 1995

Eutrophication - “The process by which a body of water acquires a high

concentration of nutrients, especially phosphates and nitrates. These typically

promote excessive growth of algae. As the algae die and decompose, high levels

of organic matter and the decomposing organisms deplete the water of available

oxygen, causing the death of other organisms, such as fish. Eutrophication is a

natural, slow-aging process for a water body, but human activity greatly speeds

up the process.” - Art, 1993

Eutrophication - “The term 'eutrophic' means well-nourished; thus,

'eutrophication' refers to natural or artificial addition of nutrients to bodies of

water and to the effects of the added nutrients….When the effects are

undesirable, eutrophication may be considered a form of pollution.” - National

Academy of Sciences, 1969

Eutrophication – “The enrichment of bodies of fresh water by inorganic plant

nutrients (e.g. nitrate, phosphate). It may occur naturally but can also be the

result of human activity (cultural eutrophication from fertilizer runoff and sewage

discharge) and is particularly evident in slow-moving rivers and shallow lakes …

Increased sediment deposition can eventually raise the level of the lake or river

bed, allowing land plants to colonize the edges, and eventually converting the

area to dry land.” - Lawrence and Jackson, 1998

Eutrophic – “Waters, soils, or habitats that are high in nutrients; in aquatic

systems, associated with wide swings in dissolved oxygen concentrations and

1 | P a g e BY Muhammad Fahad Ansari 12IEEM14

frequent algal blooms.” - Committee on Environment and Natural Resources,

2000

2 - What is fertilizer?


LACK OF OXYGENGROWTH OF BACTERIA

DEATH OF PLANTS

SUFFOCATION

GROWTH OF PLANTSADDITION OF NITRATES Eutrophication process in 6

stages

Put in order the stages of Eutrophication!LACK OF OXYGEN

GROWTH OF BACTERIADEATH OF PLANTS

SUFFOCATIONGROWTH OF PLANTS

ADDITION OF NITRATES

A fertilizer is any material, organic or inorganic, natural or synthetic, that

supplies plants with the necessary nutrients for plant growth and optimum yield.

Organic fertilizers are natural materials of either plant or animal origin, including

livestock manure, green manures, crop residues, household waste, compost, and

woodland litter. Inorganic (or mineral) fertilizers are fertilizers mined from

mineral deposits with little processing (e.g., lime, potash, or phosphate rock), or

industrially manufactured through chemical processes (e.g., urea). Inorganic

fertilizers vary in appearance depending on the process of manufacture. The

particles can be of many different sizes and shapes (crystals, pellets, granules,

or dust) and the fertilizer grades can include straight fertilizers (containing one

nutrient element only), compound fertilizers (containing two or more nutrients

usually combined in a homogeneous mixture by chemical interaction) and

fertilizer blends (formed by physically blending mineral fertilizers to obtain

desired nutrient ratios).

3 - What are the differences between organic and inorganic

fertilizers in terms of their use?

Organic fertilizers: Soil fertility on smallholder farms is almost entirely

dependant on locally available resources. Cattle manure, cereal and legume

stover, and woodland litter are the commonly used organic fertilizers, but these

are rarely applied in sufficient quantities to impact on crop yields. The use of

high quality organic fertilizers is rarely practised, although through research and

extension activities in Africa, some farmers now include legume green manures

or legume-based fallows in crop sequences. The main advantage of using

organic fertilizers is that, compared to mineral fertilizers, they are usually

available on or near the farm at very little or no cost other than labor costs of

handling, transportation, or opportunity costs of land used for their production.

Inorganic (mineral) fertilizers: Mineral fertilizers need to be applied to crop

at least two times within a growing season (split application), either basally at

planting or top-dressed during vegetative growth. The amount of inorganic


fertilizer used in most smallholder farming systems falls far below standard

extension recommendations, due to poor purchasing power, risk aversion due to

poor and unreliable rainfall, and lack of significant returns. When available,

fertilizer use is not overly labor intensive, thus allowing time for other tasks (or

for earning income elsewhere).

4 - What are the differences between organic and inorganic

fertilizers in terms of application?

The method and timing of fertilizer application is an essential component of good

farming. For organic materials, decomposition rate and timing of application

influence the release of nutrients to the crop. Organic fertilizer application

methods include broadcasting, banding, and spot application (or side-dressing).

Broadcasting requires less labor and helps to evenly cover the field surface

before incorporation into soil through plowing or hand-hoeing. Incorporation

generally increases the fertility status of the whole plow layer. If the quantity of

organic fertilizer is limited, it may be banded along furrows or spot applied, but

the seed needs to be placed away from the fertilizer. Side-dressed organic

fertilizers are not likely to have much immediate effect due to delayed nutrient

release.

Mineral fertilizers can be applied by hand or with application equipment. When

hand applied, it is essential to distribute the fertilizers uniformly and at the

recommended rates to avoid over- or under-fertilization. Application equipment

needs proper adjustment to ensure uniform spreading. Broadcast fertilizer

should be incorporated after application to enhance effectiveness or to avoid

evaporation losses of N. With banding or spot application, take care that no

fertilizer is placed too close to either the seed or the germinating plant, to avoid

damage to the seedling or roots.

5 - Discuss the Major limitations of organic and inorganic

fertilizers


Organic fertilizers

• Generally require large amounts to have desired effects

• Extra investment in labor for harvesting (green manures) and preparation

(cattle manure)

• Unavailability of seed for green manures is one of the major limitations

• Quality for most has to be enhanced by combining with expensive mineral

fertilizers

• Green manures must occupy land at a time when other food crops could

be grown.

Mineral/ inorganic fertilizers

• Require high purchasing power

• Availability is an obstacle, especially in remote areas

• Need to be applied seasonally

• High risk in low rainfall and very high rainfall areas

6 - What is Crop Residue?

The crop residue is the material left after the harvesting of crop and byproduct

of agriculture based industry.

7 - Types of Crop Residue?

Field residue

Field residue are materials left in an agricultural field or orchard after the

crop has been harvested. These residue includes stalks and stubble (stems),


leaves and seed pods. Good management of field residue can increase efficiency of

irrigation and control of erosion

e.g. stalks, leaves, and stems etc

Processed residue

Process residue are those materials left after the processing of the crop

into a usable resource. These residue include husks, seeds, bagasse and roots.

They can be used as animal fodder and manufacture of organic manure viz.

vermicompost

e.g. seed, bagasse, and roots etc

8 - Where the crop residue can use?

Livestock feed Compost Mushroom Culture Biomass energy production Production of base material for Oyster mushroom production Bedding material for animals Biogas generation Raw material for industry Fuel Production of vermicompost As packing material and thatching of houses, compost pit etc.

9 - Benefits of Nutrient Management Plan

NMPs are designed to balance nutrient applications with crop needs in order to protect water quality and enhance farm profitability.

Complex process affected by weather, production objectives, equipment availability and economics.


Reduced risk of polluting surface waters and groundwater as a result of improper nutrient application.

Efficient integration of commercial fertilizers and other nutrient sources, such as manure or bio-solids, to reduce fertilizer costs.

Improved recommendations that help achieve maximum economic yields.

10 - Positive Impacts of Fertilizer use on the Environment

Reduces soil erosion to maintain soil productivity and decrease pollution of surface waters.

Is key to producing efficient root systems to help reduce pollution of ground water.

Greatly improves land-use efficiency.

Assists in the safe disposal of degradable wastes in land redemption/reclamation.

Sustains green top growth, essential to gaseous exchange and carbon sequestration associated with energy conservation.

11 - IPM (Integrated Pest Management)

What is IPM?

An effective & environmentally sensitive approach to pest management

Relies on a combination of commonsense practices

May include the judicious use of pesticides.

A pest management philosophy that utilizes all suitable pest management techniques and methods to keep pest populations below economically injurious levels. Each pest management technique must be environmentally sound and compatible with producer objectives.

12 - What are IPM strategies?

u Physical controls

u Habitat modification

u Exclusion


u caulking, sealing

u putting up screens

u air doors

u Mechanical controls

u Sanitation

Cultural controls, for example-

To maintain a healthy lawn:

u Develop healthy soil.

u Choose the right grass type.

u Mow high, often.

u Water deeply.

u Reduce thatch build-up.

u Set realistic goals.

u Biological controls - Bt, nematodes, parasitic wasps, beneficial insects

u Least hazardous pesticides used only when absolutely necessary.

For example: Baits - gel, tamper-proof containers.

13 - Define agriculture bio diversity?

• The variety of life on Earth at all its levels, from genes to ecosystems, and the ecological and evolutionary processes that sustain it.

• The variability among living organisms and the ecological complexes of which they are part, including the diversity within species, between species and of ecosystems.’


The variety and variability of animals, plants and micro-organisms used directly or indirectly for food and agriculture (including, in the FAO definition, crops, livestock, forestry and fisheries). It comprises the diversity of genetic resources (varieties, breeds, etc.) and species used for food, fodder, fibre, fuel and pharmaceuticals. It also includes the diversity of non-harvested species that support production (e.g. soil micro-organisms, predators, pollinators and so on) and those in the wider environment that support agro-ecosystems (agricultural, pastoral, forest and aquatic), as well as the diversity of the agro-ecosystems themselves.

It has also been defined as:

Agricultural biodiversity encompasses the variety and variability of animals, plants and micro-organisms which are necessary to sustain key functions of the agro-ecosystem, its structure and processes for, and in support of, food production and food security. (FAO, 1999)

14 - WHAT IS HAPPENING TO AGRICULTURAL BIODIVERSITY?

These locally diverse food production systems are under threat and, with them, the accompanying local knowledge, culture and skills of the food producers. With this decline, agricultural biodiversity is disappearing and the scale of loss is extensive and with the disappearance of harvested species, varieties and breeds goes a wide range of unharvested species.

• More than 90 per cent of crop varieties have disappeared from farmers' fields;

• Half of the breeds of many domestic animals have been lost.

• In fisheries, all the world's 17 main fishing grounds are now being fished at or above their sustainable limits, with many fish populations effectively becoming extinct.

The genetic erosion of agricultural biodiversity is also exacerbated by the loss of forest cover, coastal wetlands and other 'wild' uncultivated areas, and the destruction of the aquatic environment. This leads to


losses of 'wild' relatives, important for the development of biodiversity, and losses of 'wild' foods essential for food provision, particularly in times of crisis.

15 - WHAT ARE THE UNDERLYING CAUSES OF THE LOSSES OF AGRICULTURAL BIODIVERSITY?

There are many causes of this decline, which has been accelerating throughout the 20th century in parallel with the demands of an increasing population and greater competition for natural resources. The principal underlying causes include:

• The rapid expansion of industrial and Green Revolution agriculture, intensive livestock production, industrial fisheries and aquaculture (some production systems using genetically modified varieties and breeds) that cultivate relatively few crop varieties in monocultures, rear a limited number of domestic animal breeds, or fish for, or cultivate, few aquatic species.

• Globalisation of the food system and marketing, and the extension of industrial patenting and other intellectual property systems to living organisms, which have led to the widespread cultivation and rearing of fewer varieties and breeds for a more uniform, less diverse but more competitive global market.

As a consequence there has been:

• Marginalisation of small-scale, diverse food production systems that conserve farmers' varieties of crops and breeds of domestic animals, which form the genetic pool for food and agriculture in the future.

• Reduced integration of livestock in arable production, which reduces the diversity of uses for which livestock are needed.

• Reduced use of 'nurture' fisheries techniques, that conserve and develop aquatic biodiversity.

Genetic erosion is the loss of genetic diversity, including the loss of individual genes,102 and the loss of particular combinations of genes


(i.e. of gene-complexes ) such as those manifested in locally adapted landraces. The term “genetic erosion” is sometimes used in a narrow sense, i.e. the loss of genes or alleles, as well as more broadly, referring to the loss of varieties. The main cause of genetic erosion in crops, as reported by almost all countries, is the replacement of local varieties by improved or exotic varieties and species. As old varieties in farmers’ fields are replaced by newer ones, genetic erosion frequently occurs because the genes and gene complexes found in the diverse farmers’ varieties are not contained in toto in the modern variety. In addition, the sheer number of varieties is often reduced when commercial varieties are introduced into traditional farming systems. While some indicators of genetic erosion have been developed, according to FAO (1996, 1998) there have been few systematic studies of the genetic erosion of crop genetic diversity which have provided quantifiable estimates of the actual rates of genotypic or allelic extinction in PGRFA. Nearly all countries say, in Country Reports to FAO in 1996, that genetic erosion is taking place and that it is a serious problem.

Variety replacement is the main cause of losses. The replacement of local varieties or landraces by improved and/or exotic varieties and species is reported to be the major cause of genetic erosion around the world. It is also cited as the major cause of genetic erosion in all regions except Africa. Examples are mentioned in 81 Country Reports, of which a number are highlighted below. • A survey of farm households in the Republic of Korea showed that of 14 crops cultivated in home gardens, an average of only 26% of the landraces cultivated there in 1985 were still present in 1993. The retention rate did not exceed 50% for any crop, and for two crops it was zero. These results are disturbing as such home gardens have traditionally been important conservation sites, especially for vegetable crops.103 • In China, in 1949, nearly 10,000 wheat varieties were used in production. By the 1970s, only about 1,000 varieties remained in use. Statistics from the 1950s show that local varieties accounted for 81% of production, locally produced improved varieties made up 15% and introduced varieties 4%. By the 1970s, these figures had changed drastically; locally produced


improved varieties accounted for 91% of production, introduced varieties 4% and local varieties only 5%. (FAO 1996, 1998)

16 - Describe the soil conservation practices?

Soil conservation is maintaining good soil health, by various practices. The aim of soil conservation is to prevent soil erosion, prevent soil's overuse and prevent soil contamination from chemicals. There are various measures that are used to maintain soil health, and prevent the above harms to soil.

Soil Conservation StrategiesThere are many ways to conserve soil, some are suited to those areas where farming is done, and some are according to the soil needs. Here are the various soil conservation practices.

Planting VegetationThis is one of the most effective and cost saving strategies. This measure is among soil conservation technique used by farmers. By planting trees, grass, plants, soil erosion can be greatly prevented. Plants help to stabilize the properties of soil, and trees act as a wind barrier and prevent soil from being blown away.

This is also among strategies used for soil conservation in urban areas, one can plant trees and plants in the landscape areas of the residential places. The best choices for vegetation are herbs, small trees, plants with wild flowers, and creepers which provide a ground cover.

Contour PlowingContour farming or plowing is used by farmers, wherein they plow across a slope and follow the elevation contour lines. This method prevents water run-off, and thus prevents soil erosion by allowing water to slowly penetrate the soil.

Maintaining the Soil pHThe measurement of soil's acidity or alkalinity is done by measuring the soil pH levels. Soil gets polluted due to the addition of basic or acidic pollutants which can be countered by maintaining the desirable pH of soil.

Soil Organisms


Without the activities performed by soil organisms, the organic material required by plants will litter and won't be available for plant growth. Using beneficial soil organisms like earthworms, helps in aeration of soil and makes the macro-nutrients available for the plants. Thus, the soil becomes more fertile and porous.

Crop Rotation PracticeCrop rotation is the soil conservation method where a series of different crops are planted one after the other in the same soil area. This method is used greatly in organic farming. It is done to prevent the accumulation of pathogens, which occur if the same plants are grown in the soil, and also depletion of nutrients.

Watering the SoilWe water plants and trees, but it is equally important to water soil to maintain its health. Soil erosion occurs if the soil is blown away by wind. By watering and settling the soil, one can prevent soil erosion from the blowing away of soil by wind. One of the effective soil conservation ways in India is the drip irrigation system which provides water to the soil without the water running-off.

Salinity ManagementExcessive collection of salts in the soil has harmful effects on the metabolism of plants. Salinity can lead to death of the vegetation and thus cause soil erosion, which is why salinity management is important.

TerracingTerracing is among one of the best soil conservation method, where cultivation is done on a terrace leveled section of land. In terracing, farming is done on a unique step like structure and the possibility of water running off is slowed down.

Bordering from Indigenous CropsIt is preferable to native plants, but when native plants are not planted then bordering the crops with indigenous crops is necessary. This helps to prevent soil erosion, and this measure is greatly opted in poor rural areas.

No-tilling Farming MethodThe process of soil being plowed for farming is called tilling, wherein the fertilizers is mixed and the rows for plantation are created. However, this method leads to death of beneficial soil organisms, loss


of organic matter and compaction of soil. Due to these side effects, the no-tilling strategy is used to conserve soil health.

These were the 10 ways to conserve soil used across the world. Soil is a very important constituent, and is developed by a long process of weathering and disintegration of rocks which turn into sand or clay. The clay like fertile soil provides home to organisms like earthworms, beetles, ants which live in it. Soil provides anchorage to plants and trees. The plants and trees provide home to birds and animals. The crops growing on the soil provide us food and clothes. Thus, soil defines the quality of life around it, which is why it is important to use these methods. Branches of environmental science like Earth science are constantly trying to find new methods, for maintaining the ecological balance. In different parts of world people studying soil science, are coming up with different new beneficial soil conservation techniques.

Water conservation Strategy

17 - Water Conservation Strategy of Pakistan?To work out a sound and cogent water conservation strategy is the need of the time, as demand for water continues to rise because of increasing use of water in agriculture and industry for the purpose of economic development and due to rapid growth of population, whereas there is limited supply of water. Water management is the biggest challenge of 21st century confronted by the country, as irrigated agriculture is 24 percent of GDP, the livelihood for the majority of country and input of agrobased industry/exports. It has been made known that a considerable amount of water is lost during its 14 conveyance for the seepage in the lengthy canals. Proper lining of the canal system could reduce these losses. According to a WAPDA Report more than 5 MAF of irrigation could be saved by lining of minor canals and addition 3.6 MAF could be saved by improvement of water courses. It is heartening to note that Government of the Punjab has introduced modern telemetery system to check and control water theft by the farmers. In order to overcome the menacing challenge of water shortage and its losses, it has become imperative to work on the lines of “Blue Revolution” which is threshold of the strategy meant for making use of more effective techniques and obtaining optimum results


for reduction in water losses. The definition of “Blue Revolution” has been coined as a system of drip irrigation that delivers water directly to the roots of crops by cutting use of water by 30 to 70 percent and raising crop yield on the average by 20 to 90 percent.The Medium Term Development Framework (MTDF) 2005-10 proposes a water conservation strategy with the aim to improve the performance and utilization of water supply and sanitation system and reducing financial dependence on the Federal and Provincial Governments pertains to i) adoption of integrated approach, rational resource use, and the introduction of water efficient techniques, (ii) containment of environment degradation, (iii) institutional strengthening, capacity building and human resource development (HRD), (iv) improving performance and utilization of local systems through better planning, management and community participation; (v) improving quality of life and easy access to water supply, especially for women, (vi) improving sanitation through sewerage and drainage schemes, (vii) promoting increased take up of household sanitation, and (viii) improving the understanding of the linkages between hygiene and health through community education campaigns, especially among the women and children. Apart from MTDF strategy following recommendations are proposed in the contest of water conservation and management;

• Crash programme for cleaning of water channels including canals/water courses and distributaries.

• Participatory water management at secondary tertiary level in collaboration with provincial irrigation departments.

• Regulating ground water pumpage by issuance of licenses to check overdraft of aquifer.

• Better water management for increasing cropping intensity with river line area.

• Technical land leveling, surge irrigation, high irrigation efficiency technology including drip and sprinkler.

• Strengthening of institutional capacity building improving financial sustainability.

• Better and more efficient use of funds.• To harness the uncultivated lands for irrigation purpose, storage of

flood water during Monsoon season by construction of a series of small dams/reservoirs on the barren lands and Barani areas of Northern Punjab, NWFP and Balochistan.

• Attracting more foreign investment by making an enrollment lucrative to it.


• Launching of incentive based public campaign emphasizing conservation of water at all levels.

18 - What is Agro meteorology?

Agro meteorology is the study and use of weather and climate information to enhance or expand agricultural crops and/or to increase crop production. Agro meteorology mainly involves the interaction of meteorological and hydrological factors, on one hand and agriculture, which encompasses horticulture, animal husbandry and forestry.

19- Site selection for Agro meteorology?

• The site of an agro meteorological station should be fairly level and free from obstructions.

• Grass cover and weeds should be removed and grass in and around the enclosure should be frequently mown to keep it uniformly short.

• Site should not be concrete, asphalt or crushed stone.

• Obstructions such as trees, buildings and nearby shrubs should not be closer to the instruments than eight to ten times their height.

• No obstructions should cast shadows during the greater part of the day.

• Ideally, the weather station should be located in a place truly representative of the natural conditions in the agricultural region concerned.

• Accessibility to the weather station - taking observations and maintenance.

• Fencing - to minimize tampering by animals and people.

20 -Discuss the Forecasting Techniques in Crop Production


1 - Yield forecast using weather parameters

Weather affects crop differently during different stages of crop growth. Thus extent of weather influence on crop yield depends not only on the magnitude of weather variables but also on the distribution pattern of weather over the crop season which, as such, calls for the necessity of dividing the whole crop season into fine intervals. This will increase number of variables in the model and in turn a large number of parameters will have to be evaluated from the data. This will require a long series of data for precise estimation of the parameters which may not be available in practice. Thus, a technique based on relatively smaller number of manageable parameters and at the same time taking care of entire weather distribution may solve the problem.

2 - Yield forecast based on plant characters

Effects of weather and inputs are manifested through crop stand, number of tillers, leaf area, number of ear heads etc. which ultimately determine crop yield. As such, plant characters can be taken as the integrated effects of various weather parameters and crop inputs. Thus the other approach to forecast crop yield is to use plant characters.

3 - Models using spectral data

Since the approach using plant characters requires collection of data from farmers' fields, the data can be used on characters which can be measured easily without involving much expertise, cost and sophisticated instruments. Some characters contributing significantly towards yield may not find place in the model due to these limitations. This calls for the necessity of including some other variables in the model along with biometrical characters which could take care of such variables indirectly.

4 - Models using spectral data

Since the approach using plant characters requires collection of data from farmers' fields, the data can be used on characters which can be measured easily without involving much expertise, cost and sophisticated instruments. Some characters contributing significantly


towards yield may not find place in the model due to these limitations. This calls for the necessity of including some other variables in the model along with biometrical characters which could take care of such variables indirectly.

5 - Models using Farmers' Appraisal

Appraisal in the forecast model for sugarcane. (Agrawal and Jain, 1996). The results revealed that a reliable forecast could be obtained using plant population and farmers’ appraisal.

6 - Integrated approach

Forecasting Techniques in Crops Models using data on plant characters alongwith agricultural inputs were found to be better than models based on plant characters alone in jowar and apple (Jain et al. 1985; Chandrahas and Narain, 1992). Often it is not possible to include all the variables in a single model. In such situations composite forecast can be obtained as a suitable combination of forecasts obtained from different models. Various strategies for combining forecasts have been suggested under different situations. (S.C.Mehta, 2000 ).

21 - Chemical characteristics of pesticides

Solubility

The ability of a pesticide to dissolve in a solvent, usually water

Soluble pesticides are more likely to move with water in surface runoff or through the soil to groundwater

Adsorption

Higher with oil-soluble pesticides

Clay and organic matter increase binding

Decreases the potential for a pesticide to move through soil.

Persistence


Ability of a pesticide to remain present and active for a long time

Provides for long-term pest control, but may harm sensitive plants and animals

May lead to illegal residues on rotational crops

Volatility

Fumigants volatilize and move gas through soil, structures or stored commodities

Several herbicides are quite volatile and pose harm when the vapor moves off target

Labels may state cut-off temperatures for application

Labels may require pesticide to be incorporated into soil

22 - How we save groundwater from pesticide

Use IPM

Consider the geology

Where is the water table?

Are there sinkholes nearby?


Temperature

Wind

Humidity

= HigherVolatility

Consider soil characteristics

Is it susceptible to leaching?

Select pesticides carefully

Is it susceptible to leaching?

Follow label directions

Identify vulnerable areas

Sandy soils

Sinkholes

Wells

Streams

Ponds

Shallow groundwater

Handle pesticides to ensure pesticide or wastes do not contaminate soils

Calibrate accurately and check for leaks!

Measure accurately and do not over apply

Mix Location

Do not mix and load near water or drains; consider a mix/load pad

Don’t mix at the same location each time; unless you have a mix/load pad

Air gap: keep the water supply above the level of the mixture


Install a back-siphon valve (check valve)

Clean up and avoid spills

Dispose of wastes properly

Triple rinse containers; use the rinse water in spray tank

Store pesticides away from water sources

DO NOT apply pesticides if heavy rain is in the forecast!


Water Logging and Salinity causes and effects


Wastewater reuse in agricultureIntroduction

The very rapid urban growth of the last few decades has produced increasing demands

for potable water. As a result of this growth and the associated industrialisation, near-

urban surface water resources typically become either fully utilised or of poor quality

unless the city is located on a major river system.

The improved sanitation coverage in large cities with water-borne sewerage systems

produces enormous volumes of wastewater for disposal. With the increasing scarcity of

freshwater resources in arid and semi-arid regions, but ever-growing demand for more

efficient food production for the expanding populations, much wider recognition is

being given to wastewater as an important resource. Wastewater reuse is likely to

become more widely practised, and it is already becoming incorporated into some

national water resources management plans, and therefore will need to be taken

account of in groundwater protection strategies.

The expanding demand for groundwater for potable supply and the desire to utilise

wastewater to conserve scarce freshwater often occur together, and wastewater reuse

can have major impacts on groundwater. In some situations, the substantial volumes of

additional recharge may completely alter the local hydrogeology. The impacts may be


both positive for water conservation and negative in relation to groundwater quality.

Improper disposal of untreated wastewater directly into aquifers or use for irrigation at

the ground surface above important aquifers can cause serious pollution problems. On

the other hand, properly controlled and managed reuse can provide significant

additional resources of good quality nutrient-rich water for arable agricultural

purposes.

APPROACHES TO WASTEWATER REUSE AND IRRIGATION

The methods employed to reuse wastewater for irrigation vary considerably, depending

on the volumes of water and areas of land available, the level of treatment employed,

the types of crops to be irrigated, the level of technical capacity and investment of the

farmers and environmental considerations. The typical, but probably not exhaustive

range is shown in the table below.


Thus, the scale ranges from localised, peri-urban, often informal irrigation of small

gardens by collected but untreated wastewater, with simple irrigation methods and few

controls, to the large, canal commanded irrigation schemes of thousands of hectares,

but still using untreated wastewater, to highly sophisticated, heavily controlled and

managed soil aquifer treatment in which the re-abstracted, fully treated effluent can be

used to grow any type of crop using sophisticated and efficient irrigation techniques.

PROTECTING GROUNDWATER QUALITY FROM WASTEWATER

IRRIGATION-LESSONS FROM MEXICO

Wastewater irrigation can pose direct health risks to the farmers and to the consumers

of the crops grown, and can cause various quality deteriorations over time to the

irrigated soils and to surface water and groundwater resources. The WHO Guidelines

for Wastewater Reuse are intended primarily to help reduce the risks to workers and

consumers from microbiological contaminants, rather than to protect the receiving

surface waters or groundwater from deterioration in chemical quality. From the general

characteristics of urban wastewater summarised in chapter 5, elevated concentrations

of salinity, nutrients, organic carbon, pathogens and suspended solids can be expected.

Where a significant industrial component of wastewater exists, this will provide added

pollutant concentrations that reflect the proportion of industrial effluents and the type

of industries, such as heavy metals and specific industrial organic compounds such as

the halogenated solvents.

Agricultural Waste Management and control

What is Waste Management?


The proper management of waste from agricultural operations can contribute in a

significant way to farm operations. Waste management helps maintain a healthy

environment for farm animals and can reduce the need for commercial fertilizers while

providing other nutrients needed for crop production. Agricultural waste typically

associated with animals includes but is not limited to manure, bedding and litter,

wasted feed, runoff from feedlots and holding areas, and wastewater from buildings

like dairy parlors.

Best management practices (BMPs) such as rotational grazing and pasture renovation

to maintain adequate vegetative cover, riparian buffers, and structures built to trap or

retain waste should be utilized in order to prevent contamination of both surface waters

and groundwater. When this waste is carried in overland flow from rain events, it is

categorized as a nonpoint source pollutant, or one that originates from diffuse areas of

land. Nonpoint source pollutants are one of the primary water quality problems in the

United States. Furthermore, runoff and waste that does not pass through a vegetated

buffer zone along the waterbody is likely to result in bank erosion and subsequent

property loss.

Why be concerned about waste management?

If not managed properly, agricultural waste from farm operations can pollute the

environment resulting in impacts to water quality and a general loss of aesthetics. The

degradation of water quality can impact adjacent waterways and groundwater both

onsite and offsite. This degradation reduces the ability of these resources to support

aquatic life and water for human and animal consumption. Nitrates, which are

commonly associated with fertilizers and agricultural waste runoff, can seep into

groundwater. Well water contaminated with nitrates is hazardous to humans,

particularly for infants, as it results in oxygen depletion in the blood. As alluded to


above, proper waste management can reduce operating costs associated with fertilizer

application if managed properly.

What are the benefits of waste management?

Like most other aspects of agricultural production, there are requirements for the

application and management of agricultural waste on farms. However, the primary

reasons behind managing agricultural waste make good sense both environmentally

and economically. Where feasible, the reuse of animal waste in farming operations can

reduce the quantity and hauling costs of commercial fertilizer. The contribution of

animal waste increases the organic matter content of soils, which not only increases

nutrient availability for crops but also improves the water holding capacity and tilth of

the soil. Good waste management reduces the instances of well water contamination

and minimizes surface water pollution.

How would one implement waste management?

Fortunately, there are planning documents and BMP options available to farmers for

managing agricultural waste. Waste management is commonly part of an overall

nutrient management plan developed for a farm. These plans play an integral role in

the comprehensive waste management planning process and are used to spell out how

farmers intend to maximize the benefit of nutrients available from farm waste products

to benefit crop production and minimize environmental impact. Although State and

Federal governments are demanding more accountability in agricultural waste

management, many such plans are developed voluntarily as an important aspect of the

business. Developing a plan for how waste is managed on your farm not only aids in

the tracking of operational costs and the making of better management decisions; it can

also be used to leverage State and Federal funding assistance. Self-regulation protects

private property rights and reduces the need for governmental control and regulations.


Site-specific waste management strategies should be developed and adhered to in

order to maximize the cost efficiency and adequately protect local environmental

resources. This will require that routine soil and waste testing take place to match the

crop needs to the nutrients available. By tracking the timing and application rates

(quantity) of agricultural waste required, the space required to store operational waste

can be determined.

Waste can be stored as a solid in building structures, or as a liquid in holding ponds or

anaerobic lagoons. Being able to store waste in an acceptable form until it is needed is

a critical component of a waste management strategy. If waste is not handled properly

or is not applied at the right time, valuable nutrients are lost and environmental and

human and animal health problems are created. Besides the management practices

noted above, the BMPs listed below can be used to improve waste handling and

application:

Avoid over-application by only applying manure to crops that can benefit from the

nutrients;

Do not apply waste to fields when heavy rain is expected and runoff potential is

high;

Exclude livestock from sensitive areas such as riparian buffers and wetlands;

Locate winter feeding areas in a relatively flat upland area;

Do not spread waste near waterways;

Employ other conservation practices that minimize runoff and erosion to fields

where waste is applied;

Avoid spillage or overflow of lagoons, ponds and structures used to house waste;

Regularly check waste application equipment and make sure it is calibrated;

Where possible, divert runoff from land above livestock areas and away from

nearby surface waters and wells;


If an alternative water supply source is unavailable for livestock, create dedicated,

limited access points to streams for drinking; and

Consider adding flush gutters to livestock confinement systems to confine waste for

future application.

Other ways to improve waste management on farms is to routinely check areas where

fuel and chemicals are stored for spills and leaks and to be sure your farm is in

compliance with applicable storage and handling regulations. Keeping up-to-date on

technologies designed to improve waste management such as composters for disposing

of livestock mortalities and integrating them into your waste management strategy is

also good practice.


agriculture pollution notes by muhammad fahad ansari 12ieem14

Education

straight fertilizers

compound fertilizers

organic materials

fertilizer use

high levelsof organic

fertilizer grades

necessary nutrients

release of nutrients