Agriculture is a major cause of water pollution, contributing to 58% of all water pollution according to the FAO. It pollutes water through both point and non-point sources. Point sources include identifiable pipes or ditches, while non-point sources are more diffuse and arise from broad human activities without a clear entry point. Major pollutants from agriculture include pesticides, fertilizers, manure, sediments, and salts. Excess fertilizers and manures can contaminate groundwater with nitrates and cause eutrophication in surface waters. Improper practices like applying pesticides or spreading manure on frozen ground greatly increase risks to water quality. Solutions include better nutrient management, cover crops, buffers, and

1. AGRICULTURE WATER POLLUTION
ATHIRA RAJAN
athirarajanmt@gmail.com

2. AGRICULTURE WATER POLLUTION
➢“Any Undesirable Change In Physical,
Chemical, Biological Quality Of Water
Due To Agriculture Sources”
➢It Is Detrimental To Human And
Agriculture Too
➢Acc. To FAO 58% Of All Water Pollution
Is Alone From Agriculture

3. AGRICULTURE AS A CAUSE
➢It Is A Cause Through Its Discharge Of Pollutants And Sediment To
Surface And/Or Groundwater, Through Net Loss Of Soil By Poor
Agricultural Practices, And Through Salinization And Waterlogging Of
Irrigated Land

4. SOURCES OF AGRICULTURE WATER
POLLUTION
❑Point Source
From A Single Discharge Point
❑Non Point Source
To More Diffuse, Landscape-level Causes

5. ❑ POINT SOURCES
• Refers To Contaminants That Enter A Waterway From A Single,
Identifiable Source, Such As A Pipe Or Ditch
• A Way To Remember What Point Source Pollution Is That You Can
Point To Where The Pollution Came From

6. NON POINT SOURCES
➢Arises From A Broad Group Of Human Activities For Which The Pollutants
Have No Obvious Point Of Entry Into Receiving Watercourses
➢Called As Diffuse Source Of AWP
➢Non-point Source Pollution Is Much More Difficult To Identify, Measure
And Control Than Point Sources

8. PESTICIDES
➢PESTICIDES And HERBICIDES Are Applied to agricultural land
to control pests that disrupt crop Production

9. PESTICIDE LEACHING
• Occurs when pesticides mix with water and move through the soil,
ultimately contaminating groundwater
• The amount of leaching is correlated with particular soil and pesticide
characteristics and the degree of rainfall and irrigation

10. FERTILIZERS
❑LEACHING, RUNOFF, AND EUTROPHICATION
• The nitrogen (N) and phosphorus (P) applied to agricultural land (via
synthetic fertilizers, composts, manures, biosolids, etc.) Can provide
valuable plant nutrients
• Excess N supplied by both synthetic fertilizers and organic sources
such as manures can lead to groundwater contamination of nitrate.

11. ➢Nitratecontaminated drinking water can cause blue baby syndrome
➢Together with excess p from these same fertilizer sources, eutrophication
can occur downstream due to excess nutrient supply, leading to anoxic
areas called dead zones

12. ❑ HEAVY METALS
• The major inputs of heavy metals (e.G. Lead, cadmium, arsenic, mercury)
into agricultural systems are fertilizers, organic wastes such as manures,
and industrial byproduct wastes
• Some farming techniques, such as irrigation, can lead to accumulation of
selenium (se) that occurs naturally in the soil
• This can result in downstream water reservoirs containing concentrations
of selenium that are toxic to wildlife, livestock, and humans

13. AGRICULTURE IMPACT ON WATER QUALITY
❑TILLAGE/PLOUGHING
✓SEDIMENT/TURBIDITY: Sediments carry phosphorus and pesticides
adsorbed to sediment particles
✓SILTATION of river beds and loss of habitat, spawning ground, etc

14. ❑ FERTILIZING
✓SURFACE WATER
Runoff of nutrients,especially phosphorus,leading to eutrophication causing taste
and odour in public water supply, excess algae growth leading to deoxygenating of
water and fish kills
✓GROUND WATER
Leaching of nitrate to groundwater;excessive levels are a threat to public health.

15. ❑ MANURE SPREADING
✓SURFACE WATER
Carried out as a fertilizer activity; spreading on frozen ground results in high levels of
contamination of receiving waters by pathogens, metals, phosphorus and nitrogen leading to
eutrophication and potential contamination
✓GROUND WATER
Contamination of ground-water, especially by nitrogen

16. ❑ IRRIGATION
✓SURFACE WATER
Runoff of salts leading to salinization of surface waters; runoff of fertilizers and
pesticides to surface waters with ecological damage, bioaccumulation in edible fish
species, etc. High levels of trace elements such as selenium can occur with serious
ecological damage and potential human health impacts.
✓GROUND WATER
Enrichment of groundwater with salts, nutrients

17. PUBLIC HEALTH IMPACT
ECOLOGICAL IMPACT
➢Contamination of water supplies primarily by pesticides and fertilizers
➢Disease outbreak
➢Microbiological contamination of food crops
➢Contamination of food crops with toxic chemicals
➢Major decline and extinctions of animal, fish and vegetation species
➢Destruction of major ecosystems

18. SOLUTIONS
➢NUTRIENT MANAGEMENT: Applying fertilizers in the proper
amount, at the right time of year and with the right method can
significantly reduce the potential for pollution.
➢COVER CROPS: Planting certain grasses, grains or clovers can
help keep nutrients out of the water by recycling excess nitrogen and
reducing soil erosion

19. ➢BUFFERS: Planting trees, shrubs and grass around fields, especially those that
border water bodies, can help by absorbing or filtering out nutrients before they
reach a water body
➢CONSERVATION TILLAGE: Reducing how often fields are tilled reduces
erosion and soil compaction, builds soil organic matter, and reduces runoff
➢DRAINAGE WATER MANAGEMENT: Reducing nutrient loadings that drain
from agricultural fields helps prevent degradation of the water in local streams
and lakes

20. THANK YOU