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Increase crop productivity through irrigation with poor quality water

Agriculture Jan 22, 2022

Chemical, physical and biological quality of irrigation water affects agricultural productivity, soil productivity, product safety, and farm labor as well as consumer health.  Chemical properties such as salts and toxins pose hazards to the soil, plants, and irrigation systems, such as corrosion of pipes and jamming of a drip by chemical wastes in the drip irrigation systems.  Physical characteristic is that the waste in the water jams the drip.  Biological characteristics, such as bacteria and germs, have a detrimental effect on human and animal health as well as on plants and irrigation systems in the soil.  Many different elements are dissolved in chinchilla water.  Some of these elements provide beneficial functions to the plant while others interfere with the beneficial elements.  In some cases, even beneficial substances in high concentrations can be toxic.

Impurities and salts are dissolved in all water sources used for irrigation, whether it is stored at the ground surface or groundwater.  Many problems like soil degradation, salinity, soil erosion, poor condition, etc. are related to the quality of irrigation water.  Water quality can affect both plant growth and the function of the irrigation system. Changes in water quality can reduce the availability of water in the crop to such an extent that it adversely affects crop production.  Some of the natural constituents that often enter the water, such as arsenic, pose a threat to existing health and agriculture and can contaminate groundwater both naturally and artificially.  Due to scarcity of drinking water in urban areas and increasing demand for high-quality water, the use of brackish water, flow of agricultural drainage, low-quality water, and treated domestic wastewater for agriculture is increasing day by day.

It is very important to pay constant attention to the management of saline water in irrigation.  To assess the risk of salinity, the water sample should be analyzed for three main factors: total dissolved salts (TDS), sodium crisis (SAR), or toxic ions.  The amount of toxic elements in groundwater or sewage water, especially before it is used for irrigation, needs to be thoroughly analyzed.

Tests of conductivity or total soluble salts are two important criteria for measuring salinity.  Soil Properties, Groundwater, and soil cover that comes in contact with water during irrigation increase or decrease the risk of salinity by reacting with the salinity of irrigation water.  Crop yields can be significantly reduced when salt water is used for irrigation.  Also, some crops are more sensitive to salinity than other crops.  What is saltwater?

Water that has a high solubility content, even if the soil moisture is sufficient, prevents the roots of the crop from absorbing water as per their requirement.  This causes water shortage in the crop.  The amount of total salinity in water can be measured by the measure of electrical conductivity.  If the electrical conductivity of water is up to 750 micron/cm (approximately 0.05% salinity) then that water is suitable for any crop and soil.  If the ratio is 750 to 2250 microns/cm, then this water can be used according to the type of soil and with care for the crop which can tolerate heat.  However, if the electrical conductivity is more than 2250 microhm/cm (approximately 0.15 salts) then it is not advisable to use such water for agriculture except in special circumstances.

 classification of saltwater:

Water class

Electrical conductivity Daisy / m

Salinity concentration mg/litre

Types of water

Non saline

<0.7

<500

Portable and irrigation water

Hardly saline

0.7-2.0

500-1500

Irrigation water

Medium saline

2.0-10.0

1500-7000

Primary drainage water and groundwater

More saline

10-25

7000-15000

Secondary drainage and groundwater

Very salty

25-45

15000-35000

Very hard groundwater

Salt water

>45

>35000

Sea water

Economic effects of soil water:

  • The decline in production lowers the standard of living of the farmer.
  • Lowering the standard of living is affecting things like health, nutrition, education.
  • Today, the villagers do not get the benefit of investing crores of rupees in irrigation.
  • Production decreases.
  • The saline area increases and the soil becomes unproductive.
  • Farmer migration increases.

Effects of salinity on the plant:

Plants absorb a lot of water through the soil.  When the water is more saline, the salinity particles form the root shield of the plant, due to which the plant cannot get energy even though it has enough water.  As a result, the plant cannot grow properly.

Signs showing the effects of salinity:

  1. Plant growth in saline water is found to be slow and stagnant compared to other areas.
  2. Comes with small and underdeveloped fruit.
  3. The leaves of plants are dark green or some plants turn blue-green.
  4. The leaves are yellow, brown spotted, and fall off.

What to watch out for when using saline water in agriculture?

  • Crops should be leveled by leveling the soil, making wide head niches, and planting crops on the slope of the ridge so that water does not come in direct contact with the seeds and salts do not accumulate in the root area.
  • Irrigation should be given lightly and in a short duration and moisture in the soil should not be allowed to evaporate.
  • After two-three irrigations give one heavy irrigation so that the salts deposited in the original vista will drain deep into the soil.
  • Whenever possible you should have a good watering can.
  • The use of a drip irrigation system is beneficial for cultivation with alkaline water.
  • Do not harvest summer crop till it is done and plan to harvest winter crop as soon as possible.
  • Efforts should be made to increase the drainage capacity of the soil, deep tillage, and use of compost, manure, green manure, etc. increase the drainage capacity of the soil and stop soil degradation.
  • Appropriate salt-tolerant crops should be selected based on water quality.  Cotton, sorghum, wheat, millet, sunflower, citrus, sugar beet, spinach, tomato,  bor, amla, pomegranate, gooseberry, etc. have relatively high salinity tolerance.
  • Fertilizer and seed rates should be higher than recommended.
  • Considering the quality of water, chemical fertilizers should be used.  It is advisable to use urea, single super phosphate in canned, DAP, and alkaline types of water.  However, avoid DAP and urea as much as possible.
  • Keep the end of the plant between two ha and the two plants less than recommended.
  • It is beneficial to make a fence around the field and keep the saltwater of the crop in the field so that the use of alkaline water washes away the salts accumulated in the root area of ​​the crop.
  • If a basic type of water is to be used for irrigation, it is beneficial to do deep tillage by adding compost manure along with gypsum in the soil.
  • If basic type water is to be used for irrigation, it is beneficial to do deep tillage by adding compost with gypsum in the soil.
  • If freshwater is available, one should irrigate with fresh water before sowing to wash away the salts deposited in the upper layer of the soil and improve the growth of the crop which is more suitable for winter crops.

Corn rows
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