Day 76 – Q 2. Soil salinisation has become a major problem in the fertile lands of India. How is soil salinistion a problem? What anthropogenic factors have led to salinity of soil? How can saline soil be cured for agriculture?
2. Soil salinisation has become a major problem in the fertile lands of India. How is soil salinistion a problem? What anthropogenic factors have led to salinity of soil? How can saline soil be cured for agriculture?
Salinity is the presence of salts (such as sodium chloride, magnesium and calcium sulfates) and bicarbonates, in soil and water.
Problems due to soil salinity:
- Agricultural Production- Inefficient osmosis due to high salt concentration can result in dehydration of the plant, causing yield decline or even death of the plant. Salinity affects production in crops, pastures and trees by interfering with nitrogen uptake, reducing growth and stopping plant reproduction.
- Water quality- High levels of salts may affect the taste of drinking water. Chloride in particular has a low taste threshold. Sodium and magnesium sulfate levels in drinking water may produce a laxative effect and reduce the suitability of a water supply for grazing animals.
- Rivers- Salt interacts with in-stream biota (animals and plants), changing the ecological health of streams and estuaries. Salts also help fine materials (such as suspended clay particles) to flocculate, allowing more sunlight to penetrate rivers and leading to harmful algal blooms.
- Terrestrial biodiversity- Salinization can lead to the destruction of remaining natural habitat in many agricultural areas and the fragmentation of many wildlife corridors.
- Soil erosion- Salinity is often associated with prolonged wetness and lack of surface cover and therefore increases the vulnerability of soils to erosion.
- Flood risk- Saline soils have limited capacity to absorb rainfall, resulting in high rates of run-off.
- Infrastructure- Salt also corrodes and destroys the infrastructure including houses, roads and playing fields.
Anthropogenic causes for salinity:
- Faulty agricultural practices where we cultivate water intense crops in less watered area.
- Excessive irrigation due to free electricity for tubewells that results in increased capillary action and thus increasing concentration of salts near plant roots.
A canal or a water body near by seeps water into near by plot and the water evaporates leaving behind the salts and increasing the salinity
Curing saline soil for agriculture:
- Soil washing- Stagnate water and flush it out, but if the water table is affected this might not yield result.
- Chemical treatment- Use of Gypsum to counter salinity
- Isolating the canal water by building side walls.
- Proper choice of agricultural practices and crops.
- Discourage borewell instead do rain water harvesting using pits.
Treating soil salinity can not only help remove its negative effects from the ecosystem and biodiversity but will also help India increase its crop production from the same arable land.
Best answer: Ramendra