3. General management practices to reduce the impact of soil salinity on crop performance: In addition to the management practices mentioned above, the following approaches may help reduce salinity impacts.
3.1. Mulching: Mulching with crop residue, such as straw, reduces evaporation from the soil surface which in turn reduces the upward movement of salts. Reduced evaporation also reduces the need to irrigate. Consequently fewer salts accumulate.
3.2. Deep Tillage: Accumulation of salts closer to the surface is a typical feature of saline soils. Deep tillage would mix the salts present in the surface zone into a much larger volume of soil and hence reduce its concentration and impact. Many soils have an impervious hard pan which hinders in the salt leaching process. Under such circumstances “chiseling” would improve water infiltration and hence downward movement of salts.
3.3. Incorporation of Organic matter: Incorporating crop residues or green-manure crops improves soil tilth, structure, and improves water infiltration which provides safeguard against adverse effects of salinity. In order for this to be effective, regular additions of organic matter (crop residue, manure, sludge, compost) must be made.
Irrigated agriculture can be sustained by better irrigation practices such as adoption of regulated deficit irrigation (RDI) or partial root zone drying methodology, and drip or micro-jet irrigation to optimise use of water. Current levels can be controlled by leaching fractions, where fresh irrigation water is available, and by drains.
The leaching fraction is the fraction of the applied water that passes through the root zone; this carries salts below the root zone. The smallest leaching fraction that maintains maximum crop productivity is called the ‘leaching requirement’. It depends on the salt content of the irrigation water and the salt tolerance of the crop.
3. General management practices to reduce the impact of soil salinity on crop performance: In addition to the management practices mentioned above, the following approaches may help reduce salinity impacts. 3.1. Mulching: Mulching with crop residue, such as straw, reduces evaporation from the soil surface which in turn reduces the upward movement of salts. Reduced evaporation also reduces the need to irrigate. Consequently fewer salts accumulate. 3.2. Deep Tillage: Accumulation of salts closer to the surface is a typical feature of saline soils. Deep tillage would mix the salts present in the surface zone into a much larger volume of soil and hence reduce its concentration and impact. Many soils have an impervious hard pan which hinders in the salt leaching process. Under such circumstances “chiseling” would improve water infiltration and hence downward movement of salts. 3.3. Incorporation of Organic matter: Incorporating crop residues or green-manure crops improves soil tilth, structure, and improves water infiltration which provides safeguard against adverse effects of salinity. In order for this to be effective, regular additions of organic matter (crop residue, manure, sludge, compost) must be made. Irrigated agriculture can be sustained by better irrigation practices such as adoption of regulated deficit irrigation (RDI) or partial root zone drying methodology, and drip or micro-jet irrigation to optimise use of water. Current levels can be controlled by leaching fractions, where fresh irrigation water is available, and by drains.The leaching fraction is the fraction of the applied water that passes through the root zone; this carries salts below the root zone. The smallest leaching fraction that maintains maximum crop productivity is called the ‘leaching requirement’. It depends on the salt content of the irrigation water and the salt tolerance of the crop.
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