Floods alter soil profile, agri output likely to be hit

Floods have significantly altered the soil profile of agriculture land across the state, causing nutrient imbalance and posing a threat to productivity by adding an impermeable layer that hinders water infiltration and root growth.

This was revealed in a study conducted by Ludhiana-based Punjab Agricultural University (PAU). The university had conducted tests in Amritsar, Gurdaspur, Ferozepur, Kapurthala and Patiala to assess the impact of floodwaters that had brought large quantities of silt from higher reaches and deposited it in the fields.

University Vice-Chancellor Satbir Singh Gosal said the floods impacted the very foundation of Punjab’s agriculture — its soil.

“While mineral-rich silt from the Himalayan foothills has added nutrients, it has also disturbed native soil profiles. Restoring balance is now critical,” he said.

The findings show sediment deposits ranging from a few inches to over one metre, with textures varying from sandy to fine loam.The pH levels were alkaline and electrical conductivity remained low, indicating no immediate salinity threat.

Encouragingly, organic carbon content averaged above 0.75 per cent, exceeding Punjab’s usual 0.5 per cent, with some samples crossing 1 per cent-mark. However, fields with heavier sand deposits showed reduced carbon levels.

Phosphorus and potassium levels fluctuated while micronutrients like iron and manganese were found in unusually high concentrations, likely due to iron-coated sand particles carried by floodwaters.

Dr. Ajmer Singh Dhatt, Director of Research at the university, warned of hardpan formation due to sediment compaction, which he said could hinder water infiltration and root growth.

Hardpan formation is the creation of a dense, hardened and often impermeable layer in the soil, which prevents water infiltration and air circulation, stopping root growth.

Dhatt recommended deep tillage using chisel ploughs in heavy soils and thorough mixing of silt and clay in lighter soils to prevent layering.

‘Use paddy straw to improve fertility’

Meanwhile, Dr. Makhan Singh Bhullar, Director of Extension Education, urged farmers to incorporate organic matter such as farmyard manure, poultry waste and green manures to rebuild soil structure and stimulate microbial activity. He also advised against burning paddy straw, recommending its incorporation to enhance fertility.

The PAU has advised farmers to follow recommended fertiliser doses and apply a 2 per cent urea spray (4 kg urea in 200 litres of water) 40–50 days after sowing. In wheat and barseem crops, farmers should look for manganese deficiency and apply 0.5 per cent foliar spray of manganese sulphate if symptoms appear.