Ludhiana, Oct 6: Recent floods have significantly altered the soil profile of agricultural land across Punjab, according to a study conducted by the Ludhiana-based Punjab Agricultural University (PAU). The changes pose a potential threat to productivity by creating a nutrient imbalance and introducing a dense, impermeable layer that can impede water infiltration and root development.
PAU conducted soil tests in districts including Amritsar, Gurdaspur, Ferozepur, Kapurthala, and Patiala to evaluate the impact of floodwaters. The floods carried large quantities of silt from higher elevations, depositing it across fields.
University Vice-Chancellor Satbir Singh Gosal noted that the floods affected 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,” he said, adding that “Restoring balance is now critical.”
The PAU findings showed sediment deposits ranging from a few inches up to over one meter, with textures varying from sandy to fine loam. The study also determined that:
- Nutrient Levels: The pH levels were generally alkaline, but low electrical conductivity indicated no immediate risk of salinity. Organic carbon content, a positive finding, averaged above zero point seven five percent, exceeding Punjab’s usual zero point five percent, with some samples surpassing the one percent mark. However, fields with heavier sand deposits showed reduced carbon levels.
- Micronutrients: Levels of phosphorus and potassium fluctuated, while micronutrients such as iron and manganese were found in unusually high concentrations. Researchers attributed this to iron-coated sand particles likely carried and deposited by the floodwaters.
Dr. Ajmer Singh Dhatt, Director of Research at the university, issued a warning about the risk of hardpan formation due to sediment compaction. Hardpan is a dense, hardened layer that is often impermeable, which hinders water infiltration, air circulation, and root growth. Dhatt said this compaction could severely obstruct water infiltration and root growth.
To mitigate the damage, PAU officials offered several recommendations:
- Soil Structure: Dr. Dhatt recommended deep tillage using chisel ploughs in heavy soils and the thorough mixing of silt and clay in lighter soils to prevent layering.
- Fertility Improvement: 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 strongly advised against burning paddy straw, instead recommending its incorporation to enhance fertility.
- Fertilizer Application: PAU advised farmers to strictly follow recommended fertilizer doses and to apply a two percent urea spray (four kilograms of urea in two hundred liters of water) between forty and fifty days after sowing.
- Manganese Deficiency: For wheat and barseem crops, farmers should monitor for signs of manganese deficiency and apply a zero point five percent foliar spray of manganese sulphate if symptoms become apparent.
