CHANDIGARH: A study conducted by Punjab Agricultural University revealed that the texture of soil and its profile have been altered and re-shaped in Punjab after recent floods.
The study also revealed that the floods caused nutrient imbalance as red sand and silt carried by floodwaters from the Himalayan foothills settled across vast stretches of agricultural fields.
The mixing has raised questions about the fertility and the viability of future crops, as the floods have added an impermeable layer that hinders water infiltration and root growth.
The study was conducted 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.
Test teams were sent to these areas to guide farmers in corrective measures before the rabi season. Over 20 soil samples were taken from each site at varying depths and distances from the river.
The analysis warns of major challenges for the upcoming rabi season as the massive sand deposition will affect soil fertility, and urgent measures are needed to restore balance. At many places, as much as 4 to 5 feet of sand has been deposited.
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 the electrical conductivity remained low, indicating no immediate salinity threat.
On the other hand, organic carbon content averaged above 0.75 per cent, exceeding the State’s usual 0.5 per cent, with a few samples crossing the 1 per cent mark.
Farmlands with heavier sand deposits showed reduced carbon levels. While phosphorus and potassium levels fluctuated, micronutrients like iron and manganese were found in unusually high concentrations, likely due to iron-coated sand particles carried by floodwaters.
To restore soil texture, PAU has advised farmers to integrate organic matter into the soil as manure, farmyard poultry waste to stimulate microbial activity and support healthy root systems.
The university has calculated that removing one foot of sand from one acre of land will require at least 350 trolleys for loading.
The university 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 berseem crops, farmers should look for manganese deficiency and apply a 0.5 per cent foliar spray of manganese sulphate if symptoms appear, the university advised.
Vice Chancellor of PAU Dr Satbir Singh Gosal said that now the state faces the twin challenges of sand deposition and formation of a dense, largely impermeable layer of soil beneath the topsoil, restricting water infiltration and root growth.
"While mineral-rich silt from the Himalayan foothills has added nutrients, it has also disturbed native soil profiles. Since sand is devoid of nutrients, it is going to affect fertility and may impact yield. Now, restoring balance is critical,’’ he said.
Gosal said that as of now, sowing of wheat has to be done in another three weeks, but in the areas where the soil has been affected, the process will get delayed and may impact productivity.
Meanwhile, Dr Rajeev Sikka, head of the soil science department, said that around 5,000 acres of farmland in Punjab has been impacted.
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.
He recommended deep tillage using chisel ploughs in heavy soils and thorough mixing of silt and clay in lighter soils to prevent layering.
On the other hand, Dr Makhan Singh Bhullar, director of extension education, urged farmers not to burn paddy straw and instead incorporate it into the soil to enhance fertility.
