Threefold surge in nitrogen use; soil health concerns raised

Dharwad

Agricultural experts and soil scientists have raised serious concerns over deteriorating soil health in Dharwad district, as the use of chemical fertilisers—especially nitrogen—continues to far exceed recommended levels. The ideal Nitrogen-Phosphorus-Potassium (NPK) ratio for balanced soil nutrition is 4:2:1. However, recent data shows a significant deviation from this norm. In 2023–24, the ratio in Dharwad peaked at 14.45:8.13:1. Although there was a slight correction in 2024–25 to 11.35:5.96:1, nitrogen (N) and phosphorus (P) levels remain alarmingly high compared to potassium (K).

Experts say this imbalance is largely driven by the excessive use of subsidised urea, which is often seen as a quick solution to improve crop growth. While it gives crops like maize and cotton a rapid green appearance, the long-term impact on soil and productivity is concerning. “Excessive nitrogen use reduces soil organic carbon, making the soil hard and less capable of retaining water. It also makes crops more vulnerable to pests, increasing farmers’ spending on pesticides,” said an agriculture expert.

Officials note that many farmers are using three to four bags of urea where only one is required. This trend is often linked to weather conditions. During heavy rainfall, crops may turn yellow due to poor soil aeration, prompting farmers to apply more urea. “Farmers see urea as a quick fix to restore the green colour of crops. While it works temporarily, it weakens the plants and makes them more prone to pest attacks and diseases,” said Manjunath Antaravalli, Joint Director of Agriculture, Dharwad. Despite higher fertiliser use, farmers are also facing a yield plateau, with productivity no longer increasing proportionately due to declining soil fertility.

The issue has gained urgency as the India Meteorological Department has forecast a below-normal monsoon (92% of the Long Period Average) for North Interior Karnataka this year. Experts stress that healthy soil is crucial for retaining moisture during dry spells, something degraded soil struggles to do. To address the problem, the Department of Agriculture is promoting alternatives such as Nano Urea, a more efficient fertiliser designed to reduce excessive chemical use.

A 500 ml bottle of Nano Urea is claimed to replace a 45 kg bag of conventional urea, though officials say awareness on its proper usage still needs improvement. Agricultural scientist Dr. Ravi Patil warned that the imbalance is not just an agricultural issue but also an environmental concern. “Excess urea releases nitrous oxide, a greenhouse gas far more potent than carbon dioxide. Farmers must adopt balanced fertilisation and efficient technologies to protect both productivity and the nvironment,” he said.