Impact of various irrigation practices on nitrate movement in soil profile and wheat productivity

Nitrate is important for plant nutrition and is considered as an index of soil fertility. Its leaching to underground water not only poses severe threat to environment but also to human health. Amount of water supplemented to crops have significant role in yield and nitrate distribution in soil. An experiment was carried out to evaluate the effect of different irrigation rates on nitrate movement, soil properties and wheat yield. Experiment was laid out in randomized complete block design with three replicates. Three irrigation levels applied were I₁ (0.5 ET₀ deficit irrigation), I₂ (1.0 ET₀; according to farmer's practice) and I₃ (1.5 ET₀; over irrigation). Wheat (Sehar-2006) was used as test crop. Irrigation levels had significant effects on most of growth and yield parameters of wheat. Maximum number of leaves per plant, 1000-grain weight and grain yield were observed in second irrigation level. Irrigation rates had significant effect on infiltration rate and soil saturated hydraulic conductivity, and a decrease in value of these parameters was observed in I₃ that was mainly due to higher moisture contents. Bulk density and porosity of the soil remained unchanged under various treatment applied.