Subsurface-Applied Coated Nitrogen Fertilizer Enhanced Wheat Production by Improving Nutrient-Use Efficiency with Less Ammonia Volatilization

Nitrogen (N) is an essential plant nutrient, therefore, N-deficient soils affect plant growth and development. The excessive and unwise application of N fertilizers result in nutrient losses and lower nutrient use efficiency that leads to the low crop productivity. Ammonia volatilization causes a major loss after N fertilization that causes environmental pollution. This experiment was conducted to evaluate the effectiveness of coating and uncoating N fertilizer in enhancing yield and nutrient-use efficiency with reduced ammonia emissions. The recommended rate of nitrogen and phosphorus, urea and di-ammonium phosphate (DAP) fertilizers were coated manually with 1% polymer solution. DAP (coated/uncoated) and potassium were applied at the time of sowing as subsurface application. While urea (coated/uncoated) was applied as surface and subsurface application. Results showed that nutrient use efficiencies of wheat were found to be maximum with the subsurface application of coated N fertilizer which increased nutrient-use efficiency by 44.57 (N), 44.56 (P) and 44.53% (K) higher than the surface application of uncoated N fertilizer. Ammonia emissions were found the lowest with subsurface-applied coated N fertilizer. Thus, coated fertilizer applied via subsurface was found the best technique to overcome the ammonia volatilization with an improvement in the yield and nutrient-use efficiency of wheat.

Corn Cropping System And Nitrogen Fertilizers Technologies Affect Ammonia Volatilization In Brazilian Tropical Soils

With the advance of the no-tillage system (NT system) in Brazil, the adoption of technologies for nitrogen fertilization in these soils become essential for increasing the efficiency of N use in the system. In this sense, the objective of this study was to quantify ammonia losses, N removal in grains, and with 2nd crop yield in NT system and conventional (T system) planting areas that received application of different N fertilizers and their technologies. Ammonia volatilization, N extraction in grains and corn yield in response to the application of conventional fertilizers were compared to urease inhibitors treated urea in NT and T systems. The treatments were: no-N (Control); Prilled urea (PU); urea + NBPT (UNBPT); urea + Cu + B (UCuB); ammonium nitrate (AN), and ammonium sulfate (AS). In the NT system, the N-NH3 losses were 49% greater than in the T system; without differences for corn yield. The fertilizers as AN, and AS had the lowest N-NH3 losses, regardless of tillage system. UNBPT reduced the mean N-NH3 loss by 33% compared to PU. UNBPT (1,200 mg kg-1) and UNBPT (180 mg kg-1) reduced by 72% and 22% the N-NH3 losses compared to PU in the NT system.