Effect of manuring on soil properties and yield of rainfed wheat

Effect of summer-season manuring with farmyard manure (FYM) and green manure (GM) on soil properties and performance of rain-fed wheat was studied in a loamy sand soil during 1994–2000. The FYM was applied at two rates, 6 and 18 t ha⁻¹, followed by a pearl millet fodder crop. The 40–50 day-old sunhemp was incorporated into soil as a green manure. The application of FYM was stopped in 1998, and green manure in 1999. Wheat crop received three N rates viz., 0, 40 and 80 kg⁻¹. Application of FYM and GM increased organic carbon in the top 0.10 m soil. Bulk density and pH of the surface layer decreased with organic manuring whereas steady-state infiltration rate increased by 25–69% and soil moisture storage by 27–65 mm per 1.8 m depth over control. Wheat grain yield was increased significantly by manuring during four of the six growing seasons. Mter withholding FYM for two years, the residual effect (1999–2000) could produce only 6 and 21% more wheat grain than control in the FYM-6 and FYM-18 treatments, respectively. In the last year of green manuring, wheat yield was 51% higher in the treated plots compared to the control yield of 1551 kg⁻¹. But its residual effect after one year produced 33% more grains. Wheat responded significantly to fertilizer N up to 80 kg ⁻¹ during most of the seasons except 1995–96 (low rainfall) and 1997–98 (high rainfall season).