Effect of Crop Residues and Biogas Slurry Incorporation in Wheat on Yield and Soil Fertility

A field experiment was conducted for two consecutive years during 1993–94 and 1994–95 to evaluate the effect of varying levels of crop residues (0, 2.5, 5.0 and 7.5 t ha⁻¹) and N (50 and 100 kg ha⁻¹) along with biogas slurry applied in the ratio of 1:4 or @ 2.0 L kg⁻¹ material against no fertilizer (control) and 100% NPK on crop yield and soil fertility. The grain yield increased significantly due to crop residues and biogas slurry at both the levels of applied nitrogen. Wheat straw nodes @ 7.5 t ha⁻¹ and biogas slurry applied along with 50 kg N ha⁻¹ brought out significant increase in grain yield over 50 kg N alone and was at par to 100 kg N ha⁻¹. Nitrogen applied @ 100 kg ha⁻¹ along with 5.0 t ha⁻¹ of wheat straw nodes and biogas slurry further increased the yield which was comparable to NPK applied @ 120:60:60 kg ha⁻¹. On the basis of two years experimentation, it is concluded that application of 7.5 t ha⁻¹ wheat straw nodes along with biogas slurry in the ratio of 1:4 can effectively be utilized in wheat for higher yield and nutrient economy. Physicochemical and biological properties of the soil showed marked improvement with the addition of wheat straw nodes and biogas slurry. Carry-over effect on mungbean was however nonsignificant by crop residues, biogas slurry and nitrogen.