Effect of phosphorus and farmyard manure applied to sunnhemp (Crotalaria juncea) on yield and nutrient uptake of sunnhemp-wheat (Triticum aestivum) cropping system and fertility status in a Typic Ustocrept of Uttar Pradesh.

摘要

Field experiments, with sunn hemp-wheat cropping system, were conducted in Uttar Pradesh, India, during 2004 and 2005, to study the effect of phosphorus (P) and farmyard manure (FYM) levels on yield and nutrient uptake of sunn hemp and their residual effect on wheat and changes in soil fertility status. The application of FYM at 5 t/ha recorded an increase of 13.9% in fibre yield over the no FYM treatment. P fertilizer application significantly increased the fibre yield of sunn hemp by 14.69% over the no P treatment at 40 kg P< sub>2O< sub>5/ha. The highest fibre yield (0.90 t/ha) was recorded with combined application of 60 kg P< sub>2O< sub>5 and 7.5 t farmyard manure/ha, which was 45.2% higher than the yield of without P and FYM. The total N, P and K uptake by sunn hemp increased significantly with applied P up to the maximum level of 60 kg P< sub>2O< sub>5/ha, but the favourable effect with FYM was recorded up to 5 t/ha only. The increase in N, P and K uptake with 60 kg P< sub>2O< sub>5/ha were 20.5, 44.0 and 54.9%, respectively, over the no P treatment. Grain and straw yield of wheat increased significantly with farmyard manure at 5 and 7.5 t/ha applied in sunn hemp over the no FYM treatment, although the yield recorded with 5 and 7.5 t FYM/ha were at par. The increase in grain and straw yield under 5 t FYM/ha was 6.60 and 14.05%, respectively. A combined dose of 60 kg P< sub>2O< sub>5 with 7.5 t FYM/ha applied in sunn hemp recorded the highest grain yield of wheat (4.55 t/ha), which was 21.3% higher than that without P and FYM. The N, P and K uptake by wheat increased significantly due to the residual effect of FYM and P applied in sunn hemp crop. The application of P and FYM had significantly improved the organic carbon and available N, P and K status in postharvest soil after 2 years of cropping.