Effects of farmyard manure and phosphorus and potassium fertilizers on soil properties in rice-wheat rotation

Summary The effects of farmyard manure (FYM) and P and K fertilizers on soil properties were studied at the end of a 3-year (1972–5) field experiment at New Delhi, India. Each year a crop of rice and wheat was grown. FYM was applied at 0 or 15 t/ha, phosphorus at 0, 30 and 60 kg P2O5/ha and potassium at 0 or 60 kg K2O/ha. Treatments included application of manure and fertilizer to rice or wheat alone or to both the crops. FYM application increased organic C, total N and available K and P in the soil, the effects being greater when both rice and wheat received FYM. Application of FYM slightly decreased the soil pH. Phosphorus and potassium fertilizer increased available P and K in the soil, respectively.