Effect of addition of organic manures on basmati yield, nutrient content and soil fertility status in north-western India.

Integrated use of chemical fertilizers with organic manure is becoming a quite promising practice to maintain higher crop productivity and to manage soil health, which is otherwise deteriorated due to intensive cultivation and imbalanced fertilizer use. Thus, the present experiment was conducted for combined application of inorganic fertilizers and organic manures for higher yield and nutrient uptake in basmati rice as well as to restore soil health. The treatments applied in the present study involve T1: control, T2: Farmyard manure (15 t ha), T3: Poultry manure (6 t ha), T4: Press mud (15 t ha), T5: Rice straw compost (6 t ha), T6: Farmyard manure (15 t ha) + 50% N (recommended dose of nitrogen), T7: Poultry manure (6 t ha) + 50% N, T8: Press mud (15 t ha) + 50% N, T9: Rice straw compost (6 t ha) + 50% N, T10: 75% N, T11: Farmyard manure (15 t ha) + 75% N, T12: Poultry manure (6 t ha) + 75% N, T13: Press mud (15 t ha) + 75% N, T14: Rice straw compost (6 t ha) + 75% N, T15: 100% N. The integrated use of organic manures and inorganic fertilizers significantly increased the grain and straw yield, macronutrients as well as micronutrients uptake in basmati due to the release of nutrients from decomposition of organic manures. Among different treatments, the addition of PM+75% N showed maximum grain yield, straw yield and sustainability yield index (44.53 q ha, 89.67 q ha and 0.91 respectively) as well as the highest uptake of nitrogen (58.29 and 65.39 kg ha), phosphorus (25.04 and 23.24 kg ha) and potassium (15.26 and 118.95 kg ha) in grain and straw, respectively. Similar results were observed for zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) uptake under treatment involving PM+75% N with values 183.9, 26.18, 339.3 and 355.8 g ha in grain and 205.3, 25.62, 2627.3 and 278 g ha in straw, respectively. Additionally, correlation studies showed that the grain and straw yield of basmati exhibited a significantly positive correlation with soil P, Cu and Fe. The study suggested that the partial substitution of inorganic fertilizers with organic manures did not lower crop yield and nutrient uptake. Thus, integrated application of organic and inorganic fertilizers can be used for the sustainability of basmati-wheat system and to retain the soil fertility which is otherwise deteriorated with sole use of inorganic fertilizers.