Abstract:
The present investigation on the integrated effect of fertilizers and organics on yield of 30th crop rice (CV. Rajshree) under rice-wheat crop rotation was under taken from a long-term experiment running at RAU, Pusa farm since Rabi, 1988-89. Initial soil of the experimental plot have pH 8.40, E.C 0.36 dSm
-1, organic carbon 5 g kg
-1, available N, P
2O
5 and K
2O 236, 19.7 and 100.0 Kg ha
-1, respectively. Four levels of recommended NPK fertilizers were used as main treatments in main plot (F
0 - 0, F
1 - 50, F
2 - 100 and F
3 -150 percent of RDF) and each main plot was divided into four sub-plots in which organics (M
0 – control i.e. no organics, M
1 –Compost @10 t ha
-1, M
2 –crop residue of previous crop and M
3 – Compost @10 t ha
-1 + crop residue) were superimposed over the chemical fertilizers as sub-plot treatments comprising a total of forty eight treatment combinations. The experiment was laid out in a split plot design with three replications. The recommended N: P
2O
5: K
2O were 120: 60: 40 for rice crop. Result reveals that the grain and straw yield of rice increased significantly with increasing levels of NPK fertilizers. Among the NPK treatments maximum grain yield of rice (45.3q ha
-1) and maximum straw yield of rice (76.6 q ha
-1) were obtained with 150 per cent NPK. However, the maximum yield at 150 percent NPK was at par with 100 per cent NPK. The yield was further increased with the conjoint application of organics in the order: compost + crop residues> compost > crop residues >no manure. The grain and straw production with the application of compost or crop residue alone were at par. The result indicated that compost @ 10 t ha
-1 could be substituted with crop residues. The grain yield of rice (38.3 q ha
-1) with 50 per cent NPK+ compost+ crop residues was found at par with the grain yield of rice (38.6 q ha
-1) obtained at 100 per cent NPK alone which suggest that compost + crop residues could save 50 per cent of the recommended dose of NPK i.e. 60 kg N, 30 kg P
2O
5and 20 kg K
2O ha
-1