Influence of integrated use of fertilizers and manures on SRI grown rice (Oryza sativa) and their residual effect on succeeding wheat (Triticum aestivum) in calcareous soil

A field experiment was conducted during 2007–08 to 2009–10 at the experimental farm of Rajendra Agricultural University, Pusa (Bihar), to assess the direct effect of integrated use of different levels of N through chemical and organic fertilizer on system of rice intensification (SRI)-grown rice (Oryza sativa L.), and residual effect on succeeding wheat [Triticum aestivum (L.) emend.Fiori & Paol.]. The experiment was conducted in randomized-block design involving 3 organic sources (FYM, vermicompost and poultry manure) at 2 levels, viz. 25 and 50% of recommended dose of nitrogen, (RDN) i.e. 120 kg N/ha and 5 levels of chemical fertilizer nitrogen (0, 50, 75, 100 and 125% RDN). Maximum plant height (102 cm), leaf-area index (5.04), panicles/m² (266), grains/panicle (121), grain yield (6.0 t/ha) and straw yield (5.4 t/ha) were recorded with application of poultry manure @ 50% RDN, which was significantly superior to its lower dose and no organic treatments. The maximum uptake of N, P and K by rice was recorded with poultry manure @ 50% RDN treatment. In case of chemical fertilizer N, maximum value of plant height, LAI, grains/panicle, grain and straw yields were recorded at 125% RDN, which was significantly superior over its lower levels including control except 100% RDN. Poultry manure @ 50% RDN also recorded maximum net returns and benefit: cost ratio.