Response of direct seeded rice and wheat crops to phosphorus application with crop residue incorporation in saline-sodic soil

Abstract

A long term field study using permanent layout was conducted to investigate the effect of P application (0, 40, 80, 120 kg P2O5 ha-1) with and without crop residue (CR) incorporation on growth and yield of direct seeded rice (DSR) and wheat crop under saline-sodic soil (ECe = 6.63 dS m-1; pHs = 8.31; SAR = 17.39 (mmolc L-1)1/2; CaCO3 = 3.47%; Extractable P = 3.92 mg kg-1; sandy loam) during growth seasons 2011 and 2012 at Soil Salinity Research Institute (SSRI) Farm, Pindi Bhattian. The experiment was planned employing split plot design with three replications. Planting methods (with and without crop residue incorporation @ 2 ton ha-1) for both DSR and wheat crop were kept in main plots and P application was in sub plots. Data on tillering, plant height, panicle length, paddy and straw yields was collected from both rice and wheat crops. On an average of two year DSR data, maximum tillers (16), panicle length (27), grain panicle-1 (89) and paddy yield (2.75 t ha-1) was produced with P application @ 80 kg P2O5 ha-1 along with CR incorporation, which was considerably better (13%) than that of P application @ 120 kg P2O5 ha-1 without CR incorporation. A significant increase (22% and 19%) over control in paddy and wheat grain yields, respectively was observed with 80 kg P2O5 ha-1 application along with CR incorporation. Overall, continuous two year CR incorporation further increased 9% paddy during the follow up year of crop harvest as compared to without CR incorporation. Maximum wheat grain yield (2.84 t ha-1) was harvested with 80 kg P2O5 ha-1 + CR and was significantly higher than grain yield (2.68 t ha-1) receiving 120 kg P2O5 ha-1 without CR incorporation. Higher concentrations of P, K and Ca2+ in plant tissues (rice and wheat) were found where P was applied @ 80 kg P2O5 ha-1 along with CR incorporation or 120 kg P2O5 ha-1 alone while Na+ and Mg2+ concentration decreased with increasing the rate of P. Overall, an increasing trend in paddy yield of DSR was observed with increasing the rate of P application without CR incorporation during both the cropping years.