Phosphorus use efficiency and yield of direct seeded rice and wheat influenced by residues incorporation and phosphorus application under saline soil

A two years field study according to split plot design was conducted to investigate the impact of crop residue (cr) incorporation and p application (0,40,80,120 kg p2o5/ha) on p use efficiency and yield of direct seeded rice (dsr) and wheat grown under saline soil (ece = 4.59 ds/m; phs = 8.38; sar = 6.57 (mmolc/l)1/2; extractable p = 4.07 mg/kg; texture = sandy clay loam),during the years 2011 and 2012. planting of dsr (with and without crop residue incorporation @ 2 tonnes/ha) were placed in main plots and p application was in sub plots. data on tillering,plant height,panicle length,1000 grain weight,paddy and straw yields were collected. on an average of two years,maximum tillers (18),panicle length (33),grain/panicle (121) and paddy yield (3.26 t/ha) were produced with p application @ 80 kg p2o5/ha along with cr incorporation. similarly in case of wheat grown after dsr,maximum tillers (17),spike length (17),grains/panicle (66) and grain yield (3.56 t/ha) were produced with p application @ 80 kg p2o5/ha along with cr incorporation. although,the growth and yield contributing parameters with this treatment (80 kg p2o5/ha + cr) performed statistically equal to 120 kg p2o5/ha without cr incorporation during both the years,but on an average of two years,grain yield of dsr and wheat was significantly superior (22 and 24%,respectively) than that of higher p rate (120 kg/ha) without cr. overall,continuous two years cr incorporation further increased (17%) paddy yields during the follow up year of crop harvest. higher p use efficiency and concentrations of p,k+ and ca2+ in both dsr and wheat plant tissues was found where 80 kg p2o5/ha was applied along with cr incorporation or 120 kg p2o5/ha alone while na+ and mg2+ concentration decreased with cr incorporation and increasing p rate. an increasing trend in dsr paddy and wheat grain yields was observed with increasing the rate of p application without cr incorporation,however,it was not as much as that of 80 kg p2o5/ha application with cr incorporation and found to be superior than rest of the treatments during both study years. © 2016,oriental scientific publishing company. all rights reserved.