Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2007.3865.3869KhanRahmat UllahGurmaniAli RazaKhanMuhammad SohailGurmaniAkber Hussain1220071021A field experiment was initiated during 2005-2006 to study the effect of gypsum application on rice and subsequent wheat crop. The direct, residual and cumulative effects of gypsum were also noticed under rice-wheat system. The gypsum was applied as 0, 1 and 2 t ha-1 with the basal dose of N, P2O5, K2O as 120, 90 and 60 kg ha-1 to both crops. Rice variety IRRI6 and wheat variety Naseer 2000 were planted in Randomized Complete Block Design with three replications in a permanent layout. The soil samples were collected from both crops before earing to study P and K concentrations. The rice yield was significantly affected by gypsum application that ranged from 4807-5472 kg ha-1. The highest rice yield was recorded by the application of 2.0 t gypsum ha-1 with an increase of 13.8% over control. Similarly all the yield components like number of panicles m-2, panicle length, plant height and 1000 grain weight were also significantly affected by gypsum application. The wheat grain yield ranged from 2598 to 4304 kg ha-1. The cumulative application of 1 and 2 t gypsum ha-1 increased the wheat yield by 25.25 and 65.66% over check, respectively. The direct and residual application of 2 t gypsum ha-1 gave an increase of 46.80 and 15.05% over the check, respectively. The application of gypsum significantly affected the P and K that ranged from 4.50-7.50 and 4.70-9.32 mg kg-1 P while 70-110 and 78-112 mg kg-1 K in rice and wheat, respectively.]]>Ahmad, M. and M. Salim,20013339340Niazi, B.H., I. Haq, M. Salim and M. Ahmad,20032673676Chand, M., N.S. Randhawa and M.K. Sinha,2005551724Dillon, K.S.,2000227243248Hussain, K., J. Iqbal, M. Mehdi, M. Hanif and S. Islam,19921992pp: 480484Street, J.J. and G. Kidder,1997Kielen, N.C.,1996pp: 65-66pp: 65-66Naseem, A.R.,2006pp: 95-96pp: 95-96Ramzan, M.C.,20013276280Shah, H.N., M.S. Maskina and P.S. Gill,2005Oryza sativa L.).]]>49437442Steel, R.G.D. and J.H. Torrie,19802nd Edn.,Pages: 481Pages: 481Szabolcs, I.,19941994