Use of low quality groundwater for reclamation of saline-sodic soil by growing rice and wheat crops

A field experiment was conducted at qaim bharwana,district jhang,pakistan on a saline-sodic soil (ece = 12.7-20.1 ds m-1,phs = 10.3-10.4,sar = 157.0-273.9 at 0-15 cm soil depth and ece = 5.4-12.1 ds m-1,phs = 9.5-10.0,sar = 70.1-171.4 at 15-30 cm soil depth) following rice-wheat rotation using tube well water (ec = 1.32 ds m-1,sar = 4.8,rsc = nil,ca:mg = 0.74) for irrigation. the treatments tested were: tw) tube well water alone,fym-20) fym @ 20 mg ha-1,gyp-100) gypsum @ 100% soil gypsum requirement (sgr) and fym+gyp) fym @ 10 mg ha-1 + gypsum @ 50% sgr. after rice 2005 harvest,soil analysis showed that phs for both the soil depths decreased non-significantly,per cent decrease over initial being maximum with gyp-100 followed by fym+gyp,tw and fym-20 at 0-15 cm,while treatment effectiveness order for ph (per cent) decrease was fym+gyp>tw>fym-20 at 15-30 cm soil depth but slightly increased with gyp-100. the ece decreased non-significantly with treatments,per cent decrease over initial being maximum with fym+gyp followed by gyp-100,fym-20 and tw at 0-15 cm. decrease in phs was significant at 15-30 cm soil depth and the treatment order was fym+gyp>tw>gyp-100>fym-20. treatments differed non-significantly to lower sar for both the soil depths,per cent decrease being maximum with fym+gyp followed by gyp-100,fym-20 and tw at 0-15 cm,while the order was fym+gyp>gyp-100>fym-20>tw at 15-30 cm soil depth. soil analysis after harvest of wheat 2005-06 depicted a decrease in phs with all the treatments,order being gyp-100>fym+gyp>fym-20>tw at 0-15 cm soil depth. at 15-30 cm depth,the treatment order to decrease phs was gyp-100>fym+gyp>tw>fym-20. maximum decrease in ece was observed with fym+gyp followed by tw,fym-20 and gyp-100 at both the 0-15 cm and 15-30 cm soil depths. maximum reduction in soil sar was observed with fym+gyp followed by gyp-100,fym-20 and tw at both the soil depths. the paddy yield of rice 2005 was maximum with fym+gyp followed by gyp-100,fym-20 and tw. the highest grain yield of wheat during 2005-06 was obtained with fym+gyp followed by fym-20,gyp-100 and tw. maximum net profit was obtained with fym+gyp followed by fym-20,gyp-100 and tw.