DHAINCHA, AN EFFECTIVE AMENDMENT IN IMPROVING SALT AFFECTED SOILS AND ENHANCING P EFFICIENCY IN RICE – WHEAT CROPPING SYSTEM

Incorporating green manure in soil increases the bioavailability of phosphate in the succeeding crop. A field experiment was conducted during 2004 – 2006 at Agriculture Research Institute, Dera Ismail Khan (NWFP) to study the effect of green manure with Dhaincha (Sesbania aculeata) on phosphate availability in salt affected soil. The green manuring with Dhaincha was compared with the organic and chemical amendments viz. FYM, Pressmud and Gypsum. Results of the study shows that all the treatments significantly (P 0.05) influenced wheat yield. The highest grain yield of 4525 Kg ha^-1 was observed in the treatment of green manuring with Dhaincha and was at par with pressmud at 0.05 level of significance. It was further revealed in the study that level of phosphate in soil increased each year, but the highest P content of 8.09 μg P g^-1 soil was recorded in green manure treatment. There was a positive correlation between P uptake and extractable phosphate (r =0.99). A close relationship (r = 0.98) between P uptake and yield was also observed in wheat crop grown during 2006.