Comparative Effect of Gypsum and Phosphogypsum on Crops Irrigated with Alkali Water under Sodic Soil Conditions

摘要

Afield experiment was conducted during 2009-10 to 2013-14 to study the comparative effect of gypsum and phosphogypsum on crops irrigated with alkali water under sodic soil conditions. Soil application of gypsum and phosphogypsum and use the equal amount of both amendments with alkali water passing through 15 cm bed was found significantly superior over RSCW (untreated plot) with respect to crop production. The maximum grain yield of rice 40.00 q ha-1 and wheat 36.41 q har' was recorded with the application of phosphogypsum and alkali water pass-ing through 15 cm bed treatment and equal amount of phosphogypsum through soil application followed by gypsum and alkali water passing through 15 cm bed treatment and equal amount of gypsum through soil application. The use of best available water (BAW),soil application of gypsum and phosphogypsum treatments was statistically at par with each other in case of rice and wheat yield. The changes in pH, electrical conductivity (EC), sodium absorption ratio (S AR) and residual sodium carbonate (RSC) valuesof alkali irrigation water were from 8.82 to 7.86, 7.88,1.19to 1.52 and 1.51 dSm10.97 to 5.31 and5.20 m mol1/2 L-"2, and 8.87 to 4.21 and 4.08 me L"1 when the alkali water was passed through 15 cm gypsum and phosphogypsum bed respectively. The considerably change value of pH, EC and exchangeable sodium percentage (ESP) with the use of different treatments. These was as increase in uptale values of N, P, K, Zn, Ca, Mg due to different treatments over control and decrease in uptake value of Na due to decreasing level of ESP. The maximum and minimum uptake was recorded in passing alkali water through 15 cm phosphogypsum treatment and untreated plot respectively.