Wheat production functions under irrigated saline environment and foliar potassium fertigation

Abstract

A field experiment was conducted for two consecutive years to develop management alternatives for wheat cultivars (salt-tolerant and salt non-tolerant) cultivated under irrigated saline environment (groundwater, 4, 8 and 12 dSm–1) and foliar potassium fertigation. The grain yield of wheat cultivars decreased with the increase in salinity levels of irrigation water. The foliar potassium fertigation during the heading stage of wheat cultivars ameliorated the adverse effect of salinity and resulted in the increase in grain yield. In this study, empirical equations for wheat yield known as production function have been developed. The production functions were developed keeping grain yield parameter as output, besides the many input parameters pertaining to quantity and quality of the irrigation water, quantity of potassium applied as foliar spray and rainfall depth during the crop growth period. The production function with higher coefficient of determination (R2) may be used to predict grain yield of both salt-tolerant and salt non-tolerant cultivars under different saline irrigation regimes, rainfall and irrigation water depths, besides the dose of potassium sulphate (K2SO4) for foliar spray. The production function which gave the highest R2 value (i.e. 0.82 for KRL-1-4 and 0.97 for HD 2894 wheat cultivars) could be used for foliar spray under different salinity regimes with high expectation of grain yield. The predicted grain yield and estimated quantity of potassium under different salinity levels of irrigation water may prove useful to different stakeholders for enhancing the wheat yield in high saline water areas. The stakeholders can predict the grain yield under similar circumstances as explained in this experiment and estimate the appropriate potassium doses to be applied for enhancing the wheat yield.