PRODUCTION-FUNCTIONS RELATING CROP YIELD, WATER-QUALITY AND QUANTITY, SOIL-SALINITY AND DRAINAGE VOLUME

Data from a long-term lysimeter experiment were used to estimate a set of production functions describing relationships between yield, water quantity and quality, soil salinity and drainage volume. The experiment simulated a variety of conditions prevailing in the San Joaquin and Imperial Valleys of California currently suffering salinity and drainage problems. Coefficients for the various estimated functions are statistically significant and the functions describe the relative effects of input water quality and quantity on yield, soil salinity, and drainage volumes for wheat, sorghum and tall wheatgrass. Possible use of these functions for decision making is discussed.