Supplement to Diagnosis and Management of Salinity Problems in Irrigated Pecan Production: Salt Leaching.

摘要

In the publication prepared in 2006 with the above title (TWRI. TR-287), we described ways to diagnose salt problems which affect irrigated production of pecans. We also discussed the concepts of minimizing soil salinization, and ways to lower soil salinity. However, the materials presented were general and introductory in nature. This article is to supplement the previous publication with technical details, and practices of salt leaching during the routine irrigation as well as salt leaching irrigation for restoration. The aim of salt leaching is to keep soil salinity of the root zone below the level that trees can tolerate. The threshold salinity of irrigated pecans is in the range of 2 to 3 dS m-1 when measured in the soil saturation extract (Fig. 1), which is an official method of measuring soil salinity (Miyamoto et al., 1986). In the areas rich in gypsum, trees may tolerate higher levels of soil salinity, probably by 1 or 2 dS m-1. Calcium and sulfate ions are less harmful to pecan trees than sodium and chloride ions (Miyamoto et al., 1985).