Submitted to: IMTA Workshop on Remote Sensing Technologies Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 1, 2005
Publication Date: April 1, 2005
Citation: Suarez, D.L. 2005. Models as a tool for soil management with examples from a field scale sodic soil reclamation project and boron leaching studies. Proceedings IMTA Workshop Analysis of Technologies for Identification of Soil Salinity Through Remote Sensing. November 17-19, 2004. Jiutepec, Morelos, Mexico. pp: 61-75. Interpretive Summary: Existing water quality guidelines and criteria for irrigation in arid regions are not adequate to met current needs for improved management. There is a need for a decision making tool that considers the interaction of multiple processes for development of site specific management plans. The process-based computer model UNSATCHEM provides a state of the art tool for evaluation of management options for optimal use of low quality waters and reclamation. Several examples are provided including how waters with elevated boron concentrations can be used for irrigation in regions with winter rain. The simulations provide information as to how the irrigation efficiency and soil adsorption properties can be used to minimize the soil solution boron concentration during the growing season. The model has wide applicability for evaluating and developing new management options for saline and sodic soils and waters.
Technical Abstract: There are increasing demands for limited fresh water for municipal and industrial use. In arid areas water use is already in excess of sustainable quantities. Irrigation as currently practiced with use of high quality waters is not likely to continue. In order to maintain agricultural productivity we need improved water use efficiency such as conversion to drip irrigation as well as alternative water supplies. Most regions have abundant quantities of low quality saline, drainage and sewage waters, most of which could be used for irrigation. This will require new strategies for water management as well as alternative crops or varieties. In many areas the overall water requirements can be met by a combination of rain, fresh water and saline water. In some instances periodic reclamation of the soil or continuous application of amendments will be necessary to control salinity sodicity and toxic element concentrations. These practices must be economically efficient and minimize degradation of waters receiving the subsequent drainage water. Computer models such as UNSATCHEM can be used as tools to analyze the performance of various management practices. Examples are given from a large scale field reclamation study using gypsum as an amendment, a field study with cyclic use of fresh and drainage water and boron leaching studies and model simulations of the impact of irrigation with high B waters.