SOIL WATER REDISTRIBUTION AND EXTRACTION PATTERNS OF DRIP-IRRIGATED TOMATOES ABOVE A SHALLOW WATER TABLE

Abstract

ABSTRACT Vegetables in Florida are often grown on plastic-mulched beds in sandy soils that commonly require irrigation even if they are subject to naturally occurring high water tables. Increasingly, these crops are being irrigated with line source drip irrigation systems. In this study, experiments were conducted in lysimeters to determine the redistribution and extraction patterns of a tomato crop under similar soil and irrigation management conditions. Soil water potential data were continuously collected using a microcomputer-based, tensiometer-pressure transducer, data acquisition system. These data were used to develop soil water equipotential lines in the bedded soil profile, from which redistribution and extraction patterns were determined. The data indicated that very little change in soil water status took place at horizontal distances of more than 250 mm from the irrigation lateral and at depths greater than 300 mm, and that this is the region in which irrigations should be concentrated for this production and management system.