AZEVEDO, A. P.; AZEVEDO, Adaisa Pessoa de.
Resumen:
In this work we analyzed the behavior of water in the root zone of a tomato (Lycopersicon Esculentun, Mill) along the crop cycle under different irrigation treatments. We tried to define which portions of the applied blades were consumed by the evapotranspiration process of the soil-plant or percolated system. The soil and hydro-climatic physical parameters, such as soil moisture in the root zone, groundwater levels, etc., as well as root growth, were studied from the observations made in the experimental area of the IAJAT - Instituto Agronômico José Augusto Trindade, in São Gonçalo, Souza, Pb, from the homogeneous micro-region 95 of the Alto Piranhas Depression. Two tomato plantations were monitored during 1984 and 1985. Irrigations were applied according to four simultaneous treatments, in specific blocks, when soil 90; 70; 50 and 30% of the available water in level basins by the furrow infiltration method. Some physicochemical characteristics of the soil were analyzed in the laboratory, such as moisture, capillary tension, porosity, bulk density, texture, pH, etc. From the data collected in the field, laboratory and meteorological station, evapotranspiration was defined by the FÃO method, 1979. The knowledge of rainfall, soil moisture, applied irrigation slides and evapotranspiration allowed the establishment of the water balance in the root zone of the crop in
study, each of the components cited being discussed. The yield and yield of each plot were analyzed from the point of view of the applied treatment and the variation of soil moisture content. Statistical analysis was made of the elements that make up the balance, as well as the results of laboratory tests. From the studies performed, it was possible to define among the applied treatments, in which soil moisture limit was the most reasonable irrigation application, in terms of water consumption and agricultural productivity.
