Monitoring the variables that constitute the soil water balance equation in a farmed field is important for reliably evaluating water deficit periods during the crop cycle, managing irrigation and estimating nutrient losses through leaching. Components of the water balance equation may vary in space and time, and the study of the temporal stability of the spatial variability of these components is essential for determining the observation points in the field (sites) for monitoring soil moisture accurately with reduced effort in […]

As the water matric potential is the most important component of the water total potential in unsaturated soils, it must be measured accurately. The aim of this study was to evaluate the effect of soil temperature on water matric potential and water total potential gradient over the period of water redistribution in a Latossolo Vermelho-Amarelo (Oxisol/Hapludox) located in the municipality of Piracicaba, SP, Brazil. In a circular plot of 3 m diameter, 10 tensiometers with pressure transducers (model SWT3 from […]

The hydraulic conductivity, determined as a function of the volumetric soil water content K(θ), is essential to solve, e.g., drainage problems. However, the results of different methods vary according to the different assumptions. The objective of this study was to compare direct field methods (Instantaneous Profile, Flux and Humidity) and indirect laboratory methods for estimating the hydraulic conductivity as a function of soil water content, K(θ). The experiment was carried out in Piracicaba, State of São Paulo (Brazil), with a […]

Water and nutrient availability in the soil at suitable times and in adequate amounts, as related to edaphic and climatic conditions, are undeniably relevant for crop yields. The objective of this work was to evaluate the actual evapotranspiration of an orange plantation, analyze its variability and verify the influence of the soil water loss on crop productivity. The experiment was carried out in Piracicaba County (SP), Brazil, on an Oxisol. The actual evapotranspiration was evaluated by a soil water balance […]

A four replicated maize (Zea mays L.) crop irrigation management experiment was carried out in a Typic Haphortox soil of Guaíra (SP), Brazil (20°27’30”S, 48°19’30”W, 495 m) from July to December, 1994. There were three treatments: tr000 – half of the recommended amount of water was applied during the crop cycle; tr0I0 – the recommended amount of water was applied only during the intermediate stage and half of it during the initial and the final stages; and trIII – the […]