Soil water storage variability in a three-dimensional analysis in the root zone of irrigated melon

ABSTRACT A detailed knowledge of the soil water storage variability in the root zone can promote recommendations regarding the ideal positioning of sensors, as well as make the calculation of soil water balance more precise and accurate. This study aimed to assess soil water storage variability in the melon root zone and indicate – based on spatial variation of soil water storage – the regions of highest rootactivity of the melon crop in different development stages. Soil waterstorage was measured using time domain reflectometry (TDR) in 40 monitoring points. The data were daily collected in two periods: (i) immediately before irrigation and (ii) 30 min after irrigation. The soil water storage variation in the melon root zone occurs with greater intensity throughout the time of vegetative growth and the highest values are always observed in the same distances and depths of the soil in all phases of growth. The region indicated as of greatest root activity of the melon crop under drip irrigation is delimited, inrelation to the stem, by the radial distance of 0.36 m and depth of0.3 m, for all development stages.