How can the inflection point of the water retention curve and the soil physical attributes be used to forecast field capacity?¹

Como utilizar o ponto de inflexão da curva de retenção de água e os atributos físicos do solo para previsão da capacidade de campo?

ABSTRACT

Agricultural productivity is closely related to soil physical attributes, specifically those that affect the soil-water relationship, as the soil serves as the main water reservoir for plants. This research aimed to determine the field capacity for different soils, using equations based on the water retention curve. The database used included 150 soil profiles from studies published by other authors encompassing information related to textural classification, soil bulk density, particle density and soil water retention. The inflection point for each soil profile and the corresponding matrix potential were generated. Multiple correlations were established between volumetric moisture at field capacity and clay, silt and sand contents. The calculated inflection point can be an estimator of field capacity, what may facilitate and speed up the calculation of water availability.

KEYWORDS:
Irrigation management; soil moisture; soil water retention curve