Profundidade efetiva de raízes e sua relação com a parte aérea da cultura do feijoeiro irrigado em sistema plantio direto

Abstract

In the projects and irrigation management is important the knowledge of the root system of crops for the appropriate control of irrigations and soil water content storage. For difficulties of the work methods, the characterization of the effective rooting is usually accomplished in the flowering stage of crop, resulting in lack of information, mainly in initial stage of growth of crop. In face of this reality, the objective of this work was to determine, to local conditions, the effective rooting depth in the development stages of the bean crop, variety Pérola, and to relate it with the parameters of the aerial part. The irrigation was accomplished by variable intervals irrigation, maintaining the soil water content between 39% and 36%, that it’s correspond to humidities at field capacity and critic for the crop, respectively. The results indicated that the effective rooting depth of studied variety, in the specific conditions that occurred this experiment, is in the layers: from 0 to 15 cm for the vegetative development, from 0 to 20 cm for the flowering/ grains filling and from 0 to 25 cm in the beginning of the physiologic maturation. The relationship between the parameters of growth of the bean crop, height and dry mass of the aerial part can be considered an appropriate instrument to estimate the effective depth of root system for irrigation management in the local of experiment. The root density related linearly to the height of plants and dry mass of the aerial part. And the maximum values of root density and parameters of the aerial part were obtained at grains filling stage.