Frequência de irrigação na cultura da soja no litoral cearense

Abstract

Soybean is a very widespread leguminous in the agronomic environment, since it presents a considerable range of use for several markets, such as food industry, biodiesel industry, green manuring, among others. Most of this material is concentrated in the Southeast, Center West and South regions, with most of the research being directed to these regions. The Brazilian Northeast, in turn, is in a productive penumbra in relation to those regions, a fact generally attributed to the lower availability of water. However, with the advent of scientific and technological development, it is now possible to produce in different regions and under less favorable conditions. In this sense, in addition to aggregating knowledge on the water management of soybean in locations considered inhospitable to the crop, such as Ceará, this research aims to evaluate the agronomic performance of the crop with different irrigation frequencies, to measure the viability of the irrigated crop in the coastal region in Ceará State. The experiment was carried out in the experimental area of the Meteorological Station, belonging to the Federal University of Ceará. The experimental design was a randomized block design with five treatments, four replicates and 1.5 m2 plots containing 45 plants. The treatments consisted of five irrigation frequencies: five, four, three, two and once a week. The response variables analyzed at the end of the cycle were: plant height, stem diameter, fresh plant mass, number of pods per plant and grain yield. The mean values of the response variables were submitted to analysis of variance and, when significant, to the Tukey test. According to the results, only the diameter of the stem was significantly influenced by the treatments. Thus, soybean production in the coastal region of Ceará can be carried out via surface drip irrigation, using weekly irrigation.