Balanço de água no solo para o milho no semiárido alagoano

Abstract

Maize production occurs in all regions of the country, normally the production is directed to the domestic market (67.2%), and is used to supply animal feed. The Brazilian semi-arid region (NEB) presents a climatic irregularity and wide-ranging meteorological variations. In addition to climatic variability, NEB soils are mostly poorly adapted to agriculture with low nutrient concentration and poor physical structure for agricultural activities. The study was conducted along the irrigated perimeter of the Sertão Alagoano Channel, where soils were collected based on their current type of use and the potential for irrigated agriculture. Soil samples were collected in the municipalities of Inhapi (Yellow Red Argissolo), Delmiro Gouveia (Quartzarenic Neossolo) and Pariconha (Neoso Regolítico). The soil was divided into 0-10, 10-20 and 20-30 cm profiles, where its physical-water characteristics were determined. The simulation of drip irrigation was performed based on rainfall and crop evapotranspiration (ETc), every two days. The Inhapi region obtained soil moisture content close to what was seen in literature for the type of soil it possesses. The region od Delmiro was the one that obtained the highest retention capacity observed and Pariconha soil moisture was much lower than was found in the literature with retention capacity 5 times lower than that found in other studies. The second planting season was the one that used the least amount of irrigation water, being considered the best time to start planting the corn crop. The water swings in the soil at different planting times, generated a series of data that may help a water management practice in the region near the channel of the backwoods of Alagoas. Through irrigation and studies of water dynamics, it is possible to increase the productivity of areas in the Alagoan semi-arid region, mainly in the region of the sertão canal. The corn crop has a high productive potential, reaching 10 t ha-1 of grains in Brazil under experimental conditions and by farmers adopting adequate technologies. In the semi-arid region, if adequate management of the planting season is done and if there is water availability through irrigation, it is possible to obtain positive results and a possible increase in local production and productivity.