Lâminas de irrigação localizada e adubação potássica na produção de milho, em condições semiáridas.

Abstract

To be harvested and sold in the green stage, maize cultivation is an important contribution to the generation of income and employment in small and medium properties and has, as a byproduct, the plant still in the green and the rest of the spikes inept marketing, serving animal feed or as raw material for the production of silage reason that aimed to evaluate the behavior and better physical and economic efficiency of water use in the cultivation of corn subjected to irrigation with different amounts of water and different levels potassium fertilization, through an experiment at the Center for Sustainable Development of Semiarid CDSA / UFCG, in the municipality of Sumé, PB, Brazil. The experimental design was randomized blocks in split plots, with six water slides and six amounts of potassium in four replications. The plots were irrigated by water depth, determined from the potential evaporation of culture (ETPC) levels: 0,25 ETpc, 0,50 ETpc, 0,75 ETpc, 1,00 ETpc, 1,25 ETpc, end 1,50 ETpc. The subplots were fertilized with different amounts of potassium (0, 20, 40, 60, 80 and 100 kg of potassium per hectare). We analyzed physiological parameters of ears of corn as CESP, DESP, PEE, PED, % EC end % MG, obtaining general average of 21.76 cm, 5.84 cm 13.38 t ha-1, 8.72 t ha-1, 7.7 t ha-1, 86.2% and 52.4% respectively. For the physiological parameters of plants were observed MVPse MVPce and overall averages of 62.4 and 49.1 t ha-1 respectively. The efficiency of water use EWU. average was 61.76 mm t-1 (2.02 kg m3). The application of 680.64 mm of water and 72.14 kg ha-1 potassium maximized the physical productivity of grain trade. When applied to a water depth of 674.70 mm and when fertilization up the soil with 71.13 kg ha-1 potassium net income was maximized.