Cultura do milho submetido a diferentes manejos de irrigação em Dourados - MS

Abstract

The media culture of maize productivity in the region of Dourados is 4800 kg/ha, and in irrigated farming this productivity may be up to three times greater. The objective of this work was to evaluate the effect of irrigation and adoption of different irrigation management on productivity of maize. The experiment was conducted on experimental unit irrigation area II of UFGD. The survey was conducted in a completely randomized design (banded) four treatments and five replications, being a grown under rainfed and irrigated with the other three different irrigation management. Each track has received a treatment: T1 – non- irrigated land; T2 – Management in soil water conditions for a voltage of 40 kPa; T3 – Management in soil water conditions for operating voltage 20 kPa and T4- Handling in atmospheric conditions. In T2 and T3 treatments irrigation management was on the basis of the readings of the tensiometros who monitored soil moisture. While T4 irrigation management was conducted in accordance with the soil water balance using meteorological data of two meteorological stations closest to experimental area. For the analysis of productive parameters was considered a useful area of 10 m2. The harvest and the evaluations were made at 149 day after sowing (DAS) whose characteristics evaluated were: water tension (kPa), plant height (AP) (cm), length of spikes (EC) (cm), number of spikes in 10 m2 (NE10), harvest index (CI) (%) of grain mass of ten plants (M10E) (g), mass of ten plants (M10P) (kg), number of spikes per plant (NE), water productivity (PA) (kg/m3) and total productivity (Ptotal) (kg ha-1). The results were submitted to variance analysis by tukey test through the statistical program ASSISTAT. Full productivity in irrigated systems was greater than in the non-irrigated land, however there was no significant difference by tukey test between the different managements in the irrigated treatments. The yields were of 3800 kg/ha-1, 9644.6 kg/ha-1, 8883.2 kg/ha-1, 8337.8 kg/ha-1 respectively for treatments T1, T2, T3 and T4. The dryland treatment suffered a water deficit of 146.68 mm throughout the cycle of culture and the most aggravating was that most of that deficit (97.74 mm) occurred in the most critical phases, the pendoamento to the grain filler. The productivity of water obtained a higher income in the treatment 2 (1.29 kg/m3), however did not differ significantly from other irrigated T3 and T4 (1.13 kg/m3). The treatments with corn cultivation with irrigation obtained greater agricultural productivity and greater water use efficiency than under dryland conditions. In the treatment with irrigation management based on soil water tension of 40 kPa were obtained the largest agricultural productivity and water. As there was no significant difference between management systems of irrigation, it is incumbent upon the producer to choose the management system of irrigation which best suit their financial, technical and operational conditions.