Efeito de lâminas de água aplicadas como irrigação suplementar no ciclo do milho safrinha sob plantio direto na região de Dourados-MS

Abstract

The knowledge of the amount of water requested by the cultures it is constituted in important aspect in the irrigated agriculture so that the development of the plants happens in a satisfactory way. Several works show the importance of the irrigation as mechanism to supply possible hydrics deficiencies during the physiological cycle of the cultures, revealing that the effects of hydrics deficiencies vary with the development stadium, existing critical periods where the plants are more sensitive to the dynamics of readiness of the soil. With base in that focus, the objective of this work was to evaluate the influence of different sheets of water applied as supplemental irrigation in the cycle of the safrinha corn under no-tillage systems in the area from Dourados-MS. The work was accomplished in the Experimental Nucleus of Agrarian Sciences of UFMS, in the campus from Dourados, in a clayey Rhodic Hapludox (Oxisol), in the period of March to September of 2005, in which the time is configured “safrinha” of the corn. The treatments, adding the rain precipitation and applied irrigation during the cycle of the culture, they resulted in total sheets of 510 mm, 410 mm, 360 mm and 160 mm (treatment not irrigated) respectively. With base in the obtained results, it can be ended that: (1) there was increment in the productivity with larger sheets of water, with maximum point in 608 mm; (2) The hydrics deficits in the critical periods reduced the productivity; (3) the supplemental irrigation was economically viable for the safrinha corn.