Características da infiltração em sulcos abertos e fechados.

Abstract

The present work had as objective to study the effect of the initial water content of the soil on the parameters of the infiltration rate equation and to compare statistically two methods of irrigation 'closed grooves and open grooves. The works were developed in a latossol of the Experimental Station of the Irrigation Project of Bebedouro, of the Superintendence of the Valley of the São Francisco (SUVALE), in Petrolina State of Pernambuco. The effect of the initial water content on the infiltration rate equation was evaluated through infiltration tests performed at different levels of soil moisture and analyzing the results through logarithmic correlation. In the comparison between the two irrigation methods, a Split Plot was used at random and the treatments were three slopes (0.15, 0.24 and 0.37%) and the three irrigation slides (3.0, 5 , 5 and 8.0 cm). Analysis of the results showed that the coefficient K of the infiltration rate equation decreased as the initial water content in the soil increased. On the other hand the exponent "n" of the infiltration rate equation was not affected with the initial water content of the soil. Comparing the two irrigation methods, the effects of the blade and interaction (blade x slope) were significant at the 13 level. Under the conditions under which the tests were conducted, it was found that when irrigated by drawing ridges with no water outlet, water infiltration was greater than infiltration into open grooves. Thus, of the methods studied the most satisfactory was the closed grooves.