FORAGE MAIZE (Zea mays L.) PRODUCTION IN THREE IRRIGATION SYSTEMS IN THE COMARCA LAGUNERA OF COAHUILA AND DURANGO, MEXICO

In the Comarca Lagunera, Mexico, water availability is the most important limiting factor for forage production. Its deficit for balance in recharging the aquifer is 450 million m(3) (Mm(3)); therefore, it is necessary to evaluate irrigation methods which may increase water productivity. The objective of this research was to evaluate three irrigation systems: subsurface drip irrigation (SDI), center pivot (CP), and gravity (G) on forage maize (Zea mays L.). Variables obtained were consumption models of applied water, foliar area index (FM), dry matter production (DM), and water productivity (WP). The study was carried out in the Comarca Lagunera, municipality of Torreon, Coahuila, Mexico, in the spring-summer cycle of the years 2006 and 2007, at two locations: 1) in the small property Campo Sagrado, and 2) the Company VERMIORGANIC S.P.R. of R.L. At the two sites, dry sowing was carried out, using Aspros 900 hybrid plants at a density of 90 000 plants ha(-1). The water applied was measured with a volumetric meter, and evaporation with a class A pan evaporation, and FM with a LAI 2000 Plant Canopy Analyzer Equipment (LI-COR, Inc. Lincoln, Nebraska, USA). Linear regression method was used in order to obtain the models; and the slopes and mean values were compared with the Student's t test (p <= 0.05). The production of DM and WP was higher (p <= 0.05) with SDI than with C and G. Based on the models, an average consumption of 0.51, 0.56, and 0.73 cm d(-1) was calculated for SDI, CP, and G (R-2 >= 0.97). With a polynomial model for FM daily increase of 0.25, 0.15, and 0.10 for SDI, CB and G (R-2 >= 0.96) was calculated. We conclude that the amount of applied water was lower in the subsurface drip irrigation system; in the three irrigation systems, water application did not surpass the evaporation of class A pan evaporation. The FM was described by a second-degree polynomial model.