Resumo

SAENZ, C.A et al. Rendimiento de grano y eficiencia en el uso del agua en maíz bajo riego complementario con agua salina. RIA. Rev. investig. agropecu. [online]. 2014, vol.40, n.3, pp.252-259. ISSN 1669-2314.

In San Luis Province, Argentina, maize is annually cultivated, with an average grain yield of 1,600 kg ha^-1, by far below of the potential yield with complementary irrigation (15,000 kg ha^-1). Quality water is not always available for irrigation. However, in semiarid region with permeable soils it is possible to reach stabilize maize yields by using supplementary irrigation with saline water. This work evaluated the yield and water use efficience of maize crop cultivation under different irrigation levels with saline water and fertilization with nitrogen and phosphorus. During two growing seasons (2005-2007) evaluated maize yield with three irrigation levels: 100% and 50% of water crop requirements, and unirrigated land; and nine fertilization treatments which the combination of different levels of nitrogen and phosphorus. The crop was sprinkler irrigated with saline water, conductivity was 4.26 dS m^-1. The statistic design for fertilization treatment was nested. Irrigation levels were determined on the basis of the historical data, and corrected biweekly by considering the soil water content. Grain yield was measured along two central lineal meters by plot and water use efficiency (WUE) was also measured. During the first year of the study the pricipitation was below average, the crop yield were statistically (α = 0.05) higher under irrigation than on the un-irrigated treatment. In the second year the precipitation was higher average, crop yield in treatments with 50% of irrigation was significantly higher than in the other ones. This year don't found response to nitrogen and phosphorus fertilization about crop yield and water use efficiency, but saline water irrigation allowed stabilized yields. In second year the higher yields were achieved with average irrigation and fertilization levels, the anirrigated treatment also achieved good performance.

Palavras-chave : Irrigation; Yield; Salinity.

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