Corn yield functions of irrigation and nitrogen in Central America

Summary This paper reports the results of a three-year field study conducted in El Salvador, Central America to develop yield response functions for corn to irrigation levels and nitrogen fertilizer. Four levels of irrigation were imposed using two application methods, furrow and trickle, in combination with four nitrogen fertilizer rates. Yields generally increased with higher levels of applied water and with higher nitrogen rates up to 200 kg N/ha, with a strong interaction between these two variables. Yield was independent of irrigation method although less water was applied with the trickle system.In cooperation with the El Salvador Ministry of Agriculture and Livestock and the United States Agency for International DevelopmentPartial support was provided under Contract AID/ta-c-1103Research Engineer, Professor of Soils, Research Agronomist, Research Assistant, Utah State University; and Agronomist, Peace Corps, respectively