ENERGY BALANCE OF IRRIGATED AND RAINFED SORGHUM PRODUCTION

Abstract

ABSTRACT: The objective of this study was to evaluate the yield and energy balance of four sorghum genotypes in irrigated and rainfed crops. The experiment was conducted in an irrigation and drainage unit at the Federal University of Grande Dourados (UFGD), in Dourados, Mato Grosso do Sul state (Brazil). The experimental design was a randomized complete block design with split plots (with and without irrigation), testing four genotypes (BRS 506, CV 007, CV 147, and EJ 7281) with four replicates (32 plots). Irrigation provided yield increase in all four genotypes. The respective yield increases were 85.89%, 71.82%, 64.28%, and 63.36% for genotypes EJ 7281, BRS 506, CV 147, and CV 007. The energy efficiency (produced/ used ratio) was on average 3.5 under irrigation, and 2.8 for rainfed crops. These results indicate the lack of competition between sorghum and sugarcane, being the first an alternative for off-season. Irrigation increased productivity, leading to an increase in yield and, consequently, in the amount of extracted energy. Yield gains in response to irrigation were more pronounced for genotype EJ 7281. There was a positive impact of irrigation on the energy balance of the four genotypes, increasing energy efficiency.

Keywords

• irrigation
• productivity
• off-season
• ethanol