FIBER SORGHUM BIOMASS YIELD, WATER USE EFFICIENCY AND ECONOMIC RESULTS UNDER DIFFERENT LEVELS OF WATER, USING SUBSURFACE AND SURFACE IRRIGATION SYSTEMS

In 2007, an attempt was made to study the biomass production and the economic results of sorghum (Sorghum bicolor L. Moench, variety H 132), growing in Greece, under two different irrigation methods, surface and subsurface, and three different amounts of irrigating water: 100%, 70% and 50% of the daily evapotranspiration (ET). The study is part of a wider research concerning the potential growing of energy plants, and using biomass for energy production. A field experiment comprising of a completely randomized block design with six treatments and four replications was conducted at the Experimental Farm Station of the University of Thessaly. Water needs were satisfied by using full (100% ET) and supplement (70% and 50% ET) amounts of irrigating water. Crop production was measured in terms of dry biomass, while gross revenue, production expenses and gross margin were the economic parameters measured and examined. The comparative data analysis of the two irrigation methods showed that the subsurface drip irrigation method significantly excels the surface one, in biomass production and other economic results.