Forage yield of sorghum regrowth in a sorghumsoybean intercropping system

Abstract

The intercropping system of forage plants aims to increase the yield and quality of the product by making the use of the available sources more efficient. This study aimed to evaluate the effects of sorghum sowing dates, soybean cultivars and cutting systems on forage production from the regrowth of an intercropping system using sorghum and soybean crops. The experiment was carried out at the University of Lavras in a typical distroferric latosol, in two crop years (2006/2007 and 2007/2008). The experiment was conducted in a randomized block design with a 5x3x3+5 factorial scheme, corresponding to five sorghum sowing dates (10/30; 11/15; 11/30; 12/15 and 12/30), using the hybrid “Volumax”, three soybean cultivars (Monsoy 8400, Conquista and Luziânia) and three cutting systems (1 - cut at ground level; 2- 15 cm above ground; 3- 30 cm above ground). Additional treatments were composed by the monoculture of sorghum, in which the five sowing dates were analyzed. In the sorghum regrowth, the sowing dates and cutting systems significantly increased the green matter and crude protein levels. Cutting system 3 provided the highest green matter (5,516 kg ha^-1), dry matter (2,395 kg ha^-1), and crude protein yields (173 kg ha^-1). The intercropping system provides the highest dry matter and crude protein yields.