Forage Production and Nutritive Value of Three Lespedeza Cultivars Intercropped into Continuous No-Till Winter Wheat

Abstract

Annual lespedezas [Kummerowia stipulacea (Maxim) Makino] have the potential to produce high quality forage during late summer when warm season forages are low in production and quality. A field study was conducted from 1992 through 1994 to determine DM, N, and digestible dry matter (DDM) production of three annual lespedeza cultivars (Korean, Kobe, and Marion). These cultivars were intercropped into two different continuous winter wheat (Triticum aestivum L.) production systems. Wheat was established in the fall under low tillage procedures in a 24-arce field, and grazed by steers from mid-November to mid-March at a stocking rate of I steer/acre. Before the wheat had reached the jointing stage, small plots were identified within the 24-acre wheat field. Inoculated lespedeza seeds were sown into the standing winter wheat in these plots, but grazing was continued on the plots and the field. At jointing, grazing was terminated on half of the plots (UNGRAZED), while the other half of the plots were grazed (GRAZED) until early May. Samples of lespedeza were collected at 18 to 20 d intervals beginning in late-June and ending in late-September, in time for the next wheat crop to be planted. All treatments were fixed in space and repeated on the same plots each year. Data were analyzed within year as a randomized complete block with cultivar as the main effect. In 1993 and 1994 Kobe produced DM, N, and DDM more (P < 0.05) under the UNGRAZED than the GRAZED management system. Management system had no effect on DM, N or DDM yield of Korean. When precipitation was above normal, Marion yielded more (P < 0.05) DM in the UNGRAZED plots than in the GRAZED plots, but Marion yield was inferior to that of Kobe and Korean under dry conditions. These results suggest that lespedeza can be intercropped in winter wheat to produce high quality forage during the summer. The availability of high quality forage, especially in late summer, can add sustainability to the livestock component of integrated livestock and winter wheat production systems in the southern Great Plains (SGP).