Introduction and management of vetch/barley forage mixtures in the rainfedareas of Pakistan - 1. Forage yield

To investigate the introduction of vetch/barley forage mixtures with a rang e of harvesting treatments in the winter season of Mediterranean-type envir onments, studies were carried out during 1994-97 at the National Agricultur al Research Centre (NARC), Islamabad, which has an annual rainfall of aroun d 1000 mm, and at a much drier site at the Arid Zone Research Centre (AZRC) at Quetta in Pakistan, which has an annual rainfall of around (223 mm). Co mmon vetch (V), barley (B), and their mixtures at seed ratios of V75B25, V5 0B50, and V25B75 were sown and 3 harvest time treatments (pre-flowering, fu ll flowering, and maturity) were imposed. At NARC, there were significant d ifferences (P < 0.01) in dry matter production between crop mixture ratios and between different harvest times. Mixtures of vetch and barley were gene rally more productive than any of the sole crops, with the yield of the bes t mixture V75B25 (7.6 t/ha) being almost twice as productive as sole vetch. Productivity at the full flowering stage was lower (5.3 t/ha) than that re corded at maturity (7.0 t/ha) and for the dual-cut pre-flowering harvest tr eatment (6.2 t/ha). At AZRC, the same trends as at NARC were observed but w ith lower yields because of the substantially lower and less well distribut ed rainfall and suboptimal temperatures. The highest dry matter was obtaine d with the treatment V75B25 (3.3 t/ha), which was approximately 50% higher in yield than sole vetch or sole barley (around 2 t/ha). Dry matter was hig hest at the maturity stage (3.2 t/ha) and lowest at the flowering stage (2. 3 t/ha), except in the sole vetch crop which was lowest in yield at the pre -flowering stage (2.7 t/ha), implying a minor interaction between seed mixt ure and harvesting stage.