Production efficiency, forage yield, nutrient uptake and quality of sorghum sudan grass hybrid (Sorghum bicolor × Sorghum sudanense) + cowpea (Vigna unguiculata) intercropping system as influenced by sowing methods and varying seed rates of cowpea

A field experiment was carried out at Palampur, Himachal Pradesh, during the rainy (kharif) seasons of 2012 and 2013, to study the effect of sowing methods and varying seed rates of cowpea [Vigna unguiculata (L.) Walp.] on forage yield of sorghum sudan grass hybrid [Sorghum bicolour (L.) Moench. × Sorghum sudanense (Piper) Stapf.] and cowpea. Broadcast sowing of sorghum sudan grass hybrid (SSGH) with 75% recommended seed rate of cowpea (33.75 kg/ha) realized significantly higher plant height, shoot number, SSGH and cowpea dry-matter accumulation, total green forage yield (34.18 t/ha), dry forage yield (10.08 t/ha) and production efficiency. Broadcast sowing of SSGH with recommended seed rate of cowpea resulted in significantly higher N (195.17 kg/ha), P (21.52 kg/ha) and K (56.86 kg/ha) uptake. Further, broadcast sowing of SSGH with 75% recommended seed rate of cowpea gave highest net returns ( 32, 001/ha), benefit: cost ratio (1.57), SSGH-equivalent yield (SSGHEY) and was followed by broadcast sowing of SSGH with recommended seed rate of cowpea.