Green Manuring for Moisture Conservation and Wheat Yield Improvement in Rainfed Agriculture

Abstract

Green manure crops are considered to be an integral part of any cropping system in rainfed Agriculture that seems to be sustainable. A study was conducted at farmers’ fields district Chakwal, Pakistan during 2014-2015 and 2015-2016 to evaluate the role of green manuring for both utilization of available soil moisture and wheat yield improvement under rainfed conditions. Six farmers^’sites were selected. Fields werewell ploughed before green manuring of cowpea (Vignaunguiculata) to conserve precipitation in Kharif season for wheatsowing in Rabi season. Cowpea was sown in the last week of June and incorporated into the soil with rotavator during last week of August. Seed rate of cowpea was 60 kg per hectare. Incorporation of cowpea was done at about 60 days after sowing (DAS). Wheat (Triticumaestivum) variety Chakwal-50 was sown, using 125 kgseed per hectare with row spacing of 22.5 cm in the last week of October during 2014-15 and in the first week of November 2015-16 in fields with and without green manuring.Mineralfertilizer was applied @120-80-60 kg N-P₂O₅-K₂O per hectare. Fresh biomass of cowpea was 17.39t ha^-1 and 16.31t ha^-1 during 2014-15 and 2015-16, respectively. It is evident from the results that performance of wheat crop was better with cowpea green manuring. Wheat grain yield was improved 13.5 per cent, wheat straw 14 per cent, plant population 4 per cent and productive tillers 7 per cent by green manuring of leguminous crop cowpea. Incorporation of cowpea as green manuring increased soil moisture contents by 11.8 per cent and 3.6 percent in 0-15 cm and 15-30 cm soil depth, respectively. Green manuring practice need to be carefully monitored for its success in relation to environmental factors, especially in rainfed parts of the world.

Keywords: Green manuring, cowpea, soil moisture, wheat, rainfed, net return