Sustainability indicators for cowpea-vegetable under green manure in a semi-arid environment

Abstract

Two experiments were conducted at the Rafael Fernandes Experimental Farm, from June to September 2015 and 2016 with the objective of evaluating and estimating sustainability indicators of cowpea-vegetable as a function of the amounts of hairy woodrose biomass incorporated into the soil in two crops. Treatments consisted of the following amounts of hairy woodrose biomass: 20, 35, 50 and 65 t ha^-1 on a dry basis. The cultivar of cowpea-vegetable planted was "BRS Itaim". The evaluated characteristics were: length of green pods, number of green pods per m², productivity and dry mass of green pods, weight of 100 green grains, yield and dry mass of green grains. In addition, the economic indicators of sustainability were evaluated: gross income, net income, rate of return and profitability index. The optimization of the agronomic efficiency of the cowpea-vegetable was obtained in the amount of 45 t ha^-1 of hairy woodrose biomass incorporated into the soil and the optimization of the agroeconomic viability of the cowpea-vegetable cultivation was reached in the quantity of hairy woodrose biomass of 37.70 t ha^-1 added to the ground. The first growing crop yielded better agroeconomic efficiency of cowpea-vegetable than the second crop. The use of hairy woodrose as green manure is economically feasible and recommended to the farmer in the production of cowpea-vegetable.