The experiment was carried out on the experimental farm, with geographic coordinates (latitude of 5º 03' 37”S, longitude of 37º 23' 50” W and altitude of 80 m), belonging to the Universidade Federal Rural do Semiárido, Brazil, with the objective of to study the agroecological production of cowpea, the landrace variety "canapun", in the Brazilian semi-arid region fertilized with hairy rose (Merremia aegyptia L.) plus black grouse (Calotropis procera). A randomized complete block design was used, with six treatments and five replications, totaling thirty experimental plots. The treatments consisted of six amounts of hairy woodrose plus rooster tree (0.0; 4.0; 8.0; 12.0; 16.0 and 20.0 t ha-1 on a dry basis). The proportion of 60% of hairy woodrose plus 40% rooster tree was used. A planting line spacing of 0.5 m and 0.3 m between plants was used, with a total area of 4.5 m2, with two plants pit-1, corresponding to 13332 plants ha-1. When harvesting the cowpea, the following characteristics were evaluated: Plant height (expressed in cm plant); pod length (expressed in cm); number of green pods plant-1 (expressed in units); number of grains per pod (expressed in units per pod); Cowpea productivity (expressed in kg ha-1) and weight of 100 green grains (expressed in g). Statistical analysis was carried out according to conventional variance analysis methods. The quantities of 16.6 and 17.3 t ha-1, were those that expressed the best agronomic development in the cowpea crop, with productivity and number of pods per plant of 3253.8 kg ha-1 and 6.6 pods plant-1, respectively. The use of hairy woodrose (Merremia aegyptia L.) and rooster tree (Calotropis procera), species adapted to the semi-arid climate, constitutes an option for organic fertilizer for family farmers.
Linhares et al. (Wed,) studied this question.