Abstract

APAEZ BARRIOS, Patricio et al. Agronomic efficiency of nitrogen, phosphorus and cowpea production using trellis maize. Terra Latinoam [online]. 2013, vol.31, n.4, pp.285-293. ISSN 2395-8030.

Cowpea (FCH), because of its high content of proteins carbohydrates, fats and fiber, is important for human diets. Increases in profitability using a trellis maize system have been observed. However, in this system the requirements of mainly nitrogen (N) and phosphorus (P) are greater. The objectives were a) to determine the effect of N and P on total biomass of FCH in trellis maize, grain yield, water use efficiency and agronomic efficiency, and b) to determine the combination of doses of N and P to generate greater profitability. In hot climate, under conditions of seasonal rainfall, cowpea was intercropped with trellis maize on July, 2011. Treatments consisted of application of 0, 75 and 150 kg of N and P ha-1. Maximum (Tmax.) and minimum (Tmin.) temperature and daily rainfall were recorded. At harvest, total biomass (TB), grain yield (GY), water use efficiency for grain (WUEG) and biomass (WUEB), agronomic efficiency of N (AEN) and P (AEP) and economic profitability were determined. The average Tmax. and Tmin. were 33 and 20 °C, respectively, and precipitation was 809 mm. N and P increased production of TB, GY, WUEG and WUEB. Addition of P stimulated a greater response to the application of N. In these environmental conditions, higher production, water use efficiency and profitability of FCH in trellis maize was achieved with 150 kg N and P ha-1. However, the greatest AEN and AEP were achieved with application of 75 kg N and P ha-1.

Keywords : Vigna unguiculata; economic profitability; water use efficiency.