Biomass production and macronutrient content in Pennisetum glaucum (L.) R. Brown as affected by organic fertilization and irrigation

Abstract

Given the growing and needing for more effective organic fertilization and irrigation on pearl millet cultivated in Brazilian semi-arid, a field experiment was conducted in 2012 and 2013 simulating the smallholder farming system adopted in the Brazilian semi-arid to explore the effect of five organic sources (bovine manure, goat manure, compost, green manure, and control) under irrigation and no irrigation conditions. The experiment was a fully factorial design with four replications. The highest values of shoot dry biomass (16.55 Mg ha-1), and plant contents of Ca, Mg and S (6.77; 4.39; and 1.47 g kg-1 of Ca, Mg and S, respectively) were found on plots where compost was applied combined with the irrigation. Whereas for crude protein crude protein (15.41%), the highest values were found where the green manure was applied combined with the irrigation. Finally, for plant N, P and K content (24.60; 2.00; 45.75 g kg-1 of N, P and K, respectively) the highest values where found where the goat manure was applied combined with the irrigation. Our findings suggest that organic amendments can affect plant dry biomass production and crude protein content (increased by 723.38 and 223.73% compared to control, respectively). The results of our study highlight the importance of considering organic fertilization and irrigation as key-factors to improve both food and forage production.