Nitrogen and potassium in biomass production and water use efficiency of irrigated wheat cv. BRS 394 in Cerrado

Abstract

The objective of this study was to evaluate the influence of nitrogen and potassium levels in biomass production and efficiency in water consumption of wheat BRS 394 in brazilian Cerrado. The experiment consisted of fractioned factorial combination of five levels of (N): (0, 70, 140, 210 and 280 kg ha−1) and five levels of potassium (K): (0, 50, 100, 150 and 200 kg ha−1), randomized block design and four replications. The shoot biomass, the number of spikelets per ear and the efficiency of water use for biomass production were evaluated as a function of the N and K levels used in the present study. Analysis of variance at 5% and 10% was performed using F test for the surface response model and when not significant to the first and second degree regression using the R software. The combination of N(238 kg ha−1) and K(97 kg ha−1) increased spikelet yield per spike (15.5), during 2019 harvest. The fertilization with N(115 and 125 kg ha−1) in an isolated way guaranteed maximum shoot biomass yield(5827 kg ha−1) and wheat water use efficiency (32.9 g L−1), during 2018 harvest, respectively. The N provided isolated increases in number of spikelets per spike in 2018 harvest, as well as for shoot biomass and water use efficiency in 2019. The main use of nitrogen fertilization and its combination with potassium provide gains in the production of shoot biomass and water use efficiency of wheat BRS 394 in brazilian Cerrado.