Nitrogen, Potassium, and Protein in Grains From Wheat Grown Under Nitrogen and Potassium Fertilizations in the Brazilian Cerrado

Nitrogen is a component of proteins contained in grains and potassium an enzymatic activator in nitrate (NO3-) assimilation and contributes to the translocation and storage of plant assimilates. Together they can increase protein contents of wheat grains. This research aimed to evaluate whether the interaction between nitrogen (N) and potassium (K) fertilizations in irrigated wheat in the Cerrado region of the Mato Grosso State increases the content and accumulation of N, K, and protein in wheat grains. The experiment was carried out in the field for two consecutive years (2014 and 2015) in the Federal University of Mato Grosso. It was designed in randomized blocks in 52 fractional factorial, composed of combinations between five doses of each of N and K, 13 treatments combinations in total with four replicates. After harvest, the grains were dried to determine the contents of N, K, and protein. The nitrogen content was influenced by nitrogen doses in both years and the accumulation significantly influenced by the nitrogen and potassium doses with an average increase among the years of 55.29% as a function of the potassium application. Nitrogen influenced the accumulation of potassium only in 2015 with effect for potassium in both years. Although there was no interaction between treatments, the influence of K on N absorption was evident. Contents and accumulations of N and K and the content of protein in wheat grains are influenced by N and K fertilizations.