Nitrogen fertilization in corn crop on the influence of soil acidity correction in the Amazon region
Zea mays. Liming. Urea. Corn production. Southeast of Pará.
In this study, the effect of nitrogen application in the absence and presence of dolomitic lime was evaluated on the morphological and productive development of corn in the 2015/16 and 2016/17 agricultural crops in the Amazon region. The treatments consisted of two agricultural crops of BR 205 corn (2015/16 and 2016/17), two sources of dolomitic limestone (0 and 2 Mg ha-1) and five nitrogen rates (0, 45, 90, 135 and 180 kg ha-1 of N) in the form of urea. A randomized block design with three replications was used, with treatments arranged in a split-plot scheme, 2 x 2 x 5, corresponding to two agricultural crops, two lime rates and five nitrogen rates. Leaf area index (LAI), ear height (AE), plant height (AP), plant diameter (SD), ear length (EC), ear diameter (DE), number of grains per ear were evaluated. (NGPE), thousand grain mass (M1000), yield (PROD) and total dry matter (MST). The use of limestone influenced higher LAI production in the two agricultural seasons. It is inferred that nitrogen fertilization provided greater development in AE, AP, DP, CE, M1000 and MST. In the 2015/16 crop year, PROD in the absence or presence of dolomitic limestone averaged approximately 8.85 and 8.92 Mg ha-1, respectively. The DE showed maximum technical efficiency when applied 98.18 kg ha-1 of N in the 2016/17 agricultural harvest. However, the application of N coverage for the NGPE variable better fit the negative linear model in the two agricultural crops.