<b>Row spacing and nitrogen and potassium fertilization in covering for the corn culture</b> - DOI: 10.4025/actasciagron.v29i4.414

Abstract

This work had the objective of evaluate the effect of row spacing reduction and nitrogen and potassium fertilization in covering, in the efficiency of absorption of nutrients, in the grain yield and components of the production and other agronomic traits of maize single-cross hybrid. The experiment was installed in Cascavel, State of Paraná, in the agricultural year of 2004/05. It was studied three row spacings (0.45; 0.67 and 0.90m), with a population of 55000 plants ha^-1. The experiment design used was that of randomized blocks with four repetitions, in a split plot scheme. It was used 13 combinations of seven nitrogen doses (8; 20; 40; 80; 120; 140 e 152 kg ha^-1 of N) with seven potassium doses (3; 7.5; 15; 30; 45; 52.5 e 57 kg ha^-1 of K₂O), adding 39 treatments. The reduction of interlineations spacing of 0.90 m to 0.45 m maintaining the same population in each area caused the increase of whole dry biomass production, more efficiency in the nitrogen and potassium absorption and also more efficiency in using N and K in the grain. The grain productivity was statistically the same in the three spacings studied. It was verified a linear increase in the productivity and of the dry biomass production in the aerial part until the doses of 152 kg ha^-1 of N in covering. The fertilization with potassium proportioned an increase of dry biomass production in the aerial part, but does not influenced in the productivity. Over 80 kg ha^-1 doses of N and 30 kg ha^-1 of K₂O resulted in a smaller efficiency in using nitrogen and potassium fertilization.