Yield, chemical composition and potassium soil removal by corn crops grown for silage production and harvested at two cut heights - DOI: 10.4025/actasciagron.v28i3.955

Abstract

The aim of this work was to evaluate the agronomical characteristics, chemical composition and removal of potassium of five different genotypes of corn grown for silage. A split-plot complete randomized block design was used, with three hybrids (DKB 390, AGX 8517, A-2560) and two varieties (ALBianco, Piratininga), using two cut heights (20 and 40 cm above soil level) and four replications per treatment. After harvest, plants were analyzed for chemical characteristics and potassium (K). Milk production and DM intake were predicted for each treatment. There was an increase in DM content with the increase in cut height (p<0.05): 31.7 e 33.9%, for 20 and 40 cm, respectively. Depending on genotype, estimates of DM yield (ton/ha) ranged from 10.24 to 12.08 for plants cut at 20 cm and from 8.92 to 10.51 for plants cut at 40 cm. On average, there was a decrease (19.1%) in potassium removal by the crop as a result of increased cut height. Increased cut height also led to a decrease in predicted milk production and an increase in predicted DMI. These results suggest that the corn genotypes under study should be harvested at the lower cut height to promote increased animal productivity per ha.