Resposta Do Milho Safrinha À Adubação Em Duas Épocas De Semeadura

Abstract

RESUMO -neste trabalho, objetivou-se avaliar a resposta do milho à adubação nPK, em semeadura realizada nos meses de janeiro e fevereiro, sucedendo a cultura da soja, em rio verde-go. o experimento foi conduzido em delineamento de blocos casualizados, num esquema fatorial 4x2, constituído por quatro opções de adubação nPK na semeadura, com ou sem adubação nitrogenada de cobertura. Foram cultivados os híbridos P 30F53 Yh e dKB 310 Pro, no primeiro e segundo anos, respectivamente, e coletados os dados de altura de plantas e de espigas, número de espigas, de fileiras por espiga, de grãos por fileira, massa de 1.000 grãos e produtividade. A produtividade de grãos do milho safrinha é influenciada pelas épocas de semeadura que definem as condições de disponibilidade hídrica, e pela adubação nitrogenada em cobertura, sem expressar resposta à adubação nPK na semeadura, que, em janeiro, favorece a produtividade, por conciliar melhor a distribuição de chuvas no final da fase de desenvolvimento vegetativo e na fase reprodutiva, etapas críticas para o potencial produtivo do milho. independentemente da época de cultivo e da adubação NPK na semeadura, a aplicação de N em cobertura promove ganho significativo de produtividade da cultura.Palavras-chave: sucessão de culturas, adubação de manutenção, veranico, Zea mays l. SECOND-SEASON CORN RESPONSE TO FERTILIZATION IN TWO SEEDING TIMESABSTRACT -this study aimed to evaluate the response of maize to nPK fertilization in sowing in january and February, succeeding soybean crop, in rio verde, State of goiás, Brazil. the experiment was conducted in a randomized block design in a 4x2 factorial scheme, and it consisted of four nPK options in seeding time, with or without nitrogen topdressing. Hybrids P 30F53 YH and DKB 310 PRO were grown in the first and second year, respectively. We collected the data of plant height, ears height, number of ears, number of rows per ear, number of grains by row, thousand kernel weight and productivity. The productivity of second-season maize grain is influenced by sowing time, which defines the conditions of water availability, and the nitrogen fertilization, without expressing response to NPK fertilizer at sowing. Seeding in january favors productivity to reconcile better distribution of rainfall at the end of the vegetative growth phase and reproductive phase, critical steps for the production of maize potential. regardless of the growing season and NPK fertilization at sowing, application of N topdressing promotes significant productivity gain.

Nitrogen fertilization in off-season corn crop in different Brazilian Cerrado environments

“…Nitrogen fertilization often results in yield gains in off-season corn crops (Mar et al, 2003;Soratto et al, 2010;Simão et al, 2018), but different studies have reported variable response patterns to the amount and time of N application. In Dourados, in state of Mato Grosso do Sul, Brazil, Mar et al (2003) obtained an increase of 1,497 kg ha -1 grains by applying 30 kg ha -1 N, corresponding to an increase of 48.5%, which reached 114.4% for a N rate of 120 kg ha -1 .…”

“…In the Cerrado biome, off-season corn is grown in several different subregions, sowed between January and March, encompassing a wide range of soil and climate conditions (Nóia Júnior & Sentelhas, 2019a), which makes it difficult to reach a consensus on the decision criteria to recommend N fertilization. The uncertain climate conditions at the end of the rainy season affect both the corn yield potential (Simão et al, 2018) and the cycling of N from the residue of the preceding crop (Rossi et al, 2013), normally soybean [Glycine max (L.) Merr.]. The intensity of these interferences varies between years and crop sites, hindering the establishment of fertilizer recommendations applicable to all situations.…”

“…In general, off-season corn has responded to moderate N fertilizer rates, despite not showing consistent patterns between cropping sites and years. In the municipality of Rio Verde, in the state of Goiás, Brazil, Simão et al (2018) found an average yield of 6.7 Mg ha -1 grains with 50 kg ha -1 N applied as topdressing, at the V3 phenological stage, over two years and two sowing times; the starter fertilizer varied from 0 to 50 kg ha -1 N. Studies in the region of Rio Paranaíba, in the state of Minas Gerais, also Brazil, showed that rates between 19 and 150 kg ha -1 N promoted yields of 3.5 to 7.6 Mg ha -1 (Gott et al, 2014;Sichocki et al, 2014). The limited response to N is usually due to the influence of climate, since drought reduces the yield potential and nutrient recovery efficiency of a crop, causing the additional amounts of N fertilizer to have a negligible effect on grain yield (Amado et al, 2013).…”

Nitrogen rates on the agronomic performance of second-crop corn single and intercropped with ruzigrass or showy rattlebox

“…According to Simão et al (2018), the sowing season defines the water availability conditions and influences the second-crop corn yield, so that the earlier sowing favors its yield. Corn was sown on March 16 in the 2018 growing season and March 6 in the 2019 growing season.…”

Methods of Soybean Genotypes Selection in Paraná State, Brazil

“…The influence of sowing time on maize grain yield in second crop is directly related to rainfall regime. Better distribution of rainfall is overriding, mainly in the final stages of vegetative development and at the beginning of reproductive development (Simão et al, 2018). Cardoso et al (2004) evaluated 12 maize sowing times from January to April, with and without water limitation.…”