ABSTRACT The objective of this work was to evaluate the agronomic performance of a second crop maize grown under different methods of inoculation with Azospirillum brasilense. The experiment was conducted in a randomized block design with 6 treatments and four replications. The treatments used were: no inoculation (T1); inoculation with A. brasilense via seed (T2); inoculation with A. brasilense via sowing furrow (T3); inoculation with A. brasilense via leaf (T4); two inoculations with A. brasilense via leaf (T5); and combination of inoculations via seed, sowing furrow, and leaf (T6). Physiological, morphological, production, and yield components of the second crop maize were evaluated. The data were subjected to analysis of variance at 0.05 probability level and when significant, the means were subjected to the Scott-Knott test at 0.05 probability level, using the R-bio statistical program. Inoculation via seed results in higher nitrate reductase enzyme activity. The inoculation with A. brasilense does not result in gains in grain yield for second crop maize; however, it improves the maize quality by increasing its gross protein contents.

ABSTRACT The aim of this study was to evaluate the development, yield and its components of soybean sown in hill drop method with variation in hole spacing, compared to the conventional sowing method in lines. The experiment was conducted in a randomized block design, with six treatments and four replications, using the variety M7739 RR IPRO with four plans per hole. The treatments consisted of population variation from 50 to 150% of the recommended one, obtained by the holes spacing alteration and a control sowed in lines with the recommended population. The control was compared to the other treatments using the Dunnett test and the hole spacing effect was evaluated by regression. The cultivar 7739 RR IPRO responds to hill drop sowing, obtaining even in lower populations, yields similar to the conventional sowing in lines. The highest yields in the hill drop sowing method are obtained in the higher populations, with a linear decrease in yield with an increase in hole spacing. Increasing hole spacing increases the number of pods and branches and reduces leaf cover, light interceptcion, plant height and first pod height.

RESUMO A antecipação da aplicação de nitrogênio em sistemas de cultivo, usando plantas de cobertura, apresenta-se como alternativa para melhorar a eficiência do uso desse nutriente e otimizar a questão operacional. Objetivou-se com este trabalho, avaliar a eficiência da antecipação da adubação nitrogenada para a cultura do milho, tendo a braquiária como cultura de cobertura. O experimento foi conduzido na área experimental da Universidade Federal de Jataí, em Jataí - GO, com histórico de plantio em sucessão soja-milho/sorgo nos últimos 20 anos, e destaque para o teor de matéria orgânica do solo que é de 39,5 g kg-1. Utilizou-se delineamento de blocos ao acaso, com fatorial 5x2+1, com 4 repetições, sendo cinco doses de N: 0; 50; 100; 150 e 200 kg ha-1 e duas épocas de aplicação na cultura da braquiária, sendo a época 1: aplicação do nitrogênio 90 dias pré-semeadura do milho e época 2: aplicação do nitrogênio 60 dias pré-semeadura do milho e um tratamento adicional com adubação nitrogenada convencional de 150 kg ha-1 de nitrogênio, aplicada na cultura do milho, dividida em adubação de plantio e cobertura. Com exceção a dose de 200 kg ha-1 de N aplicada 90 dias antes da semeadura do milho, a antecipação da adubação nitrogenada para esta cultura, utilizando a braquiária como planta de cobertura, se mostrou tão eficiente quando a adubação convencional nas condições de solo e clima em que foi realizado o trabalho, ou seja, solo com alto teor de matéria orgânica, fertilidade construída e ausência de restrição hídrica.

ABSTRACT Advancing nitrogen (N) application in cropping systems, using cover crops, is an alternative to improve the efficiency of use of this nutrient and to optimize the operational issue. The aim of this study was to evaluate the efficiency of advancing N fertilization for corn crop, with Brachiaria ruziziensis as cover crop. The experiment was conducted at the experimental field of the Federal University of Jataí / Regional Unit of Jataí, GO, Brazil, with history of soybean-corn/sorghum succession in the last 20 years and a high organic matter content in the soil, which reaches 39.5 g kg-1. A randomized complete block design was used in a 5x2 + 1 factorial scheme with 4 replicates, corresponding to five N doses: 0; 50; 100; 150 and 200 kg ha-1 and two times of application in B. ruziziensis: Time 1 - N application 90 days before planting of corn, and Time 2 - N application 60 days before planting, plus an additional treatment with conventional N fertilization, 150 kg ha-1 of N, not advanced, applied to the corn crop, split into planting fertilization and top -dressing fertilization. Except for the N dose of 200 kg ha-1 applied 90 days before corn sowing, advancing N fertilization for this crop using B. ruziziensis as cover plant proved to be as efficient as conventional fertilization for the soil and climate conditions under which the study was carried out, that is, soil with high content of organic matter, built fertility and absence of water restriction.