Effect of grazing intensities and seed furrow openers on corn development and yield in a crop-livestock system

Grazing intensity determines both agricultural and livestock production and may shift the crop-livestock system either in a positive or negative direction. High grazing intensity may affect soil physical-chemical and biological traits, affecting a no-tillage system and as a result, reduce crop yields. These effects can be mitigated by the use of a no-till seed planter equipped with different furrow openers that can interact to optimize crop yield. This study aimed to evaluate grazing intensities and seed furrow openers on corn crop development and yield in an integrated crop-livestock system. The experiment was laid out as random block design in a split-plot arrangement with four replications. Black oat + ryegrass grazing intensities were characterized by different pasture sward management, with the entrance of grazing animal at pasture heights of 25, 30, and 35 cm and exit at heights of 5, 10, and 15 cm, respectively. Grazing was a rotational basis with a treatment without grazing as a control. After the grazing period, corn was established using two seed furrow openers (double disc and shank) in the sub-plot level. Soil bulk density was evaluated before and after the grazing period as well as the depth of seed deposition, corn plant development, corn yield components and yield. Soil bulk density increased as grazing intensity increased. Corn yield dynamics were affected by grazing intensity and the type of seed furrow opener

Energy demand and distribution of corn seeds as a function of the speed of two seedrills

This work had the objective of evaluating the distribution uniformity of corn seed in two displacement speeds and two precision seedrills, in an experiment conducted in a Oxisol, with slightly inclined relief in a loamy soil. The experimental design was constituted of four treatments composed of two seeders (S1 - PSE 8/Semeato and S2 - PST 2/Super Tatu) and two velocity of seedrills (V1 = 5.2 and V2 = 8.1 km h-1). The mean value of the traction force in the bar was 9.6 kN for S1 and 8.07 kN for S2, while the slippage was 5.83 and 4.26%, for S1 and S2, respectively. The values obtained for distribution uniformity of seeds of the seeder S1 in the speeds V1 and V2 were 21.6 and 22.0, and for the seeder S2 18.0 and 19.0 cm respectively, which did not differ statistically; however for the two displacement speeds a tendency of increase of the spacing among plants with the speed increase was verified.Objetivou-se, através deste trabalho, avaliar a uniformidade de distribuição de sementes de milho em duas velocidades de deslocamento de duas semeadoras-adubadoras de precisão, em experimento conduzido em um Latossolo Vermelho distroférrico, de relevo levemente inclinado e textura muito argilosa. O delineamento experimental constituiu-se de quatro tratamentos compostos de duas semeadoras (S1-PSE 8/Semeato, S2-PST 2/Super Tatu) e duas velocidades de deslocamento (V1 = 5,2 e V2 = 8,4 km h-1). O valor médio da força de tração na barra foi de 9,6 kN para S1 e 8,07 kN para S2, enquanto a patinagem foi de 5,83 e 4,26%, para S1 e S2, respectivamente. Os valores obtidos para o espaçamento entre sementes da semeadora S1 nas velocidades V1 e V2, foram 21,6 e 22,0 e, para a semeadora S2, 18,0 e 19,0 cm respectivamente, os quais não diferiram estatisticamente entre si; verificou-se, entretanto, para as duas velocidades de deslocamento, tendência de aumento dos espaçamentos entre plantas, com o aumento da velocidade.42442

Grazing intensities and poultry litter fertilization levels on corn and black oat yield

The objective of this work was to assess the effect of poultry litter fertilization levels on corn and black oat yield using different grazing intensities, poultry litter levels (mixture of manure and bedding material) and a chemical fertilization level. The experimental design was a randomized complete block in a split-plot arrangement with four replicates. Black oat + ryegrass grazing intensities, characterized by different pasture sward management, with animal entrance at 25, 30 and 35-cm heights and exit at 5.0, 10 and 15-cm heights, were established at the main plots. After the grazing period, corn was grown at the subplots with four levels of poultry litter (0, 4,953, 9,907 and 14,860 kg ha-1), aiming to supply 0, 100, 200 and 300 kg ha-1 of nitrogen, and a treatment with chemical fertilizer, according to soil analysis. Grazing intensities had no effect on corn yield. Corn yield was 7,493, 8,458, 9,188, 10,247 and 11,028 kg ha-1, respectively, for the treatments without and with 4,953, 9,907 and 14,860 kg ha-1 of poultry litter, and the treatment with chemical fertilization. Poultry litter levels have a residual effect on the production of black oat grown in succession to corn

Força de tração necessária em função do número de linhas de semeadura utilizadas por uma semeadora-adubadora de precisão

Este trabalho teve como objetivo avaliar o comportamento da força de tração solicitada por uma semeadora-adubadora, variando o número de linhas de semeadura. O experimento foi conduzido no Núcleo Experimental de Engenharia Agrícola - NEEA, pertencente à UNIOESTE - Câmpus de Cascavel - PR, em um Latossolo Vermelho distroférico com relevo plano e textura argilosa. Utilizou-se o delineamento experimental de blocos ao acaso, composto por cinco tratamentos e quatro repetições. Foram utilizados os seguintes tratamentos: semeadora equipada com uma, duas, três, quatro e cinco linhas de semeadura, deslocada à velocidade média de 5,5 km h-1. Avaliaram-se os parâmetros de profundidade do sulco, área de solo mobilizada, força de tração média e força de tração máxima. Com o aumento do número de linhas de semeadura de uma para cinco, a força de tração média na barra aumentou de 3,7 para 8,6 kN, ou seja, houve acréscimo de 131,9%

Força de tração e potência de uma semeadora em duas velocidades de deslocamento e duas profundidades de deposição de sementes

Para este trabalho, avaliou-se o requerimento de força de tração de uma semeadora de fluxo contínuo com 14 linhas, na semeadura da aveia preta (Avena strigosa L.) em experimento conduzido em um Latossolo Vermelho distroférico, numa área com declividade média de 0,03 m m-1. O delineamento experimental foi constituído de quatro tratamentos (duas profundidades de deposição de sementes e a duas velocidades de deslocamento) com quatro repetições, totalizando dezesseis parcelas experimentais de 4 x 50 m (200 m2) em sistema de plantio direto sob resteva de milho. Com o aumento da profundidade de deposição de sementes de 1,97 cm para 2,68 cm, o requerimento de força de tração aumentou de 3,78 kN para 5,51 kN. O aumento da velocidade de deslocamento de 5,24 km h-1 para 7,09 km h-1, provocou acréscimo de 6,90% no requerimento de força de tração na barra.Traction and power required by a seed drill with 14 holes was evaluated in the oat (Avena strigosa L) seeding. The experiment was carried out in a Haplortox, in an area with mean slope of 0.03 m m-1. The experimental design consisted of four treatments (two seed deposition depths and two displacement speeds) with four repetitions, totaling sixteen experimental plots of 4 x 50 m (200 m2), in no tillage system on corn crop residue. It was concluded that the increase of the seeding depth of 1.97 cm to 2.68 cm, the draft requirement increased from 3.78 to 5.51 kN. The speed increase from 5.24 to 7.09 km h-1, caused an increase of 6,90% in the traction force of the drawbar