Luiz Carlos Ferreira de Souza

Culturas de cobertura do solo e adubação nitrogenada no milho em plantio direto

With the aim of studying the preceding soil cover crop influence upon the corn crop production components an experiment in a disttrophicxa0 Red Latossol was developed at the Nucleo de Ciencias Agrarias - NCA, of the Universidade Federal de Mato Grosso do Sul - UFMS, Campus de Dourados - MS. The experimental design was randomized blocks, with the treatments arranged in a split plots pattern, with four replications. The experimental plots were constituted by the former crops (hairy vetch and forage turnip) and the split plots were represented by five surface nitrogen doses (0, 50, 100, 150, and 200 kg N/ha-1) in the corn crop, divided into two applications, in the four and eight leaves growth stages. The preceding crops present differentiated effects on the corn cultivated afterwards production components. The hairy vetch is more effective than the forage turnip in relation to the following traits: above ground dry matter, ear diameter, one thousand grains weight, and corn grains nitrogen content. Despite the previous crop, nitrogen addition increases corn grains productivity.

INOCULAÇÃO DO FEIJOEIRO COM RHIZOBIUM TROPICI ASSOCIADA À EXSUDATO DE MIMOSA FLOCCULOSA COM DIFERENTES DOSES DE NITROGÊNIO

The aim of this work was to evaluate the effect of the Rhizobium inoculation, associated with seed exudates of Mimosa flocculosa, under different rates of nitrogen fertilization was evaluated in bean crops following soybean (Glycine max L. Merril) and corn (Zea mays L.). The experimental design was randomized blocks with four replications, with treatments arranged in sub-divided parcels. The parcels were constituted of two summer crops preceding the common bean crop: soybean and corn. In the sub-parcels three treatments involving inoculation of the common bean seeds were considered: control treatment without inoculation; bean seeds inoculated with Rhizobium tropici, strains CIAT 899 and PRF 81, and the association of Rhizobium with the exudates of the Mimosa flocculosa seeds. The sub-subparcels received of four doses of nitrogen fertilization applied on covering: 0, 40, 80 and 120 kg ha-1 N. The inoculation of Rhizobium associated with the addition of exudates of Mimosa flocculosa seeds resulted in higher shoot dry weight. Besides that, the nitrogen fertilization, on the tested doses, reduced, in a linear way, the nodulation of the bean plant. It was also verified that corn as a preceding crop for bean has contributed to the increase of the weight of 100 grains, while the addition of combined N did not contribute to the improvement on the number of beans per plant, neither of the grain yield of bean plants, independent of the dose that was used.

Efeito da época de colheita e da espessura do tegumento sobre a viabilidade e o vigor de sementes de soja

Esta pesquisa foi desenvolvida no Nucleo Experimental de Ciencias Agrarias da UFMS, em Dourados, MS, com o objetivo de avaliar a viabilidade e o vigor das sementes de nove genotipos de soja, dos quais, cinco cultivares (EMBRAPA-64, EMBRAPA-4, BR-16, FT-Abyara e IAC-100) e quatro linhagens (BRD-9527, BRD-9561, BRD-9507 e BRD-9502), com diferentes coloracoes e espessuras de tegumento, colhidas no estadio R8 e com 14 dias apos este estadio. Apos a colheita, determinaram-se a espessura do tegumento das sementes, a porcentagem de embebicao de agua pelas sementes, a viabilidade das sementes, pelos testes de germinacao e de tetrazolio e o vigor, pelos testes de emergencia em areia, teste de tetrazolio e pelo envelhecimento acelerado. As sementes das linhagens BRD-9561 (tegumento preto), BRD-9527 (tegumento marrom), BRD-9502 e BRD-9507 (tegumento amarelo) apresentam maior espessura de tegumento, mas a espessura nao e uma caracteristica que per si assegura melhor qualidade fisiologica das sementes, independente da epoca de colheita. O retardamento de colheita reduziu a germinacao e o vigor das sementes e ainda aumentou a porcentagem de embebicao de agua pelas sementes.

Physical properties and particle-size fractions of soil organic matter in crop-livestock integration

Crop-livestock integration represents an interesting alternative of soil management, especially in regions where the maintenance of cover crops in no-tillage systems is difficult. The objective of this study was to evaluate soil physical and chemical properties, based on the hypothesis that a well-managed crop-livestock integration system improves the soil quality and stabilizes the system. The experiment was set up in a completely randomized design, with five replications. The treatments were arranged in a 6 x 4 factorial design, to assess five crop rotation systems in crop-livestock integration, and native forest as reference of soil undisturbed by agriculture, in four layers (0.0-0.05; 0.05-0.10; 0.10-0.15 and 0.15-0.20 m). The crop rotation systems in crop-livestock integration promoted changes in soil physical and chemical properties and the effects of the different systems were mainly detected in the surface layer. The crops in integrated crop-livestock systems allowed the maintenance of soil carbon at levels equal to those of the native forest, proving the efficiency of these systems in terms of soil conservation. The systems influenced the environmental stability positively; the soil quality indicator mineral-associated organic matter was best related to aggregate stability.

Infiltração de água no solo em sistemas de plantio direto e convencional

This work had the objective of studying the infiltration of water in cultivated soil under different tillage systems and crop rotation and the adaptation of Horton and Kostiakov-Lewis equations for estimating the water infiltration rate using a portable sprinkler infiltrometer. Field tests were accomplished in four systems of crop rotation, cultivated in plots of no tillage and conventional tillage systems. The quality of adjustment of models was evaluated through non-linear regressions among estimated values and mean values observed for each treatment. It may be concluded that the no tillage system provided values of water infiltration rate in the soil higher than the conventional tillage system; among the studied treatments, the succession soybean-oat provided higher value of the final infiltration rate. The quality of the adjustment of models was satisfactory and the equation of Horton proved to be more adequate for estimating the rate of infiltration.

Desempenho agrônomico de soja em função da sucessão de culturas em sistema de plantio direto

With the objective of evaluating the effect of crop rotation or succession on soybeans agronomic performance in no tillage system, an experiment was carried out in a distrophic Red Latosol, at the Nucleo Experimental de Ciencias Agrarias da Universidade Federal de Mato Grosso do Sul, in the county of Dourados-MS. The experimental procedure was a randomized blocks design with nine treatments and four replications. The plots had 36 meters of length and 11 meters of width (396 m2), where were mechanically sawed 26 lines of soybeans, at intervals of 0,45 meters between lines. The treatments were composed of nine systems of crop succession: system 1: corn/vetch/corn/vetch/soybeans; system 2: cotton/oat/cotton/sorghum/soybeans; System 3: soybean/wheat/soybeans/corn/millet/soybeans; system 4: corn/grazing turnip/corn/sorghum/soybeans; system 5: corn/oat/corn/beans/millet/soybeans; system 6: rice/grazing turnip/rice/oat/soybeans; system 7: rice/sorghum/rice/beans/millet/soybeans; system 8: cotton/wheat/cotton/wheat/soybeans and system 9: cotton/grazing turnip/cotton/oat/soybeans. The dry matter of the aerial part of the soybean plants in full flowering stadium, plants height and first pod insertion, number of pods per plant, the productivity and the 100 grains mass, were evaluated. It was concluded that the crop rotation or crops succession was not influenced by the plant height, pods insertion and number of pods per plant. On the other hand, the rotation systems of rice/sorghum/rice/beans/millet/soybean and soybeans/wheat/soybeans/corn/millet/soybean, provided the soybeans the higher grains yield.

PRODUTIVIDADE DE GRÃOS DE MILHO IRRIGADO EM FUNÇÃO DA CULTURA ANTECESSORA E DE DOSES DE NITROGÊNIO

Com o objetivo de verificar se a posicao da semente na espiga afeta diferentemente a produtividade e outros caracteres da planta e se essa diferenca pode ser ampliada por meio de ciclos seletivos, foi conduzido o presente trabalho. Para isto, na safra 1995/1996, foram semeadas, em lote isolado, cerca de 3.000 plantas da populacao CMS-39 e, por ocasiao da colheita, tomadas 300 espigas ao acaso. De cada espiga, foram coletadas sementes das extremidades e, posteriormente, as sementes da ponta de cada espiga foram misturadas e o mesmo foi realizado com as sementes da base. Esse procedimento foi repetido de modo analogo por cinco ciclos seletivos. As dez subpopulacoes, cinco da ponta e cinco da base, foram avaliadas em experimentos conduzidos nas safras 2000/2001 e 2001/2002. O delineamento utilizado foi o de blocos casualizados, com seis repeticoes, segundo esquema de parcelas subdivididas. Os tratamentos nas parcelas foram os cinco ciclos seletivos e, nas subparcelas, a origem das sementes, ponta ou base. Foram considerados os caracteres numero de dias para o florescimento masculino e feminino, altura de espiga e produtividade de graos. Constatou-se que a origem da semente da ponta ou da base nao alterou a expressao de varios caracteres avaliados e nao foi possivel, com a precisao experimental obtida, detectar efeito da selecao indireta para o vigor de polen pela posicao dos graos na espiga, em todos os caracteres considerados.

Supplemental irrigation in the cycle of "safrinha" corn under no-tillage system

The objective of this study was to evaluate different water depths applied as supplemental irrigation in the cycle of safrinha corn under no-tillage systems, and their influence on the physiology, productivity and economical viability in the area of Dourados, MS. The work was accomplished in the Experimental Nucleus of Agrarian Sciences in Great Dourados Region, UFGD, in the period from March to September, 2005. For the analysis of the data the following physiologic characteristics were determined: leaf area, height of ear insertion, plant height, ear dry matter, total dry matter and mass of 100 grains. The productivity of grains was determined correcting the water content for 13%. The treatments with supplemental irrigation were of 160, 360, 410 and 510 mm. In the calculation of economical viability, the financial indexes were used for the cost of production of the safrinha corn in 2005, and the tariffs of energy ratified in the ANEEL no 74. The results lead to the following conclusions: the increment of the applied water depths promoted linear increases in the physiology of the plant; the supplemental irrigation was essential to increase the productivity of the safrinha corn; and the largest productivity of the safrinha corn did not result in greater net income.

Teor de proteína e de óleo nos grãos de soja em função do tratamento de sementes e aplicação de micronutrientes

Conduziu-se este trabalho, com o objetivo de verificar o efeito do uso de inoculante, fungicida, e micronutrientes na produtividade e na composicao quimica dos graos de soja. Na safra de 2005/2006, foi realizado um estudo com diferentes tratamentos de sementes e aplicacao foliar de micronutrientes. Avaliaram-se caracteristicas agronomicas e a produtividade, assim como o teor de oleo, de proteina e de outros nutrientes das folhas e dos graos de soja. Altura de planta foi influenciada significativamente pelos tratamentos aplicados, sendo que a menor media de altura de planta foi observada na testemunha, 89,75 cm. O diâmetro de caules, o numero de vagens por planta e a massa de 100 sementes nao foram influenciados pelos tratamentos. Nas condicoes que o experimento foi desenvolvido, em solos de boa fertilidade, os tratamentos adotados nao influenciaram significativamente na produtividade e nos teores de proteina e de oleo dos graos, assim como na composicao quimica foliar e dos graos de soja.

Quality of bean seeds harvested by a combine in semi-mechanized system

The objective of this work was to analyze the physic and physiologic quality of bean seeds. The bean seeds variety was the Iapar 81. The system of harvesting used was the semi-mechanized. The seeds were harvested by a combine, model Axial Flow 2388. The quality analysis that considered the influence of four operation speeds (6.5; 8.8; 10.2 and 10.8 km h-1), two threshing cylinder velocity (430 and 480 rpm) and latent effect of mechanical damages during seeds storage (0; 60; 120 and 180 days) was studied. The impurity content, the mechanical damage, the electrical conductivity, the vigor and the seed germination were determined. The smallest values of impurity content were obtained in the displacement speeds of 10.2 and 10.8 km h-1, on the threshing cylinder velocity of 430 rpm, while there was not any effect of the speed when 480 rpm was used. The largest values of mechanical damage, vigor and germination were obtained in the displacement speeds of 8.8; 9.9 and 9.2 km h-1, respectively. The smallest value of electric conductivity was obtained in the speed of 7.7 km h-1, regardless of the threshing cylinder velocity. By working with 480 rpm on the threshing cylinder velocity it was obtained the smallest values impurities content, vigor and germination, and larger values of mechanical damage and electric conductivity. The seed vigor and germination did not decrease with the storage time of 180 days.