O objetivo deste trabalho foi avaliar o potencial de práticas culturais, adotadas na entressafra, para reduzir a população e os danos causados por Pratylenchus brachyurus em soja. Realizou-se um experimento em área naturalmente infestada, nas safras 2010/2011, 2011/2012 e 2012/2013, em Vera, MT. Os tratamentos foram: milheto (Pennisetum glaucum) 'ADR 7010' (2010/2011) e 'ADR 300' (nas entressafras seguintes); milho (Zea mays) 'BRS 1010' (2010/2011) e 'GNZ 2005' (nas entressafras seguintes); braquiária ruziziensis (Urochloa ruziziensis); capim-marandu (U. brizantha 'Marandu'); crotalária (Crotalaria ochroleuca); C. juncea; C. spectabilis; C. spectabilis + milheto 'ADR 300' (de 2011/2012 em diante); alqueive mecânico (duas gradagens + herbicida); pousio (sem controle de ervas daninhas); e testemunha (alqueive químico, com aplicação de herbicida). O alqueive mecânico, as crotalárias e C. spectabilis + milheto reduziram a população do nematoide antes da semeadura e nos estádios iniciais da soja. Após a colheita da soja, a população de nematoides não diferiu entre os tratamentos, o que indica que a multiplicação destes na cultura foi maior nos manejos com menor população inicial. O uso de C. spectabilis, milheto e C. spectabilis + milheto contribuíram para as maiores produtividades de soja. O cultivo de C. spectabilis, solteira ou consorciada ao milheto 'ADR 300', é a melhor opção para reduzir a população e os danos causados por P. brachyurus à soja na entressafra.

The objective of this work was to evaluate the effect of roots and straw of palisade grass (Urochloa brizantha) and Ruzi grass (U. ruziziensis), used as cover crops in autumn-winter, on soybean performance. Seven treatments were evaluated in a randomized complete block design, with four replicates: fallow, during autumn-winter; straw of U. ruziziensis or U. brizantha 'BRS Piatã', distributed in plots kept under fallow in the winter, without roots; plots only with roots of U. ruziziensis or U. brizantha, without straw; and plots with straw and roots of U. ruziziensis or U. brizantha. The grass species were planted during the 2014/2015 crop season, and treatments were evaluated at the end of the 2015/2016 crop season, without drought during the soybean cycle. The oil and protein contents of soybean grains were not affected significantly by the treatments. However, the cultivation of grass species during autumn-winter increased soybean grain yield in comparison with fallow. Grass root effects are more expressive than those of straw. The combined presence of roots and straw confers a better performance to soybean than the isolated presence of roots or straw.

The integrated crop- livestock-forest system can enhance the production of soybeans, meat and wood in regions characterized by sandy soils and warm climate. The aim of this study was to evaluate the yield of soybean, Urochloa ruziziensis grass and eucalyptus in an integrated system during the first four years after the establishment of eucalyptus in the northwestern region of Paraná state, Brazil. The experiment was established in October 2009, using soybean (summer) -U. ruziziensis (autumn/winter) succession between single rows of Corymbia maculata (eucalyptus species). The spacing between tree rows and eucalyptus plants in the row were 14 and 4.2 m, respectively. Adjacent plots had the same soybean-U. ruziziensis succession, but without eucalyptus. The spatial variability of soybean grain yields and grass shoot dry matter production was evaluated with and without trees, and the data was analyzed using geostatistics, with the results expressed as spatial variability maps. The tree component did not significantly affect soybean yield in the first two growing seasons. In the 3rd and 4th growing season (2011/12 and 2012/13), the interference of eucalyptus reduced the soybean grain yield by 2.9 and 27.0%, respectively, and the effect was stronger close to the tree rows. In July 2012, the tree component reduced the shoot dry matter productivity of U. ruziziensis by 29.2%. At 19 and 35 months after eucalyptus planting, the cumulative wood volume production was 0.73 and 5.17 m³ ha-1, respectively

O objetivo deste trabalho foi avaliar o efeito de alturas de pastejo e épocas de dessecação de uma pastagem de Urochloa ruziziensis e da adubação nitrogenada sobre o desempenho da soja. Foram testadas três alturas (15, 35 e 50 cm) de pastejo contínuo da pastagem por bovinos, durante seis meses, além de um piquete sem pastejo, que constituíram quatro experimentos distintos. Em cada experimento, utilizou-se o delineamento de blocos ao acaso, em arranjo de parcelas subdivididas. Nas parcelas principais, foram alocadas quatro épocas de dessecação da pastagem (35, 28, 20 e 8 dias antes da semeadura da soja); e, nas subparcelas, foram realizados dois tratamentos (sem e com 30 kg ha^-1 de N, aplicado a lanço na semeadura). O manejo da pastagem de U. ruziziensis a 35 cm de altura confere maior produtividade de grãos de soja cultivada em sucessão à pastagem. Os intervalos de 8 a 35 dias, entre a dessecação da pastagem de U. ruziziensis e a semeadura da soja, não alteram o desempenho agronômico da cultura. Após o manejo da pastagem de U. ruziziensis, a aplicação de 30 kg ha^-1 de N à soja, em semeadura, proporciona maior altura de plantas e de inserção da primeira vagem, mas não altera a produtividade de grãos.

The objective of this work was to evaluate how branch and stem variables contribute to grain yield in individual soybean (Glycine max) plants, cultivated at different planting densities, in a modern cultivar with indeterminate growth type. A field experiment was carried out during the 2013/2014 and 2014/2015 crop seasons, in a randomized complete block design with 12 replicates, using the cultivar NK7059 RR at four planting densities: 135, 235, 315, and 440 thousand plants per hectare. Grain yield per plant was evaluated and represented phenotypic plasticity, while the number of branches per plant, percentage of grain production in branches, and separate yield components from branches and stems were considered as the independent variables. The number of pods in branches per plant was found to be the most important variable for soybean plasticity. In addition, the number of pods per plant on stems, number of branches per plant, and the percentage of grain production in branches were also associated with plasticity. Contrastingly, the number of grains per pod and the mass of a thousand grains in the branches and stems contributed little to plasticity in 'NK7059 RR' soybean.

The objective of this study was to evaluate the pig slurry application effects on chemical attributes of a Hapludox soil managed under no-tillage system. Treatments consisted of 50, 100 and 200 m³ ha-1 per year of pig slurry application, and a control with replacement of P and K exported through harvested grains. Attributes related to soil chemical reaction, exchange complex, and nutrient contents were determined in soil samples collected in the ninth year of experimentation from 0 - 0.025, 0.025 - 0.05, 0.05 - 0.10, 0.10 - 0.20, 0.20 - 0.40 and 0.40 - 0.60 m soil depths. The continuous application of high doses of pig slurry on the Oxisol surface under no-tillage acidifies the soil and increases Al, P, Cu, and Zn contents down to 0.2-m depth, and K levels down to 0.6-m depth.