ResumoO arroz é importante fonte de energia e proteínas para a população mundial, principalmente na Ásia e Oceania. No Brasil, juntamente com o feijão, constitui a base da alimentação. Tecnologias sustentáveis que reduzam custos da produção e aumentem a produtividade do arroz podem garantir seu suprimento em períodos de alta demanda Cover crops, nitrogen rates and seeds inoculation with Azospirillum brasilense in upland rice under no-tillage AbstractRice is an important source of energy and protein for the world population, mainly in Asia and Oceania. In Brazil, together with common beans, it is the population's basic food. Sustainable technologies that reduce rice production costs and increase productivity can warrant its supply on period of high demand. The objective of this study was to evaluate different preceding cover crops (millet [Pennisetum americanum], sunn hemp [Crotalaria juncea], pigeon pea [Cajanus cajan], Brachiaria ruziziensis, millet + sunn hemp and millet + pigeon pea), rates of nitrogen (N) fertilization at sidedressing (0, 40, 80 and 120 kg ha -1 ) and the effects of seed inoculation with Azospirillum brasilense in upland rice under no-tillage system on crop growth and yield. The experimental design was in complete randomized blocks, in a factorial scheme 6x4x2 with four replications. The experiment was set up on a Red Oxisol in Selvíria, State of Mato Grosso do Sul, Brazil, in 2011/2012. Pigeon pea preceding rice cropping provided higher rice yield only in comparison with B. ruziziensis. The rice yield as function of rates of N at sidedressing fit to a quadratic function. There was no influence of seeds inoculation with A. brasilense on rice yield, however, there was interaction between the inoculation and cover crops on the leaf of N content, number of panicles per m 2 , dry rice plants and weight of 100 grains.

INTRODUÇÃOO Brasil está entre os dez principais produtores mundiais de arroz, com cerca de 11,5 milhões de toneladas, em área de 2,7 milhões de hectares (Conab 2011). O arroz inundado, cultivado na região subtropical do Brasil, responde por 70% da produção brasileira de arroz (IBGE 2006). Segundo Heinemann & Stone (2009), a área disponível para aumento da produção, nesta região, é limitada, principalmente em função do alto impacto no meio ambiente e problemas sociais, como a competição pela demanda industrial de água e uso doméstico. Assim, há aumento de interesse em sistemas de produção de arroz de terras altas predominantes no Centro-Oeste do Brasil.

INTRODUÇÃOA cultura do feijão (Phaseolus vulgaris L.) constitui-se em uma das mais importantes explorações agrícolas do Brasil, não só pela área cultivada e pelo valor da produção, mas, também, por ser considerada a principal fonte de proteínas, para as camadas da população de menor poder aquisitivo (Soratto 2002). ABSTRACT RESUMOTendo-se em vista a sua importância, em âmbi-to nacional, faz-se necessário o conhecimento sobre as práticas de adubação adotadas por produtores, as quais, juntamente com outras práticas culturais, como a irrigação e os tratamentos fitossanitários, contribuem para o aumento da produtividade e do custo de produção das culturas agrícolas.De acordo com Malavolta (1979), o nitrogê-nio (N) é um dos nutrientes mais absorvidos pelo Economic analysis of bean yield according to nitrogen levels and cover cropsNitrogen is the nutrient applied in greater amounts in bean crops, the most limiting to the growth and development of bean plants and the most onerous to its production cost. A good option for producers to reduce costs, concerning nitrogen fertilizers, is the use of ground cover plants, also known as green manures. So, this study aimed at evaluating the production costs and profitability rates of different treatments involving cover crops and topdressing nitrogen doses, in irrigated no-tillage bean crops, in the winter of 2010 and 2011. The experiment was conducted in an experimental area, in Selvíria, Mato Grosso do Sul State, Brazil, in a typical Oxisol. The treatments consisted of six cover crops (Crotalaria juncea, millet, pigeon pea, Crotalaria juncea + millet, pigeon pea + millet and fallow ground), and four nitrogen doses (0 kg ha ). The total operating cost, gross revenue, operating profit, profitability index and equilibrium productivity and price were evaluated. It was concluded that the use of Crotalaria juncea as a ground cover crop resulted in the highest values for total operating cost and operating profit and the highest profitability indexes, and that increased nitrogen levels also increased the total operating cost, with an increasing trend for productivity and, consequently, for the equilibrium price.

RESUMOCo-inoculation of Rhizobium tropici and Azospirillum brasilense in common beans grown under two irrigation depths 1 The alternative technique of co-inoculation or mixed inoculation with symbiotic and non-symbiotic bacteria has been studied in leguminous plants. However, there are few field studies with common beans and under the influence of the amount of irrigated water. Thus, the objective of this study was to evaluate the efficiency of inoculation and coinoculation of common beans with Rhizobium tropici and Azospirillum brasilense under two irrigation depths. The experiment was carried out in the winter of 2012 and 2013, in Selvíria, state of Mato Grosso do Sul. The experimental design was composed of randomized blocks in split-plot scheme with two irrigation depths in the plots (recommended for common beans and 75% of the recommended) and five forms of nitrogen (N) supply in the split-plots (control noninoculated with 40 kg ha . The use of 75% of the recommended irrigation depth provides similar grain yield to the recommended irrigation depth in common beans cropped in winter.

Com a expansão e diversidade do sistema plantio direto, deve-se avaliar os benefícios econômicos gerados ao longo dos ciclos produtivos, com destaque para aqueles relacionados aos restos culturais da cultura antecessora e ao manejo da adubação nitrogenada da cultura sucessora. Este trabalho objetivou avaliar a viabilidade econômica de quatro doses de nitrogênio em cobertura, na produtividade de grãos de feijoeiro de inverno cultivado no sistema plantio direto, após diferentes culturas. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições, em esquema fatorial 8x4, com 32 tratamentos constituídos pela combinação de restos culturais (milho; milho -Azospirillum brasilense; Urochloa ruziziensis; Urochloa ruziziensis - Azospirillum brasilense; milho + U. ruziziensis; milho -A. brasilense + U. ruziziensis; milho + U. ruziziensis- A. brasilense; milho -A. brasilense + U. ruziziensis- A. brasilense) e doses de nitrogênio em cobertura (0 kg ha-1, 30 kg ha-1, 60 kg ha-1 e 90 kg ha-1). Concluiu-se que o maior acréscimo de produtividade de grãos do feijoeiro de inverno irrigado por aspersão foi obtido com a utilização de 90 kg ha-1 de nitrogênio em cobertura, em sucessão a Urochloa ruziziensis, sem a inoculação de Azospirillum brasilense. Recomenda-se, para obtenção da maior margem de ganho, a aplicação de 90 kg ha-1 de nitrogênio em cobertura, na cultura do feijoeiro em sucessão às outras culturas, exceto para Urochloa ruziziensis inoculada.

In modern agriculture, there is a challenge for adequately nourishing plants using sustainable techniques, mitigating the use of mineral fertilizers, especially nitrogenous fertilizers, which are the most used for corn crops. The objective of this study is to evaluate the accumulation potential of nitrogen, phosphorus and potassium in: a) cover crops (millet, crotalaria, pigeon pea, millet + crotalaria, millet + pigeon pea and fallow) and b) corn plants sown in succession to the cover crops and with application of nitrogen doses (0, 40, 80 and 120 kg ha . Inoculation via seeds using Azospirillum brasilense did not increase the accumulation of dry matter and nutrients of corn plants. It is recommended to cultivate corn in succession to the millet + crotalaria and the aplication of 80 to 100 kg ha -1 of N in topdressing aiming at better nutrition of the plants.

The adequacy of the best sowing times and the choice of rice cultivars is determinant for greater investment and return in upland rice cultivation. Thus, this study identified the best sowing time and the cultivar that expresses its yield potential, being adaptable and stable, in a low altitude Cerrado region. The study was conducted during the agricultural year 2016/17. The soil of the site is a typical clayey dystrophic Red Latosol. The experimental design was in randomized blocks, in factorial scheme with four sowing times in spring/summer season (October, November, December and February), each with eight upland rice cultivars (BRS Esmeralda, ANa 5015, ANa 6005, IPR 117, IAC 500, IAC 203, BRSGO Serra Dourada and ANa 7211) and four replicates. The following parameters were evaluated: days elapsed from emergence to flowering and harvesting, number of panicles m-2 , number of filled spikelets per panicle, thousand grain weight and yield. Analyzes of adaptability and stability were performed as well as the principal components analysis. Except for the hundred grains weight, sowing times and cultivars interacted significantly for all characteristics evaluated. The cultivar BRS Esmeralda was adapted and stable to the different sowing times, being the most productive mainly when sown in October. The high yields were correlated with better grain filling, according principal components analysis.

The rationalization of water use, the increase in productivity and the reduction of nutrient losses are among the current challenges of agriculture. Recently, the upland rice cultivar BRS Esmeralda with more tolerance to drought was released. Thus, the objective of this study was to evaluate the hydric variation and nitrogen sources in topdressing in upland rice cultivar BRS Esmeralda. The experiment was conducted at the Education and Research Farm of UNESP located in Selvíria, Mato Grosso do Sul (MS) state, in 2013/14 and 2014/15. The experiment was conducted in the field under randomized blocks with a split-plot design with three hydric variations as plots (irrigation with a recommended water depth for rice + rainfall; irrigation with 75% of the recommended water depth + rainfall; and without irrigation + rainfall) and four nitrogen sources as subplots (urea, ammonium sulfate, urea + sulfate and coated urea) with four replications. The reduction in water availability delayed the flowering and ripening and reduced the production of dry matter of upland rice. There was a decrease in the productivity of rice grains upon decrease in water availability in the year with incidence of dry spell during the reproductive stage. On the other hand, there was no interference of hydric variation on grain yield in the year with a 14-day water deficit during the vegetative stage. Nitrogen sources provided similar rice productivity. In similar environmental conditions of this work, it is recommended to irrigate upland rice when drought periods occur during the reproductive stage with the recommended depth and that N fertilization in topdressing be carried out with the fertilizer that presents the lowest cost per kg of N.