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Glyphosate and atrazine are two herbicides used worldwide to ensure high yields in different types of crops. Despite the importance of herbicides, their application may have negative effects on non-target organisms, including bacteria used in biological control and biological nitrogen fixation. Therefore, this research aimed to analyze the in vitro effect of glyphosate and atrazine on the growth of bacteria Azospirillum brasilense, Bacillus subtilis, Bacillus thuringiensis, Chromobacterium subtsugae, and Saccharopolyspora spinosa. The design used was completely randomized, and the doses of the herbicides evaluated were 1.0, 2.0, 3.0 and 4.0 L ha-1. The results showed that glyphosate and atrazine affected the development of the bacteria under study. Atrazine showed a lineal increasing effect between the doses used and inhibition of bacterial growth. Therefore, the dose of 4.0 L ha-1 of this herbicide was the one that showed the highest inhibition of bacteria, whereas glyphosate at a dose of 2.0 L ha-1 showed the highest inhibition of bacteria compared to doses of 1.0, 3.0 and 4.0 L ha-1.

The southeastern mesoregion of the Brazilian Pará state is an important soybean producer, and the second-crop system can increase the local agricultural production. However, Latosols with medium to very clayey texture predominate in the region and, despite being suitable for farming, they naturally have low levels of available phosphorus (P). This study aimed to evaluate the yield of second-crop cowpea [Vigna unguiculata (L.) Walp] under doses of residual P in a Yellow-Latosol. Two experiments were installed under field conditions. The experimental design was randomized blocks, with five treatments (residuals of 0, 50, 100, 150 and 200 kg ha-1 of P2O5) and four replications. The first experiment consisted of cultivating second-crop cowpea after the soybean harvest, with phosphate doses provided during the soybean planting, and the second of second-crop cowpea after the rice harvest, with phosphate doses provided during the rice planting. The 1,000-grain weight and production of pods, husks and grains were evaluated. The production of pods and husks were higher in the area with residual P. The highest yield was obtained in the residual dose of 200 kg ha-1 of P2O5, reaching a grain yield of 1,256 kg ha-1 after the soybean harvest and 885 kg ha-1 after the rice harvest. RESUMO A mesorregião sudeste paraense é importante produtora de soja, e o cultivo em safrinha pode incrementar a produção agrícola local. No entanto, na região, predominam Latossolos de textura média a muito argilosa, os quais, apesar de adequados ao uso agrícola, possuem, naturalmente, baixos níveis de fósforo disponível. Objetivou-se avaliar a produtividade de feijão-caupi [Vigna unguiculata (L.) Walp] em safrinha sob doses de fósforo residual em Latossolo Amarelo. Foram instalados dois experimentos em condições de campo. O delineamento experimental foi em blocos casualizados, com 5 tratamentos (residuais de 0, 50, 100, 150 e 200 kg ha-1 de P2O5) e 4 repetições. O primeiro experimento consistiu de cultivo de feijão-caupi em safrinha após a safra da soja, com as doses fosfatadas fornecidas durante o plantio da soja, e o segundo de feijão-caupi em safrinha após a safra do arroz, com as doses fosfatadas fornecidas durante o plantio do arroz. Avaliaram-se o peso de mil grãos e produção de vagens, cascas e grãos. Houve maior produção de vagens e cascas em área com residual de fósforo. A maior produtividade foi obtida no residual da dose de 200 kg ha-1 de P2O5, atingindo-se produtividades de grãos de 1.256 kg ha-1 após a safra da soja e 885 kg ha-1 após a safra do arroz.

The practices of soil amendment and fertilization carried out over the years have allowed the improvement of the fertility in some of them in the Brazilian soils. The objective of this study was to evaluate the performance of soybean in response to phosphate fertilization in soil with improved fertility. The research was carried out during the 2015-2016 harvest season in a dry-land area in the municipality of São Desidério, Bahia. The experiment was arranged in randomized blocks, with five treatments and four replicates. Treatments were composed by doses of phosphate fertilizer (0, 70, 140, 210 and 280 kg P2O5 ha-1). The following variables were evaluated: plant height, height of insertion of the first pod, number of stems per plant, number of pods per plant, thousand grain weight, productivity, and the analysis of macro and micronutrients in the leaf. Soybean plants did not respond to phosphorus applied to soil with built fertility. Under the conditions of this study, phosphorus fertilization in soil with improved fertility did not promote productivity. Although the plants did not respond to foliar macro and micronutrients as a function of phosphate fertilization, there was no reduction of these in response to high doses.

This study aimed to evaluate the growth, production, and leaf contents of macronutrients, as well as the yield of forage sorghum cultivated on the alleys of Gliricidia (Gliricidia sepium (Jacq.) Kunth ex Walp.) and Leucaena (Leucaena leucocephala (Lam.) de Wit) in the presence and absence of mineral fertilization. The experiment was conducted in two different periods: During the 2016/2017 double crop (cultivation carried out at the end of the crop cycle) and during the 2017/2018 crop (cultivation carried out at the beginning of the crop cycle). A randomized block design, in which the first factor refers to cultivation systems (single sorghum, sorghum cultivated in Gliricidia alleys, and sorghum cultivated in Leucaena alleys) and the second factor refers to mineral fertilization (presence and absence of fertilization), in a 3 &times, 2 factorial arrangement was used. The leguminous plants were cut, and the residues were deposited in the alleys. The cultivation in alleys without mineral fertilization increased total forage biomass when compared to the single crop cultivation. Cultivation in Leucaena alleys showed a higher leaf content of nitrogen (N) when compared to the single crop, both in the presence and absence of mineral fertilization. In the double crop, sorghum cultivated in Leucaena alleys without fertilization presented a higher forage yield (up to 67%) when compared to the single crop system. However, there was no difference in yield when mineral fertilization was applied to the treatments. Overall, the alley crops were able to increase the morphological (plant height (PH), stem diameter (SD), panicle diameter (PD), and panicle length (PL) and yield (leaf dry mass (LDM), stem dry mass (SDM), total green mass (TGM), and total dry mass TDM) variables of the crop, improving the productivity of forage sorghum.

Apesar do resíduo de frigorífico ser abundante em nutrientes, em especial elevado teor de fósforo da farinha de carne e ossos, faz necessário a avaliação desse produto em comparação a outras fontes comerciais. Objetivou-se avaliar componentes de produção e produtividade do capim Mombaça em função de diferentes fontes fosfatadas e ausência de adubação de cobertura. O experimento foi conduzido em delineamento de blocos casualizados com quatro repetições. Os 36 tratamentos foram obtidos numa combinação fatorial (3x6x2), sendo três fontes de fertilizantes fosfatados (Superfosfato simples, Basifós e Farinha de carne e osso) e seis doses de adubação fosfatada (0; 35; 70; 140; 210; 280) kg ha-1 de P2O5 e a aplicação ou não da adubação de cobertura de nitrogênio e potássio (100 kg de ureia; 60 kg de cloreto de potássio e 0 kg ha-1 de adubação de cobertura). Foram avaliados altura de plantas, perfilhamento e massa seca da parte aérea do capim Mombaça. A fonte alternativa farinha de carne e ossos promoveu acréscimo na altura de plantas, número de perfilhos e massa de forragem em capim Mombaça, mesmo quando comparada com diferentes fontes comerciais.Palavras-chave: adubação, resíduos de frigorífico, Panicum maximum. MEAT AND BONE MEAL AND COVER FERTILIZATION ON MOMBASA GRASS PRODUCTIVITY ABSTRACT: Although the refrigerator residue is abundant in nutrients, in particular high phosphorus content of meat and bone meal, it is necessary to evaluate this product in comparison to other commercial sources. The objective of this study was to evaluate the production and productivity components of the Mombasa grass as a function of different phosphate sources and absence of cover fertilization. The experiment was conducted in a randomized complete block design with four replicates. The 36 treatments were obtained in a factorial combination (3x6x2), with three sources of phosphate fertilizers (Superphosphate simple, Basifós and Meat and bone meal) and six doses of phosphate fertilization (0; 35; 70; 140; 210; 280) kg ha-1 of P2O5 and the application or not of nitrogen and potassium fertilization (100 kg of urea, 60 kg of potassium chloride and 0 kg ha-1 of cover fertilization). Plant height, tillering and dry mass of the aerial part of the Mombasa grass were evaluated. The alternative source of meat and bone meal promoted an increase in plant height, number of tillers and forage mass in Mombasa grass, even when compared to different commercial sources.Keywords: fertilizer, slaughterhouse waste, Panicum maximum.

Among the forage species cultivated in South America, the genus Urochloa is the most used, and the cultivar Marandu of U. brizantha is the most widely planted in Brazil. The objective of this study was to evaluate forage performance in association with Azospirillum brasilense, combined with nitrogen (N) fertilisation. The study was conducted under field conditions in Araguaína, Tocantins, in the central region of Brazil, between March 2016 and March 2017. Four N fertiliser rates (0, 12.5, 25 and 50kg/ha of N per cutting cycle) were combined with two inoculation treatments (inoculated and non-inoculated), with evaluations carried out in three periods of the year (transition, dry and wet seasons). Marandu grass plants inoculated with A. brasilense had greater plant height, number of tillers and forage production than non-inoculated plants, regardless of the N rate. Inoculation with A. brasilense allowed a 20% reduction in N fertilisation. Our results indicate that inoculation with A. brasilense in Marandu grass, as well as increasing forage production, can help to mitigate the stresses caused by the dry season.

Among the several factors that may influence nodulation and the efficiency of biological nitrogen fixation for soybean plants, nutrient availability is among the most important. This study aimed to evaluate the inoculation with Bradyrhizobium japonicum and doses of phosphorus on the development of soybean in a Vertisol, in Tocantins. The experimental design was completely randomized in a 4 × 2 factorial scheme, with four replications. Four doses of phosphate fertilization (0, 100, 200, and 300 kg ha-1 P2O5) were studied, combined with two inoculation treatments with Bradyrhizobium japonicum (inoculated and not inoculated). The following variables were evaluated: plant height, stem diameter, nodules per plant, dry mass of nodules, dry mass of plant, dry mass of root, number of pods and number of grains per pod. Under greenhouse conditions and soil with good availability of phosphorus, there is no influence of the doses on the inoculation with Bradyrhizobium japonicum. Soils with good availability of phosphorus have low response to the application of phosphate fertilizer.

Despite the importance of the Amazonian species Schizolobium amazonicum, there is still no official protocol to favor the germination process of its seeds. The objective of this study was to evaluate methods of overcoming dormancy of paricá seeds and the quality of seedlings produced. The work was carried out at the Federal Institute of Education, Science and Technology of Tocantins-Campus Araguatins. The experimental design was a completely randomized design with seven treatments and four replications. The treatments consisted of: intact seeds; lateral mechanical scarification of the tegument with electric emery for 2 seconds; lateral mechanical scarification of the tegument, using sandpaper number 50 for 1 minute + immersion in water at room temperature for 12 hours; chemical scarification of the tegument with caustic soda at 20% concentration for 30 minutes; chemical scarification of the tegument with caustic soda at a concentration of 20% for 45 minutes; immersion in water at 80 ºC + stay in water (room temperature) for 12 hours; immersion in water at 90 ºC + stay in water (room temperature) for 12 hours. The treatment with lateral mechanical scarification of the integument using electric emery for 2 seconds is the most suitable for overcoming dormancy in paricá seeds. Methods of overcoming dormancy had no influence on the quality of paricá seedlings.

Despite the benefits of no-till practices, soil compaction is a problem that can cause, among other things, mechanical impediment to root growth and less response to soil fertilization. The objective of this study was to evaluate the effect of subsoiling and doses of phosphate fertilization on soybean that have been cultivated over ten years under no-till systems in the Brazilian Cerrado. The experiment consisted of a randomized complete block design in a 2 × 4 factorial arrangement. Two managements in consolidated no-tillage area were considered: with and without subsoiling, along with four levels of phosphate fertilization: 0, 100, 300 and 400 kg ha-1 of P2O5. The practice of subsoiling in an area with ten years of no-till system provided an increase of 124.38 kg ha-1 in soybean productivity. Soybean plants grown under no-tillage system, with subsoil management, showed better development and pod production. The maximum phosphorus efficiency, with subsoiling, was achieved with the dose of 172 kg ha-1 of P2O5, yielding 5,693.4 kg ha-1. In the no-tillage system, the maximum efficiency dose and crop yield were 159 kg ha-1 of P2O5 and 5434.2 kg ha-1, respectively.