ABSTRACT The world population is expected to rise by two billion in a few decades, boosting demand for soybean (Glycine max L.). Brazil has the world’s largest tropical agricultural area, accounting for 40 % of the world’s soybean output. This study was conducted to understand the potential and limitations of tropical soybean yield, estimate the amounts of main inputs (water and nutrients), and assess management to reach the crop yield potential (YP). We used CROPGRO-Soybean model, based on well-conducted experiments in different locations in Brazil. We generated estimates of YP and water-limited crop yield potential (YP-W), and explored long-term scenarios to evaluate the impact of sustainable practices on water management. Yield gap (YG) and agricultural efficiency (EA) were computed based on simulations and actual yield. The total water and nutrients required to achieve the YP in Brazil were also calculated. According to our simulations, YP ranged from 3,952 to 6,084 kg ha–1; YP-W from 3,133 to 5,186 kg ha–1, and YG from 589 to 4,401 kg ha–1. On average, drought stress negatively affected 14 % of YP, while 42 % of YP was lost due to management failures. Irrigation was needed in 26 % of the soybean-planted areas in Brazil to mitigate the risks associated to seasonal rainfall variations. Our findings revealed that it was possible to save around 20 % of the water through conservative soil practices and 25.0 106 Mg of macronutrients (N = 356 kg ha–1, P = 31 kg ha–1, K = 104 kg ha–1) annually is required to reach the exploitable soybean yield. decades Glycine L.. L L. . L.) worlds s area 4 output nutrients, , nutrients) YP. (YP) CROPGROSoybean CROPGRO Soybean model wellconducted well waterlimited limited YPW, YPW W (YP-W) longterm long term (YG EA (EA calculated 3952 3 952 3,95 6084 6 084 6,08 ha–1 ha1 ha 1 3133 133 3,13 5186 5 186 5,18 58 4401 401 4,40 average failures 2 soybeanplanted planted variations 250 25 0 25. 10 N 35 (YP (YP-W 395 95 3,9 608 08 6,0 ha– 313 13 3,1 518 18 5,1 440 4,4 39 9 3, 60 6, 51 5, 44 4,

ABSTRACT: Microbial biodiversity of an environment can contribute to plant growth and increase crop yield. Plant extracts from soybean (Glycine max (L.) Merrill) were investigated on soybean plants grown after inoculation with these extracts. Soil samples were collected from two important Brazilian soybean-growing regions to produce the extracts used in the experiments. The extracts were produced with material collected from aboveground biomass and rhizosphere of soybean plants cultivated in a controlled greenhouse (phase 1). The extracts produced in phase 1 were applied in a sequential experiment (phase 2). Phase 2 was conducted to examine the plant microbiome after the microbial alteration process in the greenhouse through seed inoculation with the extracts produced previously. Samples of aboveground biomass were collected to determine root dry matter and crop yield. Bacterial 16S rRNA sequences were processed to determine the final microbial content of soybean. The inoculated treatments had lower species diversity; however, the phyla Firmicutes and Bacteroidetes were more abundant in the treatments than in the non-inoculated treatment. The soybean plant stem in the inoculated treatment also had a positive response to enrichment of the bacterial classes Betaproteobacteria, Bacilli and Flavobacteria. Inoculation affected the microbial composition of soybean plants. The alteration of microbiome changes revealed differences for crop yield between the inoculated and non-inoculated treatments, with up to 93.5 % higher crop yields per plant according to the extract applied.

Resumo: O objetivo deste trabalho foi avaliar o uso da altura do dossel da planta como variável de ajuste para melhorar as medições indiretas do índice de área foliar (IAF). Três experimentos foram conduzidos com diferentes culturas - milho (Zea mays), soja (Glycine max) e cana-de-açúcar (Saccharum officinarum) -, para comparar o desempenho do IAF medido indiretamente (IAFind) e corrigido pela variável de ajuste com o IAF medido diretamente (IAFref). Sem a correção proposta, o IAFind tendeu a ser superestimado em 20%, em média, em relação ao IAFref, para as três culturas. Após o uso da altura da colheita para ajustar o IAFind, observaram-se fortes relações positivas entre o IAFref e o IAFind corrigido (R2 = 0,96); a superestimação foi reduzida para 4% e o erro médio quadrático diminuiu para 0,35 m2 m-2. A variável altura do dossel mostra-se promissora para correção do IAF das culturas de soja, milho e cana-de-açúcar.

Abstract: The objective of this work was to evaluate the use of plant height as a calibration variable for improving indirect measurements of the leaf area index (LAI). Three experiments were conducted with different crops - corn (Zea mays), soybean (Glycine max), and sugarcane (Saccharum officinarum) -, to compare the performance of the LAI measured indirectly (LAIind) and corrected by the calibration variable with the LAI measured directly (LAIref). Without the proposed correction, the LAIind tended to be overestimated by 20%, on average, compared with the LAIref, for the three crops. After crop height was used to adjust the LAIind, a strong positive relationship was observed between the LAIref and the corrected LAIind (R2 = 0.96); overestimation was reduced to 4% and the root-mean-square error decreased to 0.35 m2 m-2. The variable canopy height is promising for the correction of the LAI of the soybean, corn, and sugarcane crops.

O Programa Nacional de Fortalecimento da Agricultura Familiar (Pronaf) incluiu agricultores familiares no quadro das políticas públicas, ao seguir as tendências das políticas da década de 1990 de democratizar acesso a recursos financeiros. A sustentabilidade foi inserida no programa. Neste estudo, o propósito geral foi analisar os objetivos do Pronaf, no contexto do desenvolvimento econômico. Considerou-se que o Pronaf não permitiria avaliar a relação entre atividades desenvolvidas e resultados obtidos pelo programa. Assim, seria inconsistente. Além de analisar documentos oficiais, outros objetivos específicos foram analisar a consistência do Pronaf e, em caso de inconsistência, propor uma matriz de estrutura lógica. Nenhum projeto foi encontrado, apenas a legislação. A análise desta não permitiu o preenchimento da matriz e isso indica inconsistência. Propôs-se uma matriz completa.

The National Program for Strengthening Family Agriculture (Pronaf) has included family farmers into the scope of public policies, by following the trends of policies from the 1990s to democratize access to financial resources. Sustainability has been put into the program. In this study, the overall purpose was analyze the objectives of Pronaf, in the context of economic development. We found out that Pronaf would not allow evaluating the relation among activities conducted and results obtained by the program. Thus, it would be inconsistent. Besides analyzing official documents, other specific objectives were to analyze the consistency of Pronaf and, in case of inconsistency, propose a logical framework matrix. No project was found, only the legislation. The analyse of the latter does not allow filling the matrix and this indicates an inconsistency. A full matrix was proposed.

El Programa Nacional de Fortalecimiento de la Agricultura Familiar (Pronaf) incluyó agricultores familiares en el marco de las políticas públicas, al seguir las tendencias de las políticas de la década de 1990 para democratizar el acceso a los recursos financieros. La sostenibilidad se ha insertado en el programa. En este estudio, el objetivo general es analizar los objetivos del Pronaf en el contexto del desarrollo económico. Se considera que Pronaf no permite evaluar la relación entre las actividades y los resultados obtenidos en el programa. Por hipótesis, no sería coherente. Además de la búsqueda de documentos oficiales, otros objetivos específicos fueron analizar la consistencia del Pronaf, y en caso de discrepancia, proponen una matriz del marco lógico. Ningún proyecto se encuentra, sólo la legislación. Este análisis no permite el llenado de la matriz, lo que indica incompatibilidad. Se propuso una matriz completa.