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.
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.
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 Maize (Zea mays) is considered one of the most important crops for world food security. Globally, Brazil is the second largest maize producer and the fourth largest maize consumer. The climate variables is one of the main determining factors for crop yield. Given the possibility of future climate changes, our objective was to evaluate the impact of climate change on maize crop growth and development, assessed strategies to cope with the future crop andto quantify the impacts on various producing regions of Brazil. The DSSAT/CERES-Maize model was calibrated with field data and then used to simulate current and six future climate scenarios, according to the AgMIP protocols. We selected three regional climate circulation models (GCMs) and two representative concentration pathways (RCPs) for the period of 2040-2069. For most of the producing regions, the simulations showed a decreasing trend during both the summer and autumn sowing seasons, except the autumn crops in Southern Brazil. We found the air temperature rise as the main factor for yield decreasing, and this finding provides an adaptation option to cope with future climate, as the country has a great latitudinal range for crop management, meaning genotypes with extended cycles could compensate the climate change, and thereby avoid the yield loss for maize crops.
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.
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.
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.