Soybean Yield Responses to Micronutrient Fertilizers

The availability of commercial products containing micronutrients for the management of crops has increased in recent years, but there are experimental results showing great variability in response to their application. A literature review was made in 28 scientific articles about the answers in the soybean yield in Brazilian agriculture due to the application of fertilizer containing micronutrients. Then, the aim of this chapter is to approach the efficiency of sources, doses, application methods, time, and yield results achieved in recent years by Brazilian research with the application of micronutrients in soybean. Adequate doses and sources of micronutrient increase Brazilian soybean yield, especially in that soil with low micronutrient content. High yields can be obtained in soils that have micronutrient levels considered adequate or high without their application. To right choice of micronutrients fertilizers, the farmer must know about solubility and other characteristics, including easiness to handling and applying and price. In general, the application method does not result in differences in soybean productivity. Thus, when applying micronutrients in the soil, topdressing or seed furrow, and leaf, and seed treatment, the most important aspects seem to be the time and dose to provide the nutrients in adequate amounts the plant requires

Fontes alternativas de potássio em cafeeiros para melhoria da fertilidade do solo, da produtividade e da qualidade de bebida

The objective of this work was to evaluate alternative sources of potassium for improving soil fertility and coffee productivity and beverage quality. The experiment was conducted in a coffee (Coffea arabica) crop, planted in an Oxisol area, in the municipality of Patrocínio, in the state of Minas Gerais, Brazil. The treatments consisted of the K sources TK47 and Super Greensand (SG) – both based on glauconite silicate mineral –, at the following doses: 0 kg ha-1 K2O (control); 42, 84, 168, and 336 kg ha-1 K2O from TK47; 618 kg ha-1 K2O from KCl; and 168 kg ha-1 K2O from SG. A randomized complete block design was used, with four replicates in each treatment. The experimental units consisted of three rows with ten plants each, using the eight central plants as the useful plot. Potassium fertilization with TK47 increased soil fertility, correcting soil acidity and elevating K+, P, and Ca2+ contents, effective cation exchange capacity, and Zn2+ and Fe2+ levels in the soil. Fertilization with 336 kg ha-1 K2O from TK47, in a single dose, provides grain yield and polyphenol oxidase activity similar to those of fertilization with 618 kg ha-1 K2O from KCl, in a split-dose, but a better sensory analysis of the resultant beverage.O objetivo deste trabalho foi avaliar fontes alternativas de potássio para melhoria da fertilidade do solo e da produtividade e da qualidade de bebida do cafeeiro. O experimento foi conduzido em lavoura de café (Coffea arabica) plantada em área de Latossolo, no Município de Patrocínio, no Estado de Minas Gerais. Os tratamentos consistiram da aplicação das fontes de K TK47 e Super Greensand (SG) – ambas baseadas no mineral silicatado glauconita –, nas seguintes doses: 0 kg ha-1 de K2O (controle); 42, 84, 168 e 336 kg ha-1 de K2O de TK47; 618 kg ha-1 de K2O de KCl; e 168 kg ha-1 de K2O de SG. Utilizou-se o delineamento de blocos ao acaso, com quatro repetições por tratamento. As unidades experimentais foram constituídas por três linhas de dez plantas cada uma, tendo-se considerado as oito plantas centrais como parcela útil. A adubação potássica com TK47 aumentou a fertilidade do solo, com correção da acidez e com elevação dos teores de K+, P, Ca2+, da capacidade de troca de cátions efetiva, e dos níveis de Zn2+ e Fe2+ no solo. A adubação com 336 kg ha-1 de K2O de TK47, em dose única, proporciona produção de grãos e atividade de polifenoloxidase semelhantes às da fertilização com 618 kg ha-1 de K2O de KCl, de forma parcelada, mas melhor análise sensorial da bebida resultante

Tamanho de parcela e efeito de bordadura no melhoramento de Urochloa ruziziensis

The objective of this work was to assess the need for a border area and to estimate the optimum plot size in experiments for the evaluation of Urochloa ruziziensis. Plant height and green mass production of eight half‑sib progenies of U. ruziziensis were evaluated in two cuttings. A randomized complete block design was used, with four replicates and 16 m2 plots. Each plot was subdivided into 32 strata of 0.5 m2, with each stratum being considered as a basic unit. To determine the need for a border area, analysis of variance was carried out considering the position of the basic unit in the plot. Estimates of optimum plot size were made by the maximum curvature of the coefficient of variation method and by the resampling method. The use of borders does not affect the mean performance and classification of the half‑sib progenies evaluated. The use of 3 m2 plots is enough to obtain good experimental accuracy in an experiment with half‑sib progenies of U. ruziziensis.O objetivo deste trabalho foi avaliar a necessidade de bordadura e estimar o tamanho ótimo de parcela em experimentos para avaliação de Urochloa ruziziensis. Foram avaliadas a altura das plantas e a produção de massa verde de oito progênies de meio‑irmãos de U. ruziziensis, em dois cortes. Utilizou-se o delineamento de blocos ao acaso, com quatro repetições e parcelas de 16 m2. Cada parcela foi subdividida em 32 estratos de 0,5 m2, sendo cada estrato considerado como uma unidade básica. Para determinar a necessidade de bordadura, foi realizada análise de variância, tendo-se considerado a posição da unidade básica na parcela. As estimativas do tamanho ótimo da parcela foram realizadas pelo método da máxima curvatura do coeficiente de variação e pelo método da reamostragem. O uso de bordaduras não altera o desempenho médio e a classificação das progênies de meio‑irmãos avaliadas. O emprego de parcelas com 3 m2 é suficiente para obter boa precisão experimental em experimento com progênies de meio‑irmãos de U. ruziziensis.

COFFEE YIELD AND PHOSPHATE NUTRITION PROVIDED TO PLANTS BY VARIOUS PHOSPHORUS SOURCES AND LEVELS

Phosphorus (P) is considered one of the nutrients that most limits crop yields, especially in soils with an advanced degree of weathering. To evaluate P dynamics and availability in soil resulting from various P doses and sources and to assess the resulting P content of coffee leaves and the final coffee yield, an experiment was conducted in the municipality of Três Pontas, MG, Brazil, in a Red Argisol (Ultisol) area. Fertilization, except for P fertilization, was performed based on the soil analysis results. The annual P doses tested were 0, 75, 150, 300, 450 and 600 kg ha-1 P2O5. Two P sources, simple superphosphate and magnesium thermal phosphate, were evaluated and compared in the study. A physicochemical analysis of the soil and an analysis of leaf dry matter were performed. The available P content in the soil increased as a result of the applications of the two sources. The leaf P levels stabilized at approximately 1.8 and 1.9 g kg-1 for simple superphosphate and magnesium thermal phosphate, respectively, as a result of the application of approximately 300 kg ha-1 P2O5. The coffee responded to P fertilization in the production phase. Averaged over three harvests, the yield per harvest showed gains of 45.3% and 40.3% for simple superphosphate and magnesium thermal phosphate, respectively, with the application of the highest studied dose, 600 kg ha-1 P2O5

Effect of Magnesium on Gas Exchange and Photosynthetic Efficiency of Coffee Plants Grown under Different Light Levels

The aim of the present study was to investigate the effects of magnesium on the gas exchange and photosynthetic efficiency of Coffee seedlings grown in nutrient solution under different light levels. The experiment was conducted under controlled conditions in growth chambers and nutrient solution at the Department of Plant Pathology of the Federal University of Lavras. The treatments consisted of five different Mg concentrations (0, 48, 96, 192 and 384 mg·L−1) and four light levels (80, 160, 240 and 320 µmol photon m−2·s−1). Both the Mg concentration and light levels affected gas exchange in the coffee plants. Photosynthesis increased linearly with the increasing light, indicating that the light levels tested were low for this crop. The highest CO2 assimilation rate, lowest transpiration, and highest water use efficiency were observed with 250 mg·Mg·L−1, indicating that this concentration was the optimal Mg supply for the tested light levels

Alternative sources of potassium in coffee plants for better soil fertility, productivity, and beverage quality

The objective of this work was to evaluate alternative sources of potassium for improving soil fertility and coffee productivity and beverage quality. The experiment was conducted in a coffee (Coffea arabica) crop, planted in an Oxisol area, in the municipality of Patrocínio, in the state of Minas Gerais, Brazil. The treatments consisted of the K sources TK47 and Super Greensand (SG) - both based on glauconite silicate mineral -, at the following doses: 0 kg ha-1 K2O (control); 42, 84, 168, and 336 kg ha-1 K2O from TK47; 618 kg ha-1 K2O from KCl; and 168 kg ha-1 K2O from SG. A randomized complete block design was used, with four replicates in each treatment. The experimental units consisted of three rows with ten plants each, using the eight central plants as the useful plot. Potassium fertilization with TK47 increased soil fertility, correcting soil acidity and elevating K+, P, and Ca2+ contents, effective cation exchange capacity, and Zn2+ and Fe2+ levels in the soil. Fertilization with 336 kg ha-1 K2O from TK47, in a single dose, provides grain yield and polyphenol oxidase activity similar to those of fertilization with 618 kg ha-1 K2O from KCl, in a split-dose, but a better sensory analysis of the resultant beverage.O objetivo deste trabalho foi avaliar fontes alternativas de potássio para melhoria da fertilidade do solo e da produtividade e da qualidade de bebida do cafeeiro. O experimento foi conduzido em lavoura de café (Coffea arabica) plantada em área de Latossolo, no Município de Patrocínio, no Estado de Minas Gerais. Os tratamentos consistiram da aplicação das fontes de K TK47 e Super Greensand (SG) - ambas baseadas no mineral silicatado glauconita -, nas seguintes doses: 0 kg ha-1 de K2O (controle); 42, 84, 168 e 336 kg ha-1 de K2O de TK47; 618 kg ha-1 de K2O de KCl; e 168 kg ha-1 de K2O de SG. Utilizou-se o delineamento de blocos ao acaso, com quatro repetições por tratamento. As unidades experimentais foram constituídas por três linhas de dez plantas cada uma, tendo-se considerado as oito plantas centrais como parcela útil. A adubação potássica com TK47 aumentou a fertilidade do solo, com correção da acidez e com elevação dos teores de K+, P, Ca2+, da capacidade de troca de cátions efetiva, e dos níveis de Zn2+ e Fe2+ no solo. A adubação com 336 kg ha-1 de K2O de TK47, em dose única, proporciona produção de grãos e atividade de polifenoloxidase semelhantes às da fertilização com 618 kg ha-1 de K2O de KCl, de forma parcelada, mas melhor análise sensorial da bebida resultante

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora