Doses of green manure as side dressing on organic production of broccoli

O efeito do adubo verde varia com a forma de aplicação, com as espécies empregadas, com o clima e com o manejo. Há carência de estudos sobre as doses de adubo verde para a produção de hortaliças. É pouco conhecido também o comportamento do N proveniente do adubo verde. O objetivo do trabalho foi estudar o efeito de doses de adubo verde na mineralização e volatilização do nitrogênio da massa vegetal e no crescimento e produção orgânica do brócolis. O trabalho foi desenvolvido no Departamento de Fitotecnia da UFV, com o cultivar ‘Piracicaba Precoce’, empregando-se como adubo verde a mucuna-cinza (Mucuna pruriens). O experimento foi instalado em delineamento de blocos casualizados, com cinco repetições e oito tratamentos: C12AV0 (12 Mg ha-1 de composto); C12AV4 (12 Mg ha-1 de composto + 4 Mg ha-1 de adubo verde); C12AV8 (12 Mg ha-1 de composto + 8 Mg ha-1 de adubo verde); C12AV12 (12 Mg ha-1 de composto + 12 Mg ha-1 de adubo verde); C25 (25 Mg ha-1 de composto); AV12 (12 Mg ha-1 de adubo verde); AM (Adubação Mineral); TA (Testemunha Absoluta). Foram avaliados o teor de N mineral no solo, a taxa de decomposição, teor de nutrientes e volatilização de N do adubo verde, a área do dossel, o estado nutricional, a produção e a exportação de N do brócolis. As doses 12 Mg ha-1 de composto combinadas com 4 ou 8 Mg ha-1 de adubo verde resultaram em produções similares às obtidas com AM. C12AV4, C12AV8 e C12AV12 resultaram em maiores áreas de dossel. N, K e Mg foram liberados mais rapidamente do que outros macronutrientes durante a decomposição dos resíduos do adubo verde. C12AV4 e C12AV8 resultaram em maiores teores de N mineral no solo que C12AV0 e menores que C12AV12 ao final do ciclo da cultura. As maiores perdas relativas de N por volatilização ocorreram com o suprimento de adubo mineral, seguido pelas maiores doses de adubo verde combinado com composto. O adubo mineral resultou nos maiores teores foliares de N assim como também nos maiores valores de N exportados com a colheita.The effect of green manuring depends on both the way of application, the species used, the climate and management practices. There is a lack of studies about green manure dose for vegetable crops production. It is also poorly known the fate of the N originated from the green manures. The objectives of this work were to study the effect of green manure dose on N mineralization and volatilization from legume biomass and on the growth and yield of organically grown broccoli. The work was carried out on the Departamento de Fitotecnia da Universidade Federal de Viçosa, with the ‘Piracicaba Precoce’ cultivar, using grey velvet bean (Mucuna pruriens) as the green manure. The experiment was set up in the completely randomized block design, with five repetitions and eight treatments: C12GM0 (12 Mg ha-1 of compost); C12GM4 (12 Mg ha-1 of compost + 4 Mg ha-1 of green manure); C12GM8 (12 Mg ha-1 of compost + 8 Mg ha-1 of green manure); C12GM12 (12 Mg ha-1 of compost + 12 Mg ha-1 of green manure); C25 (25 Mg ha-1 of compost); GM12 (12 Mg ha-1 of green manure); MF (Mineral fertilizer); CONTROL (No fertilization). It was evaluated the N-mineral content in the soil, the decomposition rate and N volatilization of green manure biomass, the canopy area, nutritional status, yield and N export on broccoli crop. The doses of 12 Mg ha-1 of compost plus 4 or 8 Mg ha-1 of green manure resulted in yields similar to the ones obtained with MF. C12 GM4, C12GM8 and C12GM12 resulted in greater canopy areas. N, K and Mg were released faster than other macronutrients during the decomposition of green manure residues. C12GM4 and C12GM8 resulted in higher N-mineral content in the soil than C12GM0 and lower content than C12GM12 by the date of broccoli harvest. The higher relative losses of N through volatilization happened with MF supply, followed by the higher doses of green manure plus compost. The mineral fertilization resulted in the higher leaf content of N, as well as in the higher quantities of N exported by harvest.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Nutrição nitrogenada e produção de brócolis cultivado com diferentes doses de mucuna em duas épocas

As pesquisas com adubação verde em olericultura tratam de estudos sobre espécies, época de aplicação e formas de manejo. O objetivo deste trabalho foi avaliar o efeito de doses de mucuna-cinza sobre o estado nutricional de N, a produtividade e a transferência de nitrogênio proveniente da fixação biológica (N-FBN) para o brócolis, na primavera- verão e no inverno-primavera. Os tratamentos consistiram de 0 a 12 t ha^-1 de mucuna-cinza acrescidos de 12 t ha^-1 de composto orgânico, além dos tratamentos adubação mineral, 12 t ha^-1 de mucuna, 25 t ha^-1 de composto e testemunha absoluta. Na primavera-verão as doses de mucuna resultaram em plantas com teor de N de 27,47 g kg^-1 e produtividade de 9,25 t ha^-1. No inverno-primavera o teor de N-FBN no N-total de brócolis em função das doses de adubação com mucuna-cinza ajustou-se a um modelo quadrático, atingindo 35,81% com a aplicação de 12 t ha^-1 da leguminosa. Ainda no inverno-primavera a produtividade em razão das doses de adubação com mucuna-cinza ajustou-se a um modelo linear, atingindo 14,16 t ha^-1. O fornecimento de 8 ou 12 t ha^-1 de mucuna resultou em produtividades superiores às obtidas com 25 t ha^-1 de composto, e a adubação com fertilizante mineral resultou em maior produtividade. O cultivo de inverno-primavera evidenciou a contribuição das doses de mucuna, as quais elevaram o teor de N-total, a transferência de N-FBN da mucuna e a produtividade da cultura.The research on green manuring of vegetable crops usually deals either with green manure species, timing or management while this paper aimed to evaluate the effects of doses of velvet-bean on N status and yield and on NBF-N transfer to broccoli crop in Spring-Summer and in Winter-Spring seasons. The treatments consisted from 0 to 12 t ha^-1 of velvet-bean residue plus 12 t ha^-1 of organic compost, besides mineral fertilizer, 12 t ha^-1of velvet-bean, 25 t ha^-1 of compost and control. In the Spring-Summer season the doses of velvet-bean residue resulted in plants with 27.47 g kg^-1 of N and yield of 9.25 t ha^-1. In the Winter-Spring the accumulation of N-FBN in broccoli plants adjusted to a quadratic model reaching 35.81% of Total-N at the dose of 12 t ha^-1 of velvet-bean. Yet in the Winter- Spring season, broccoli yield adjusted to a linear model as a function of velvet-bean doses, reaching 14.16 t ha^-1. The supply of 8 or 12 t ha^-1 of velvet-bean residue resulted in higher yield than the supply of 25 t ha^-1 of compost and the supply of mineral fertilizer resulted in the highest yields. Cropping in the Winter-Spring season allowed the contribution of velvet-bean dose to express. The increasing doses of velvet-bean enhanced the N content in leaves, the yield and the BNF-N transfer to the crop

Land Equivalent Ratio in the Intercropping of Cucumber with Lettuce as a Function of Cucumber Population Density

Lettuce and cucumber are two important vegetables cultivated in greenhouses. Intercropping can increase the yield without increasing the demands for inputs. A more efficient use of resources in production systems can reduce costs and environmental impacts. We evaluated the land equivalent ratio (LER) of intercropping cucumber and lettuce as a function of the cucumber population. An experiment was conducted in a greenhouse to evaluate the cucumber population density (100, 85, 70, and 55% of 2.35 plants m−2) and two lettuce cultivars, ‘Lucy Brown’ and ‘Vanda’. The cucumber population density affected the amount of photosynthetically active radiation that reached the lettuce. The higher the density, the lower the total fresh mass and yield of the two lettuce cultivars. Fruit yield per plant and per area decreased and increased, respectively, as the density increased. LER was highest when cucumber was intercropped with ‘Vanda’ lettuce. LER increased with the density of ‘Vanda’ but decreased for ‘Lucy Brown’. ‘Lucy Brown’ produced commercial traits (head formation) only at the lowest density (55%). The presence of lettuce did not affect the cucumber yield per plant or per area. The intercropped system used land more efficiently than monocultured crops of lettuce and cucumber, with better results for ‘Vanda’ than ‘Lucy Brown’

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