Green Manure Species Research Articles

Green Manure Species for Phytoremediation of Soil With Tebuthiuron and Vinasse.

Tebuthiuron is often used to control weed growth in sugarcane cultures. This herbicide is highly toxic and can persist in soil for up to 2 years according to its degradation half-life. Hence, its residual effect is highly hazardous for the environment and local habitants via leaching, surface runoff. Screening out of species of green manure as potential phytoremediators for tebuthiuron in soil, with and with no vinasse, accordingly is the scientific point of this study. Green manure species selected for the trial in greenhouse were jack bean [Canavalia ensiformis (L.) DC.], pigeon pea [Cajanus cajan (L. Millsp.)], velvet bean [Mucuna pruriens (L.) DC.)], and millet [Pennisetum glaucum (L.) R.Br.], and Crotalaria juncea L. as bioindicator of this herbicide. The determination/quantification of height, stem diameter, and number of leaves in all plants were monitored, as well as other morphological traits for drafting any inference on biomass production. Moreover, ecotoxicity bioassays were performed from soil samples at the beginning and at the end of the experiment. Results showed preliminary evidence of effective phytoremediation capacity by M. pruriens and P. glaucum in soils with tebuthiuron, as the growth of C. juncea was sustained. Both Gompertz approach and principal component analysis predicted that these green manure species could grow healthier and for longer periods in soils containing tebuthiuron and vinasse and, thus, reduce physiological anomalies due to ecotoxicity. The implications of this study may aid in the implementation of cost-effective strategies targeting decontamination of tebuthiuron in sugarcane crops with vinasse application in fertigation.

DESEMPENHO DO CAFÉ CONILON CONSORCIADO COM ADUBOS VERDES EM ÁREA DE TRANSIÇÃO AGROECOLÓGICA

Objetivou-se com este trabalho avaliar as características morfo-agronômicas do cafeeiro conilon submetido a diferentes manejos de espécies de adubos verdes. Foram avaliados cafeeiros contendo as espécies de adubo verde: feijão guandu, feijão de porco, mucuna preta e margaridão mexicano, em ambas as entrelinhas adjacentes (100%) e apenas na entrelinha localizada na entrelinha superior (50%), além de um tratamento testemunha (adubação convencional). A unidade experimental constituiu-se de uma planta de cafeeiro, variedade clonal “Incaper 8142” Conilon Vitória variedade 12 V (precoce), com espaçamento de 2,30 x 2,60 m, com cinco repetições. Utilizou-se bordadura de uma planta de cafeeiro entre as unidades experimentais. As varáveis avaliadas foram: comprimento do maior ramo ortotrópico (ALT); diâmetro dos ramos ortotrópicos (DRO); número de ramos plagiotrópicos lançados (NRP); número de nós produtivos dos ramos plagiotrópicos (NP); litros de café colhido in natura (LTS); quilogramas de café cereja produzidos por planta (kg). O manejo 50% de feijão guandu foi superior ao convencional para a maioria das características avaliadas, portanto pode ser recomendado, para o primeiro ano de transição.

Effectiveness and limitation of A-nZVI for restoration of a highly As-contaminated soil

To restore highly degraded soil with severe arsenic (As) contamination, effective mitigation of As mobility and bioavailability is considered as the primary step. In this study, the capability of an air-stabilized nano zero-valent iron (A-nZVI) to decrease soil As solubility and leachability was investigated. Further, the effect of A-nZVI on recovery of soil biological function was analyzed by measuring changes in dehydrogenase activity, bacterial community and development of two pioneering plant species. Results showed that A-nZVI exhibited a prominent sorption capacity for both arsenite and arsenate (92.4 and 44.1 mg g−1). With A-nZVI application at ≥0.2%, 44.2–74.7% decline in soil As solubility was achieved in neutral water extraction, while consistently higher As extractability was determined with synthetic precipitation leaching procedure (SPLP, pH 4.2). Compared to adjacent forest soil (F-CK), microbial community of the tested soil was featured by 66% lower abundance of Actinobacteria while an elevated richness of Gemmatimonadetes, both of which showed apparent shift toward F-CK with A-nZVI. 0.2% A-nZVI was most effective in promoting dehydrogenase activity and ryegrass growth. Further, by two-dimensional mapping with the Zr-oxide diffusive gradients in thin films (DGT), averaged DGT-As in rhizosphere of alfalfa (a green manure species) decreased by 47.1% with 0.2% A-nZVI. These results highlight that A-nZVI is critically essential for fixation of soil labile As and thus provides a favorable starting point for recovery of soil health.

Desempenho de Schinus terebinthifolia em sucessão a plantas de cobertura

Objetivou-se com este estudo avaliar os efeitos do cultivo e decomposição de plantas de cobertura sobre o crescimento e produção de biomassa de pimenta rosa cultivada em sucessão. Os tratamentos pré-cultivo foram constituídos de quatro espécies de adubos verdes (guandu; feijão de porco; crotalária; mucuna). Os tratamentos foram arranjados do delineamento experimental de blocos ao acaso, com seis repetições. As avaliações a campo consistiram na quantificação da biomassa fresca e seca da parte aérea das diferentes espécies de adubo verde. Foram colhidas quatro plantas inteiras por parcela, da pimenta rosa, para avaliar as médias de produção de massa fresca e seca da parte aérea e raízes. Os dados obtidos foram submetidos à análise de variância e, quando significativos pelo teste F (p<0,05), as médias foram comparadas por Tukey. Concluiu-se que a mucuna-preta, feijão-guandu, feijão-de-porco e crotalária são alternativas como adubação verde no cultivo de pimenta rosa em sucessão. O melhor desempenho da pimenta rosa em termos de produção de biomassa ocorreu em sucessão a mucuna. Somente a análise do acúmulo de biomassa pelos adubos verdes e pela planta sucessora são insuficientes para orientar a escolha de um sistema de produção.

Biomass Productivity of Different Winter Cover Crops and Their Effect on Soil Physical Properties

The cultivation of cover crops is a vegetative practice considered an alternative for sustainable soil management, due to its beneficial action in different aspects of soil properties. Thus, the present work aimed to evaluate the effect of cultivation of different species of cover crops on soil density, porosity and diameter of soil aggregates. The experimental design was in randomized blocks, with four replications. The treatments consisted of four species of winter green manure: black oat, forage turnip, forage pea, and common vetch, a consortium of black oat + forage turnip and area kept fallow (control). The following evaluations were performed: dry matter production of cover crops, macroporosity, microporosity, total porosity, soil density, geometric mean diameter and weighted average diameter. The cultivation with forage turnip and the consortium of black oat + forage turnip presented higher dry matter productivity, decreased soil density, increased soil porosity, improved the distribution in relation to macropores and aggregate stability.

Growth, flowering and fruiting of Campomanesia adamantium (Cambess) O. Berg intercropped with green manure species in Agroforestry Systems

Besides enabling economic activity, the domestication of indigenous species in situ configures a strategy for the conservation of genetic resources in Agroforestry Systems (AFSs), as well as an ecological restoration strategy. Successful productivity and restoration through AFSs require active intervention with agroecological practices, e.g., the use of green manure. We evaluated how planting different green manure species in consortium with Guavira influences its reproductive period, growth, and productivity in different spatial arrangements. Guavira, Campomanesia adamantium, is a shrub that is native to the Brazilian Savannah and has fruticulture potential. To evaluate growth, we measured plant height and canopy cover and to evaluate fruit yield, we monitored reproductive phenology among different treatments. Guavira grows better in less dense areas with Crotalaria breviflora and Cajanus cajan rather than with Canavalia ensiformis. In all inter-row spacing of Guavira and green manure species, the reproductive phases were highly seasonal, with flowering and fruiting lasting for 2 and 4 months, respectively. Guavira plants that grew in consortium with green manure in different inter-row spacing presented different flowering times, but this difference was not reflected in fruit production. Fruiting and growth appear to be affected by inter-row spacing, as well as by the species used in the consortium. Thus, these variables must be considered carefully when implementing an agroforestry system.

Preliminary results of using green manure species as a cost-effective option for forest restoration

Preliminary results of using green manure species as a cost-effective option for forest restoration

Phytoextraction of diuron, hexazinone, and sulfometuron-methyl from the soil by green manure species

The herbicides diuron, hexazinone, and sulfometuron-methyl present a potential risk of environmental contamination and are widely used for weed control in sugarcane cultivation. Our objectives were to measure the tolerance of Canavalia ensiformes (L.) DC., Stilizobium aterrimum L., Raphanus sativus L., Crotalaria spectabilis Röth, Lupinus albus L., and Pennisetum glaucum (L.) R. Br. To the herbicides diuron, hexazinone, and sulfometuron-methyl to assess the capacity of these species to extract and accumulate the herbicides in their tissues. Before sowing the green manure species, the soils were individually contaminated with the three 14C-radiolabeled herbicides. 14C-diuron and 14C-sulfometuron-methyl showed higher values remaining in the soil (>90%) for all species of green manure compared to hexazinone (<80%). The green manure species analyzed showed greater potential to remedy soils contaminated with hexazinone than the other herbicides. C. ensiformes showed high phytoextraction of hexazinone when compared to the other species, removing 11.2% of the pollutant from the soil, followed by L. albus (8.6%), S. aterrimum (7.3%), R. sativus (4.8%), C. spectabilis (2.5%), and P. glaucum (1.1%). The results indicate that the phytoextraction of diuron, hexazinone and sulfometuron-methyl is dependent on the species of green manure and can be an important tool for the decontamination of areas polluted by these herbicides.

Taxa de decomposição foliar de espécies utilizadas em sistemas agroflorestais

Os sistemas agroflorestais (SAFs) promovem a sustentabilidade do agroecossistema através das interações energéticas e da ciclagem de nutrientes por meio da produção e decomposição de biomassa sobre o solo. O objetivo deste trabalho foi avaliar a decomposição foliar de espécies utilizadas na adubação verde e de interesse econômico em sistemas agroflorestais. O estudo foi realizado no SAF experimental da Universidade Federal do Oeste do Pará (UFOPA). Analisou-se a decomposição foliar de seis espécies, sendo cacau (Theobroma cacao L.), cumaru (Dipteryx odorata (Aubl.) Forsyth) e pimenta-do-reino (Piper nigrum L.) consideradas de interesse econômico e feijão-de-porco (Canavalia ensiformis (L.) DC.), gliricídia (Gliricidia sepium (Jacq.) Walp.) e guandú (Cajanus cajan (L.) Huth) consideradas espécies de adubação verde. Para acompanhar a decomposição, utilizou-se o método de litter bags com o experimento alocado nos períodos mais chuvoso e menos chuvoso. Os dados de massa foliar remanescente foram analisados estatisticamente pelo teste Tukey e ajustados por meio de equação não-linear para obtenção da constante de decomposição (k) e tempo de meia-vida (t1/2). As espécies apontadas para adubação verde apresentaram as maiores de taxas de decomposição ao final do experimento, nas quais a gliricidia e feijão de porco obtiveram as maiores taxas. Dentre as espécies escolhidas por interesse econômico, a pimenta do reino apresentou retorno de nutrientes ao solo superiores as espécies cumaru e cacau. O período seco obteve perda de massa mais lenta que o período chuvoso.

Soil macrofauna in green manures preceding cotton growing

The objective of this work was to evaluate the abundance of the soil macrofauna in four green manure species, before the cotton crop. The experimental design was a randomized block design with four treatments: Mucuna pruriens (gray mucuna), Canavalia ensiformes (pork bean), Cajanus cajan (pigeon pea) and Crotalaria juncea (crotalaria). The macrofauna was captured by means of collections with collections using pitfall traps. The data were processed through the cluster analysis to verify the similarity among green manure species as to the occurrence of soil macrofauna. The orders Orthoptera, Coleoptera L (Larval), Hymenoptera and Coleoptera (adult), respectively, had the highest local relative abundance. There was a significant effect of the cover plants on the taxonomic groups and relative density of the soil macrofauna. Green manures were more determinant in the abundance and relative density of the soil macrofauna than the region climate. Up to 60 days after sowing the cotton crop, there was a beneficial influence of the green manures on the soil macrofauna.

Which spatial arrangement of green manure is able to reduce herbivory and invasion of exotic grasses in native species?

The practice of using green manure for ecological restoration has grown so significantly that there is a shortage of seeds for purchase on the market. Nonetheless, there is very little literature available demonstrating the effects and benefits commonly cited for green manure for addressing important environmental filters, such as herbivory and invasive grasses. Our objective is to determine which spatial sowing arrangement including green manure promotes the lowest rates of herbivory on native species and decreases cover by invasive grasses in ecological restoration. We experimentally tested three sowing configurations of green manure intercropping with native species: T1 the lowest herbivoy rate for both native and green manure, mixture of native and green manure species in the same row, T2, alternating rows of green manure and native species, and T3, rows of native species intercropped with a 2m wide strip of green manure. We found that (1) green manure species experience greater damage from herbivory than do native species, with average values ranging from 1.8 times higher values in green manure than natives in T1, 2.9 times in T2, and 2.7 times in T3 (when sown in rows and in broader strips, green manure and native species attract more herbivorous insects than if they were sown together [muvuca]); and (2) when green manure and native species are planted mixed in the same row they produce greater soil cover, and thus limit invasion by undesired species. The use of green manure has been identified as an alternative method for overcoming the environmental filters of herbivory and invasive grasses in restoration areas. Considering the demand for information that supports the use of green manure for purposes of ecological restoration, the novel results of the present study fill a void and should prove to be of great interest to researchers and practitioners. In addition, the presented results provide information on efficient and low-cost restoration techniques that are necessary for the activity to gain scale, enabling countries to meet the large restoration targets.

Tillage System Comparison in Organic Farming: Effects on N Mineralization, Soil Microbial Biomass, and Yield

The nitrogen supply can be a yield-limiting factor in organic farming, especially when reduced tillage is applied. An organic field experiment was conducted from 2007 to 2013 to analyse the potential of the nitrogen supply through the efficient use of green manure crops in different tillage systems. Three farming systems were compared: a stubble cleaner system (SC) and a plough system (PL), both in a cereal-based crop rotation, and another plough system in a crop rotation that included alfalfa grass ley (PLALF). In the fifth year of the experiment, the experimental design was extended into a split plot design, and seven green manure treatments ( Lolium perenne , Phacelia tanacetifolia , Sinapis alba , a mixture of Sinapis alba and Trifolium resupinatum , Trifolium resupinatum , Vicia sativa , and bare fallow as the control) were integrated into each of the three systems. The effects of the three systems and the green manure treatments on N mineralization, the soil microbial biomass and the yield of the main crops of oats and field beans in the sixth and seventh years of the experiment were analysed. The results showed that the choice of green manure species was of minor importance in the PLALF system. This system generally success- fully supplied N to the oats with oat yields from 3.6 to 5.1 t per ha. Vicia sativa was the most promising green manure crop in the SC and PL systems, with the N min values and oat yields (4.0 and 4.6 t per ha) being similar to those in the PLALF system. In the subsequent year, the PLALF system again was more successful in most of the N min assessments than the PL and SC systems, which often had rather similar results. In addition, a main crop of field beans was able to compensate for the differences in the N min content, and the yields were similar in all three systems (3.1 to 3.7 t per ha). The microbial biomass in the top soil was significantly increased in the reduced tillage system compared to the plough systems. In conclusion, reduced tillage in organic farming can promote soil microorganisms and be competitive if the nitrogen supply is improved through the efficient use of green manure or an adequate leguminous main crop.

Cinza de biomassa é um produto eficiente para uso em sistema de produção de cereais em base agroecológica?

Foi avaliada durante quatro anos, a capacidade da cinza de biomassa (CB) na construção da fertilidade do solo em sistema de produção de cereais em base agroecológica. O delineamento experimental foi em blocos completos casualizados, com seis doses: 0, 2, 4, 6, 8 e 10 Mg ha-1 de CB e três repetições. Após correção do solo e cultivo de um consórcio de adubação verde de verão e de inverno, deu-se início à seguinte sequência de cultivos: milho; ervilhaca; milho; ervilhaca + aveia; milho; aveia; soja; todos sem aplicação de fertilizantes. Após a primeira e a quarta safras, foram coletadas amostras de solo, na camada de 0-0,20 m para análise de atributos de fertilidade. Houve aumento linear dos teores de P e K no solo com a adição da CB, mas, não houve efeito sobre o pH, teores de Ca e Mg e de metais pesados do solo. As produtividades de milho e soja não foram afetadas pela aplicação da CB em nenhum ano. Assim, o uso da CB em sistema agroecológico de produção não apresenta efeitos nocivos ao sistema e é uma fonte segura de K, devido à ausência de fontes não solúveis deste elemento serem uma das limitações para suprimento deste nutriente às culturas.

Effects of long-term green manure application on the content and structure of dissolved organic matter in red paddy soil

Dissolved organic matter (DOM) plays important roles in soil biogeochemistry activity and nutrients transportation in soils, but studies regarding the long-term effects of green manures on the content and structure of DOM in red paddy soil have not been reported yet. A long-term green manure experiment established in 1982 was utilized to test the DOM contents in different treatments, and the spectral characteristics of DOM were investigated by using ultraviolet-visible (UV-Vis) spectrometry and Fourier transform infrared (FTIR) spectrometry. The experiment included four cropping systems: rice-rice-milk vetch (RRV), rice-rice-rape (RRP), rice-rice-ryegrass (RRG) and rice-rice-winter fallow (RRF), among them, milk vetch, rape, and ryegrass are popular winter green manure species in southern China. The results showed that the content of dissolved organic carbon (DOC), which is widely used to estimate the concentration of DOM, was significantly promoted after the incorporation of green manures compared with the other sampling stages. The contents of aromatic groups and the degree of humification of DOM increased in RRV and RRP, suggesting more complex compositions of the soil DOM after long-term application of milk vetch and rape. The contents of phenol, alcohol and carboxylic acid group at the mature stage of early rice were significantly higher than those at the stage of after green manures turned over, especially for the RRV treatment. The absorption ratio of FTIR indicated that winter plantation of rape increased the aromatic-C/aliphatic-C ratio, and ryegrass increased the aromatic-C/carboxyl-C ratio. In conclusion, long-term planting of milk vetch and rape as green manures increased the degree of aromaticity, humification and average molecular weight of DOM, and made the DOM more stable in red paddy soil.

Yield of sweet potato as a function of organic fertilization and intercropping with Crotalaria juncea

In the northern region of Brazil, information for the sweet potato regarding suitable soil management, especially organic fertilisation and intercropping with species of green manure, are still in the early stages. The aim of this research therefore, was to evaluate the effect of poultry litter on the yield of sweet potato roots grown under a monocrop system and when intercropped with sunn hemp (Crotalaria juncea) under the soil and climate conditions of the State of Roraima. The experiment was carried out in the field from August to December of 2014, in the Sector for Olericulture of the School of Agricultural Technology, on the Murupu Campus of UFRR in the town of Boa Vista, Roraima. A randomised block experimental design was used, with three replications, in a (5 × 2) + 1 factorial scheme, representing five doses of poultry litter (0, 5, 10, 15 and 20 t ha-1), with sweet potato as both a monocrop and intercropped with sunn hemp, and one additional treatment with organic and mineral fertiliser. Slips of the Granfina variety of sweet potato were used for planting. Seeds of sunn hemp were sown in double rows between the rows of sweet potato 30 days after planting the slips, with the first cutting carried out 90 days after sowing. The addition of poultry litter to the soil increased the total production of sweet potato roots for the crop planted in Roraima, whether intercropped or not with sunn hemp. Despite the benefits to sweet-potato yield from the addition of poultry litter and the intercrop with sunn hemp, total productivity was greater in the additional treatment that received organic and mineral fertiliser.

Decomposition and nitrogen mineralization from green manures intercropped with coffee tree

The knowledge about the rate of decomposition and nitrogen mineralization of green manures provides synchronization with the higher absorption stage by the coffee tree. The rate of decomposition and nitrogen mineralization varies according to the species of green manure and with the environmental factors. The aim of the present study was to evaluate the decomposition and nitrogen mineralization of two green manures intercropped with coffee trees for three different periods. The experiment was divided into two designs for statistical analysis, one referring to the characterization of plant material (fresh mass, dry matter, dry matter content, nitrogen concentration and accumulation in the jack bean (Canavalia ensiformis) and hyacinth bean (Dolichos lablab) and another to evaluate the rate of decomposition and N mineralization of these species. The decomposition rate decreased in both species as their growth time increased in the field. The decomposition was influenced by the phenology of green manures. Nitrogen mineralization of the jack bean decreased as the growth period in the field increased and was faster than hyacinth bean only when cut at 60 days. The N mineralization was slower than mass decomposition in both species.

Pentachlorophenol dissipation and ferrous iron accumulation in flooded paddy soils with contrasting organic matter contents and incorporation of legume green manures

The effects of different amendment rates (1 and 3%) of Chinese milk vetch (Astragalus sinicus L.) and bird vetch (Vicia cracca L.) on the dissipation of extractable pentachlorophenol (PCP) residues were investigated in two flooded paddy soils with contrasting soil organic matter (SOM) contents. Following incorporation of the legume green manures, whether acetate-extractable ferrous iron [Fe(II)NaOAc] is useful for revealing the reductive dechlorination mechanism of PCP in flooded paddy soils was verified. The kinetic parameters of PCP dissipation and Fe(II)NaOAc accumulation were estimated using logistic curve fitting. Correlation and regression analyses were performed on PCP, Fe(II)NaOAc, water-soluble organic carbon (WSOC), pH, and oxidation-reduction potential data. The kinetic parameters of PCP dissipation and Fe(II)NaOAc accumulation varied significantly with the amendment rate of legume green manure. The changes in pH value and WSOC content varied significantly with the level of SOM and with the amendment rate of legume green manure. At a low amendment rate of green manure, the pH increase and WSOC consumption greatly enhanced Fe(II)NaOAc accumulation and contributed to PCP dissipation. The rate of PCP dissipation decreased with decreasing pH and WSOC accumulation, especially in the high-SOM soil amended with the higher rate of green manure. Legume green manure species had no effect on PCP dissipation. In terms of soil chemistry, Fe(II)NaOAc was found to be the key variable that could explain the mechanisms involved in the reductive dissipation of PCP in flooded paddy soils with contrasting SOM contents and incorporation of legume green manures.

Green manure affects cut flower yield and quality of ‘Vegas’ rose bushes

Rose cultivation requires many inputs for satisfactory production, making the process expensive. Nowadays, alternative practices have been used for sustainable crop production. Green manure is an agricultural practice that aims to maintain or improve soil fertility, increasing its yielding capacity. The objective of this research was to evaluate the effect of green manure with legumes on the yield and quality of ‘Vegas’ roses. Grafted rose seedlings were cultivated in open field for 30 months. Legumes used as green manure and planted intercropped with rose bushes were forage peanut (Arachis pintoi) and jack bean (Canavalia ensiformis). Pigeon pea (Cajanus cajan) was grown in a separate area, cut, macerated, and applied in the rows between rose bushes every 3 months. Plants of control group received no green manure, only mineral fertilizer and cattle manure, as in all other treatments. The experimental design was randomized block with four treatments (three green manure species plus the control) and seven replications. The highest yield and quality of flower stems in ‘Vegas’ occurred with addition of pigeon pea on the soil surface or chemically treated (control). Forage peanut and jack bean are not suitable for intercropping with ‘Vegas’ rose bushes due to possible nutrient and water competition.

Macronutrients release by green manure species grown in cerrado/pantanal ecotone

Macronutrients release by green manure species grown in cerrado/pantanal ecotone

REGENERAÇÃO NATURAL DE ESPÉCIES EM UMA ÁREA DEGRADADA SOB PROCESSO DE REABILITAÇÃO

This study was conducted in an area degraded by the construction of Hydroelectric of Ilha Solteira, SP, Brazil, being in rehabilitation process for 15 years. During this period were implemented green manure species and currently being planted with Brachiaria decumbens Stapf. This work objetive to make the phytosociological survey of tree species that arose spontaneously in this area in the rehabilitation process. The phytosociological sampling included 28 plots with dimension of 10x10m. In each plot a survey of existing species. Parameters were also obtained phytosociological species. The phytosociological survey sampled 88 plants and the species Machaerium acutifolium Vogel greater sociological importance, showing higher density, frequency, dominance, and index value of coverage. Overall, the study area had low diversity because of the 88 plants sampled, 85 belonged to the species Machaerium acutifolium Vogel. Measures taken for rehabilitation of the area studied in begin of the process favored the natural regeneration of these species. The low average plant height, the predominance of small stem diameters, and low tree diversity, indicating that the area is in an early successional stage.