Variations in soil physico-chemical properties, soil stocks, and soil stoichiometry under different soil layers, the major forest region Liupan Mountains of Northwest China / Variações nas propriedades físico-químicas do solo, estoques e estequiometria do solo sob diferentes camadas de solo, a principal região florestal das montanhas Liupan do noroeste da China

Liupan Mountains are an important region in China in the context of forest cover and vegetation due to huge afforestation and plantation practices, which brought changes in soil physio-chemical properties, soil stocks, and soil stoichiometries are rarely been understood. The study aims to explore the distribution of soil nutrients at 1-m soil depth in the plantation forest region. The soil samples at five depth increments (0-20, 20-40, 40-60, 60-80, and 80-100 cm) were collected and analyzed for different soil physio-chemical characteristics. The results showed a significant variation in soil bulk density (BD), soil porosity, pH, cation exchange capacity (CEC), and electric conductivity (EC) values. More soil BD (1.41 g cm-3) and pH (6.97) were noticed in the deep soil layer (80-100 cm), while the highest values of porosity (60.6%), EC (0.09 mS cm-1), and CEC (32.9 c mol kg-1) were reflected in the uppermost soil layer (0-20 cm). Similarly, the highest contents of soil organic carbon (SOC), total phosphorus (TP), available phosphorus (AP), total nitrogen (TN), and available potassium (AK) were calculated in the surface soil layer (0-20 cm). With increasing soil depth increment a decreasing trend in the SOC and other nutrient concentration were found, whereas the soil total potassium (TK) produced a negative correlation with soil layer depth. The entire results produced the distribution of SOCs and TNs (stocks) at various soil depths in forestland patterns were 0→20cm > 20→40cm > 40→60cm ≥ 60→80cm ≥ 80→100 cm. Furthermore, the stoichiometric ratios of C, N, and P, the C/P, and N/P ratios showed maximum values (66.49 and 5.46) in 0-20 cm and lowest values (23.78 and 1.91) in 80-100 cm soil layer depth. Though the C/N ratio was statistically similar across the whole soil profile (0-100 cm). These results highlighted that the soil depth increments might largely be attributed to fluctuations in soil physio-chemical properties, soil stocks, and soil stoichiometries. Further study is needed to draw more conclusions on nutrient dynamics, soil stocks, and soil stoichiometry in these forests.

As montanhas de Liupan são uma região importante na China no contexto de cobertura florestal e vegetação devido às enormes práticas de florestamento e plantação, que trouxeram mudanças nas propriedades físico-químicas do solo, e estoques e estequiometrias do solo raramente são compreendidos. O estudo visa explorar a distribuição de nutrientes do solo a 1 m de profundidade do solo na região da floresta plantada. As amostras de solo em cinco incrementos de profundidade (0-20, 20-40, 40-60, 60-80 e 80-100 cm) foram coletadas e analisadas para diferentes características físico-químicas do solo. Os resultados mostraram uma variação significativa nos valores de densidade do solo (BD), porosidade do solo, pH, capacidade de troca catiônica (CEC) e condutividade elétrica (CE). Mais DB do solo (1,41 g cm-3) e pH (6,97) do solo foram observados na camada profunda do solo (80-100 cm), enquanto os maiores valores de porosidade (60,6%), CE (0,09 mS cm-1) e CEC (32,9 c mol kg-1) foram refletidos na camada superior do solo (0-20 cm). Da mesma forma, os maiores teores de carbono orgânico do solo (SOC), fósforo total (TP), fósforo disponível (AP), nitrogênio total (TN) e potássio disponível (AK) foram calculados na camada superficial do solo (0-20 cm). Com o aumento do incremento da profundidade do solo, uma tendência decrescente no SOC e na concentração de outros nutrientes foi encontrada, enquanto o potássio total do solo (TK) produziu uma correlação negativa com a profundidade da camada do solo. Todos os resultados produziram a distribuição de SOCs e TNs (estoques) em várias profundidades de solo em padrões de floresta 0 → 20cm> 20 → 40cm> 40 → 60cm ≥ 60 → 80cm ≥ 80 → 100 cm. Além disso, as relações estequiométricas de C, N e P, as relações C / P e N / P, apresentaram valores máximos (66,49 e 5,46) em 0-20 cm, e valores mais baixos (23,78 e 1,91) em solo de 80-100 cm profundidade da camada. Embora a relação C / N fosse estatisticamente semelhante em todo o perfil do solo (0-100 cm). Esses resultados destacaram que os incrementos de profundidade do solo podem ser amplamente atribuídos a flutuações nas propriedades físico-químicas do solo, estoques e estequiometrias do solo. Mais estudos são necessários para tirar conclusões adicionais sobre a dinâmica dos nutrientes, estoques de solo e estequiometria do solo nessas florestas.

Effect of a Compound Microbial Fertilizer on Growth， Quality， and Soil Properties of Andrographis paniculata / 中国实验方剂学杂志

ObjectiveTo study the effect of a microbial compound fertilizer on the growth， quality， and soil properties of Andrographis paniculata and provide a basis for its application in the cultivation and production of A. paniculata. MethodThrough five treatment tests in pots， the control group （CK， no fertilization）， the treatment A group （chemical fertilization）， the treatment B group （microbial fertilization at 2.5 g·kg-1 soil）， the treatment C group （microbial fertilization at 7.5 g·kg-1 soil）， and the treatment D group （microbial fertilization at 12.5 g·kg-1 soil） were established. The effects of a compound microbial fertilizer on the agronomic properties， the content of active ingredients， the number of rhizosphere soil bacteria， Actinomycetes， and fungi， and soil physicochemical properties of A. paniculata were studied. ResultAs compared with the CK group and the treatment A group， the plant height， leaf number， leaf area， and above-ground and below-ground fresh weight of A. paniculata were significantly increased after microbial fertilization， with differences in different growth periods. The effect of the compound microbial fertilizer on the content of andrographolide， dehydrated andrographolide， neandrographolide， and 14-deoxyandrographolide differed. The content of andrographolide significantly increased by 26.13% and 13.23% in the treatment C group， respectively， as compared with the CK group and the treatment A group （P<0.05）. The content of neandrographolide increased with the increasing amount of microbial fertilizer， and the content in the treatment D group increased by 9.06% and 50.33%， respectively， as compared with the CK group and the treatment A group （P<0.05）， which was the most obvious. The content of 14-deoxyandrographolide in the treatment B group significantly increased by 42.04% and 1.74%， respectively， as compared with the treatment A group and the CK group （P<0.05）. The content of dehydrated andrographolide content in the treatment B group increased most significantly， significantly increasing by 11.73% and 27.74%， respectively， as compared with the CK group and the treatment A group （P<0.05）. The soil pH of the treatment B， C， and D groups was higher than that of the CK group and the treatment A group. The content of total nitrogen and effective phosphorus increased most significantly in the treatment B group， and the content of fast-acting potassium increased most significantly in the treatment D group. The application of the compound microbial fertilizer increased the number of rhizosphere soil bacteria and Actinomycetes， which was significantly higher than that in the CK group and the treatment A group （P<0.05）， and increased with the increase of applied amount. The number of fungi decreased with the increase of the compound microbial fertilizer application， which was significantly different from that in the CK group （P<0.05）. The fungi/bacteria of all treatment groups were significantly lower than those of the CK group （P<0.05） and increased with the increase of microbial fertilizer application. ConclusionThe application of the compound microbial fertilizer transforms the plant-soil-microbial system in a benign direction， which is beneficial to the growth of A. paniculata and the accumulation of active ingredients.

Spatial variability of soil fertility under agroforestry system and native forest in eastern Amazonia, Brazil

The usage of spatial tools might be helpful in the optimization of decision-making regarding soil management, with technologies that assist in the interpretation of information related to soil fertility. Therefore, the present study evaluated the spatial variability of chemical attributes of the soil under an agroforestry system compared to a native forest in the municipality of Tomé-açu, Eastern Amazon, Brazil. Soil samples were performed at 36 points arranged in a 55 x 55 m grid. The soils were prepared and submitted to analysis in order to determine pH in H2O, exchangeable calcium, magnesium, potassium and aluminium, available phosphorus, potential acidity, organic matter, bases saturation and aluminium saturation. For each soil attribute, the spherical, gaussian and exponential models were adjusted. After the semivariograms fitting, data interpolation for assessment of spatial variability of the variables was performed through ordinary kriging. The spherical and gaussian models were the most efficient models in estimation of soil attributes spatial variability, in most cases. Most of variables presented a regular spatial variability in their respective kriging maps, with some exceptions. In general, the kriging maps can be used, and we can take them as logistical maps for management and intervention practices in order to improve the soil fertility in the study areas. The results principal components indicate the need for integrated management of soil chemical attributes, with localized application of acidity correctors, fertilizers and other types of incomes, using the spatial variability of these fertility variables.

Nest refuse of Acromyrmex balzani (Hymenoptera: Formicidae) increases the plant vigor in Turnera subulata (Turneraceae) / O substrato de descarte de Acromyrmex balzani (Hymenoptera: Formicidae) aumenta o vigor da planta Turnera subulata (Turneraceae)

Abstract Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p < 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.

Resumo Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p < 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.

Amazonian soil fungi are efficient degraders of glyphosate herbicide; novel isolates of Penicillium, Aspergillus, and Trichoderma / Os fungos do solo amazônico são degradadores eficientes do herbicida glifosato; novos isolados de Penicillium, Aspergillus e Trichoderma

Abstract Pesticide residues that contaminate the environment circulate within the hydrological cycle can accumulate within the food chain and cause problems to both environmental and human health. Microbes, however, are well known for their metabolic versatility and the ability to degrade chemically stable substances, including recalcitrant xenobiotics. The current study focused on bio-prospecting within Amazonian rainforest soils to find novel strains fungi capable of efficiently degrading the agriculturally and environmentally ubiquitous herbicide, glyphosate. Of 50 fungal strains isolated (using culture media supplemented with glyphosate as the sole carbon-substrate), the majority were Penicillium strains (60%) and the others were Aspergillus and Trichoderma strains (26 and 8%, respectively). All 50 fungal isolates could use glyphosate as a phosphorous source. Eight of these isolates grew better on glyphosate-supplemented media than on regular Czapek Dox medium. LC-MS revealed that glyphosate degradation by Penicillium 4A21 resulted in sarcosine and aminomethylphosphonic acid.

Resumo Resíduos de agrotóxicos que contaminam o meio ambiente circulam no ciclo hidrológico, podendo se acumular na cadeia alimentar e causar problemas tanto à saúde ambiental quanto humana. Por sua vez, microrganismos são bem conhecidos por sua versatilidade metabólica e capacidade de degradar substâncias quimicamente estáveis, incluindo xenobióticos recalcitrantes. O estudo atual se concentrou na bioprospecção nos solos da floresta amazônica para encontrar novas linhagens de fungos capazes de degradar com eficiência o herbicida onipresente na agricultura e no meio ambiente, o glifosato. Entre os 50 fungos isolados (usando meio de cultura suplementado com glifosato como única fonte de carbono), a maioria eram isolados do gênero Penicillium (60%) e os outros eram isolados de Aspergillus e Trichoderma (26 e 8%, respectivamente). Todos os 50 isolados de fungos foram capazes de usar glifosato como fonte de fósforo. Oito desses isolados cresceram melhor em meio suplementado com glifosato do que em meio Czapek Dox regular. LC-MS revelou que a degradação do glifosato por Penicillium 4A21 resultou nos metabólitos sarcosina e ácido aminometilfosfônico.

The impact of cow dung augmentation on soil restoration and bio-accumulation of metals (Lead and Cadmium) in Pheretima posthuma (Annelida: Clitellata) / O impacto do aumento de esterco de vaca na restauração do solo e bioacumulação de metais (chumbo e cádmio) em Pheretima posthuma (Annelida: Clitellata)

Abstract To investigate the role of cow dung in soil reclamation and bio assimilation along with bio accumulation of heavy metals in earthworm (P. posthuma) (N=900) earthworms were used and treatment groups of CD-soil mixture of different proportion of cow dung were designed. Nonlethal doses of lead acetate and cadmium chloride were added in treatment groups. Mature P. posthuma were released in each experimental pot maintaining the favorable conditions. The pH, carbon, nitrogen, phosphorus, exchangeable cations, and heavy metal level of each mixture was evaluated. The results indicated that bio-assimilation of Pb and Cd by P. posthuma were significantly (P ˂ 0.01) higher in different soil-CD treatments compared to control. Highest bio-assimilation of both metals was observed in T1 of both groups (Pb = 563.8 mg/kg and Cd = 42.95 mg/kg). The contents of both metals were significantly (P ˂ 0.05) lowered in casting. The nutrient concentration in the final castings of all soil-CD treatments were also equally transformed from less or insoluble to more soluble and available for plants, except for carbon level which increased with CD proportion. It is concluded that cow dung as organic matter has a positive effect on soil reclamation and bio-assimilation of metals by P. posthuma.

RESUMO Para investigar o papel do esterco de vaca na recuperação do solo e bioassimilação, juntamente com a bioacumulação de metais pesados ​​em minhocas (P. posthuma) (N = 900), minhocas foram usadas e grupos de tratamento de mistura CD-solo de diferentes proporções de esterco de vaca foram projetados. Doses não letais de acetato de chumbo e cloreto de cádmio foram adicionadas aos grupos de tratamento. P. posthuma maduros foram liberados em cada vaso experimental, mantendo as condições favoráveis. Foram avaliados o pH, carbono, nitrogênio, fósforo, cátions trocáveis ​​e nível de metais pesados ​​de cada mistura. Os resultados indicaram que a bioassimilação de Pb e Cd por P. posthuma foi significativamente (P ˂ 0,01) maior em diferentes tratamentos de solo-CD em relação ao controle. A maior bioassimilação de ambos os metais foi observada em T1 de ambos os grupos (Pb = 563,8 mg / kg e Cd = 42,95 mg / kg). O conteúdo de ambos os metais foi significativamente (P ˂ 0,05) reduzido na fundição. A concentração de nutrientes nas fundições finais de todos os tratamentos de solo-CD também foi igualmente transformada de menos ou insolúvel para mais solúvel e disponível para as plantas, exceto o nível de carbono que aumenta com a proporção de CD. Conclui-se que o esterco de vaca como matéria orgânica tem um efeito positivo na recuperação do solo e na bioassimilação de metais por P. posthuma.

Detection of microorganisms with antibacterial activities from different industrial wastes and GC-MS analysis of crude microbial extract / Detecção de microrganismos com atividades antibacterianas de diferentes resíduos industriais e análise por GC-MS do extrato microbiano bruto

Abstract Many soil microorganisms' i.e., bacteria and fungi produce secondary metabolites called antibiotics. These are used for the treatment of some of the bacterial, fungal and protozoal diseases of humans. There is a need for isolation of a broad spectrum of antibiotics from microorganisms due to the emergence of antibiotic resistance. In the present study two antibiotic producing bacteria Klebsiella pneumoniae and Bacillus cereus were isolated from pharmaceutical and poultry feed industry of Hattar, Haripur Pakistan. Total 10 waste samples were collected from different industries (Marble, Ghee, Soap, Mineral, Steel, Poultry Feed, Pharmaceutical, Qarshi, Cosmetic and Glass). Thirty-three bacterial strains were isolated from industrial wastes of these ten different industries. Fourteen out of thirty-three bacterial strains exhibited antimicrobial activities against at least one of the test microbes considered in this study including Escherchia coli, Staphylococcus aureus and Salmonella typhi. The bacteria were isolated by standard serial dilution spread plate technique. Morphological characterization of the isolates was done by Gram staining. Nine bacterial isolates out of fourteen were initially identified as B. cereus and five as K. pneumoniae through biochemical characterization. The antibacterial activities were tested by well diffusion method. Maximum number of antibiotic producing bacteria were isolated from pharmaceutical and poultry feed industry based on the results of primary screening, the most potential isolates S9, S19, S20, S22 and S23 were selected for secondary screening. The maximum activity against E. coli and S. aureus was recorded by bacterial isolate S19 i.e zones of inhibition of 6.5mm and 9mm while S20 showed 7.5mm and 6mm zones respectively. Molecular identification was carried out on the basis of 16S rRNA sequence analysis. Finally, the isolates were identified as B. cereus accession number LC538271and K. pneumoniae accession number MT078679. Analysis of bacterial extract S20 through GC-MS indicated the presence of 8 compounds of diverse nature and structure. Present study suggests that wastes of pharmaceutical and poultry feed industry may have antibiotic producing bacteria. These bacteria could be utilized for the production of antibiotics. B. cereus and K. pneumoniae isolated from wastes of poultry feed and pharmaceutical industries have the potential to produce antibiotics and could be used to control the microbial growth.

Resumo Muitos microrganismos do solo, ou seja, bactérias e fungos produzem metabólitos secundários chamados antibióticos. Eles são usados ​​para tratamento de algumas doenças bacterianas, fúngicas e protozoárias em humanos. Há necessidade de isolamento de um amplo espectro de antibióticos de microrganismos devido ao surgimento de resistência aos antibióticos. No presente estudo, duas bactérias produtoras de antibióticos, Klebsiella pneumoniae e Bacillus cereus, foram isoladas da indústria farmacêutica e de ração avícola de Hattar, Haripur, Paquistão. Um total de 10 amostras de resíduos foi coletado de diferentes indústrias (mármore, ghee, sabão, mineral, aço, ração para aves, farmacêutica, Qarshi, cosmética e vidro). Trinta e três cepas bacterianas foram isoladas de resíduos industriais dessas dez diferentes indústrias. Quatorze das 33 cepas bacterianas exibiram atividades antimicrobianas contra pelo menos um dos micróbios de teste considerados neste estudo, incluindo Escherchia coli, Staphylococcus aureus e Salmonella typhi. As bactérias foram isoladas pela técnica de placa de diluição em série padrão. A caracterização morfológica dos isolados foi feita por coloração de gram. Nove isolados bacterianos de 14 foram inicialmente identificados como B. cereus e cinco como K. pneumoniae por meio de caracterização bioquímica. As atividades antibacterianas foram testadas pelo método de difusão em poço. O número máximo de bactérias produtoras de antibióticos foi isolado da indústria farmacêutica e de ração avícola com base nos resultados da triagem primária, os isolados mais potenciais S9, S19, S20, S22 e S23 foram selecionados para a triagem secundária. A atividade máxima contra E. coli e S. aureus foi registrada pelo isolado bacteriano S19, ou seja, zonas de inibição de 6,5 mm e 9 mm, enquanto S20 mostrou zonas de 7,5 mm e 6 mm, respectivamente. A identificação molecular foi realizada com base na análise da sequência 16S rRNA. Finalmente, os isolados foram identificados como B. cereus número de acesso LC538271 e K. pneumoniae número de acesso MT078679. A análise do extrato bacteriano S20 por meio de GC-MS indicou a presença de oito compostos de natureza e estrutura diversas. O presente estudo sugere que resíduos da indústria farmacêutica e de ração para aves podem conter bactérias produtoras de antibióticos. Essas bactérias podem ser utilizadas para a produção de antibióticos B. cereus e K. pneumoniae isolados de resíduos de rações de aves e indústrias farmacêuticas têm potencial para produzir antibióticos e podem ser usados ​​para controlar o crescimento microbiano.

Soil insects associated with sugarcane crop in Mato Grosso do Sul, Brazil / Insetos de solo associados à cultura de cana-de-açúcar em Mato Grosso do Sul, Brasil

Pest insects are one of the major factors affecting the productivity of sugarcane, and especially those associated with the soil, which damage the crop if not controlled. There is little information on the insect associated with the soil in the sugarcane crop in the state of Mato Grosso do Sul, Brazil. This study evaluated the occurrence, abundance and population variation of soil-associated insects in sugarcane crops in four counties in the state of Mato Grosso do Sul during a period from September 2009 to August 2010. For the capture of insects, deep in the soil trenches were (50 x 50 x 30 width x length x depth). It was observed that county of Maracaju has a high incidence of soil insects in sugarcane crop. Specimens of the family Scarabaeidae are abundant in sugarcane fields of the state of Mato Grosso do Sul, being Liogenys suturalis the predominant species. Soil insects of the Chrysomelidae family were found with greater abundance in Dourados and Naviraí while Noctuidae, represented only by the Hyponeuma taltula, occurred mainly in Dourados. Insects of the family Termitidae occur in sugarcane fields in the counties of Maracaju and Naviraí but not in Nova Alvorada do Sul and Dourados. Sphenophorus levis and Metamasius hemipterus were alsoreported in the sugarcane fields from Maracaju, being the occurrence these species the first record in the Mato Grosso do Sul State. The determined occurrence of different soil insects in the sugarcane fields may help in their management in the four counties studied.

Os insetos-praga são um dos principais fatores que afetam a produtividade da cana-de-açúcar e, principalmente, aqueles associados ao solo, que prejudicam a cultura se não forem controlados. Existem poucas informações sobre a fauna de insetos associada ao solo na cultura da cana-de-açúcar no estado de Mato Grosso do Sul (MS), Brasil. O objetivo deste estudo foi avaliar a ocorrência, abundância e variação populacional de insetos associados ao solo em lavouras de cana-de-açúcar em quatro municípios do estado de Mato Grosso do Sul durante o período de setembro de 2009 a agosto de 2010. Para a captura de insetos, foram feitas trincheiras (50 cm x 50 cm x 30 cm - largura x comprimento x profundidade) no solo. Observou-se que o município de Maracaju apresenta alta incidência de insetos de solo na cultura da cana-de-açúcar. Exemplares da família Scarabaeidae são abundantes nos canaviais do MS, sendo Liogenys suturalis a espécie predominante. Insetos de solo da família Chrysomelidae foram encontrados com maior abundância em Dourados e Naviraí enquanto Noctuidae, representado apenas por Hyponeuma taltula, ocorreu principalmente em Dourados. Insetos da família Termitidae ocorrem em canaviais nos municípios de Maracaju e Naviraí, mas não em Nova Alvorada do Sul e Dourados. Sphenophorus levis e Metamasius hemipterus (Coleoptera: Curculionidae) também foram encontrados nos canaviais de Maracaju, sendo a ocorrência dessas espécies o primeiro registro no MS. A ocorrência determinada de diferentes insetos de solo nos canaviais auxiliará o manejo nos quatro municípios estudados.

Efecto de prácticas agroecológicas en la conservación del suelo de la Zona de Reserva Campesina de San Isidro, Pr dera, Valle del Cauca / Effect of agroecological practices on soil conservation of the San Isidro Peasant Reserve Zone / Efeito das práticas agroecológicas na conservação do solo na Zona de Reserva Camponesa de San Isidro, Pradera, Valle del Cauca

RESUMEN La biodiversidad del suelo está amenazada por cambios antropogénicos mundiales, como la intensifìcación del uso del suelo, la deforestación y fenômenos climáticos extremos. En esta investigación se identificó el estado de indicadores de respuesta biológica del suelo al manejo agroecológico de los sistemas de producción de Zona de Reserva Campesina de San Isidro, municipio de Pradera, Valle del Cauca, Colombia. Se tomaron muestras de la capa superior del suelo en multiples sitios de cada sistema productivo. Se realizó análisis de textura del suelo, análisis de atributos químicos (pH, M.O., FF K, Ca, Mg, Na, Fe, Mn, Cu, Zn y B), cuantificación microbiana y de mesofauna, y se analizaron indicadores de manejo agroecológico en cada uno de los 15 agroecosistemas. Se encontró que prevalece una labranza conservacionista y que entre las propiedades químicas del suelo que pueden mejorarse está el pH y que se debe fortalecer el manejo de materia orgánica. Se concluye que el actual manejo agroecológico realizado por la comunidad requiere incorporación de materia orgánica teniendo en cuenta la textura del suelo de cada agroecosistema para mejorar condiciones relacionadas con aireación, humedad y erosión del suelo. Se evidenciaron resultados promisorios en indicadores biológicos del suelo; sin embargo, se requieren esfuerzos adicionales para fortalecer su potencial ya que muchas propiedades evaluadas son el reflejo de multiples procesos, por lo tanto, es necesario establecer vínculos directos entre la biodiversidad del suelo y la producción de cultivos para implementar las prácticas de gestión.

ABSTRACT Soil biodiversity is threatened by global anthropogenic changes, such as intensification of land use, deforestation and extreme climatic events. This research identified the status of indicators of soil biological response to agroecological management of production systems in the San Isidro Peasant Reserve Zone, municipality of Pradera, Valle del Cauca, Colombia. Topsoil samples were taken from multiple sites in each production system. Soil texture analysis, chemical attribute analysis (pH, M.O., FF K, Ca, Mg, Na, Fe, Mn, Cu, Zn and B), microbial and mesofauna quantification, and agroecological management indicators were analyzed in each of the 15 agroecosystems. It was found that conservation tillage prevails and that among the soil chemical properties that can be improved is pH and that organic matter management should be strengthened. It was concluded that the current agroecological management carried out by the community requires the incorporation of organic matter taking into account the soil texture of each agroecosystem to improve conditions related to soil aeration, humidity and erosion. Promising results were evidenced in soil biological indicators; however, additional efforts are required to strengthen their potential since many properties evaluated are the reflection of multiple processes, therefore, it is necessary to establish direct links between soil biodiversity and crop production in order to implement management practices.

RESUMO A biodiversidade do solo é ameaçada por mudanças antropogénicas globais, tais como intensificação do uso da terra, desmatamento e eventos climáticos extremos. Esta pesquisa identificou o status dos indicadores de resposta biológica do solo ao manejo agroecológico dos sistemas de produção na Zona de Reserva Camponesa de San Isidro, município de Pradera, Valle del Cauca, Colômbia. Amostras de solo superior foram coletadas de multiplos locais em cada sistema de produção. Análise da textura do solo, análise de atributos químicos (pH, M.O., FF K, Ca, Mg, Na, Fe, Mn, Cu, Zn e B), quantificação microbiana e mesofauna, e indicadores de manejo agroecológico foram analisados em cada um dos 15 agroecossistemas. Constatou-se que a lavoura de conservação prevalece e que entre as propriedades químicas do solo que podem ser melhoradas está o pH e que o manejo da matéria orgânica deve ser reforçado. Conclui-se que o atual manejo agroecológico realizado pela comunidade requer a incorporação de matéria orgânica, levando em conta a textura do solo de cada agroecossistema para melhorar as condições relacionadas à aeração, umidade e erosão do solo. Resultados promissores foram evidenciados nos indicadores biológicos do solo; entretanto, esforços adicionais são necessários para fortalecer seu potencial, já que muitas propriedades avaliadas são um reflexo de múltiplos processos, portanto, é necessário estabelecer vínculos diretos entre a biodiversidade do solo e a produção de culturas para implementar práticas de gestão.

Antagonist activities and phylogenetic relationships of actinomycetes isolated from an Artemisia habitat / Actividades antagónicas y relaciones filogenéticas de actinomicetos aislados de un hábitat de Artemisia

Abstract Diverse habitats have been screened for novel antimicrobial actinomycetes, while others remain unexplored. In this study, we analyzed the bioactivities of actinomycetes cul-tured from rhizosphere soils of the desert plant Artemisia tridentata and the nearby bulk soils. Actinomycetes were screened for antifungal and antibacterial activities toward a panel of plant pathogens; all comparisons were between activities of rhizosphere soil isolates toward those of its counterpart bulk soil. A selected group of the strongest antifungal isolates were also tested against two antifungal-drug resistant strains of Candida albicans. 16S rDNA partial sequences and phylogenetic analysis of isolates that showed broad-spectrum antifungal activities were performed. Forty-two out of 200 and two soil isolated actinomycetes were selected for their strong antifungal activities. The highest proportion of isolates (p <0.05) from rhizosphere soil of an old plant showed antagonism against gram-positive bacteria (0.483 and 0.224 propor-tions against Bacillus subtilis and Rathayibacter tritici, respectively), and phytopathogenic fungi (0.259, 0.431, and 0.345 proportions against Fusarium oxysporum, Rhizoctonia solani and Pythium ultimum, respectively), while the highest antagonism against the gram-negative bacteria predominated in isolates from the bulk soils. Isolates from a rhizosphere soil of a young plant were characterized for strong antagonist activities against Fusarium oxysporum (0.333 proportion, p<0.05). Phylogenetic analysis of 16S rDNA sequences showed that isolates that exhibited strong antifungal activity were genetically similar. We conclude that the rhizosphere soil of A. tridentata is an excellent source for discovery of actinomycetes with potentially novel antifungal compounds.

Resumen En la búsqueda de actinomicetos antimicrobianos se han estudiado diversos hábitats, pero muchos permanecen aún sin explorar. En este estudio analizamos las actividades biológicas de cultivos de actinomicetos provenientes de suelos rizosféricos de la planta desértica Artemisia tridentata y de suelos no asociados a sus raíces. Los actinomicetos fueron seleccionados por sus actividades antifúngicas y antibacterianas contra un panel de patógenos de plantas. Todas las comparaciones fueron entre las actividades de los aislados rizosféricos y aquellas de los aislados no asociados a las raíces. Un grupo selecto de los aislados con las mayores actividades antifúngicas fueron también evaluados contra 2 cepas de Candida albicans resistentes a antifúngicos. Se realizó la secuenciación parcial del ARNr 16S y el análisis filogenético de los aislados que mostraron actividades antifúngicas de amplio espectro. Se seleccionaron 42 de 202 actinomicetos aislados por sus fuertes actividades antifúngicas. La mayor proporción de aislados de suelo rizosférico de plantas viejas mostraron antagonismo contra bacterias gram positivas y hongos fitopatógenos (proporciones de 0,259; 0,431 y 0,345 contra Fusarium oxyspo-rum, Rhizoctonia solani y Pythium ultimum, respectivamente), mientras que la mayor actividad antagónica contra las bacterias gram negativas predominaron en aislados de suelo no asociado a raíces. Los aislados de suelo rizosférico de plantas jóvenes se caracterizaron por una fuerte actividad antagónica contra F. oxysporum (proporción de 0,333, p < 0,05). El análisis filogenético de secuencias del ADNr 16S mostró que los aislados que presentaron fuerte actividad antifúng-ica fueron genéticamente similares. Concluimos que el suelo rizosférico de A. tridentata es una fuente excelente para el descubrimiento de actinomicetos productores de compuestos antifúngicos potencialmente novedosos.

Efecto de la cobertura vegetal en escarabajos coprófagos (Coleoptera: Scarabaeinae) y sus funciones ecológicas en un bosque andino de Colombia / Effect of vegetation cover on dung beetles (Coleoptera: Scarabaeinae) and their ecological functions in an Andean forest of Colombia

Resumen Introducción: Los escarabajos coprófagos cumplen funciones importantes en los ecosistemas terrestres, pero las presiones antrópicas los afectan negativamente. Estos efectos están bien documentados en los bosques neotropicales de tierras bajas, pero se han estudiado poco en los bosques andinos. Objetivo: Evaluar cómo los atributos de los ensambles de escarabajos coprófagos y tres de sus funciones ecológicas difieren en tres tipos de cobertura vegetal, y determinar las relaciones entre atributos y funciones, y entre funciones. Métodos: Los escarabajos coprófagos se capturaron con trampas pitfall y se midieron las funciones ecológicas a través de un experimento de campo en la hacienda "El Ocaso" (Colombia), en tres tipos de cobertura vegetal: bosque secundario, bosque mixto y pastos para ganado (tres sitios independientes por cobertura). Los atributos del ensamble que se evaluaron fueron: abundancia, número de especies, biomasa y longitud corporal media ponderada; las funciones medidas fueron: remoción de estiércol, excavación del suelo y dispersión secundaria de semillas. Resultados: Se encontró que tanto los atributos del ensamble como las funciones ecológicas se vieron afectados negativamente en las coberturas vegetales más alteradas, particularmente en los pastos ganaderos. La mayoría de los atributos de ensamblaje se correlacionaron positivamente con las funciones; la excavación del suelo y la dispersión secundaria de semillas tuvieron una fuerte correlación positiva con la remoción de estiércol. Conclusiones: Los ensambles de escarabajos coprófagos juegan importantes funciones ecológicas y son sensibles a las alteraciones del ecosistema. Este estudio muestra cómo los escarabajos coprófagos y sus funciones se ven afectados negativamente cuando el bosque se transforma en pastizales para ganado en los ecosistemas forestales andinos poco estudiados y altamente fragmentados.

Abstract Introduction: Dung beetles perform important functions in terrestrial ecosystems, but anthropic pressures affect them negatively. These effects are well documented in neotropical lowland forests but have been studied little in Andean forests. Objective: To evaluate how the attributes of the dung beetle assemblages and three of their ecological functions differ in three types of vegetation cover, and to determine the relationships between attributes and functions, and among functions. Methods: Dung beetles were captured with pitfall traps, and ecological functions were measured through a field experiment in the farm "El Ocaso" (Colombia), in three types of vegetation cover: secondary forest, mixed forest and cattle pasture (three independent sites per cover). The assemblage attributes that were evaluated were abundance, number of species, biomass, and weighted mean body length; functions measured were dung removal, soil excavation, and secondary seed dispersal. Results: It was found that both the assemblage attributes and the ecological functions were negatively affected in the more disturbed vegetation covers, particularly in cattle pastures. Most of the assemblage attributes correlated positively with functions; soil excavation and secondary seed dispersal had a strong positive correlation with dung removal. Conclusions: Dung beetle assemblages play important ecological functions and they are sensitive to ecosystem disturbances. This study shows how dung beetles and their functions are affected negatively when forest is transformed to cattle pasture in the understudied and highly fragmented Andean forest ecosystems.

Can dark septate endophytic fungi (DSE) mobilize selectively inorganic soil phosphorus thereby promoting sorghum growth? A preliminary study / ¿Los hongos endófitos septados oscuros (DSE) pueden movilizar selectivamente el fósforo inorgánico y promover así el crecimiento del sorgo? Un estudio preliminar

Abstract Phosphate fertilizers tend to precipitate with soil components, affecting fertilization efficiency and causing negative environmental effects. Soil microorganisms have been used to solve this problem. However, the ability of dark septate endophytic fungi (DSE) to dissolve phosphates and increase crop yield are not well known. The activity of DSE fungi capable of solubilizing reagent grade phosphates was studied in a Typic Hapludoll (Hapludol típico). The effect of the fungi on the inorganic phosphorus fractions was evaluated and an experiment was conducted in pots with sorghum as a crop. No fungal structures were found in the roots. Curvularia sp. aerial biomass and root length increased; however, P concentration was not affected. Although the results are not conclusive, they represent an advance in the potential use of DSE fungi as P solubilizers to treat crop nutrition.

Resumen Los fertilizantes fosfatados tienden a precipitar con componentes del suelo, lo que afecta la eficiencia de la fertilización y causa efectos negativos. Para resolver este problema se han utilizado microorganismos del suelo. Sin embargo, no se conoce bien la capacidad de los hongos endófitos septados oscuros (ESO) para disolver fosfatos y aumentar el rendimiento de los cultivos. Se estudió en un hapludol típico (typic hapludoll) la actividad de hongos ESO capaces de solubilizar fosfatos de grado reactivo. Se evaluó el efecto de los hongos sobre las fracciones de fósforo inorgánico y se realizó un experimento en macetas con sorgo como cultivo. No se encontraron estructuras fúngicas en las raíces. Curvularia sp. aumentó la biomasa aérea y la longitud radical, pero la concentración de fósforo no se vio afectada. Aunque los resultados no son concluyentes, representan un avance en el uso potencial de hongos ESO como solubilizadores de fósforo para tratar la nutrición de cultivos.

Seasonal Fluctuations of N, P and K in Leaves Influenced Nutrient Requirement During Fruit Development Stages in Different Olive Genotypes

Abstract: Olive is grown in semi-arid climatic conditions; however, little is known about mineral changes in olive plant and nutrient requirements during the production period. Hence, the current study was conducted under Pothwar agro-climatic conditions in order to select appropriate stage of macronutrients (N, P, K) application in relation to soil and leaf nutritional status during 2017 and 2018 growing seasons. Soil and leaf analysis were performed at four different phenological stages (i.e. flowering, fruit setting, fruit enlargement and fruit maturity stages). The results revealed that the assessed macronutrient in leaf and soil varied significantly among varieties, phenological stages and growing year. The results revealed also that nitrogen level was found to decrease from fruit set (1.56%) to fruit enlargement stage (1.47%). Leaf and soil N, P and K contents were found higher before the flowering (stage 1) and depleted after fruit harvesting (stage 4), regardless of olive varieties. However, high yielding varieties showed lower nutrients after fruit harvesting (stage 4). Therefore, N content in leaf and soil gradually decreased during fruit growth and development. Whereas, K content in leaf and soil sharply declined from fruit maturity to fruit ripening stage. Overall, the trend of nutrient depletion showed that plants need phosphorus for fruit setting, nitrogen before and after fruit setting, and potash after pit hardening or at oil accumulation stages.

Effect of Potassium Solubilizing Bacteria on Rhizosphere Soil Microenvironment of Paris polyphylla var. yunnanensis / 中国实验方剂学杂志

ObjectiveTo investigate the effects of the inoculation of potassium-solubilizing bacteria on the rhizosphere soil microenvironment of Paris polyphylla var. yunnanensis. MethodThe effects of different potassium-solubilizing bacteria on the physical and chemical properties， microbial community structure， and soil enzyme activity in the rhizosphere soil of P. polyphylla var. yunnanensis were investigated by pot planting at room temperature. The correlation of various indexes was analyzed. ResultThe inoculation with different potassium-solubilizing bacteria could significantly affect the physical and chemical properties of rhizosphere soil of P. polyphylla var. yunnanensis. The mass fractions of available nitrogen， available phosphorus， and available potassium were 24.5-90.5 mg·kg-1， 2.53-25.9 mg·kg-1， and 132-312 mg·kg-1， respectively， and the soil pH was 7.08-7.75， which were in line with the optimal ranges of P. polyphylla var. yunnanensis planting. The inoculation of different potassium-solubilizing bacteria could affect the number of bacteria， actinomycetes， and fungi in rhizosphere soil to varying degrees. The transformation of soil from "fungal type" to "bacterial type" marks the improvement of soil fertility. It also affected the enzyme activity of rhizosphere soil， and the activities of neutral phosphatase， protease， and polyphenol oxidase showed an increasing trend. The correlation analysis showed that the number of bacteria was negatively correlated with the number of fungi （r=-0.856， P<0.01）， positively correlated with the number of actinomycetes， the content of available nitrogen and available potassium， and negatively correlated with soil pH. ConclusionThe inoculation of potassium-solubilizing bacteria can effectively improve the content of available potassium， available nitrogen， available phosphorus， and other nutrients in the rhizosphere soil of P. polyphylla var. yunnanensis， improve soil fertility， alleviate the continuous cropping obstacles of P. polyphylla var. yunnanensis， and lay a theoretical foundation for the green and sustainable development of P. polyphylla var. yunnanensis.

Yield， Quality， and Soil Microecology of Panax ginseng Under Different Forests / 中国实验方剂学杂志

ObjectiveTo explore the forest type and soil environment suitable for Panax ginseng. MethodThe yield， quality， soil chemical properties， soil enzyme activity， and soil microbial metabolism of 9-year-old P. ginseng under different forests were investigated. ResultThe quality of P. ginseng was significantly different among forest types. To be specific， P. ginseng under the Quercus mongolica forest had the highest quality， with the total saponin content of 2.27% which was 51.89% higher than that in P. ginseng under Larix gmelinii forest. The yield of P. ginseng under Q. mongolica forest and L. gmelinii forest （30 g·m-2） was the highest， 62.5% higher than that under Betula platyphylla forest. The soil content of organic matter， Cu， and Zn， and activity of sucrase and urease under Q. mongolica forest were lower than those under other forest types. The utilization rate of D-galacturonic acid by soil microorganisms under Q. mongolica forest was higher than that under other forest types， but the utilization rate of L-phenylalanine was lower than that under other forest types. The utilization rate of 2-hydroxybenzoic acid by soil microorganisms of B. platyphylla forest was significantly lower than that under other forest types. There was a negative correlation between soil Zn and ginsenoside Rb1 and Rc， and between soil K and ginsenoside Rb2 and Rb3. Mn and Cu were positively correlated with most saponins. The results of redundancy analysis showed that the soil microorganisms using carbon sources of amino acids， esters， acids， and sugars were the main factors causing the differences in P. ginseng among different forest types. ConclusionThe yield and quality of P. ginseng under Q. mongolica forest were the best， followed by the forest with different tree species， and coming in last was the B. platyphylla forest. This study is expected to provide theoretical support for the improvement of P. ginseng yield and quality and the improvement of ecological planting technology.

Correlation Between Functional Components in Codonopsis pilosula Roots and Soil Factors / 中国实验方剂学杂志

ObjectiveTo explore the correlation between the content of 4 functional components in Codonopsis pilosula roots from different areas and soil factors， and thereby to lay a theoretical basis for soil ecological regulation and improvement of quality of C. pilosula roots. MethodThe content of lobetyolin， atractylenolide Ⅲ， alcohol extract， and polysaccharides， as well as soil fertility and 16 soil factors in 24 batches of samples from different producing areas were determined. Principal component analysis （PCA） and Pearson's correlation analysis were used to explore the key soil factors leading to the variation of chemical component content in C. pilosula roots. ResultThe content of lobetyolin and atractylenolide Ⅲ in samples from Longxi was the highest， and the content of polysaccharides peaked in samples from Huguan. The content of lobetyolin was in positive correlation with soil total nitrogen， total phosphorus， total potassium， alkali-hydrolyzable nitrogen， and available potassium （P<0.01）， as well as soil organic matter， pH， available manganese， and available zinc （P<0.05）. There was a positive correlation between pH and atractylenolide Ⅲ content （P<0.05）. Soil total potassium was in positive correlation with alcohol extract and polysaccharide content （P<0.01）. Soil available zinc was positively correlated with alcohol extract and the polysaccharide content （P<0.05）. Sample sites with higher PCA scores were Pingshun， Huguan， and Longxi， which were significantly positively correlated with the content of polysaccharides in C. pilosula roots in different habitats. ConclusionThe content of functional components in C. pilosula roots can be improved by raising soil organic matter content and applying specific fertilizers.

Effects of Exogenous Fusarium oxysporum and Trichoderma viride on Soil Fungal Community of Panax ginseng / 中国实验方剂学杂志

ObjectiveTo investigate the effects of exogenous Fusarium oxysporum and Trichoderma viride on the diversity of soil fungal community and carbon metabolic function of cultivated Panax ginseng. MethodIllumina HiSeq 2500 high-throughput sequencing combined with Biolog-ECO was used to analyze the species diversity and functional diversity of soil fungal communities in P. ginseng soil under different exogenous treatments. ResultThe results of high-throughput sequencing showed that the number and species of microorganisms in the soil were significantly changed after exogenous microorganisms were added. The soil fungi with relative abundance greater than 1% included Mortierella sp.，Fusarium sp.，Humicola sp.，and Simplicillium sp. Mortierella sp. in each treatment group significantly increased. Humicola sp. and Simplicillium sp. could be induced to increase by exogenous addition of F. oxysporum，while T. viride at a high concentration could significantly inhibit the growth of F. oxysporum. As revealed by Biolog and principal component analysis （PCA），the average well color development （AWCD） in the high-dose T. viride group （MG） was significantly higher than that in the control group （QS）and the low-dose F. oxysporum group（LD）. The utilization abilities for amino acids，carboxylic acids，polymers， and amines were enhanced in the MG group，but the microbial metabolic activity was reduced in the high-dose F. oxysporum group （LG）. There was no significant increase in the utilization of phenolic acids by soil microorganisms in both groups. ConclusionExogenous addition of F. oxysporum can lead to the growth and reproduction of other pathogenic fungi. Exogenous addition of T. viride can enhance the soil fungal community structure and metabolic diversity，inhibit the proliferation of F. oxysporum，and improve the soil microbial environment of cultivated P. ginseng.

Correlation analysis between continuous cropping obstacle of Gastrodia elata and Ilyonectria fungi and relieving strategy / 中国中药杂志

The continuous cropping obstacle of Gastrodia elata is outstanding, but its mechanism is still unclear. In this study, microbial changes in soils after G. elata planting were investigated to explore the mechanism correlated with continuous cropping obstacle. The changes of species and abundance of fungi and bacteria in soils planted with G. elata after 1, 2, and 3 years were compared. The pathogenic fungi that might cause continuous cropping diseases of G. elata were isolated. Finally, the prevention and control measures of soil-borne fungal diseases of G. elata were investigated with the rotation planting pattern of "G. elata-Phallus impudicus". The results showed that G. elata planting resulted in the decrease in bacterial and fungal community stability and the increase in harmful fungus species and abundance in soils. This change was most obvious in the second year after G. elata planting, and the soil microbial community structure could not return to the normal level even if it was left idle for another two years. After G. elata planting in soils, the most significant change was observed in Ilyonectria cyclaminicola. The richness of the Ilyonectria fungus in soils was significantly positively correlated with the incidence of G. elata diseases. When I. cyclaminicola was inoculated in the sterile soil, the rot rate of G. elata was also significantly increased. After planting one crop of G. elata and one to three crops of P. impudicus, the fungus community structure in soils gradually recovered, and the abundance of I. cyclaminicola decreased year by year. Furthermore, the disease rate of G. elata decreased. The results showed that the cultivation of G. elata made the Ilyonectria fungi the dominant flora in soils, and I. cyclaminicola served as the main pathogen of continuous cropping diseases of G. elata, which could be reduced by rotation planting with P. impudicus.

Planning of ecologically suitable areas for Ligusticum chuanxiong under background of soil cadmium pollution / 中国中药杂志

Chuanxiong Rhizoma is a traditional Chinese medicinal material mainly produced in Sichuan and Chongqing of China. In recent years, the cadmium content in Chuanxiong Rhizoma produced in most of the genuine producing areas has exceeded the standard, which makes Chuanxiong Rhizoma difficult to be exported. To solve the problem of excessive cadmium content in soil, this study employed the MaxEnt model to simulate the potential geographic distribution of Ligusticum chuanxiong and evaluate important environmental factors, and re-plan its ecologically suitable areas based on the mineral distribution characteristics and soil cadmium pollution status. The results showed that the places suitable for L. chuanxiong growing covered an area of 335 523.69 km~2, mainly in central and eastern Sichuan, southern Shaanxi and most parts of Chongqing. Among them, the highly suitable areas of L. chuanxiong were mainly concentrated in Chengdu, Ya'an, Deyang, and Mianyang. Solar radiation, annual precipitation, and annual range of temperature were evaluated as important variables affecting the distribution of L. chuanxiong, with the contribution rates of 62.3%, 13.3%, and 6.8%, respectively. In addition, Qionglai county, Chongqing county, Mianyang city(Youxian district and Fucheng district), Qingchuan county, and Xinjin county were classified into the first-class ecologically suitable zone, covering a total area of 2 768.87 km~2. The se-cond-class ecologically suitable zone was even wider, involving such counties as Tongjiang county, Renshou county, Jianyang county, and Nanjiang county, and the total area reached 43 616.92 km~2. The re-planning of the ecologically suitable areas for L. chuanxiong has provided strong data support for the cultivation and resource development of L. chuanxiong and also new ideas for solving the problem of excessive cadmium content in L. chuanxiong.

Effects of chloropicrin fumigation on soil and growth and development of Panax notoginseng / 中国中药杂志

The continuous cropping obstacle of Panax notoginseng is serious, and effective control measures are lacking. Soil disinfection with chloropicrin(CP) has been proven to be effective in reducing the obstacles to continuous cropping of other crops. In order to ascertain the effect of CP in the continuous cropping of P. notoginseng, this paper explored the influences of CP at different treatment concentrations(0,30,40,50 kg/Mu, 1 Mu≈667 m~2) on soil macro-element nutrients, soil enzyme activity, growth and development of P. notoginseng, and the accumulation of medicinal components. The results showed that CP fumigation significantly increased the content of total nitrogen, alkali-hydrolyzable nitrogen, ammonium nitrogen, nitrate nitrogen, and available phosphorus in the soil, but it had no significant effect on potassium content. The soil protease activity showed a trend of first increasing and then decreasing with the prolonging of the treatment time. Both the soil urease and acid phosphatase activities showed a trend of first decreasing and then increasing with the prolonging of the treatment time. The higher the CP treatment concentration was, the lower the urease and acid phosphatase activities would be in the soil. The protease activity was relatively high after CP40 treatment, which was better than CP30 and CP50 treatments in promoting the nitrogen-phosphorus-potassium accumulation in P. notoginseng. The seedling survival rates after CP0, CP30, CP40, and CP50 tratments in October were 0, 65.56%, 89.44%, and 83.33%, respectively. Compared with the CP30 and CP50 treatments, CP40 treatment significantly facilitated the growth and development of P. notoginseng, the increase in fresh and dry weights, and the accumulation of root saponins. In summary, CP40 treatment accelerates the increase in soil nitrogen and phosphorus nutrients and their accumulation in P. notoginseng, elevates the seedling survival rate of P. notoginseng, enhances the growth and development of P. notoginseng, and promotes the accumulation of medicinal components. CP40 treatment is therefore recommended in production.