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For assessing the effect of management on the suppressive potential of the brown calcareous soils on the lesion length caused by Rhizoctonia solani Kühn in the bean crop it was conducted this experiment under semicontrolled conditions. It was used a complete random design with two types of fertilization (urea: 225 kg ha-1 and compost: 7 t ha-1) and soils from two fields with different agricultural management (conventional and organic). Soil were used in natural state and sterile through autoclaved and 4 replicates by treatment. The bean cultivar selected was CC 25-9N and the strain of R. solani was AG-4-HGCuLT-Rs-36. The lesion length was superior in the non-sterilized soils from the conventional management. Fertilization used in the studied did not influence on the obtained results. The multiple regression analysis demonstrated that the lesion leght will decrease by increments in permeability and organic matter content for both managements, but in the conventional will do the same by auments in pH-KCl. Besides, the lesion length showed significant simple regressions for both managements with stable aggregates and pH-KCl, but with the content of organic matter is significant only for the organic management, meanwhile in the conventional management were significant with permeability and P Olsen. The soil under organic management showed a higher suppressive potential with lower lesion length and 28 % of dependence of the evaluated soil properties status. [ABSTRACT FROM AUTHOR]

The goal of this research was to assess alternatives of biofertilization with Fosfotic, Safermycorrhiza, and their combination in the potato variety Superchola under semi-controlled conditions. The experiment was carried out in a greenhouse and the substrate used was a typical Andisol of the region. A Completely Randomized Design was used with three replications. These alternatives and their combinations with the NPK dose that is used in the region and with different reductions of it, were evaluated, forming a total of 23 treatments. The best integral results were obtained with the treatments in which mineral fertilization is combined with some of the biofertilization alternatives (Fosfotic and Safer-mycorrhizas), with which it is suggested that these studies be continued under field conditions in the Andisols of Carchi -Ecuador. It is demonstrated that both the inoculations with Fosfotic and Safer-mycorrhizas, as well as their joint inoculation, can constitute viable alternatives in the cultivation of potatoes in these soils. However, the reduction of the mineral fertilizers without combine that with biofetilizers implies a reduction of the production, so it is not recommendable. [ABSTRACT FROM AUTHOR]

Two areas (a natural and an agricultural ecosystem), located on brown calcareous soil (correlated to Order Inceptisol, Subgroup Mollic Eutrudept in the Soil Taxonomy system), were chosen with the aim of assessing the effect of agricultural land use on soil quality using the compared scenarios perspective. The physical indicators analyzed were aggregate stabled, permeability coefficient, the factor of structure, lower and upper limits of plasticity, as well as, the index of plasticity. The chemical indicators measured were pH (H2O), pH (KCl), organic matter content, and levels of P2O5 and K2O. Soil microbiology was analyzed by plate counting. For mesofauna extraction was used the funnel methodology of Berlese-Tullgren. Data processing was done using STATGRAPHICS vs 5.0 on Windows 7. The results demonstrated that the physical status of the soil was good in both ecosystems. Significant differences were found for pH, organic matter content, levels of P2O5 and K2O, and in the microbial population. However, no differences were found in mesofauna components; but, the principal components analyses showed that the differentiation between both ecosystems is more defined by the mesofauna and microbiological indicators. [ABSTRACT FROM AUTHOR]

Seven farms (two state, two cooperatives, and three private farms) were selected for assessing effects of farm management on the microbial biomass and the structure of the microbial community, as well as, the responses to seasonality on these two bio-indicators in these three representative farming systems. All farms are located on brown calcareous soil. Soil samples from the 0-20 cm depth were collected from two fields of each farm. Soil microbial community was assessed through two analyses: microbial biomass carbon and phospholipid fatty acid. The technological differences in soil management, among the three farming systems, affected both microbial biomass carbon and the microbial community composition. The differences were most pronounced between the private and the state farms. The statistical analyses demonstrated that the total of phospholipid fatty-acid were significantly higher in cooperative farms. The use of fallow in these farms seems to have positive effects on soil microbial communities. Seasonality has a clear effect on both indicators. Summarizing, both indicators demonstrated sensible responses to disturbances caused by farm management and seasonality in the conditions of Cuban agriculture. [ABSTRACT FROM AUTHOR]

The unavailability of chemical fertilizers to obtain high yields in Cuban agriculture has led to the development of other organ-mineral fertilizers, such as Agromena - G, produced by the Empresa Geominera del Centro in Villa Clara. The objective of this work was to characterize the organ-mineral fertilizer Agromena - G, based on the determination of the main physical and chemical properties of the fertilizer for its mechanized application in the improvement of soils and the increasing of crops yield. The methodology included the determination of physical properties as granulometry, apparent density and humidity of the organ-mineral fertilizer. In addition, chemical properties such as pH, electrical conductivity, available phosphorus and organic matter were determined. The physical properties of the organ-mineral fertilizer Agromena - G, show that its granulometry (approximately 50% of the grains smaller than 1 mm) favors its use since it facilitates its acquisition by the plants. The other determined properties behave within acceptable values for the most common granular fertilizers. The physical properties of this fertilizer favor its mechanized application both by broadcast fertilizing machines and with machines for localized fertilization. The chemical properties of this organ-mineral fertilizer demonstrated its potential use as an alternative for managing plant nutrition although it is recommended the surveillance of indicators as electrical conductivity and cations concentrations, especially Na+, in clayed soils susceptible to salinity problems. [ABSTRACT FROM AUTHOR]

The objective of this research was to compare the spectral signature of two soil types, Cambisol and Vertisol, cultivated with sugarcane in the Villa Clara province, Cuba. The soil samples were collected at two levels: 1) Landscape level of the province (DC), 2) within a field (CE). The vis-NIR spectral signatures were acquired in the laboratory by means of a diode array spectrophotometer covering the wavelength range from 399 to 1697 nm. The results showed that the absorbance spectra of these two soil types can clearly be distinguished, which suggests that the soil type could be derived from the spectra. The light absorbance by the soil varied with wavelength in each soil type in DC and CE. A visual comparison of the spectral shape and the variation between a field and landscape within the same soil group showed some similitude. Around the wavelength of 1400 nm in both soil types the absorbance values increase and consequently decrease again. These characteristics bring a good match of the spectral signatures of DC and CE. In addition, in CE an increasing pattern of soil absorbance was observed as organic matter (OM %) increases. This pattern was observed around 399 nm and 580 nm while for Cambisol and Vertisol respectively. [ABSTRACT FROM AUTHOR]

La presente investigación evaluó alternativas de biofertilización con el empleo de bacterias solubilizadoras de fósforo y hongos micorrízicos arbusculares, a través de los productos comerciales Fosfotic® y Safer Micorrizas®, respectivamente, en el cultivo de la papa cv. Superchola, en suelos Andisoles del Carchi, Ecuador. El experimento se realizó en condiciones de producción en un área de 360 m², subdividida en seis parcelas de 60 m² cada una (5 m de ancho x 12 m de largo), donde se ubicaron seis tratamientos correspondientes a un control fertilizado y diferentes dosis de fósforo más la inoculación con Fosfotic® y Safer Micorrizas®. La distancia de plantación fue de 1 m entre surcos y 0,50 m entre plantas. Se evaluaron las variables: longitud de tallo, número de tallos brotados, número total de tubérculos por planta y su clasificación por calibre, así como el rendimiento total y por calibre, además de realizar un análisis económico de los tratamientos estudiados. Los mejores resultados se obtuvieron con el 100 % de la fertilización a base de NK+75 % P+Fosfotic®+Safer Micorrizas® y con 100 % de la fertilización a base de NK+25 % P+Safer Micorrizas®; los cuales también mostraron los mayores beneficios económicos. Estos resultados demuestran la viabilidad del uso de estos biofertilizantes en la región del Carchi, Ecuador. [ABSTRACT FROM AUTHOR]