Erosion is the natural process which has

The bean plant has a very high demand for nutrients, and as it has a short cycle, requires that the nutrients be readily available when needed, so as not to limit productivity. The use of organic fertiliser in beans is efficient, since due to the short cycle, the crop displays a satisfactory response to this type of fertilisation. The aim of this study was to evaluate the effects of organic fertiliser on the biometric parameters of the cowpea that reflect the productivity of bean plants. The experiment was carried out in the vegetable garden of the Federal University of Ceará, Piei Campus, and consisted of five treatments: control, mineral fertiliser, and organic fertiliser at doses of 100, 200 and 300% of the nitrogen recommendation for mineral fertilisation. At the time of harvest, 1 O plants were collected from the working area of each plot to evaluate the number of pods per plant, grains per pod, 100-grain weight and mean pod length. The variables evaluated in the field experiment were

The efficient use of natural resources in production systems is essential for achieving ecological balance and sustainability in these systems. Current agricultural production systems have intensified the use of fertilisers and pesticides that contribute to an increase in energy flow, accelerating the process of degradation. The aim of this study was to evaluate, using emergy analysis, the environmental performance of different irrigated production systems for different sources of water, energy and fertiliser, and of rainfed systems under different types of soil preparation. The irrigated systems were studied in the experimental area of the Sewage Treatment Station (ETE) in Tianguá, Ceará (CE), and the rainfed models at the Fazenda Normal Farm in Quixeramobim, CE. Emergy analysis basically consists of three stages: construction of the systemic energy flow diagram, elaboration of the emergy evaluation table, and calculation of the emergy indicators. A mean value of 0.04 was found under the rainfed production systems, which shows less environmental stress compared to the irrigated systems, 0.30. The influx of economic resources into agricultural systems increases the environmental load and reduces renewability. Treated domestic effluent and photovoltaic solar energy afforded an increase in emergy yield and in the environmental sustainability of the production models.

Although hyperspectral remote sensing techniques have increasingly been used in the nutritional quantification of plants, it is important to understand whether the method shows a satisfactory response during the various phenological stages of the crop. The aim of this study was to quantify the levels of phosphorus (P), potassium (K), calcium (Ca) and zinc (Zn) in the leaves of Vigna Unguiculata (L.) Walp using spectral data obtained by a spectroradiometer. A randomised block design was used, with three treatments and twenty-five replications. The crop was evaluated at three growth stages: V4, R6 and R9. Single-band models were fitted using simple correlations. For the band ratio models, the wavelengths were selected by 2D correlation. For the models using partial least squares regression (PLSR), the stepwise method was used. The model showing the best fit was used to estimate the phosphorus content in the single-band (R² = 0.62; RMSE = 0.54 and RPD = 1.61), band ratio (R² = 0.66; RMSE = 0.65 and RPD = 1.52) and PLSR models, using data from each of the phenological stages (R² = 0.80; RMSE = 0.47 and RPD = 1.66). Accuracy in modelling leaf nutrients depends on the phenological stage, as well as the amount of data used, and is more accurate with a larger number of samples.

Em vista das variações climáticas ocasionadas pelas mudanças do clima mundial, a agricultura busca novas alternativas de plantas que possam se desenvolver e produzir em condições adversas (seca ou chuvas excessivas). O objetivo do presente trabalho foi avaliar a germinação e o desenvolvimento inicial de sementes do feijão enxofre sob diferentes potenciais osmóticos. As sementes foram postas para germinar em papel germitest embebido em solução de cloreto de sódio nos potenciais osmóticos: 0; -0,1; -0,2; -0,3; -0,4; -0,5; -1; -1,5; -2,0 MPa. Para a análise dos dados foram utilizados os índices de velocidade de germinação (IVG), coeficiente de velocidade de germinação CVG (%), porcentagem de germinação, comprimento da radícula (CRF) e hipocótilo final (CHF), tempo médio de germinação (TMG). Observou-se redução nos índices de IVG, G (%), CVG (%), CRF, CHF e aumento no TMG, nos potenciais de -0,1; -0,2; -0,3; -0,4; MPa. O IVG apresentou redução em todos os potenciais. Conclui-se que a variedade feijão enxofre não reduziu sua germinação em função das condições de potencial hídrico, fato que não foi observado nos demais parâmetros (IVG, TMG e CVG%), que apresentaram interferências negativas significativas, mostrando que apesar de ser exposto a situações de baixa disponibilidade hídrica, o feijão enxofre não reduz seu estande, mostrando potencial de uso em áreas de seca ou solos salinos. Palavras-chave: Feijão Enxofre. Germinação. Potencial Osmótico. AbstractIn view of the climatic variations caused by changes in the global climate, agriculture seeks new alternatives of plants that can develop and produce in adverse conditions (drought or excessive rain). The purpose of this study was to evaluate the germination and early development of sulfur beans seeds under different osmotic potentials. The seeds were put to germinate in germitest paper soaked in sodium chloride solution osmotic potential: 0; -0.1; -0.2; -0.3; -0.4; -0.5; -1; -1.5; -2.0 MPa. For data analysis  the germination speed index (IVG), germination speed CVG coefficient (%), germination percentage, length of the radicle (CRF) and hypocotilum (CHF), average time of germination (TMG) were used. Reduction was observed in the indices of IVG, G (%), CVG (%), CRF, CHF and increase in TMG, the potential of-0.1 0.2 0.3;0.4; MPa.  IVG exhibited reduction in all  the potentials. It is concluded that the sulfur beans variety did not reduce its  germination conditions of water potential, a fact that was not observed in the other parameters (IVG, TMG and CVG%) which ave significant adverse interference, showing that despite being exposed to situations of low water availability the sulfur beans does not reduce its stand, showing potential for use in dry areas or saline soils. Keywords: Sulfur Beans. Germination. Osmotic Potential.

Candiota region comprises the largest reserve of coal in Brazil and it has presented increasing changes in land use and cover due to the introduction and expansion of silviculture and soybean crops, which in turn can change the water quality and infiltration capacity in the soil. This work aims to map the contamination potential of surface and groundwater in the region of Candiota and surroundings, RS, Brazil, and to identify the spatial differences in the vulnerability. The following maps were used: Digital Elevation Model for hydrological modeling; hydrogeological; soil types; and land use and cover, from Landsat 8 images. Curve-Number (CN) values were used to map the initial infiltration potential for water into the soil. The resulting vulnerability maps indicated the regions with higher or lower susceptibility. The latent vulnerability map attributed a lower potential of groundwater contamination to non-aquifer areas (where aquifers are non-existent or have low productivity), and a higher potential to areas with greater surface water accumulation, due to relief and preferential flow direction. The adapted specific vulnerability map was essential to evaluate the influence of the soil hydrological type and land use and cover on aquifer vulnerability, identifying areas where the influence of soil texture or land use and cover was greater. In addition, it pointed out the susceptibility to surface runoff. The final map represented better the contamination potential for surface water than for groundwater, since it had a high influence of the runoff capacity, which locally influences inversely the contamination of groundwater and surface water. Regarding groundwater, it represented better the risk of contamination through

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Acid soils have been responsible for the poor performance of most plant species, and liming is an efficient way of correcting the pH of such soils. The aim of this study was to assess the performance and establishment of the Brachiaria hybrid 'Mulatto II' under different doses and forms of limestone application. The experimental design was of five doses of limestone (0, 0.5, 1, 2, and 4 t ha -1 ) and two forms of application (broadcasting over the surface, and broadcasting followed by hoeing the top 20 cm of soil) with three replications, in 3 x 3 metre plots of the Brachiaria hybrid 'Mulatto II'. The greatest number of germinated seeds was at the dose of 4 t ha -1 limestone when incorporated into the soil. For height, the greatest values found were at the maximum dose of limestone when incorporated into the soil. Dry matter production was not influenced by the form of limestone application, however production increased with the supply of limestone. The hybrid variety proved easily adaptable to different soil and climate conditions.