La erosión es la principal forma de degradación en el mundo, en consecuencia de la pérdida de suelo, agua y nutrientes, provocando daños directos e indirectos. El objetivo de este trabajo es cuantificar las pérdidas de N, P y K por erosión hídrica en condiciones de lluvia simulada mediante la aplicación de seis pruebas de erosión en cultivo continuo de especies de ciclo estacional, incluyendo cultivos aislados y cultivos intercalados. El estudio se llevó a cabo en el campo en la Estación Experimental de Agronomía en Eldorado do Sul (RS), Brasil, en un Argisol Rojo Distrófico típico. Para el análisis de la pérdida de nutrientes, se aplicaron seis ensayos de erosión con lluvia simulada a los tratamientos entre finales de octubre y mediados de diciembre, utilizando el simulador de lluvia con brazos giratorios de Swanson. Las pérdidas de N y P se vieron influenciadas por las condiciones de la superficie, con la eliminación parcial de los residuos del cultivo y la no movilización del suelo. La excepción fue K, debido a su alta solubilidad en el suelo con baja actividad coloidal, que se perdió fácilmente en la escorrentía superficial del agua del suelo, independientemente de la cobertura total de la superficie del suelo por los residuos de los cultivos.

Soil physical structure is related to porous space dynamics, which is affected by pedogenetic conditions, land uses, and agricultural practices. Thus, the objective of this work was to evaluate physical and structural attributes of Cambissolos under different uses in the Terra de Esperança Settlement Project, in Chapada do Apodi, Governor Dix-Sept Rosado, Rio Grande do Norte, Brazil, and detect the most sensitive attributes for the distinction of environments using multivariate analysis. The study areas with different land uses were: Native Forest Area 1 (NFA1), Native Forest Area 2 (NFA2), Native Forest Area 3 (NFA3) (reference areas), Conventional Management Area (CMA) Agroecological Area (AEA), and Cajaraneira (Spondia sp.) Orchard Area (COA). Areas with agricultural uses were characterized through physical and structural analyses, using disturbed and undisturbed soil samples collected from their 0.00-0.10, 0.10-0.20, and 0.20-0.30 m soil layers. The soil classes of the areas, according to the Brazilian Soil Classification System (SiBCS) were Cambissolo Haplico Carbonatico vertissolico (NFA1); Cambissolo Haplico Ta Eutrofico tipico (NFA2 and COA); Cambissolo Haplico Ta Eutrofico vertissolico (NFA3); and Cambissolo Haplico Carbonático tipico (CMA and AEA). The results of the attributes analyzed were expressed as mean of three replications per soil layer of each area, using multivariate analysis. Soil textures varied from sandy clay loam to clay. The total sand fraction presented negative correlations with clay dispersed in water, gravimetric moisture (GM), volumetric moisture (VM), total porosity determined (TPd) and microporosity (MiP); and positive correlations with soil density (SD), and basic infiltration rate (BIR), denoting pedogenetic influence. The SD presented significant correlation with GM, VM, TPd, MiP, macroporosity (MaP), aeration porosity (AP) and BIR, denoting its importance for the physical structure of the soil, and its dynamics. The most relevant attributes for the discrimination of the soil physical structure were the inorganic fractions clay and sand, porosity, degree of flocculation, aggregates, and soil mechanical resistance to penetration. The physical and structural attributes of the Cambissolos Haplicos were generally preserved, when compared to the current conditions of the NFAs, despite the different land use and managements. However, the soils of NFA1 (0.20-0.30 m layer), CMA, and AEA areas indicate fragility in aggregate stability and degree of flocculation due to the predominance of the sand fraction. The COA presented more favorable physical and structural conditions to the development of agricultural crops, especially on the surface layers, mostly influenced by their clay, TPd, AP, GM, VM, and soil mechanical resistance to penetration.

Diante de um cenário de escassez hídrica cada vez mais evidenciado, o aproveitamento de águas pluviais apresenta-se como uma alternativa viável com vantagens sociais, ambientais e econômicas. No âmbito do Instituto Nacional do Semiárido – INSA com intuito de melhorar a qualidade da água armazenada e sua posterior utilização, tem sido adotado o descarte do primeiro milímetro. Para utilização segura de águas pluviais, essas devem receber algum tratamento visando garantir sua qualidade, especialmente a característica microbiológica. Assim, para que sejam atenuados os riscos sanitários envolvidos na utilização da água da chuva, essa deve passar pelo menos, pelo processo de desinfecção como determina a NBR 15.527/2019 e a Portaria do Ministério da Saúde 888/2021. A utilização do cloro como desinfectante, embora bastante difundida, pode apresentar problemas como a geração de subprodutos. Assim, a busca por soluções que substitua ou complemente a desinfecção com cloro é fundamental. Nesse contexto, a radiação ultravioleta apresenta-se como uma solução com bastante potencial para tratar as águas pluviais de forma a fornecer uma melhor qualidade minimizando a liberação de produtos químicos e materiais perigosos. Assim, a utilização da radiação ultravioleta como complemento a cloração na desinfecção de águas tem se mostrado bastante eficaz, com isso, pode-se vislumbrar que na realidade do INSA, sua utilização atinja níveis para uso irrestrito.

Bell peppers are an economically and socially important vegetable, and cultivation technologies aim to reduce production costs and increase yields, which can be achieved through the use of organic fertilization and irrigation. Therefore, this study aimed to evaluate the production and post-harvest quality of bell pepper fruits using different fertilization sources in Neossol soil. The experiment was conducted in a randomized block design with five treatments and five replications (T1= 30% (1/2 topsoil + 1/2 bovine manure) and 70% soil; T2= 30% (traditional organic compost) and 70% soil; T3= 30% (organic compost Bokashi) and 70% soil; T4= 30% (Biobokashi granules) and 70% soil; and T5 - control, 100% soil and fertirrigation). The following characteristics were evaluated: number of fruits per plant (NF), fresh fruit mass (FFM), longitudinal fruit length (LFL), transverse diameter (TD), fruit yield (Y), total soluble solids content (SS), vitamin C (Vit. C), titratable acidity (TA), and ratio (SS/TA). The mean results were subjected to normality and homogeneity of variance tests, and analysis of variance. Using the F-test, the treatment means were compared using Tukey's test (p≤0.05). Treatments T1, T2, and T4 provided higher values for FFM, LFL, TD, and Y. There was no statistical difference between treatments for the variables SS, TA, and Ratio. The highest vitamin C content occurred in T5 and T1, with no statistical difference between them. It is concluded that treatments T1 and T2 had higher fruit production. Post-harvest quality, regarding vitamin C content, stood out in treatments T5 and T1. The mixture of bovine manure with soil and topsoil (T1), as well as the traditional organic compost (T2) and bokashi (T3), showed viability in terms of production and post-harvest quality compared to T5 (fertigation).