Water erosion degrades the soil and contaminates the environment, and one influential factor on erosion is slope length. The aim of this study was to quantify losses of soil (SL) and water (WL) in a Humic Cambisol in a field experiment under natural rainfall conditions from July 4, 2014 to June 18, 2015 in individual events of 41 erosive rains in the Southern Plateau of Santa Catarina and to estimate soil losses through the USLE and RUSLE models. The treatments consisted of slope lengths of 11, 22, 33, and 44 m, with an average degree of slope of 8 %, on bare and uncropped soil that had been cultivated with corn prior to the study. At the end of the corn cycle, the stalk residue was removed from the surface, leaving the roots of the crop in the soil. Soil loss by water erosion is related linearly and positively to the increase in slope length in the span between 11 and 44 m. Soil losses were related to water losses and the Erosivity Index (EI 30 ), while water losses were related to rain depth. Soil losses estimated by the USLE and RUSLE model showed lower values than the values observed experimentally in the field, especially the values estimated by the USLE. The values of factor L calculated for slope length of 11, 22, 33, and 44 m for the two versions (USLE and RUSLE) of the soil loss prediction model showed satisfactory results in relation to the values of soil losses observed.
The conversion of native grassland into farmland causes changes in the soil. Tillage has profound effects on soil organic matter. The intensification of soil tillage decreases soil quality by reducing aggregate stability. Soil aggregate stability and soil organic matter are key indicators for soil quality and environmental sustainability in agro-ecosystems. The aim of the present study is to evaluate the total organic carbon content and the physical and chemical fractions of the organic matter in a soil under different uses and types of management over 27 years. Four soil tillage treatments with two annual crops were evaluated (no-tillage, NT; rotating tillage, RT; minimum tillage, MT; and conventional tillage, CT), as well as bare soil (BS) (standard plot of the Universal Soil Loss Equation-USLE) and natural grassland (NG) as a reference area. The experiment was carried out in an Inceptisol (Cambissolos) in southern Brazil. We determined total organic carbon (TOC) and particulate organic carbon (POC), and organic carbon associated with soil minerals (OCam). The chemical fractionation of carbon was into fulvic and humic acids, and humin. In addition, soil aggregates were divided into five size classes. The type of soil tillage affected the soil organic carbon content, namely TOC, POC, and OCam, as well as the composition of the physical and chemical fractions and their distribution in the arable soil layer. There was a positive relationship between stable aggregates and organic carbon in the soil: the higher the proportion of aggregates in class 1, the higher the organic carbon content. The results support the hypothesis that the carbon stock depends on intensification of a conservation tillage system with a continuous input of C through biomass, which maintains and supplies a continuous flow of C to the carbon transformation processes in the soil.
O estudo das modificações do carbono do solo provocadas pela mudança de uso da terra possibilita adotar medidas que reduzam os riscos de futuros impactos negativos. O objetivo da pesquisa foi quantificar e comparar os teores (COT) e os estoques (EC) de carbono orgânico total do solo em diferentes usos da terra na região do Planalto Sul de Santa Catarina. Foram selecionadas áreas sob floresta natural (FN), plantio de pinus (PP), campo natural pastejado (CP) e sucessão de lavoura e pastagem (LP). Amostras de solo foram coletadas nas camadas de 0-5, 5-10, 10-20 e 20-40 cm, onde foram determinados os teores e calculados os estoques de carbono orgânico total por dois métodos, considerando a camada equivalente e a massa equivalente de solo. Os diferentes usos da terra influenciam os COT e os EC, os quais são maiores na condição de FN. Os valores de COT foram, respectivamente, 33,9; 27,1; 26,0 e 23,2 g kg-1 para FN, PP, CP e LP, na média da camada de 0-40 cm, enquanto os EC até a profundidade de 40 cm foram, respectivamente, 121,5; 113,8; 112,4 e 100,6 Mg ha-1 com base na camada equivalente de solo e 121,5; 102,2; 99,1 e 89,8 Mg ha-1 após correção pela massa equivalente de solo. A adequada gestão de uso do solo, a recuperação de matas e a florestação das terras são passos importantes para permitir o sequestro de carbono no solo.
Studying the changes in soil properties caused by different land uses allows measures to be adopted that will reduce the risk of future negative effects. The aim of this study was to evaluate soil physical properties and quantify water infiltration for different types of land use in the Santa Catarina Plateau of southern Brazil. The research was conducted on a 1,200 ha rural property. The land use types selected were natural forest (NF), planted pine (PP), crop-livestock integration (CLI), and burned natural rangeland (BR). A sample survey was carried out in nine different areas for each land use. Samples were collected from four soil layers and the soil bulk density (Bd), total porosity (Tp), and macropore (Ma), micropore (Mi), and biopore (Bio) volumes were measured. Water infiltration tests were performed to obtain the initial (ii) and final (fi) water infiltration rates into the soil, and the total amount of water that had infiltrated the soil (Ti). In NF, Bd was lower and Tp was higher than in other types of land use. The forest vegetation (NF and PP) had higher Ma and Bio volumes in the superficial layers of the soil. Water infiltration was markedly different between land use types. The NF had the highest ii, fi, and Ti values followed by PP, whereas the CLI and BR areas had drastically lower infiltration parameters with BR having the lowest values. The variables ii, fi, and Ti correlated positively with Tp, Ma, and Bio, but negatively with Bd. ResumoO estudo das modificações nos atributos do solo provocadas pela forma de utilização das terras possibilita a adoção de medidas que reduzam riscos de futuros impactos. A pesquisa teve por objetivos quantificar atributos físicos do solo e a infiltração de água em diferentes modalidades de uso da terra no Planalto Sul Catarinense. O estudo foi conduzido em propriedade rural de 1.200 ha, onde foram selecionadas áreas sob floresta natural (FN), plantio de pinus (PP), integração lavoura-pecuária (ILP) e campo natural pastejado e submetido à queima (CN). Para isso, realizou-se levantamento amostral em nove glebas distintas para cada tipo de uso. Foram coletadas amostras de solo em quatro camadas para determinação da densidade do solo (Ds), porosidade total (Pt), macroporos (Ma), microporos (Mi) e bioporos (Bio).Testes de infiltração de água no solo foram realizados para obtenção das taxas de infiltração inicial (ii) e final (if) e da lâmina total infiltrada (It). Na FN a Ds é menor e a Pt maior do que nos demais tipos de uso da terra. A vegetação florestal (FN e PP) se destaca com maiores volumes de Ma e Bio nas camadas superficiais do solo. A infiltração de água apresenta diferenças acentuadas entre os tipos de uso. A FN tem maiores valores de ii, if e It, seguida pelo PP, enquanto CN e ILP tem redução drástica nos parâmetros de infiltração, com menores valores no CN. As variáveis ii, if e It correlacionam-se positivamente com Pt, Ma e Bio e negativamente com Ds. Palavras-chave: Qualidade do solo. Lavoura, pecuária e floresta. Permeabilidade do solo.
Water (WL), soil (SL), phosphorus (P) and potassium (K) losses by water erosion and subsurface flow are influenced by soil management and by soil fertilization with swine slurry (SS). The study was conducted between 09/2014 and 11/2015, in a Haplic Dystrudept, to evaluate the 0 (zero), 50, 100 and 200 m³ ha-1 SS doses applied to millet (Pennisetum americanum), black oats (Avena strigosa) and crotalaria (Crotalaria ochroleuca), compared with a soil without cultivation and without SS. The soil total porosity (Tp) and macroporosity (Ma), the P and K concentration in the soil, in the runoff, and in the subsurface flow, the dry mass of the aerial part (DM) of crops, and the WL and SL were determined. The main results show the application of SS in the soil results in an increase in Tp and Ma, as well as in the concentration of P and K in the soil and the DM of the plants, in relation to the absence of SS. Water erosion decreases with an increased dose of SS applied to the soil in the interval between 50 and 200 m3 ha-1. The increase in the dose of SS increases the concentration and total losses of P and K in the runoff and decreases the concentration of these nutrients in the subsurface flow in the interval between 50 and 200 m3 ha-1. The increase of DM of the plants, in the interval between 13.75 and 22.82 t ha-1 , decreases SL at an average rate of 2.90 t ha-1. The concentration of K in the subsurface flow water was negatively related to the concentration of the element in the subsurface flow.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.