Environmental vulnerability applied to the territorial planning of a tropical semiarid basin.

Tropical semiarid regions are naturally prone to environmental damage. Human activity can worsen this situation. To understand how human actions affect the ecosystem, plan land use effectively, and establish targeted management practices, assessing environmental vulnerability is crucial. This study focuses on a sub-basin receiving water transfers from the São Francisco River in Brazil's semiarid region. Here, we map and evaluate how land use and occupation alter natural vulnerability. We also propose zoning strategies to support water resource management and implement sustainable development policies in the region. To achieve this, we conducted an integrated analysis of physical factors (soil types, geology, climate, vegetation, and landforms) and spatial land-use data using geographic information systems (GIS) and map algebra techniques. Map algebra allowed us to combine these various datasets within the GIS environment, enabling the creation of maps that synthesize both natural and environmental vulnerability across the study area. Following analysis of these vulnerability maps, our findings reveal a high level of vulnerability. The areas with high to very high degrees of natural vulnerability coincide with the places that have high slopes, high altitudes, Lithic Neosols, and thick vegetation. Furthermore, the interaction between environmental factors and human activity exacerbates vulnerability. Based on the environmental vulnerability assessment, we defined four environmental management zones. These zones require distinct protection measures and management approaches. As a method to potentially improve the basin's vulnerability scenario, soil conservation measures are recommended. This approach is highly relevant for managing land in tropical semiarid regions and, with adaptations to specific regional factors, can be applied globally.

Beyond land use planning and ecosystem services assessment with the conservation use potential framework: A study in the Upper Rio das Velhas basin, Brazil.

Human actions can damage the ecosystems and affect the services depending on them, with ample detrimental consequences. In earlier studies, the Conservation Use Potential (PCU) framework proved useful in assessing the capacity for aquifer recharge, suitable land uses and resistance to erosion at the river basin scale. On the other hand, the joint analysis of PCU and land uses allowed identifying the adequacy of current uses in relation to suitability (natural uses) in various basins. This was especially useful from the management perspective in basins with environmental conflicts, where current uses differed from suitability, because the PCU indicated how and where the conflicts should be mitigated. Besides the use as management tool, the PCU has potential to shed light over environmental issues such as ecosystem services, but that was not tempted so far. The aim of this work was therefore to bridge that knowledge gap and frame the PCU's application from the standpoint of Ecosystem Services (ES) assessment. We demonstrated how the PCU could be used to improve provision (recharge), support (sustainable agriculture) and regulation (resistance to erosion) services in a specific basin with land use conflicts (the Upper Rio das Velhas basin, located in Minas Gerais, Brazil), through the planning of suitable uses. It was noted that the studied basin is mostly composed of Very Low, Low and Medium potentials. These classes occur because steep slopes, fragile soils and lithologies with high denudation potential and low nutrient supply dominate in the basin. On the other hand, urban sprawl has a negative impact on all ES, while maintaining agricultural areas with appropriate management can effectively regulate erosion. As per the current results, the premise of using the PCU as joint management-environmental tool was fully accomplished, and is recommended a basis for public policy design and implementation in Brazil and elsewhere.

Three Biannual Rotations Cycles with Residue Incorporation Affect Wheat Production and Chemical Soil Properties.

BACKGROUND: There are few reports of crop rotations with high residue incorporation in terms of their effects on indicator crop yields and soil properties, so this study evaluated the effect of two medium-term biannual rotations on wheat yield development and soil chemical properties after six years of rotation. METHODS: The experiment was conducted with two biannual rotations (canola-wheat and bean-wheat) and four residue incorporation levels (0%, 50%, 100%, and 200%) in an Andisol in south central Chile. Wheat grain yield and residue production were evaluated during each biannual cycle during three cycles of crop rotation, and soil chemical properties were evaluated at final evaluation. RESULTS: The use of beans as a wheat preculture partially improved grain yield in 7.3%. The chemical properties of the soil showed an increase in pH (0.08 units), organic matter content (15 g kg-1), and concentrations of P (2.8 mg kg-1), S (7.4 mg kg-1), and Al (0.03 cmol+ kg-1) after canola cultivation, while after bean cultivation there was an increase in the available N concentration (3.7 mg kg-1). The use of increasing doses of residue allowed for an increase in the soil pH and decrease in the exchangeable Al concentration. CONCLUSION: The continuous incorporation of the residues produced within the biannual rotations evaluated in this volcanic soil did contribute to improving some chemical properties of the soil without affecting wheat crop yield.

Can mulch be effective in controlling exotic grasses and promoting natural regeneration in ecological restoration?

Mulching use in agriculture has been known since 1802 as the practice of spreading dry leaves and straw on the soil to prevent erosion and water loss. Our study evaluated the mulch effectiveness in the establishment of regenerating seedlings and its contribution to the control of exotic grasses. The studies were carried out in an ecological restoration area in the municipality of Itapira-SP. The treatment with mulching consisted in chemical desiccation with glyphosate herbicide application, keeping the dry grass on the ground. In the control treatment, after chemical weeding, the grass was removed with manual mowing, exposing the soil. Eight months after implantation, we sampled all regenerating seedlings in 100 plots of 50 x 50 cm in each treatment. We considered as seedlings all individuals of tree species less than 100 cm tall. We calculated richness, abundance, similarity, and the relationship of the frequency of seedlings to the height of the mulch. We sampled eight species with 42 seedlings, with only one not identified. The highest abundance and species richness were found in the treatment with mulch (n = 34 individuals; eight species), the most abundant being Schinus terebinthifoliaRaddi (14 individuals) followed by Solanum mauritianumScop. (11 individuals), and Platypodium elegansVog. (three individuals). The presence of exoticgrasses was lower in the plots of the mulching (13%) compared to the control treatment (67%). The highest frequency of seedlings was obtained with mulch height from 21 to 37 cm. We suggest that adaptive management practices, such as the use of the mulching technique, can be implemented in ecological restoration areas, because they favor the natural regeneration of native seedlings and can contribute to the control of exotic grasses, but the height of the layer must be controlled.(AU)

Modeling of soil loss by water erosion in the Tietê River Hydrographic Basin, São Paulo, Brazil / Modelagem da perda de solo por erosão hídrica na Bacia Hidrográfica do Rio Tietê, São Paulo, Brasil

Since the mid-16th century, the Tietê River has been an important route for the territorial occupation and exploitation of natural resources in the interior of São Paulo and Brazil. Currently, the Tietê River is well known for environmental problems related to water pollution and contamination. However, little attention has been focused on water erosion, which is a serious issue that affects the soils and waters of the hydrographic basin. Thus, this work aimed to estimate soil loss caused by water erosion in this basin, which has an area of approximately 72,000 km², using the Revised Universal Soil Loss Equation (RUSLE). The RUSLE parameter survey and soil loss calculation were performed using geoprocessing techniques. The RUSLE estimated an average soil loss of 8.9 Mg ha-1 yr-1 and revealed that 18% of the basin's territory presents high erosion rates. These are priority zones for conservation practices to reduce water erosion and ensure long-term soil sustainability. The estimated sediment transport was 1.3 Mg ha-1 yr-1, whereas the observed sedimentation, which was calculated based on data from the fluviometric station, was 0.8 Mg ha-1 yr-1. Thus, the results were equivalent considering the large size of the study area and can be used to assist in managing the basin. Estimating soil losses can help in the planning of sustainable management of the Tietê River Hydrographic Basin and highlights the importance of minimizing water erosion, thus helping to prevent additional pollution and contamination with sediments, agrochemicals, and fertilizers.(AU)

Desde meados do século 16, o rio Tietê tem sido uma importante rota de ocupação territorial e exploração dos recursos naturais do interior de São Paulo e do Brasil. Atualmente, o Rio Tietê é bastante conhecido pelos problemas ambientais relacionados à poluição e contaminação das águas. No entanto, pouca atenção tem sido dada à erosão hídrica, que é um problema sério que afeta os solos e as águas da bacia hidrográfica. Assim, este trabalho teve como objetivo estimar as perdas de solo causadas pela erosão hídrica nesta bacia, que tem uma área de aproximadamente 72.000 km², utilizando a Equação Universal de Perdas de Solo Revisada (RUSLE). O levantamento dos parâmetros RUSLE e o cálculo das perdas de solo foram realizados utilizando técnicas de geoprocessamento. O RUSLE estimou uma perda média de solo de 8,9 Mg ha-1 ano-1 e revelou que 18% do território da bacia apresenta altas taxas de erosão. Estas são zonas prioritárias para práticas de conservação para reduzir a erosão hídrica e garantir a sustentabilidade do solo a longo prazo. O transporte de sedimentos estimado foi de 1,3 Mg ha-1 ano-1, enquanto a sedimentação observada, calculada com base nos dados da estação fluviométrica, foi de 0,8 Mg ha-1 ano-1. Assim, os resultados foram equivalentes considerando a grande extensão da área de estudo e podem ser utilizados para auxiliar na gestão da bacia. A estimativa das perdas de solo pode auxiliar no planejamento do manejo sustentável da Bacia Hidrográfica do Rio Tietê e destacar a importância de minimizar a erosão hídrica, auxiliando na prevenção de poluição adicional e contaminação por sedimentos, agroquímicos e fertilizantes.(AU)

Litter decomposition by soil fauna: effect of land use in agroecosystems.

Soil fauna plays a key role in organic matter decomposition. Litter decomposition depends on the relationships of soil fauna and microorganisms as well as climate and litter quality. The decomposer community is sensitive to land use. Thus, physical-chemical disturbances, like soil tillage, can exercise important control on the soil fauna. In order to study the effect of land use and its impact on litter decomposition by soil fauna, a litter-bag experiment was conducted in the Pampa Serrana region, Azul district, Argentina. Litter-bags were made in three different mesh-sizes, allowing the access of micro, micro + meso and micro + meso + macrofauna. Four different treatments were defined: naturalized grassland and three agricultural agroecosystems under different tillage systems, i.e., conservation tillage, conventional-conservation tillage and conventional tillage. Decomposition rate and remaining litter were measured across three different seasons. We found that naturalized grassland obtained the highest decomposition rates and the least remaining litter compared to conservation and conventional tillage systems. No difference in litter decomposition was identified among agricultural agroecosystems. Micro + meso + macrofauna presented the highest decomposition rate and the lowest remaining litter of soil fauna groups, in all agroecosystems. In contrast, microfauna decomposition rate was the lowest and produced the highest remaining litter. Micro + mesofauna presented values of decomposition rate and remaining litter that differed significantly from the rest of the groups in some seasons. These results highlight the importance of soil fauna in litter decomposition and the negative effects of different land use systems on litter decomposition by soil fauna.

Desenvolvimento de porta-enxerto de videira em consórcio com plantasde cobertura do solo / Development of vine rootstock in intercropped with soil cover crops

A utilização de plantas de cobertura do solo, no cultivo da videira é uma técnica importante, principalmente para regiões de clima tropical devido às elevadas temperaturas do ar e do solo. Objetivou-se com este trabalho avaliar o desenvolvimento do cultivar de porta-enxerto de videira IAC 572 ‘Jales’, consorciadocom diferentes plantas decobertura do solo. O experimento foi conduzido em área experimental da Universidade Estadual do Mato Grosso do Sul -Unidade Universitária de Cassilândia. O delineamento experimental foi em blocos ao acaso, com cinco repetições de duas plantas do porta-enxerto, totalizando dez plantas úteis por tratamento. Os tratamentos foram definidos pelas plantas de cobertura: milheto (Pennisetum glaucum); crotolária (Crotalaria juncea); e mamona (Ricinus communis). Foram avaliadas a altura das plantas, diâmetro de caule, número de ramos e teor relativo de clorofila. O desenvolvimento de porta-enxerto IAC 572 ‘Jales’, é favorecido pelo cultivo consorciado com crotalária e milheto na entrelinha de plantio, pois contribui para maior altura de plantas e maior teor relativo de clorofila. A utilização da cultura da mamona, em consórcio com o porta-enxerto, deve ser evitada. Tais resultados demonstram a importância de se conhecer a interação entre e espécie cultivada e as plantas de cobertura do solo. Desta forma, outras espécies devem ser avaliadas, para cultivo em consócio com a cultura da videira em regiões tropicais.

The use of soil cover crops in the cultivation of the vine is an important technique, especially for tropical climate regions due to high air and soil temperatures. Therefore, this work aimed to evaluate the development of the vine rootstock cultivar “IAC 572 ‘Jales’, intercropped with different types of soilcover plants in the Brazilian Cerrado. The experiment was conducted in an experimental area at the State University of Mato Grosso do Sul -Cassilândia University Unit. The experimental design performed on randomized blocks and with five replications of two rootstock plants, totaling ten useful plants per treatment. The treatments were defined by cover crops: millet (Pennisetum glaucum); crotalaria (Crotalaria juncea); and castor (Ricinus communis). Plant height, stem diameter, number of branches and relative chlorophyll content were evaluated. The development of IAC 572 'Jales' rootstock is favored by the intercropping with crotalaria and millet between the planting rows, as it contributes to greater plant height and higher relative chlorophyll content. The use of castor bean culture, in consortium with the rootstock, should be avoided. These results demonstrate the importance of knowing the interaction between the cultivated species and the ground cover crops. Thus, other species must be evaluated, for cultivation in association with the culture of the vine in tropical regions.

Effect of Amazonian tree species on soil and pasture quality in silvopastoral systems / Efeitos de espécies arbóreas amazônicas sobre o solo e qualidade daforragem em sistemas silvipastoris

With the expansion of livestock in the Amazon region, a high percentage of pasture areas are degraded and unproductive. Novel strategies are needed, including the use of native tree species, to simultaneously achieve economic and ecosystem benefits. This study aimed at assessing the effects of five multipurpose native tree species on soil fertility and forage quality of Urochloa brizantha pastures in the southern Amazon. Soil and forage samples were collected under the crown and adjacent to 25 isolated trees belonging to five species during a dry and a rainy season. The presence of native trees positively affected the level of potassium, calcium and manganese in the soil, as well as the mineral matter and crude protein of the forage, especially in the dry season, suggesting a protective effect against the seasonal drought. The tree species had variable effects on soil fertility and forage quality. Soil under Apeiba tibourbou had higher potassium levels, while the forage under Handroanthus serratifolius had higher protein and fiber content. Our results indicate that it is important to diversify silvopastoral systems in the Amazon through the use of native tree species, contributing to the design of novel silvopastoral strategies in the region. Common multipurpose tree species with widespread natural distribution could be used as a complementary aspect of pasture management to provide a protective effect against drought, contribute to enhanced nutrient cycling and even increase forage quality.

Com a expansão da pecuária na região amazônica, um alto percentual de pastagem está degradada e improdutiva. São necessárias novas estratégias, incluindo o uso de espécies de árvores nativas, para obter simultaneamente benefícios econômicos e ecossistêmicos. Este estudo objetivou avaliar os efeitos de cinco espécies arbóreas nativas multifuncionais na fertilidade do solo e qualidade da forragem em pastagens de Urochloa brizantha na Amazônia Meridional. Para isso, amostras de solo e forragem foram coletadas sob a copa e áreas adjacentes de 25 árvores isoladas pertencentes a cinco espécies durante uma estação seca e uma chuvosa. A presença de árvores nativas afetou positivamente o nível de potássio, calcio e magnésio no solo, bem como aumentou a matéria mineral e proteína bruta da forragem, especialmente na estação seca, sugerindo um efeito protetivo contra a seca sazonal. As espécies arbóreas tiveram efeitos variáveis sobre a fertilidade do solo e qualidade da forragem. O solo sob Apeiba tibourbou apresentou aumento nos teores de potássio, enquanto a forragem sob Handroanthus serratifolius apresentou melhor qualidade no que se refere a proteínas e fibras. Nosso estudo indica a importância da diversificação dos sistemas silvipastoris na Amazônia por meio do uso de espécies arbóreas nativas, contribuindo para o desenho de estratégias silvipastoris inovadoras na região. Espécies arbóreas multifuncionais comuns de ampla distribuição natural podem ser utilizadas como um aspecto complementar do manejo de pastagens para fornecer um efeito protetivo contra a seca, aprimorar a ciclagem de nutrientes e aumentar a qualidade da forragem.

Soil losses in the State of Rondônia, Brazil / Perdas de solo no Estado de Rondônia, Brasil

In the state of Rondônia, deforestation, and inadequate soil use and management have intensified the water erosion process, causing degradation of agricultural land. Modeling is a tool that can assist in the adoption of targeted and effective measures for soil and water conservation in the region. In this context, the objective of the research was to model soil losses due to water erosion in the state of Rondônia using the Revised Universal Soil Loss Equation (RUSLE). The parameters related to rain erosivity, relief, erodibility, and soil cover, as well as the conservation practices of the state of Rondônia, were considered. The modeling steps were performed with the aid of the Geographic Information System. Results were validated with data of total sediments transported with water discharge. The estimated total soil loss was about 605 million tons per year, corresponding to an average loss of 22.50 Mg ha-1 year-1. In 19% of the state, the erosion rate was higher than the soil loss tolerance(T), and these areas should be prioritized for adopting measures to mitigate the erosion process. The RUSLE underestimated the generation of sediments at 0.56 Mg ha-1 year-1, which corresponds to an error of 18.60%. Results obtained can assist in the development of different soil use and management scenarios and provide options for policymakers to encourage soil conservation in the state of Rondônia.(AU)

No Estado de Rondônia, o desmatamento, o uso e o manejo inadequado dos solos têm intensificado o processo de erosão hídrica, gerando a degradação de terras agrícolas. Nesse cenário, a modelagem é uma ferramenta que pode auxiliar na adoção de medidas direcionadas e eficazes de conservação do solo e da água na região. Assim, o objetivo do trabalho foi modelar as perdas de solo por erosão hídrica no Estado de Rondônia utilizando a Equação Universal de Perda de Solo Revisada (RUSLE). Foram considerados os parâmetros referentes a erosividade da chuva, relevo, erodibilidade e cobertura do solo e as práticas conservacionistas do Estado de Rondônia. As etapas da modelagem foram realizadas com auxílio de Sistema de Informações Geográficas. Os resultados foram validados com dados de coleta de sedimentos totais transportados com a descarga dágua. A perda de solo total estimada foi cerca de 605 milhões de toneladas ao ano, correspondente a uma perda média de 22,50 Mg ha-1 ano-1. Em 19% do Estado a taxa erosiva foi superior aos limites de tolerância de perda de solo (TPS), sendo que essas áreas devem ser priorizadas para adoção de medidas de mitigação do processo erosivo. A RUSLE subestimou a geração de sedimentos em 0,56 Mg ha-1 ano-1, o que corresponde a um erro de 18,60%. Os resultados obtidos podem contribuir para elaborar distintos cenários de manejo e uso do solo e fornecer alternativas aos formuladores de políticas agrícolas e ambientais, com o intuito de incentivo a conservação do solo no Estado de Rondônia.(AU)

Effect of Amazonian tree species on soil and pasture quality in silvopastoral systems / Efeitos de espécies arbóreas amazônicas sobre o solo e qualidade daforragem em sistemas silvipastoris

With the expansion of livestock in the Amazon region, a high percentage of pasture areas are degraded and unproductive. Novel strategies are needed, including the use of native tree species, to simultaneously achieve economic and ecosystem benefits. This study aimed at assessing the effects of five multipurpose native tree species on soil fertility and forage quality of Urochloa brizantha pastures in the southern Amazon. Soil and forage samples were collected under the crown and adjacent to 25 isolated trees belonging to five species during a dry and a rainy season. The presence of native trees positively affected the level of potassium, calcium and manganese in the soil, as well as the mineral matter and crude protein of the forage, especially in the dry season, suggesting a protective effect against the seasonal drought. The tree species had variable effects on soil fertility and forage quality. Soil under Apeiba tibourbou had higher potassium levels, while the forage under Handroanthus serratifolius had higher protein and fiber content. Our results indicate that it is important to diversify silvopastoral systems in the Amazon through the use of native tree species, contributing to the design of novel silvopastoral strategies in the region. Common multipurpose tree species with widespread natural distribution could be used as a complementary aspect of pasture management to provide a protective effect against drought, contribute to enhanced nutrient cycling and even increase forage quality.(AU)

Com a expansão da pecuária na região amazônica, um alto percentual de pastagem está degradada e improdutiva. São necessárias novas estratégias, incluindo o uso de espécies de árvores nativas, para obter simultaneamente benefícios econômicos e ecossistêmicos. Este estudo objetivou avaliar os efeitos de cinco espécies arbóreas nativas multifuncionais na fertilidade do solo e qualidade da forragem em pastagens de Urochloa brizantha na Amazônia Meridional. Para isso, amostras de solo e forragem foram coletadas sob a copa e áreas adjacentes de 25 árvores isoladas pertencentes a cinco espécies durante uma estação seca e uma chuvosa. A presença de árvores nativas afetou positivamente o nível de potássio, calcio e magnésio no solo, bem como aumentou a matéria mineral e proteína bruta da forragem, especialmente na estação seca, sugerindo um efeito protetivo contra a seca sazonal. As espécies arbóreas tiveram efeitos variáveis sobre a fertilidade do solo e qualidade da forragem. O solo sob Apeiba tibourbou apresentou aumento nos teores de potássio, enquanto a forragem sob Handroanthus serratifolius apresentou melhor qualidade no que se refere a proteínas e fibras. Nosso estudo indica a importância da diversificação dos sistemas silvipastoris na Amazônia por meio do uso de espécies arbóreas nativas, contribuindo para o desenho de estratégias silvipastoris inovadoras na região. Espécies arbóreas multifuncionais comuns de ampla distribuição natural podem ser utilizadas como um aspecto complementar do manejo de pastagens para fornecer um efeito protetivo contra a seca, aprimorar a ciclagem de nutrientes e aumentar a qualidade da forragem.(AU)

Desenvolvimento de porta-enxerto de videira em consórcio com plantasde cobertura do solo / Development of vine rootstock in intercropped with soil cover crops

A utilização de plantas de cobertura do solo, no cultivo da videira é uma técnica importante, principalmente para regiões de clima tropical devido às elevadas temperaturas do ar e do solo. Objetivou-se com este trabalho avaliar o desenvolvimento do cultivar de porta-enxerto de videira IAC 572 ‘Jales, consorciadocom diferentes plantas decobertura do solo. O experimento foi conduzido em área experimental da Universidade Estadual do Mato Grosso do Sul -Unidade Universitária de Cassilândia. O delineamento experimental foi em blocos ao acaso, com cinco repetições de duas plantas do porta-enxerto, totalizando dez plantas úteis por tratamento. Os tratamentos foram definidos pelas plantas de cobertura: milheto (Pennisetum glaucum); crotolária (Crotalaria juncea); e mamona (Ricinus communis). Foram avaliadas a altura das plantas, diâmetro de caule, número de ramos e teor relativo de clorofila. O desenvolvimento de porta-enxerto IAC 572 ‘Jales, é favorecido pelo cultivo consorciado com crotalária e milheto na entrelinha de plantio, pois contribui para maior altura de plantas e maior teor relativo de clorofila. A utilização da cultura da mamona, em consórcio com o porta-enxerto, deve ser evitada. Tais resultados demonstram a importância de se conhecer a interação entre e espécie cultivada e as plantas de cobertura do solo. Desta forma, outras espécies devem ser avaliadas, para cultivo em consócio com a cultura da videira em regiões tropicais.(AU)

The use of soil cover crops in the cultivation of the vine is an important technique, especially for tropical climate regions due to high air and soil temperatures. Therefore, this work aimed to evaluate the development of the vine rootstock cultivar “IAC 572 ‘Jales, intercropped with different types of soilcover plants in the Brazilian Cerrado. The experiment was conducted in an experimental area at the State University of Mato Grosso do Sul -Cassilândia University Unit. The experimental design performed on randomized blocks and with five replications of two rootstock plants, totaling ten useful plants per treatment. The treatments were defined by cover crops: millet (Pennisetum glaucum); crotalaria (Crotalaria juncea); and castor (Ricinus communis). Plant height, stem diameter, number of branches and relative chlorophyll content were evaluated. The development of IAC 572 'Jales' rootstock is favored by the intercropping with crotalaria and millet between the planting rows, as it contributes to greater plant height and higher relative chlorophyll content. The use of castor bean culture, in consortium with the rootstock, should be avoided. These results demonstrate the importance of knowing the interaction between the cultivated species and the ground cover crops. Thus, other species must be evaluated, for cultivation in association with the culture of the vine in tropical regions.(AU)

The Effect of Soil Management on Pore Size Distribution and Water Infiltration

Abstract Water infiltration into soil varies significantly with soil type and management practices. Management practices alter soil physical properties, such as porosity and pore size distribution, which play an important role in infiltration. This study was conducted to assess the effect of the long-term use of two different soil tillage systems (conventional, CT, and no-tillage, NT) on soil structure and water infiltration to understanding of the relationship between physical conditions induced by tillage and water infiltration. The experiments were carried out on a Humic Cambisol in southern Brazil from 1995 to 2016. Soil density, porosity, aggregate diameter and soil water infiltration were evaluated under conventional tillage right after one plowing and two subsequent discings (CT0), and six months after these tillage operations (CT6). The results show that different management systems affect differently soil physical properties and, thus, water infiltration. By mechanical mobilization CT brings about modifications in soil structure which promote an increase in total porosity and mesopority, and a decrease in soil microporosity. This in turn results in an increase in the proportion of larger pores in the plow layer and a decrease in soil density, but also in a decrease in aggregate stability. The CT0 measurements showed the highest infiltration rates which were up to 15 times greater than in the NT treatment. The higher infiltration rate in CT0 wears off with time, but in the CT6 measurements six months after tillage it was still 2 times higher than under NT. Tillage, at least initially, increases total porosity and mesoporosity, while at the same time decreasing microporosity. This results in a larger saturated hydraulic conductivity (K). An increase in total porosity alone does not necessarily increase K, if there is an increase in small pores at the cost of decreasing the number of larger pores.

Soil losses in the State of Rondônia, Brazil / Perdas de solo no Estado de Rondônia, Brasil

ABSTRACT: In the state of Rondônia, deforestation, and inadequate soil use and management have intensified the water erosion process, causing degradation of agricultural land. Modeling is a tool that can assist in the adoption of targeted and effective measures for soil and water conservation in the region. In this context, the objective of the research was to model soil losses due to water erosion in the state of Rondônia using the Revised Universal Soil Loss Equation (RUSLE). The parameters related to rain erosivity, relief, erodibility, and soil cover, as well as the conservation practices of the state of Rondônia, were considered. The modeling steps were performed with the aid of the Geographic Information System. Results were validated with data of total sediments transported with water discharge. The estimated total soil loss was about 605 million tons per year, corresponding to an average loss of 22.50 Mg ha-1 year-1. In 19% of the state, the erosion rate was higher than the soil loss tolerance(T), and these areas should be prioritized for adopting measures to mitigate the erosion process. The RUSLE underestimated the generation of sediments at 0.56 Mg ha-1 year-1, which corresponds to an error of 18.60%. Results obtained can assist in the development of different soil use and management scenarios and provide options for policymakers to encourage soil conservation in the state of Rondônia.

RESUMO: No Estado de Rondônia, o desmatamento, o uso e o manejo inadequado dos solos têm intensificado o processo de erosão hídrica, gerando a degradação de terras agrícolas. Nesse cenário, a modelagem é uma ferramenta que pode auxiliar na adoção de medidas direcionadas e eficazes de conservação do solo e da água na região. Assim, o objetivo do trabalho foi modelar as perdas de solo por erosão hídrica no Estado de Rondônia utilizando a Equação Universal de Perda de Solo Revisada (RUSLE). Foram considerados os parâmetros referentes a erosividade da chuva, relevo, erodibilidade e cobertura do solo e as práticas conservacionistas do Estado de Rondônia. As etapas da modelagem foram realizadas com auxílio de Sistema de Informações Geográficas. Os resultados foram validados com dados de coleta de sedimentos totais transportados com a descarga d'água. A perda de solo total estimada foi cerca de 605 milhões de toneladas ao ano, correspondente a uma perda média de 22,50 Mg ha-1 ano-1. Em 19% do Estado a taxa erosiva foi superior aos limites de tolerância de perda de solo (TPS), sendo que essas áreas devem ser priorizadas para adoção de medidas de mitigação do processo erosivo. A RUSLE subestimou a geração de sedimentos em 0,56 Mg ha-1 ano-1, o que corresponde a um erro de 18,60%. Os resultados obtidos podem contribuir para elaborar distintos cenários de manejo e uso do solo e fornecer alternativas aos formuladores de políticas agrícolas e ambientais, com o intuito de incentivo a conservação do solo no Estado de Rondônia.

Production and profitability of crop rotation systems in southern Brazil / Produção e rentabilidade de sistemas de rotação de culturas no sul do Brasil

Crop rotation is one of the pillars of conservation agriculture. This practice has offered a series of advantages in terms of improving soil physical, chemical, and biological conditions. These advantages result in yield increases for all economic crops involved in the rotation systems and may also reduce production costs. In this context, the aim of this study was to compare the profitability of crop rotation systems with different levels of crop diversification. The experimental design was randomized blocks, with five treatments and four replications. The treatments included one less diversified crop rotation system (control) with soybean and wheat and four more diversified crop rotation systems (involving three or more species), including soybean, wheat, black oats, maize, canola, barley, blue lupine, white oats, beans, radish, triticale, rye, hairy vetch, and sorghum, under no-tillage conducted during a threeyear cycle. Analyses were conducted considering productivity, operating cost, and economic profit. The highest accumulated gross yields were obtained in the more diversified crop rotation systems. The results show that the more diversified crop rotation systems were more profitable. When the opportunity cost was included, the most diversified crop rotations presented greater economic feasibility. The less diversified crop rotation system presented a negative economic profit. The crop rotation systems including beans presented the highest economic profit.(AU)

A rotação de culturas é um dos pilares da agricultura de conservacionista. Esta prática tem uma série de vantagens, melhorando as condições físicas, químicas e biológicas do solo. Isto resulta em aumentos de produtividade de todas as culturas econômicas envolvidas nos sistemas de rotação, podendo também reduzir os custos de produção. Neste contexto, o objetivo deste estudo foi comparar a rentabilidade dos sistemas de rotação de culturas com diferentes níveis de diversificação. O desenho experimental foi de blocos ao acaso, com cinco tratamentos e quatro repetições. Os tratamentos foram compostos de um sistema de rotação de culturas pouco diversificado (controle), com trigo no inverno, seguido de soja no verão, e quatro sistemas de rotação de culturas diversificados (envolvendo três ou mais espécies), incluindo soja, trigo, aveia preta, milho, canola, cevada, tremoço azul, aveia branca, feijão, rabanete, triticale, centeio, ervilhaca peluda, sorgo e trigo mourisco, conduzido em plantio direto, por um ciclo de três anos. Para as análises foram considerados a produtividade, a receita, o custo operacional, a margem bruta e o lucro econômico. Os maiores rendimentos brutos foram obtidos em sistemas de rotação de culturas mais diversificados. Os resultados mostram que sistemas mais diversificados de rotação de culturas são mais rentáveis e economicamente mais vantajosos. Quando considerado o custo de oportunidade, apenas as rotações de culturas mais diversificadas apresentaram viabilidade econômica. O sistema de rotação de culturas menos diversificado não apresentou lucro econômico. Os sistemas de rotação de culturas que incluíam o feijão foram os apresentaram o melhor desempenho econômico.(AU)

Modelagem espacial da erosão hídrica do solo associada à sazonalidade agroclimática na região sul do Rio Grande do Sul, Brasil / Spatial modeling of soil water erosion associated with agroclimatic seasonality in the southern region of Rio Grande do Sul, Brazil

RESUMO A erosão hídrica constitui um sério problema de degradação do solo, com impacto em diversas áreas. Sua mensuração é de extrema importância e onerosa. Os modelos empíricos de estimativa de perdas de solo, como a Equação Universal de Perda de Solo Revisada (RUSLE), são utilizados para suprir essa demanda. Consideram-se poucos estudos no Brasil que avaliam o efeito da sazonalidade agroclimática nas estimativas de perda de solo por erosão hídrica em bacias hidrográficas. Dessa forma, o objetivo deste estudo foi avaliar a sazonalidade agroclimática na estimativa de perdas de solo por meio da RUSLE e identificar os fatores que controlam a erosão na Bacia Hidrográfica do Arroio Fragata (BHAF). O fator erosividade da chuva (R) e a média anual de precipitação foram calculados por meio de dados de quatro estações pluviométricas.. O fator erodibilidade do solo (K) foi obtido a partir de informações de solo. O fator topográfico (LS) foi gerado com base no modelo digital de elevação (MDE) e o fator cobertura do solo e práticas conservacionistas (CP) por meio de imagens do satélite Landsat8/OLI. A variação sazonal teve efeito na perda de solo, com maiores taxas de erosão no período de verão e primavera. Perdas de solo entre 5 e 50 Mg ha-1ano-1 foram registradas em 24% da BHAF, associadas a períodos de chuvas mais erosivas, maior declividade e baixa cobertura vegetal. Os fatores da RUSLE com maior contribuição na erosão foram R, LS e CP. A abordagem apresentada pode ser útil para quantificar as perdas de solo em bacias hidrográficas.

ABSTRACT Water erosion is a serious soil degradation problem, with impact in several areas. Its measurement is extremely important and costly. Empirical models of soil loss estimation, such as the revised universal soil loss equation (RUSLE), are used to meet this demand. Few studies in Brazil are considered to evaluate the effect on agroclimatic seasonality in the estimates of soil loss due to water erosion in watersheds. Thus, the objective of this study was to evaluate the agroclimatic seasonality in the estimation of soil losses through RUSLE and to identify the factors that control erosion in the watershed of the Fragata stream. Rainfall erosivity (R) was calculated by means of precipitation data for four seasons and annual average. The soil erodibility factor (K) was obtained from soil information. The topographic factor (LS) was generated from the Digital Elevation Model (MDE) and the soil cover factor and conservationist practices (CP) through Landsat8/OLI satellite images. Seasonal variation had an effect on soil loss, with higher erosion rates in the summer and spring months. Soil losses between 5 and 50 Mg ha-1ano-1 were recorded in 24% of the BHAF, associated with periods of more erosive rainfall, higher slope and low vegetation cover. RUSLE factors with the greatest contribution to erosion were R, LS, and CP. The approach presented can be useful in quantifying soil losses in river basins.

Composition of the soil fauna community and leaf litter stock in agro-forestry systems and secondary forestry / Composição da comunidade da fauna do solo e estoque da serapilheira foliar em sistemas agroflorestais e floresta secundária

Agro-Forestry Systems (AFS), in addition to being a means of providing income, can be considered an alternative way of helping conserve biodiversity, both above and below ground. The aim of this study was to evaluate the accumulation of tree leaf litter and its nutrient content as well as the composition of fauna in the soil-litter layer in two Agro-Forestry Systems (AFS-1 and AFS-2), using as reference an area of secondary Forest (SF), in the Quilombola do Campinho da Independência community, Paraty, in the state of Rio de Janeiro (RJ), Brazil. The collection of accumulated leaf litter and soil-litter fauna was carried out from four sample points in each area and at two different seasons of the year, the rainy and the dry season. The leaf litter stock and its nutrient content (Ca, Mg, P, K and N) were measured. The extraction of fauna was carried out according to Tüllgren's method, modifying the Berlese funnel. The stock of accumulated leaf litter differed between the two areas only in the rainy season; the amounts were smaller in AFS-2. In general, the Agro-Forestry Systems were very similar to the secondary forest in terms of levels and/or stock of nutrients in the majority of cases, at least in one of the seasons studied. The composition of the soil fauna groups in the Agro-Forestry System (AFS-1 and AFS-2) had a high degree of similarity to that found in the forest, and these systems mainly favour the populations of groups like Collembola and Formicidae.

Os sistemas agroflorestais (SAFs) além de proporcionarem geração de renda, podem ser considerados como uma alternativa para conservação da biodiversidade, tanto acima quanto abaixo da superfície do solo. O objetivo desse estudo foi avaliar o estoque de serapilheira acumulada e seus estoques de nutrientes, bem como, a composição da fauna do conjunto solo-serapilheira, em dois sistemas agroflorestais (SAF-1 e SAF-2), utilizando como referência uma área de floresta secundária (FS), na comunidade Quilombola do Campinho da Independência, Paraty - RJ. A coleta da serapilheira acumulada e da fauna do sistema solo-serapilheira foi realizada a partir de quatro pontos amostrais em cada área, em duas épocas do ano, seca e chuvosa. Foi quantificado o estoque de serapilheira foliar, e seus estoques e teores de nutrientes (Ca, Mg, P, K e N). A extração da fauna foi realizada a partir do método modificado de Tüllgren, baseado no funil de Berlese. O estoque de serapilheira foliar acumulada só variou entre as áreas na estação chuvosa, sendo os menores valores quantificados no SAF-2. De maneira geral, os sistemas agroflorestais apresentaram semelhanças em comparação com a floresta para a maioria dos teores e/ou estoques de nutrientes, em pelo menos uma das épocas de avaliação. A composição dos grupos da fauna do solo dos sistemas agroflorestais (SAF-1 e SAF-2) apresentou um elevado grau de similaridade com a floresta, e estes sistemas favoreceram principalmente as populações de grupos como os Collembola e Formicidae.

Production and profitability of crop rotation systems in southern Brazil / Produção e rentabilidade de sistemas de rotação de culturas no sul do Brasil

Crop rotation is one of the pillars of conservation agriculture. This practice has offered a series of advantages in terms of improving soil physical, chemical, and biological conditions. These advantages result in yield increases for all economic crops involved in the rotation systems and may also reduce production costs. In this context, the aim of this study was to compare the profitability of crop rotation systems with different levels of crop diversification. The experimental design was randomized blocks, with five treatments and four replications. The treatments included one less diversified crop rotation system (control) with soybean and wheat and four more diversified crop rotation systems (involving three or more species), including soybean, wheat, black oats, maize, canola, barley, blue lupine, white oats, beans, radish, triticale, rye, hairy vetch, and sorghum, under no-tillage conducted during a threeyear cycle. Analyses were conducted considering productivity, operating cost, and economic profit. The highest accumulated gross yields were obtained in the more diversified crop rotation systems. The results show that the more diversified crop rotation systems were more profitable. When the opportunity cost was included, the most diversified crop rotations presented greater economic feasibility. The less diversified crop rotation system presented a negative economic profit. The crop rotation systems including beans presented the highest economic profit.

A rotação de culturas é um dos pilares da agricultura de conservacionista. Esta prática tem uma série de vantagens, melhorando as condições físicas, químicas e biológicas do solo. Isto resulta em aumentos de produtividade de todas as culturas econômicas envolvidas nos sistemas de rotação, podendo também reduzir os custos de produção. Neste contexto, o objetivo deste estudo foi comparar a rentabilidade dos sistemas de rotação de culturas com diferentes níveis de diversificação. O desenho experimental foi de blocos ao acaso, com cinco tratamentos e quatro repetições. Os tratamentos foram compostos de um sistema de rotação de culturas pouco diversificado (controle), com trigo no inverno, seguido de soja no verão, e quatro sistemas de rotação de culturas diversificados (envolvendo três ou mais espécies), incluindo soja, trigo, aveia preta, milho, canola, cevada, tremoço azul, aveia branca, feijão, rabanete, triticale, centeio, ervilhaca peluda, sorgo e trigo mourisco, conduzido em plantio direto, por um ciclo de três anos. Para as análises foram considerados a produtividade, a receita, o custo operacional, a margem bruta e o lucro econômico. Os maiores rendimentos brutos foram obtidos em sistemas de rotação de culturas mais diversificados. Os resultados mostram que sistemas mais diversificados de rotação de culturas são mais rentáveis e economicamente mais vantajosos. Quando considerado o custo de oportunidade, apenas as rotações de culturas mais diversificadas apresentaram viabilidade econômica. O sistema de rotação de culturas menos diversificado não apresentou lucro econômico. Os sistemas de rotação de culturas que incluíam o feijão foram os apresentaram o melhor desempenho econômico.

Flow accumulation based method for the identification of erosion risk points in unpaved roads.

The unsuitable construction of unpaved roads has been causing problems related to the formation of erosive processes, sediments in watersheds, bogs, flooding, and holes. Presuming that the areas where flow accumulation intersects unpaved roads represent risk points, our objectives are (1) to develop a qualitative method based on the GIS software management tool (FlowAccRoad) for the identification of the intersection points between flow accumulation and roads and (2) to verify the discrepancy between the points of intersection produced by digital elevation models (DEM) accounting for different spatial resolutions. In the GIS environment, we used the Shuttle Radar Topography Mission (SRTM) and Goiania (GOI) digital elevation models for the modeling of flow accumulation and vectorization of the unpaved roads, both of which are based on the Bandeira Stream Watershed in Goiania, Goiás, Brazil. This highlights that 54 points of intersection between the flow accumulation and unpaved roads present problems related to erosive processes and quagmires, among others. The FlowAccRoad method identified the principal critical points observed in the field, using both the DEM of 30.4 m of spatial resolution (SRTM) and also of 4.8 m of spatial resolution (GOI). From the FlowAccRoad method, we observed that 91% of the risk points identified through the GOI DEM were located less than 20 m from valid points in the field by using GPS. Analyzing the SRTM DEM, only 45% of the critical risk points identified by the method were located less than 20 m from valid points in the field.

Efectividad de cuatro prácticas agroecológicas de conservación de suelos, frente a procesos erosivos hídricos en Guasca - Cundinamarca / Effectiveness of four agroecological soil conservation practices against water erosion processes in hillside soils in Guasca-Cundinamarca / Efetividade de quatro práticas agroecológicas de conservação de solos contra processos de erosão em Guasca -Cundinamarca

Resumen Introducción. Una cuarta parte de los suelos agrícolas del mundo padece algún grado de deterioro, especialmente por factores antrópicos, no obstante, reducir el daño es posible cuando se desarrollan prácticas adecuadas de producción. Objetivo. Evaluar la efectividad de prácticas agroecológicas de conservación de suelos de ladera en el municipio de Guasca - Cundinamarca. Materiales y métodos. Se establecieron cuatro tratamientos: barreras vivas, barreras muertas, zanjas de infiltración, terrazas y un testigo, por cada tratamiento se realizaron 4 repeticiones, para un total de 20 unidades experimentales (UE). Se establecieron cultivos asociados de arveja (Pisum sativum), fríjol (Phaseolus vulgaris) y zanahoria (Daucus carota), en surcos en contrapendiente, obteniendo 6 surcos por UE. En cada UE se instaló una zanja recubierta con polietileno, con el objetivo de conducir el volumen de agua escurrido y los sólidos arrastrados al recipiente colector final. Del volumen obtenido, después de una respectiva homogenización con un agitador manual, se obtuvieron muestras de 200 ml para posteriormente secarlas y pesarlas en laboratorio. Resultados. Las pérdidas de suelo y agua por escorrentía presentaron un comportamiento variable, lo que puede ser atribuido a la interacción entre la intensidad y frecuencia de las precipitaciones, textura de suelo, manejo histórico del suelo y la variedad de prácticas de conservación empleadas. Conclusión. Todas las prácticas de conservación de suelos implementadas contribuyeron a reducir la pérdida de sedimentos, siendo las zanjas de infiltración la mejor práctica de conservación, presentando una reducción del 87,8 % de las pérdidas frente al testigo.

Abstract Introduction. A quarter of the world's agricultural soils suffer some degree of deterioration, especially due to anthropic factors. However, regeneration of soils is possible when conservation strategies are developed. Objective. Evaluate the effectiveness of soil conservation agroecological practices in the retention of hillside soils in the municipality of Guasca-Cundinamarca. Materials and methods. Four treatments were established: live barriers, dead barriers, infiltration ditches, terraces and a control. For each treatment, four repetitions were performed, for a total of 20 experimental units (EU). Pea (Pisum sativum), bean (Phaseolus vulgaris) and carrot (Daucus carota) crops were established in furrows in counter-slope, obtaining 6 furrows per EU. In each EU a ditch covered with polyethylene was installed, with the aim of driving the volume of drained water and the solids dragged towards a final collector vessel. From the volume obtained, after a respective homogenization with a manual agitator, samples of 200 ml were obtained for subsequent drying and weighing in the laboratory. Results. The losses of soil and water by runoff presented a variable behavior, which can be attributed to the interaction among factors such as intensity and frequency of rainfall, soil texture, historical soil management and the variety of conservation practices used. Conclusion. All the soil conservation practices implemented contributed to reduce the loss of sediments, infiltration ditches being the best conservation practice, presenting an 87.8 % reduction in losses compared with the control.

Resumo Introdução. Uma quarta parte dos solos agrícolas do mundo padece algum grau de deterioro, especialmente por fatores antrópicos, não obstante, reduzir o dano é possível quando se desenvolvem práticas adequadas de produção. Objetivo. Avaliar a efetividade das práticas agroecológicas de conservação dos solos de ladeira no município de Guasca - Cundinamarca. Materiais e métodos. Estabeleceram-se quatro tratamentos: barreiras vivas, barreiras mortas, trincheiras de infiltração, terraços e um controle, por cada tratamento realizaram-se 4 repetições, para um total de 20 unidades experimentais (UE). Estabeleceram-se culturas associadas de ervilha (Pisum sativum), feijão (Phaseolus vulgaris) e cenoura (Daucus carota), em sulcos em contra pendente, obtendo 6 sulcos por UE. Em cada UE instalou-se uma trincheira recoberta com polietileno, com o objetivo de conduzir o volume de água escorrido e os sólidos arrastrados ao recipiente coletor final. Do volume obtido, despois de uma respetiva homogeneização com um agitador manual, obtiveram-se amostras de 200 ml para posteriormente serem secadas e pesadas no laboratório. Resultados. As perdas do solo e água pelo escorrimento apresentaram um comportamento variável, o que pode ser atribuído à interação entre a intensidade e a frequência das precipitações, textura de solo, manejo histórico do solo e a variedade das práticas de conservação empregadas. Conclusão. Todas as práticas de conservação de solos implementadas contribuíram a reduzir a perda de sedimentos, sendo as trincheiras de infiltração a melhor prática de conservação, apresentando uma redução do 87,8 % das perdas frente ao controle.

Modeling of water erosion by the erosion potential method in a pilot subbasin in southern Minas Gerais / Modelagem da erosão hídrica pelo método de erosão potencial em uma sub-bacia hidrográfica de referência no sul de Minas Gerais

Soil losses due to water erosion threaten the sustainability of agriculture and the food security of current and future generations. This study estimated potential soil losses and sediment production under different types of land uses in a subbasin in the Municipality of Alfenas, southern Minas Gerais, southeastern Brazil. The objective of this research was to evaluate the application of the Potential Erosion Method by the Intensity of Erosion and Drainage program and correlate the findings with the results obtained by the Revised Universal Soil Loss Equation as well as geoprocessing techniques and statistical analyses. In the Potential Erosion Method, the coefficient indicating the mean erosion intensity was 0.37, which corresponded to erosion category IV and indicated weak laminar erosion processes, and the total soil loss was 649.31 Mg year-1 and the mean was 1.46 Mg ha-1 year-1. These results were consistent in magnitude with those obtained in the Revised Universal Soil Loss Equation, which estimated a mean soil loss of 1.52 Mg ha-1 year-1 and a total soil loss of 668.26 Mg year-1. The Potential Erosion Method suggests that 1.5% of the area presents potential soil losses above the soil loss tolerance limit, which ranged from 5.19 to 5.90 Mg ha-1 year-1, while the Revised Universal Soil Loss Equation indicated that 7.3% of the area has potential soil losses above the limit. The maximum sediment discharge was 60 Mg year-1, meaning that 9.3% of the total soil loss reached the depositional areas of the river plains orwatercourses. The Potential Erosion Method was efficient in the evaluation of water erosion in tropical soils, and the results were consistent with models widely employed in the estimation of soil losses. Thus, the model can support the evaluation of soil losses in Brazil and is a robust tool for evaluating thesustainability of agricultural activities.(AU)

Perdas de solo por erosão hídrica colocam em risco a sustentabilidade agrícola e a segurança alimentar das gerações atuais e futuras. Assim, este trabalho estimou as perdas potenciais de solo e a produção de sedimentos em diferentes tipos de usos da terra em uma sub-bacia hidrográfica no Município de Alfenas, sul de Minas Gerais, Sudeste do Brasil. A pesquisa teve como objetivo avaliar a aplicação do Método de Erosão Potencial pelo programa Intensidade de Erosão e Escoamento, correlacionando com os resultados obtidos pela Equação Universal de Perdas de Solo Revisada, aliado às técnicas de geoprocessamento e de análise estatística. No Método de Erosão Potencial, o coeficiente que indica a intensidade média da erosão foi de 0,37, ou categoria IV de deterioração, que aponta processos de erosão laminar de grau fraco, com perda total de solo de 649,31 Mg ano-1 e média de 1,46 Mg ha-1 ano-1. Os resultados corresponderam, em magnitude, aos obtidos na Equação Universal de Perdas de Solo Revisada, com perda média de solo de 1,52 Mg ha-1 ano-1 e total de 668,26 Mg ano-1. O Método de Erosão Potencial sugere que 1,5% da área possui perdas potenciais de solo acima do limite da Tolerância de Perda de Solo, que variou de 5,19 a 5,90 Mg ha-1 ano-1, enquanto a Equação Universal de Perdas de Solo Revisada indicou que 7,3% da área possui perdas potenciais de solo acima do limite. A descarga máxima de sedimentos foi de 60 Mg ano-1, ou seja, 9,3% da perda total de solo atinge asáreas deposicionais do deflúvio ou cursos dágua. O Método de Erosão Potencial mostrou eficiência naavaliação da erosão hídrica em solos tropicais, com resultados consistentes com modelos amplamenteempregados na estimativa de perdas de solo, e dão suporte para a avaliação das perdas de solo no Brasil,sendo assim, uma ferramenta robusta para avaliar a sustentabilidade das atividades agrícolas.(AU)