The faxinal management system is an endangered agro-silvopastoral system which forms part of the local traditional management in the Paraná federal state (Brazil). Significant changes in land management since the 1970s caused farmers to look for alternatives to increase the productivity of their farms. The introduction of new pasture species is causing land degradation problems, of which soil erosion is the most important challenge. Therefore, in this study, we assessed the environmental consequences of introducing exotic pasture species, such as Brachiaria decumbens. To achieve this goal, ten erosion plots were installed with exotic and native pastures (Paspalum notatum Flüggé) to quantify soil and water losses in paired plots. Total rainfall per event, soil properties (soil cover, texture, organic matter, bulk density, porosity, and soil penetration resistance), and pasture production were also estimated. Our results showed a decrease in organic matter and porosity and an increase of the bulk density in the exotic pasture plots. Soil erosion monitoring showed higher soil losses for the exotic cultivated plots (359.8 g m −2 or 3.6 mg ha −1) than for the native plots (90.7 g m −2 or 0.91 mg ha −1). The highest percentage of bare soil surfaces and compaction coincided with the highest soil erosion rates measured in the exotic pastures. However, the mean fodder production in the exotic plots was almost five times higher (987 kg DM ha −1) than in the native ones (204 kg DM ha −1). These findings confirm that farmers have an internal conflict. They want to optimize the production of fodder, but this leads to high soil erosion rates and reduces soil fertility in the medium-and long-term. The traditional, less productive pastoral system is more sustainable from an environmental and cultural point of view. However, this system may not be sustainable from an economic point of view.

Brazil is one of the main producers of pork meat in the world. It is well-known that the agricultural sector is a key component of the economic development of this country, where super-intensive fields are only competitive in the globalized market. For the farmers, the application of swine manure to fertilize the soil can increase the yearly income, but it also may cause serious environmental problems related to soil health and soil quality. In this research, we assessed the effects of applying liquid swine manure in a tropical soybean (Glycine max) plantation to better understand when this technique stops being effective and starts causing a threat to soil health and quality. Therefore, we compared values of several soil properties and the soybean yield on treated fields at 10 random points belonging to 7 different plots that were treated with the liquid swine manure over a period ranging from 0 to 15 years. The results showed a positive linear trend in soybean production from 2.45 to 3.08 Mg ha−1 yr−1. This positive trend was also recorded for some key soil parameters such as porosity and exchangeable cations content (Ca, Mg, K, and Al). Additionally, positive effects were also found for organic matter content after 10 years of application. Our findings suggest that the use of liquid swine manure has a positive effect on soybean yield and improves soil quality, particularly on mixed farms where pigs are intensively raised nearby cultivated fields.

No-tillage and inter-crops have been progressively introduced into traditional Brazilian tobacco plantations. However, there is a lack of information about their impact on soil erosion rates and soil properties. We studied 10 experimental plots in Paraná (Brazil) that rotated from no-tillage tobacco to two different inter-crop types (black beans and oats) and conventionally tilled tobacco to quantify erosion rates from September 2014 to February 2016. The results show that soil loss (18 Mg ha −1 ) and runoff coefficient (8.3%) were higher under conventional tillage tobacco than under no-tillage tobacco (3.4 Mg ha −1 and 0.6%). Bulk density was higher at the end of the cropping cycle than at the beginning. We concluded that conventional crops increased soil erosion, and the use of inter-crops and no-tillage is highly recommended for soil and water conservation. The findings should be valid for other regions that have similar cropping systems and environmental conditions.

The Brazilian faxinal is a traditional agrosilvopastoral system, which combines extensive grazing, subsistence cropping and low impact forest extraction, managed within a communal property system. Today it is at serious risk of disappearing due to increasing grazing pressure and logging activities that are leading to environmental problems such as forest fragmentation and soil degradation. The objectives of the study were to: a) evaluate soil physical degradation levels in different grazing areas within the faxinal system; and b) correlate soil degradation, fodder quantity and livestock dynamics in different pasture areas according to the household's location. Landscape mapping, vegetation surveys, and livestock grazing dynamics were assessed. In addition, soil physical parameters were evaluated for each land use (e.g., resistance, bulk density, porosity, moisture, and water infiltration rates). Results showed that livestock grazing and household locations are the main driving forces that lead to forest fragmentation. The household location creates three interrelated gradients in the communal grazing land: 1) soil physical degradation decreases from the pasture areas to araucaria forests; 2) fodder quantity decreases from pastures to araucaria forests; and 3) the livestock grazing intensity decreases from pastures to araucaria forests. In addition, some management practices to mitigate land degradation, including improvement of pastures, installation of removable troughs for drinking water in the upland areas and restriction of livestock from the riparian zone, have been proposed.

Recebido: 30/09/15; Aceito para publicação: 07/07/16 RESUMO O tabaco é uma espécie de vegetal com ciclo temporário (150 a 180 dias). A planta chega a uma altura de 1,10 metros com raio de 60 cm. Suas folhas podem atingir 60 cm de cumprimento e 25 cm de largura. Essas características contribuem para a interceptação da água da chuva indicando variações na umidade do solo. Portanto o objetivo deste artigo foi avaliar a espacialização da umidade superficial do solo e a influência da planta do tabaco na distribuição desta umidade em Plantio Direto e Plantio Convencional. Foram identificados 10 pontos de coleta em cada área. As coletas foram realizadas de outubro a fevereiro. Foi utilizada a técnica de perfis transversais entre os camalhões com coletas quinzenais. Para o monitoramento da umidade do solo utilizou-se uma sonda com sensor de umidade com profundidade de 5 cm. Foram mensuradas a exposição do solo e a morfologia da planta do tabaco. A umidade média no Plantio Direto foi 7% superior ao Plantio Convencional à cobertura morta influenciou na distribuição da umidade no Plantio Direto apenas nos dois primeiros meses e depois foi perdendo sua eficiência. A morfologia da planta contribuiu para a distribuição da umidade do solo.Palavras-chave: Fumicultura; Formas de Cultivo; Umidade do Solo; Morfologia da Planta. MOISTURE ASSESSMENT OF SURFACE SOIL IN TOBACCO FARMING IN TILLAGE AND CONVENCTIONA PLANTING IN SOUTHEAST REGION PARANA. ABSTRACTTobacco is a species of plant with temporary cycle (150-180 days). During this period the plant reaches about 1.10 meters high with an average radius of 60 cm. Its leaves can reach 60 cm long and 25 cm wide. These characteristics contribute to rainwater interception indicating variation in soil moisture. Therefore the objective of this article was to evaluate the spatial distribution of surface soil moisture and the influence of the tobacco plant in the distribution of this moisture in an agricultural area with notillage and conventional. We identified 10 sampling points in each area. The collections were initiated in October to February. We used the technique of transversal profiles between the furrows with sampling every 15 days. Soil moisture was collected through a device with humidity sensor with a depth of 5 cm. The collections were always performed in the same locations. We measured also soil exposure and the tobacco plant morphology. The average moisture in no-tillage was only 7% higher than conventional tillage and biomass coverage influences the moisture distribution in no-tillage only in the first two months and then loses its efficiency. The morphology of the plant contributes significantly to the distribution of soil moisture.

ResumoEste artigo tem como objetivo avaliar a produção de sedimentos oriunda dos caminhos preferenciais dos animais no Faxinal Marmeleiro de Cima, Município de Rebouças, Paraná. O Sistema de Faxinal é uma forma de uso e ocupação característica da região Centro-Sul do Estado do Paraná. Neste sistema, existe o criadouro comunitário, onde os animais são criados de forma extensiva sem limites entre as propriedades. A constante mobilização dos animais, tanto nas áreas de pastagens como nas áreas de fl oresta do Faxinal, acabam dando origem a caminhos preferenciais que atuam como canais efêmeros em períodos de chuva, servindo como conectores entre os sedimentos do sistema (vertentes) com os canais fl uviais. Foram identifi cados 16 perfi s, sendo 8 (oito) perfi s em caminhos preferenciais que dão acesso aos corpos hídricos (zona ripária). Os demais foram identifi cados em caminhos preferenciais existentes nas áreas de pastagens na vertente (terras altas). Utilizou-se da técnica de perfi s transversais, (profi lometers) para avaliar a perda de solo nestes caminhos. Ao término, do monitoramento, foi constatado que os perfi s que dão acesso aos rios apresentaram maior erosão (6,7 kg/m 2 ), enquanto que os caminhos preferenciais das pastagens ao longo da vertente (terras altas) indicaram uma erosão em torno de 4,9 kg/m 2 . AbstractThis paper aims to evaluate the production of sediments coming from the preferential paths of animals in Faxinal Marmeleiro de Cima, County of Rebouças, Parana. The Faxinal system is a characteristic way of use and occupancy in the South Central region of Paraná v. 13, nº 3 (2012) www.ugb.org.br Revista Brasileira de Geomorfologia

The catchment area of River das Antas (Irati, Paraná, Brazil) is of high importance both for human consumption and irrigation. Within Irati, this river passes through a rural area and through the city of Irati, crossing both poor and rich neighbourhoods. We selected three study areas downstream (a rural area, poor community, and rich neighbourhood) in which we measured turbidity, the concentration of sediments and pH during rainy days. Our results showed downstream trends of increasing turbidity and concentrations of sediments with decreasing pH. The values of turbidity and of concentration of sediments were significantly different in the rural area, while the pH values were significantly different between the three study areas. These findings highlight the effect of agricultural activities in the generation of sediments and turbidity. The—presumably expected—effects of organic urban waste from the poor neighbourhood were also detected in the pH values. We conclude that efforts should be made to ensure that land planning and training/education programmes on sustainable farming practices are undertaken by the authorities to reduce water pollution and its effects on water bodies during rainfall events, since paving streets is not a feasible option in the short term due to the high costs associated with this measure.

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