Water Replenishment in Agricultural Soils: Dissemination of the IrrigaPot Technology

The challenge confronted by farmers during prolonged periods of soil water stress is to guarantee the restoration of water and maintain the productivity of agricultural crops. Even in regions such as Amazon, the variability in the precipitation regime should be considered in agricultural planning. There are regions in which 80% of annual rainfall is concentrated between December and June. It is exactly during this period of low rainfall that small-scale family-based farmers need technological assistance to guarantee that their crops remain irrigated in order to maintain their income in this rural environment. The IrrigaPot arises as an alternative that is able to access rainfall that has been stored since the rainy season and provide it to plants when the soil is dry. The pots are maintained full with 20 liters of water, and through capillary action the soil maintains them constantly humid. This technology does not require specific knowledge with respect to irrigation regimes and is necessary for the farmer to dedicate his time to replacing water. The technology is totally automated through a simple system using a float, tubes, and connectors that connect a rubber hose to the lids of the pots buried in the soil

Zoneamento agroecológico para a região de Ribeirão Preto utilizando um sistema de informações geográficas.

Objetivando contribuir com a metodologia de identificação de potencialidades de uso das terras, este trabalho apresenta uma proposta de zoneamento agroecológico da quadrícula de Ribeirão Preto, SP, localizada entre as coordenadas de 21o00'S a 21o30'S e 47o30'W a 48o00'W, com base em características de solo, relevo e clima, utilizando-se de um Sistema de Informações Geográficas. Para caracterizar o regime térmico-hídrico da área utilizou-se os dados de temperatura do ar e de chuva, de 22 localidades, referentes ao período de 1967 a 1996. De acordo com os critérios adotados, quanto a capacidade de uso das terras, o zoneamento identificou seis unidades de utilização da área: agricultura (I); agricultura (II); agricultura (III); pecuária; agrossilvicultura e preservação. As principais conclusões referentes à área de estudo foram: o regime térmico-hídrico é praticamente homogêneo, a vocação dominante é para agricultura (I) representando aproximadamente 191.118 hectares, correspondentes a 66,3% da área e cerca de 82,5% das terras possuem vocação para agropecuária e 10,4% devem ser preservadas ou utilizadas seguindo técnicas conservacionistas

Modelling carbon stock and carbon sequestration ecosystem services for policy design: a comprehensive approach using a dynamic vegetation model

Ecosystem service (ES) models can only inform policy design adequately if they incorporate ecological processes. We used the Lund-Potsdam-Jena managed Land (LPJmL) model, to address following questions for Mexico, Bolivia and Brazilian Amazon: (i) How different are C stocks and C sequestration quantifications under standard (when soil and litter C and heterotrophic respiration are not considered) and comprehensive (including all C stock and heterotrophic respiration) approach? and (ii) How does the valuation of C stock and C sequestration differ in national payments for ES and global C funds or markets when comparing both approach? We found that up to 65% of C stocks have not been taken into account by neglecting to include C stored in soil and litter, resulting in gross underpayments (up to 500 times lower). Since emissions from heterotrophic respiration of organic material offset a large proportion of C gained through growth of living matter, we found that markets and decision-makers are inadvertently overestimating up to 100 times C sequestrated. New approaches for modelling C services relevant ecological process-based can help accounting for C in soil, litter and heterotrophic respiration and become important for the operationalization of agreements on climate change mitigation following the COP21 in 2015

Impact of agricultural expansion on water footprint in the Amazon under climate change scenarios

Agricultural expansion and intensification are main drivers of land-use change in Brazil. Soybean is the major crop under expansion in the area. Soybean production involves large amounts of water and fertiliser that act as sources of contamination with potentially negative impacts on adjacent water bodies. These impacts might be intensified by projected climate change in tropical areas. A Water Footprint Assessment (WFA) serves as a tool to assess environmental impacts of water and fertiliser use. The aim of this study was to understand potential impacts on environmental sustainability of agricultural intensification close to a protected forest area of the Amazon under climate change. We carried out a WFA to calculate the water footprint (WF) related to soybean production, Glycine max, to understand the sustainability of the WF in the Tapajós river basin, a region in the Brazilian Amazon with large expansion and intensification of soybean. Based on global datasets, environmental hotspots — potentially unsustainable WF areas — were identified and spatially plotted in both baseline scenario (2010) and projection into 2050 through the use of a land-use change scenario that includes climate change effects. Results show green and grey WF values in 2050 increased by 304% and 268%, respectively. More than one-third of the watersheds doubled their grey WF in 2050. Soybean production in 2010 lies within sustainability limits. However, current soybean expansion and intensification trends lead to large impacts in relation to water pollution and water use, affecting protected areas. Areas not impacted in terms of water pollution dropped by 20.6% in 2050 for the whole catchment, while unsustainability increased 8.1%. Management practices such as water consumption regulations to stimulate efficient water use, reduction of crop water use and evapotranspiration, and optimal fertiliser application control could be key factors in achieving sustainability within a river basin

Estimation of sediment production in oil palm expansion areas in the Amazon

ABSTRACT Currently, an activity that has become strategic at a national level is the cultivation of oil palm (Elaeis guineensis) in the northeast region of the Pará State, in eastern Brazilian Amazon. However, the impacts of this crop expansion on the hydro-sedimentological cycle are still unknown. Therefore, this study estimated the impacts of oil palm crop expansion on sediment production in a sub-basin under consolidated use of this crop. The Soil and Water Assessment Tool (SWAT) model was applied in the Mariquita sub-basin, calibrated by the flow regionalization technique, using data measured in the field with a current meter. Simulation results indicated an increase in sediment production between the years 2008 and 2013, which can be attributed to the large reduction of areas of secondary vegetation that were replaced by pasture, oil palm and general agriculture. Oil palm areas had a lower average monthly sediment yield in the rainiest period in all simulated years, compared with areas of general agriculture and pasture

Estimation of sediment production in oil palm expansion areas in the Amazon

<div><p>ABSTRACT Currently, an activity that has become strategic at a national level is the cultivation of oil palm (Elaeis guineensis) in the northeast region of the Pará State, in eastern Brazilian Amazon. However, the impacts of this crop expansion on the hydro-sedimentological cycle are still unknown. Therefore, this study estimated the impacts of oil palm crop expansion on sediment production in a sub-basin under consolidated use of this crop. The Soil and Water Assessment Tool (SWAT) model was applied in the Mariquita sub-basin, calibrated by the flow regionalization technique, using data measured in the field with a current meter. Simulation results indicated an increase in sediment production between the years 2008 and 2013, which can be attributed to the large reduction of areas of secondary vegetation that were replaced by pasture, oil palm and general agriculture. Oil palm areas had a lower average monthly sediment yield in the rainiest period in all simulated years, compared with areas of general agriculture and pasture.</p></div

Indicadores da condição hídrica do solo com soja em plantio direto e preparo convencional Indicators of soil water condition for soy bean under no-tillage and conventional tillage

Indicadores da condição hídrica do solo foram avaliados em um experimento de campo, em Eldorado do Sul, RS, Brasil. Utilizou-se um Argissolo Vermelho Distrófico típico, utilizado durante oito anos em sistema plantio direto e preparo convencional. A cultivar de soja Fepagro Rs(-1)0, foi semeada em 20/11/2003, com 0,40 m entre fileiras e 300 mil plantas por hectare, em tratamentos irrigados e não irrigados. Variáveis do sistema solo-planta-atmosfera foram monitoradas e a ênfase neste trabalho visou aos períodos secos; monitoraram-se, também, variações no potencial matricial da água no solo, entre 0,075 e 1,20 m de profundidade. Verificou-se que o tempo de secagem do solo foi mais prolongado nas parcelas sob plantio direto indicando, em períodos de secagem, potenciais matriciais menos negativos, menores temperaturas máximas e menor amplitude térmica que em preparo convencional; também, a altura de plantas e o índice de área foliar apontaram que maiores estoques de água em plantio direto podem reduzir efeitos do déficit hídrico em soja cultivada neste sistema de manejo. Esses indicadores reforçam a importância da análise integrada de respostas das culturas em um enfoque sistêmico de manejo de solo e água.<br>Soil water condition indicators were assessed in a field experiment conducted in Eldorado do Sul, Brazil. The Paleudult soil of the experimental area has been managed during eight years under no-tillage and conventional tillage. Soy bean cultivar Fepagro Rs(-1)0 was sown on November 20, 2003, with 0.40 m of row spacing and 300,000 plants ha-1, with and without irrigation. Variables of soil, plant and atmosphere were monitored with emphasis during drought periods. Variations of the matrix water potential were monitored from 0.075 to 1.20 m of soil depth. A regular delay was observed in the soil drying process in no-tilled plots, in particular during drought periods, indicating higher water storage in no-tillage than in conventional tillage. Higher matrix water potential, lower maximum temperature and smaller thermal amplitude were observed in no-tillage, in comparison to the conventional tillage. Indirect indicators, such as plant height and leaf area index, were in accordance to the higher water storage in no-tilled plots, due to reductions of water deficit in plants. This set of indicators demonstrated the importance of evaluating crop responses in a systemic approach to soil and water management