• Authors:
    • Hairiah, K.
    • Weise, S.
    • Sonwa, D.
    • Mbile, P.
    • Agus, F.
    • Edadinata, A.
    • Meadu, V.
    • Robiglio, V.
    • Budidarsono, S.
    • Hyman, G.
    • Gockowski, J.
    • White, D.
    • Murdiyarso, D.
    • Dewi, S.
    • Van Noordwijk, M.
    • Swallow, B.
  • Year: 2007
  • Authors:
    • Palm, C.
    • Anupama, K.
    • Bantilan, C.
    • Mackensen, J.
    • Albrecht, A.
    • Ong, C.
    • Tomich, T.
    • Kandji, S.
    • Van Noordwijk, M.
    • Verchot, L.
  • Source: Mitigation and Adaptation Strategies for Global Change
  • Volume: 12
  • Issue: 5
  • Year: 2007
  • Summary: Agriculture is the human enterprise that is most vulnerable to climate change. Tropical agriculture, particularly subsistence agriculture is particularly vulnerable, as smallholder farmers do not have adequate resources to adapt to climate change. While agroforestry may play a significant role in mitigating the atmospheric accumulation of greenhouse gases (GHG), it also has a role to play in helping smallholder farmers adapt to climate change. In this paper, we examine data on the mitigation potential of agroforestry in the humid and sub-humid tropics. We then present the scientific evidence that leads to the expectation that agroforestry also has an important role in climate change adaptation, particularly for small holder farmers. We conclude with priority research questions that need to be answered concerning the role of agroforestry in both mitigation and adaptation to climate change.
  • Authors:
    • Klemick, H.
  • Year: 2007
  • Summary: With tropical deforestation a major contributor to greenhouse gas emissions and biodiversity loss, the land use decisions of small-scale farmers at the forest margins have important implications for the global environment. In some tropical forests, such as the Eastern Brazilian Amazon, farmers practice a shifting cultivation system that maintains large amounts of land under forest fallow. I examine whether local benefits of fallowing such as soil restoration, erosion mitigation and hydrological regulation are of sufficient value to farmers to stem the expansion of permanent cropland at the expense of forest. I quantify the value of ecosystem services provided by fallow to agriculture and test whether local forest externalities are economically significant, using farm survey and GIS data from the Eastern Amazon. I estimate a production function to determine the contribution of on-farm and upstream fallow to income, using an instrumental variables approach to address endogeneity. I find that on-farm and upstream fallow are both associated with higher farm income. This result both confirms the agronomic evidence that fallow boosts yields and suggests that fallow provides positive hydrological externalities to downstream farms. I also examine whether farmers respond strategically to their neighbors' land use, taking advantage of ecosystem services provided by upstream farms. I use a spatial econometric model to estimate the effect of upstream farms' fallow on downstream land allocation. I find no evidence that farmers alter their fallowing based on land use upstream. I then investigate whether market failures encourage fallowing. If farmers cannot purchase inputs used in cultivation due to liquidity constraints, they may keep more land under fallow than optimal. I use the estimated production function parameters to determine whether each farm's allocation of land between cropping and fallow is efficient from an individual perspective. I then estimate the effect liquidity indicators on land use efficiency. I find that over-fallowing is negatively associated with commercial credit use and off-farm income, suggesting that liquidity constraints do hinder agricultural intensification. Because I find evidence to support the existence of positive externalities to fallow, the loosening of liquidity constraints that encourage fallowing has ambiguous implications for community-level welfare.
  • Authors:
    • Desjardins, R. L.
    • Campbell, C. A.
    • Hutchinson, J. J.
  • Source: Agricultural and Forest Meteorology
  • Volume: 142
  • Issue: 2-4
  • Year: 2007
  • Summary: One of the main options for greenhouse gas (GHG) mitigation identified by the IPCC is the sequestration of carbon in soils. Since the breaking of agricultural land in most regions, the carbon stocks have been depleted to such an extent, that they now represent a potential sink for CO, removal from the atmosphere. Improved management will however, be required to increase the inputs of organic matter in the top soil and/or decrease decomposition rates. In this paper we use data from selected regions to explore the global potential for carbon sequestration in arable soils. While realising that C sequestration is not limited to the selected regions, we have, however, focussed our review on two regions: (i) Canadian Prairies and (ii) The Tropics. In temperate regions, management changes for an increase in C involve increase in cropping frequency (reducing bare fallow), increasing use of forages in crop rotations, reducing tillage intensity and frequency, better crop residue management, and adopting agroforestry. In the tropics, agroforestry remains the primary method by which sequestration rates may be significantly increased. Increases in soil C may be achieved through improved fertility of cropland/pasture; on extensive systems with shifting cultivation cropped fallows and cover crops may be beneficial, and adopting agro forestry or foresting marginal cropland is also an alternative. In addition, in the tropics it is imperative to reduce the clearing of forests for conversion to cropland. Some regional analyses of soil C sequestration and sequestration potential have been performed, mainly for temperate industrialized North America where the majority of research pertaining to C sequestration has been carried out. More research is needed, especially for the Tropics, to more accurately capture the impact of region-specific interactions between climate, soil, and management of resources on C sequestration, which are lost in global level assessments. By itself, C sequestration in agricultural soils can make only modest contributions (3-6% of fossil fuel contributions) to mitigation of overall greenhouse gas emissions. However, effective mitigation policies will not be based on any single 'magic bullet' solutions, but rather on many modest reductions which are economically efficient and which confer additional benefits to society. In this context, soil C sequestration is a significant mitigation option. (c) 2006 Elsevier B.V. All rights reserved.
  • Authors:
    • Thakare, R.
    • Gupta, V. R.
  • Source: Indian Journal of Agricultural Research
  • Volume: 41
  • Issue: 4
  • Year: 2007
  • Summary: Effect of irrigated and rainfed cropping systems on carbon and nitrogen mineralization was studied. Maximum C and N mineralization observed under irrigated cropping systems than rainfed. Sorghum-chickpea-groundnut showed highest mineralization under irrigated condition. While monocropping and intercropping with legumes enhances the rate of mineralization under rainfed situation. Mineralization was found to be highest during grand growth period of crops. Application of integrated nutrient supply increased C and N mineralization as compared to their individual application. The FYM+wheat straw+green manuring application augmented the mineralization under soybean-wheat crop sequence.
  • Authors:
    • Foster, Mercedes S.
  • Source: Bird Conservation International
  • Volume: 17
  • Issue: 1
  • Year: 2007
  • Summary: Migration routes used by Nearctic migrant birds can cover great distances; they also differ among species, within species, and between years and seasons. As a result, migration routes for an entire migratory avifauna can encompass broad geographic areas, making it impossible to protect continuous stretches of habitat sufficient to connect the wintering and breeding grounds for most species. Consequently, ways to enhance habitats converted for human use (i.e. for pasture, crop cultivation, human settlement) as stopover sites for migrants are especially important. Shelterbelts around pastures and fields, if planted with species targeted to support migrant (and resident) bird species that naturally occupy mature forest habitats and that are at least partially frugivorous, could be a powerful enhancement tool for such species, if the birds will enter the converted areas to feed. I tested this approach for Nearctic migrant birds during the spring migration through an area in Chiapas, Mexico. Mature forest tree species whose fruits are eaten by birds were surveyed. Based on life form, crop size and fruit characteristics, I selected three tree species for study: Cymbopetalum mayanum (Annonaceae), Bursera simaruba (Burseraceae) and Trophis racemosa (Moraceae). I compared the use of fruits of these species by migrants and residents in forest with their use of the fruits of isolated individuals of the same species in pasture and cropland. All three plant species Were useful for enhancing converted habitats for forest-occupying spring migrants, although species differed in the degree to which they entered disturbed areas to feed on the fruits. These tree species could probably enhance habitats for migrants at sites throughout the natural geographic ranges of the plants; in other geographic areas for other target bird groups, other tree Species might be more appropriate.
  • Authors:
    • Odebode, S. O.
    • Akinbile, L. A.
  • Source: American-Eurasian Journal of Sustainable Agriculture
  • Volume: 1
  • Issue: 1
  • Year: 2007
  • Summary: Sustainability, which involves the ability to use a resource in ways that ensure little or no damage to guarantee continuous use of the resources, was the focus of the study. A focus group discussion was employed using farms to take inventory of the soil conservation practices they consider to be sustainable, from which 15 practices were validated. The study identified the determinants of the farmers' use of the practices in the study area. Quantitative data were gathered from 112 respondents sampled though systematic technique from five communities with the use of questionnaire. The results of the study shows that the farmers are aware of most of the practices. The soil conversation practices they often make use of multiple cropping, use of cover crops, crop rotation and the use of fallow system. They also plant multipurpose tree species for erosion control, and use organic manure with inorganic fertilizer at varying degrees to enhance productivity and ensure sustainability. Correlation test at P<0.05 shows that farm size, income, labour use, their other income generating activities and there level of awareness had significant relationship with respondents use of the sustainable soil conservation practices. Multiple regression analysis shows that factors that determine farmers use of those soil conservation practices are their level of awareness of the practices, farm size, income, labour use of their income generating activities in which they are involved. The factors determined 72% of the variation in respondents' use of conservation practices. Farmers should therefore be assisted with respect to those factors to ensure the sustainable use of the soil, which is very important in their income generating activities as farmers.
  • Authors:
    • Grace, P. R.
    • Post, W. M.
    • Hennessy, K.
  • Source: Carbon Balance and Management
  • Volume: 1
  • Year: 2006
  • Authors:
    • Perez, A.
    • Ali, M.
    • Pollack, S.
    • Lucier, G.
  • Year: 2006
  • Summary: The U.S. fruit and vegetable industry accounts for nearly a third of U.S. crop cash receipts and a fifth of U.S. agricultural exports. A variety of challenges face this complex and diverse industry in both domestic and international markets, ranging from immigration reform and its effect on labor availability to international competitiveness. The national debate on diet and health frequently focuses on the nutritional role of fruit and vegetables, and a continued emphasis on the benefits of eating produce may provide opportunities to the industry. In the domestic market, Americans are eating more fruit and vegetables than they did 20 years ago, but consumption remains below recommended levels. In terms of per capita consumption expressed on a fresh-weight basis, the top five vegetables are potatoes, tomatoes, lettuce, sweet corn, and onions while the top five fruit include oranges, grapes (including wine grapes), apples, bananas, and pineapples. The industry also faces a variety of trade-related issues, including competition with imports. During 2002-04, imports accounted for 21 percent of domestic consumption of all fresh and processed fruit and vegetables, up from 16 percent during 1992-94.
  • Authors:
    • Al-Kaisi, M.
  • Source: Integrated Crop Management
  • Volume: IC-496
  • Issue: 11
  • Year: 2006