• 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:
    • Suryadi, M.
    • Nagai, N.
    • Siregar, M.
  • Source: CAPSA Working Paper
  • Issue: 98
  • Year: 2006
  • Summary: This report is the outcome of the second phase of the AGRIDIV project in Indonesia. The goal of this second phase study is to examine the performance of farming, marketing and processing of CGPRT crops at two dryland sites that have different cropping patterns. The two selected sites were Siswa Bangun and Restu Baru village. The results would by no means represent a national average. Hence, the description of farming, marketing and processing of those crops given here forms a source of in-depth quantitative and qualitative information that might have wider validity. Findings relate to maize and cassava commodity systems. Policy recommendations are presented.
  • Authors:
    • Verchot, L.
    • Palm, C.
    • Albrecht, A.
    • Cadisch, G.
    • Mutuo, P.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 71
  • Issue: 1
  • Year: 2005
  • Summary: Losses of carbon (C) stocks in terrestrial ecosystems and increasing concentrations of greenhouse gases in the atmosphere are challenges that scientists and policy makers have been facing in the recent past. Intensified agricultural practices lead to a reduction in ecosystem carbon stocks, mainly due to removal of aboveground biomass as harvest and loss of carbon as CO2 through burning and/or decomposition. Evidence is emerging that agroforestry systems are promising management practices to increase aboveground and soil C stocks and reduce soil degradation, as well as to mitigate greenhouse gas emissions. In the humid tropics, the potential of agroforestry (tree-based) systems to sequester C in vegetation can be over 70 Mg C ha-1, and up to 25 Mg ha-1 in the top 20 cm of soil. In degraded soils of the sub-humid tropics, improved fallow agroforestry practices have been found to increase top soil C stocks up to 1.6 Mg C ha-1 yr-1 above continuous maize cropping. Soil C accretion is linked to the structural development of the soil, in particular to increasing C in water stable aggregates (WSA). A review of agroforestry practices in the humid tropics showed that these systems were able to mitigate N2O and CO2 emissions from soils and increase the CH4 sink strength compared to cropping systems. The increase in N2O and CO2 emissions after addition of legume residues in improved fallow systems in the sub-humid tropics indicates the importance of using lower quality organic inputs and increasing nutrient use efficiency to derive more direct and indirect benefits from the system. In summary, these examples provide evidence of several pathways by which agroforestry systems can increase C sequestration and reduce greenhouse gas emissions.
  • Authors:
    • Tinulele, I.
    • Prawiradilaga, D. M.
    • Koh, L. P.
    • Sodhi, N. S.
    • Putra, D. D.
    • Tan, T. H. T.
  • Source: Biological Conservation
  • Volume: 122
  • Issue: 4
  • Year: 2005
  • Summary: Unprecedented deforestation is currently underway in Southeast Asia. Since this trend is likely to continue, it is critical to determine the value of human-modified habitats (e.g., mixed-rural habitat) for conserving the regional native forest avifauna. The impacts of ongoing deforestation on the highly endemic avifauna (33%) of Sulawesi (Indonesia) are poorly understood. We sampled birds in primary and secondary forests in the Lore Lindu National Park in central Sulawesi, as well as the surrounding plantation and mixed-rural habitats. Species richness, species density and population density of forest birds showed a consistent decreasing trend in the following order: primary forests > secondary forests > mixed-rural habitat > plantations. Although primary forests contained the highest proportion (85%) of a total of 34 forest species recorded from our point count surveys, 40-yr old secondary forests and the mixed-rural habitat showed high conservation potential, containing 82% and 76% of the forest species, respectively. Plantations recorded only 32% of the forest bird species. Fifteen forest species had the highest abundance in primary forests, while two species had higher abundance outside primary forests. Our simulations revealed that all forest birds that were sensitive to native tree cover could be found in areas with at least 20% continuous native tree cover. Our study shows that although primary forests have the highest conservation value for forest avifauna, the potential of degraded habitats, such as secondary forests and the mixed-rural habitat, for conserving forest species can be enhanced with appropriate land use and management decisions. (C) 2004 Elsevier Ltd. All rights reserved.
  • Authors:
    • Jones, P. G.
    • Atieno, F.
    • Kruska, R. L.
    • McCrabb, G.
    • Thornton, P. K.
    • Reid, R. S.
  • Source: Environment, Development and Sustainability
  • Volume: 6
  • Issue: 1-2
  • Year: 2004
  • Summary: Climate change science has been discussed and synthesized by the world's best minds at unprecedented scales. Now that the Kyoto Protocol may become a reality, it is time to be realistic about the likelihood of success of mitigation activities. Pastoral lands in the tropics hold tremendous sequestration potential but also strong challenges to potential mitigation efforts. Here we present new analyses of the global distribution of pastoral systems in the tropics and the changes they will likely undergo in the next 50 years. We then briefly summarize current mitigation options for these lands. We then conclude by attempting a pragmatic look at the realities of mitigation. Mitigation activities have the greatest chance of success if they build on traditional pastoral institutions and knowledge (excellent communication, strong understanding of ecosystem goods and services) and provide pastoral people with food security benefits at the same time.
  • Authors:
    • Dale, B. E.
    • Kim, S.
  • Source: Biomass and Bioenergy
  • Volume: 26
  • Issue: 4
  • Year: 2004
  • Summary: The global annual potential bioethanol production from the major crops, corn, barley, oat, rice, wheat, sorghum, and sugar cane, is estimated. To avoid conflicts between human food use and industrial use of crops, only the wasted crop, which is defined as crop lost in distribution, is considered as feedstock. Lignocellulosic biomass such as crop residues and sugar cane bagasse are included in feedstock for producing bioethanol as well. There are about 73:9 Tg of dry wasted crops in the world that could potentially produce 49:1 GL year-1 of bioethanol. About 1:5 Pg year-1 of dry lignocellulosic biomass from these seven crops is also available for conversion to bioethanol. Lignocellulosic biomass could produce up to 442 GL year-1 of bioethanol. Thus, the total potential bioethanol production from crop residues and wasted crops is 491 GL year-1, about 16 times higher than the current world ethanol production. The potential bioethanol production could replace 353 GL of gasoline (32% of the global gasoline consumption) when bioethanol is used in E85 fuel for a midsize passenger vehicle. Furthermore, lignin-rich fermentation residue, which is the coproduct of bioethanol made from crop residues and sugar cane bagasse, can potentially generate both 458 TWh of electricity (about 3.6% of world electricity production) and 2:6EJ of steam. Asia is the largest potential producer of bioethanol from crop residues and wasted crops, and could produce up to 291 GL year -1 of bioethanol. Rice straw, wheat straw, and corn stover are the most favorable bioethanol feedstocks in Asia. The next highest potential region is Europe (69:2 GL ofbioethanol), in which most bioethanol comes from wheat straw. Corn stover is the main feedstock in North America, from which about 38:4 GL year -1 of bioethanol can potentially be produced. Globally rice straw can produce 205 GL of bioethanol, which is the largest amount from single biomass feedstock. The next highest potential feedstock is wheat straw, which can produce 104 GL of bioethanol. This paper is intended to give some perspective on the size ofthe bioethanol feedstock resource, globally and by region, and to summarize relevant data that we believe others will 0nd useful, for example, those who are interested in producing biobased products such as lactic acid, rather than ethanol, from crops and wastes. The paper does not attempt to indicate how much, if any, of this waste material could actually be converted to bioethanol.
  • Authors:
    • Moreira, A.
    • Martins, G.
    • Mccann, J.
    • German, L.
    • Kern, D.
    • Lehmann, J.
  • Source: Amazonian Dark Earths
  • Volume: Part 2
  • Year: 2004
  • Authors:
    • Thomas, R. J.
    • Fisher, M. J.
  • Source: Environment, Development and Sustainability
  • Volume: 6
  • Issue: 1-2
  • Year: 2004
  • Summary: Three of the nine physiographic regions that comprise the 8.2 million km2 (Mkm2) of the central lowlands of tropical South America have undergone substantial conversion from the native vegetation in the last 30 years, a good deal of it to introduced pastures. The converted lands were either formerly treeless grasslands of the Brazilian Shield and the Orinoco Basin, or semi-evergreen seasonal forest mainly in the east and southwest of the Amazon Basin in Brazil. There are about 0.44Mkm2 of introduced Brachiaria pastures in the former grasslands and we estimate that there are 0.096Mkm2 of introduced pastures in the Amazon Basin, mostly Brachiaria species. Based on extensive descriptions of the land systems of the central lowlands by Cochrane et al. (1985) we extrapolated data of carbon (C) accumulation in the soil under introduced pastures on the eastern plains of Colombia (about 3 t Cha-1 yr-1), which are treeless grasslands of the Orinoco Basin, to estimate the probable change in C stocks as a result of conversion to pasture elsewhere. Losses of above-ground C on conversion of the former grasslands is negligible, while in contrast the forests probably lose about 115 t C for each ha converted. We estimated the mean time since conversion started and allowed for the degradation of the pastures that commonly occurs. We concluded that introduced pastures on the former grasslands have been a net sink for about 900 million t (Mt) C, while conversion of the forest has been a net source of about 980 Mt C, leading to a net source of about 80 Mt C for the central lowlands as a whole. We identify a number of issues and possible methodologies that would improve precision of the estimates of the changes in C stocks on conversion of native vegetation to pasture.
  • Authors:
    • Shively, G. E.
    • Zelek, C. A.
  • Source: Land Economics
  • Volume: 79
  • Issue: 3
  • Year: 2003
  • Summary: We present a method for measuring the opportunity cost of sequestering carbon on tropical farms. We derive the rates of carbon sequestration for timber and agroforestry systems and compute incentive compatible compensating payment schedules for farmers who sequester carbon. The method is applied to data for an agricultural watershed in the Philippines. Area- and land quality-adjusted total costs are estimated. The present value of the opportunity cost of carbon storage via land modification falls between $3.30 and $62.50 per ton. Carbon storage through agroforestry is found to be less costly than via a pure tree-based system.
  • Authors:
    • Lal, R.
  • Source: Critical Reviews in Plant Sciences
  • Volume: 22
  • Issue: 2
  • Year: 2003
  • Summary: An increase in atmospheric concentration of CO2 from 280 ppmv in 1750 to 367 ppmv in 1999 is attributed to emissions from fossil fuel combustion estimated at 270 +/- 30 Pg C and land use change at 136 +/- 55 Pg. Of the emissions from land use change, 78 +/- 12 Pg is estimated from depletion of soil organic carbon (SOC) pool. Most agricultural soils have lost 50 to 70% of their original SOC pool, and the depletion is exacerbated by further soil degradation and desertification. The restoration of degraded soils, conversion of agriculturally marginal lands to appropriate land use, and the adoption of recommended management practices on agricultural soils can reverse degradative trends and lead to SOC sequestration. Technological options for SOC sequestration on agricultural soils include adoption of conservation tillage, use of manures, and compost as per integrated nutrient management and precision fanning strategies, conversion of monoculture to complex diverse cropping systems, meadow-based rotations and winter cover crops, and establishing perennial vegetation on contours and steep slopes. The global potential of SOC sequestration and restoration of degraded/desertified soils is estimated at 0.6 to 1.2 Pg C/y for about 50 years with a cumulative sink capacity of 30 to 60 Pg. The SOC sequestration is a cost-effective strategy of mitigating the climate change during the first 2 to 3 decades of the 21(st) century. While improving soil quality, biomass productivity and enhanced environment quality, the strategy of SOC sequestration also buys us time during which the non-carbon fuel alternatives can take effect.