68189 JANUARY 2012 ABOUT THE AUTHOR Assessing the Carbon Benefits of Improved ADEMOLA BRAIMOH is a Senior Natural Resources Land Management Technologies Management Specialist at the World Bank’s Agriculture and Rural Development (ARD) Ensuring food security under changing climate conditions is one of the major Department in Washington, D.C. He has broad expertise in challenges of our era. Agriculture must not only become increasingly agriculture, environment, water, and natural resources productive, but must also adapt to climate change while reducing greenhouse management. gas emissions. Soil carbon sequestration, the process by which atmospheric APPROVING MANAGER carbon dioxide is taken up by plants through photosynthesis and stored as Mark Cackler, Sector Manager, carbon in biomass and soils, can support these goals. First, soil carbon Agricultural and Rural Develop- ment. enhances agricultural productivity, which reduces rural poverty; second, it limits greenhouse gas concentrations in the atmosphere; and third, it reduces the impact of climate change on agricultural ecosystems. This SmartLesson describes the potential benefits of selected land management technologies that sequester carbon. Background Agriculture is the economic foundation of expansion for food, fiber, and fuel. The net many developing countries, employing up to increase in agricultural land during the 1980s two-thirds of the workforce and contributing and 1990s was more than 100 million hectares between 10 and 30 percent of gross domestic across the tropics. About 55 percent of this product (GDP). For the poorest people, GDP new agricultural land came at the expense of growth originating in agriculture is about intact forests, while another 28 percent came four times more effective in raising incomes from the conversion of degraded forests than GDP growth originating from other (Gibbs et al. 2010). sectors (World Bank, 2010). Yet agricultural growth rates have declined significantly over With effective policies, agriculture can also be the last decade, and food insecurity remains a part of the solution to climate change. pervasive. Food production must increase by Climate-smart agriculture (CSA) seeks to 70–100 percent by 2050 to meet the demands increase productivity in an environmentally of a world with 9 billion people and changing and socially sustainable way, strengthen diets. farmers’ resilience to climate change, and reduce agriculture’s contribution to it by Agriculture is highly vulnerable to climate reducing greenhouse gas emissions and change and needs to adapt to it. Under increasing soil carbon storage. Historically, optimistic lower-end projections of agricultural soils have lost more than 50 billion temperature rise, climate change may reduce tons of carbon. Some of this carbon, however, crop yields by 10 to 20 percent, whereas can be recaptured through improved land increased incidence of droughts and floods management practices. may lead to a sharp increase in prices of some of the main grain crops by the 2050s. While There is a growing global momentum to agriculture is the sector most susceptible to rapidly scale up CSA, but there is a more climate change, it is also a major cause of it, urgent need to improve the knowledge base directly contributing about 14 percent of for facilitating investments in land greenhouse gas emissions, or approximately management technologies that increase the 30 percent when considering land-use change, storage of soil organic carbon. The Economic including deforestation driven by agricultural and Sector Work (ESW) on Soil Carbon SMARTLESSONS — JANUARY 2012 1 Assessment (P124234) was carried out to fulfill this need. costs. Such technologies include integrated nutrient and The study involved: water management, mulching and residue management, no-tillage, crop rotation, cover crops, and agroforestry — 1. A meta-analysis to provide better estimates of soil the integrated land use system combining trees and shrubs carbon sequestration rates; with crops and/or livestock. Increases in crop yields derive from the ability of the land management technologies to 2. An ecosystem simulation modeling technique to maintain soil organic matter and biological activity at levels predict future carbon storage in global cropland soils; suitable for soil fertility. The pattern of increase in yield, and however, varies from crop to crop. The profitability of no- tillage systems derives primarily from less labor requirement 3. An assessment of the cost-effectiveness of the land for seedbed preparation and other tillage operations management technologies in mitigating climate change. compared to conventional tillage systems. In Zambia, yields have doubled for maize and increased 60 percent for cotton The ESW began in October 2010 and will be disseminated in compared to the conventional tillage system. Farmers also January 2012. frequently reported significant crop yield increases for maize, sorghum, millet, cotton, and groundnut in Lessons Learned agroforestry systems, but relatively high labor inputs are required to reduce the competition effects of trees from Lesson 1: Soil carbon sequestration is profitable to the negatively impacting crop growth. Inorganic fertilizers also farmers. show relatively high profits because they provide nutrients that can be readily absorbed by plants. They are less In addition to storing soil carbon, sustainable land environmentally friendly, however, due to nitrous oxide management technologies can be beneficial to farmers emissions associated with high application rates of nitrogen because they can increase yields and reduce production fertilizers, and fossil fuel-based emissions associated with Figure 1: Tradeoffs between profitability and carbon sequestration of sustainable land management technologies. Thresholds for classification were $50 profit and 4.1 tons of sequestered carbon dioxide. 2 SMARTLESSONS — JANUARY 2012 fertilizer production and transportation. including trees in croplands, and establishing barriers across sloping areas tend to take land out of production for a Lesson 2: Soil carbon sequestration can be maximized significant period of time. They reduce the amount of land by managing trade-offs and synergies. available for cultivation in the short run, but can lead to overall increases in productivity and stability in the long Tradeoff occurs when attempts to increase carbon storage run. The time-averaged, above-ground biomass of crop reduces productivity (profitability). On the other hand, residues and other technologies in the lower left quadrant synergy implies a positive correlation between carbon of Figure 1 is relatively small compared to that of sequestration and profitability. Increasing food security agroforestry systems (see photos below). Also, the biomass under a changing climate requires the analysis and of crop residues does not accumulate easily, resulting in identification of the land management technologies that lower mitigation benefits (see photos below). maximize synergies and minimize tradeoffs. Synergies between profitability and mitigation are found in two Judicious fertilizer application counters soil nutrient agroforestry systems: intercropping and alley farming (top depletion, reduces deforestation and expansion of right quadrant of Figure 1). Intercropping is growing crops cultivation to marginal areas, and increases crop yields. near existing trees, whereas alley farming is growing crops Yields also increase with manure application and simultaneously in alleys of perennial, preferably leguminous accumulation of soil carbon, but with patterns that depend trees or shrubs. Both are important strategies for increased on crop type. Manure is less profitable than inorganic productivity and resilience of the farming system. fertilizer because of the labor costs associated with collecting and processing manure (top left quadrant of Land management technologies in the lower right quadrant Figure 1). Manure also has quite low nutrient contents of Figure 1 have high mitigation potentials but are modestly relative to inorganic fertilizers, so a large amount needs to profitable. Afforestation, improved fallow involving the be applied on relatively small fields. This explains why use of fast-growing trees to accelerate soil rehabilitation, manure works well for small-scale intensive and high-value Figure 2: Relationship between private benefits and public costs. Thresholds for classification were $50 profit and $5.50 for public costs. SMARTLESSONS — JANUARY 2012 3 vegetable gardening. Manure systems are also associated water quality, and biodiversity, are public goods that accrue with high methane emissions. The relatively high to society but not to the farmers engaged in market profitability of no-tillage derives primarily from the transactions alone. Without government intervention, poor decrease in production costs after the establishment of the agricultural land management will intensify land system. degradation and contribute additional greenhouse gases in the atmosphere. Lesson 3: Sustainable land management practices generate benefits to the farmers, but at varying costs Public cost refers to government support toward the to the public. implementation of land management practices. This includes investments in seeds and seedlings, input subsidies, extension Carbon sequestration provides private benefits to the services, and other administrative costs. The pattern of farmers through enhancement of soil fertility that leads to public support is as crucial as the amount of support for the increases in crop yields and more efficient production. full realization of productivity, mitigation, and adaptation However, other benefits, such as improved air quality, benefits in agriculture. Public support measures that focus Maize growing under Faidherbia trees. Crop harvesting. The residues are left on the soil surface as mulch. Photo credit: Curt Carnemark Photo credit: World Agroforestry Center Table 1: Relative importance of different factors for adopting improved land management practices. Synthesized from Liniger et al. (2011). Key *= Low importance, **= Moderate importance; ***= High importance. 4 SMARTLESSONS — JANUARY 2012 on research, investments in improved land base of land management practices at the management, and land tenure rather than local level can be also improved through on input support are generally more effective, careful targeting of capacity development benefit more farmers, and are more programs. sustainable in the long run. There is also the need to boost financial Technologies that involve significant change support for early action in climate-smart in land use (afforestation, improved fallows) agriculture. For technologies with and landscape alteration (terracing, cross- significant private returns, grant funding slope barriers) incur high public costs but or loans may be more suitable to overcome generate low private benefits (lower right adoption barriers. For technologies such as quadrant of Figure 2). The low profits suggest conservation agriculture that require that farmers may be reluctant to privately specific machinery inputs, the initial costs invest in these technologies. Strong public of investment can be considerable. Thus, involvement in these technologies is justifiable, payment for ecosystem services schemes given their relatively high mitigation could be used to support farmers and potentials. Crop residues, cover crops, crop break the adoption barrier. There is also rotation, and rainwater harvesting with lower the potential for carbon finance to support profits and also manure and no tillage that farmers during the initial period before generate relatively higher profits require the trees in agroforestry systems generate minimal government support (lower left and an economic return. The costs to the public upper left quadrants of Figure 2, respectively). sector could be lower if some of the costs These technologies generally have low are borne by the private sector. For mitigation potentials. The relatively high instance, the private sector may be public cost of inorganic fertilizer (top right involved in establishing tree plantations or quadrant, Figure 2) reflects the use of subsidies in developing improved seeds and in spurring farmers’ access to the technology. seedlings. Lesson 4: Adoption of sustainable land Conclusion management practices faces considerable barriers despite the private benefits they A new global vision that appreciates and generate. rewards the productivity, mitigation, and adaptation benefits of soil carbon Despite the fact that improved land sequestration is required. Progress in management technologies generate private agriculture is slower than most people had benefits, their adoption faces many hoped for under the UN Framework socioeconomic and institutional barriers. Convention on Climate Change (UNFCCC). Table 1 suggests that lack of credit and inputs However, some good news came out of and land tenure problems are by far the most the recently concluded Conference of important factors for adoption. However, Parties (COP) in Durban, where, for the improved availability of inputs is a necessary first time, it was agreed to initiate a formal but insufficient condition for adoption of work program under the UNFCCC land management practices. Better market Subsidiary Body for Scientific and prices for crops and other agricultural produce Technological Advice (SBSTA). Placing are crucial. Secure land rights are a agriculture under a firm global agreement precondition for climate-smart agriculture, as in future could help provide a policy DISCLAIMER they provide incentives for local communities framework for fully incorporating SmartLessons is an awards to manage land more sustainably. agriculture into adaptation and mitigation program to share lessons learned in development-oriented advisory strategies. There is a need to integrate the services and investment Behavioral change through education is public sources of climate finance with operations. The findings, required to enable changeover to improved those supporting food security into a interpretations, and conclusions land management technologies. For single mechanism to support climate- expressed in this paper are those instance, conservation agriculture — the smart agriculture. Countries must be of the author(s) and do not necessarily reflect the views of IFC farming system involving no-tillage, residue prepared to access new and additional or its partner organizations, the management, and use of cover crops — is finance. Readiness for carbon Executive Directors of The World highly knowledge-intensive, requiring those sequestration and climate-smart Bank or the governments they promoting its adoption to acquire training agriculture can be achieved through represent. IFC does not assume any responsibility for the and practical experience. Learning hubs, capacity building for strengthening the completeness or accuracy of the regional platforms, scientific research, south- institutional and implementation information contained in this south knowledge exchange, and technical framework for climate-smart agricultural document. Please see the terms support mechanisms will increase innovation development, and identifying early-action and conditions at www.ifc.org/ and facilitate adoption of improved land investments in land management smartlessons or contact the program at smartlessons@ifc.org. management technologies. The knowledge technologies for different locales. 5 SMARTLESSONS — JANUARY 2012