On the Way of Sustainable Agriculture Conservation Agriculture

Global Prospects and Challenges. Jat, R.A., K.L. Sahrawat, and A.H. Kassam. 2014. CAB International, Wallingford, U.K. 393 pp. €160.00 (hardcover). ISBN13 978-1-78064-259-8. Conservation Agriculture in Subsistance Farming. Case Studies from South Asia and Beyond. Chan C., and J. Fantle-Lepczyk. 2015. CAB International, Wallingford, U.K. 264 pp. £85.00 (hardcover). ISBN-13: 978-1-78064-423-3. The Ecology of Agricultural Landscapes. Long-Term Research on the Path to Sustainability. Hamilton, S.K., J.E. Doll, and G.P. Robertson. 2015. Oxford University Press, Oxford. U.K. 432 pp. £19.85 (hardcover). ISBN 978-0-19-977335-0. Agricultural practices affect natural resources, including soil and water, and ecosystem services and functions and thus food production and quality. After a long series of technological developments, it became clear during the 20th century that tillage-based agricultural systems do not provide agricultural sustainability because they cause disruption of soil-mediated ecosystem services, reduce soil productivity, increase soil erosion, lead to loss of organic matter, and damage to soil structure. Different practices to mitigate soil erosion were attempted, such as minimizing soil disturbance (reduced tillage or no-till seeding), maintaining continuous organic soil cover of mulch and plants, and crop rotation and diversification. Simultaneous application of all these practices is known as conservation agriculture (CA). After starting in the United States in the 1930s, CA is now practiced on approximately 125 million ha of arable cropland worldwide. It is most widely applied in the Americas, Australia, and New Zealand. Recently, it has spread to Asia, Europe, and Africa. Besides retention of soil capacity, CA promises greater productivity and profit through reduction in inputs (i.e., fertilizers) and greater adaptability of farming to climactic conditions. Despite the difficulties of establishment of CA in the initial years (e.g., control of pests, diseases, and weeds) and perceived risk of loss in productivity in some cases, CA offers great benefits over the long term for rich farmers with large holdings and poor farmers with small holdings because it increases yield and decreases interannual variability. Recently, a multistakeholder CA community of practice has begun to facilitate the uptake and spread of CA internationally (http://www.fao.org/ag/ca/index.html), and farmers are increasingly engaged in finding ways to apply CA. Conservation Agriculture Global Prospects and Challenges provides country- and region-specific overviews of the current status and future prospects of CA and discusses CA experiences under different agroclimatic and socioeconomic conditions. Research findings on soil quality, carbon sequestration, crop yield, climate-change mitigation and adaptation, pest and disease dynamics, and economic returns are discussed. The problems encountered in scaling up CA and efforts and political steps required for future development and spread are detailed for large regions with intensive agriculture, such as the United States, as well as for small-scale farming systems in, for example, Southeast Asia. The numerous contributing authors of the book believe that CA-based farming may be the best available option for attaining sustainable food security, alleviating poverty, and enhancing ecosystem services and functions. Conservation Agriculture in Subsistence Farming has its origins in the 2013 conference Frontiers in Agriculture in South Asia and Beyond held in Nepal. It introduces results of studies on the potential of CA farming in small households in Nepal, India, and Malawi. Throughout the book, authors provide insight into the world of people who face undernourishment and evidence of the prevalence of underweight and stunted children. CA for poor smallholders in India and Nepal is only now being developed and promoted, and its implementation will be challenging. The research presented shows that CA has a positive impact on soil quality that leads to higher grain production, increased profits, livestock-system intensification, and greater labor productivity. Benefits of CA appear to differ between men and women, but data on this finding are limited. A case study from Malawi indicates that applying CA practices helps create a sense of time and control for women. They became more involved in decision-making processes at the household and community level; therefore, CA may contribute to diminishing the gender gap in agriculture. Some of the main constraints to the adoption of CA in Southeast Asia are the limited availability of agricultural training and inputs due to large infrastructure problems. That CA requires fewer inputs and increases yield should eventually lead to increased adoption of CA by local farmers. Beyond CA's obvious benefits, CA practices may enhance the ecosystem services provided to agriculture in several ways. For example, ladybugs and bees play essential roles in, for example, pest control and pollination. Their requirements in a managed landscape, however, are often little known, and provision of their highly important services may not be fully effective in such landscapes. The heterogeneous landscape structure of CA may improve functioning of beneficial insects. The Ecology of Agricultural Landscapes describes the long-term (almost 30 years) ecological research at the Kellogg Biological Station. The row-crop agricultural system at the station includes annual and perennial crops and unmanaged reference communities that reflect either a gradient of synthetic chemical inputs or a gradient of successional stages. Delivery of ecosystem services, such as food and fuel provision, biological pest control, clean water, soil fertility, and climate stabilization through mitigation of greenhouse gas emissions, and their interactions in these different systems were measured through long-term observation. An important result, among several, was that rotational management (e.g., legume cover crops and mechanical weed control in the row-crop rotation system) allowed a two-thirds reduction in the amount of synthetic nitrogen and herbicide required to produce high yields. Landscape diversity and heterogeneous land cover around the fields were strongly correlated with aphid suppression because the abundance of natural predators was relatively high. Several economic valuations of ecosystem services are discussed, from simple ones such as the calculation of the lost value of biological control services based on predicted yield loss and associated increased insecticide costs to determining supply and demand for ecosystem services by eliciting information from farmers. Valuation of ecosystem services needs ecological, economic, and social indicators. As in the case of CA, adoption of new management practices that provide ecosystem services depends on farmers’ willingness, their attitudes, awareness, education, and ability to differentiate between private and public goods. Practices that save labor or inputs or improve farmstead water quality, for example, without reducing income are more likely to be taken up by farmers. Farmers may need to be compensated for CA practices that affect profitability over the longer term. All three books have a rather scientific style in that they present case studies and detailed overviews of research projects aided by graphs and tables. They cannot be considered easy reading for those unfamiliar with such work, but they will be of value to anyone who wants up-to-date information on CA and research. These publications show that finding the right balance between ecological and economic constraints and benefits is crucial for the wide-scale adoption of sustainable agriculture and sustainable, long-term conservation of the environment and biodiversity.