Page 98 - FAO-IPCC Expert meeting on climate change

Appendix 01: Speakers’ summary notes
yields typical of many parts of [Sub-Saharan Africa] and [South Asia] ...and crop residues are of high value as fodder or fuel and can account for a large portion of total crop value.” Hence they suggest that farmers in these regions will be very reluctant to adopt practices such as no-till that reduce farm income while offering only intangible medium- and long-term benefits.
The example of no-till and its effects on soil functions and ultimately crop production offers a number of important points. First, the benefit of no-till to erosion and runoff is regionally specific – there is a significant reduction at the cost of a minor short-term yield in temperate regions but no significant benefit (at the cost of a greater yield reduction)
in sub-tropical and tropical regions. Second, to realize the benefits of no-till adoption, a comprehensive nutrient management program must be implemented at the same time. Finally, the degree of societal acceptance (as well as the specific measures to be implemented) must be locally addressed if new measures are to be successful.
Summary: Research gaps and priorities
1. Land that is at risk of being abandoned due to declines in agricultural productivity caused by loss of soil functions should be identified. This includes land currently at risk and land where abandonment is likely under regionally relevant climate change scenarios.
2. Locally appropriate measures need to be identified or developed to address the specific soil threats causing the loss of soil functions in these high-risk landscapes and programs that support adoption of these measures implemented.
Both of these priorities were identified by the Intergovernmental Technical Panel on Soils in the SWSR (FAO and ITPS 2015) as well as many other authors through time. The recent adoption of the Voluntary Guidelines on Sustainable Soil Management (FAO 2016) by FAO Council gives some impetus to the second priority, as do ongoing programs such as the World Overview of Conservation Approaches and Technologies (WOCAT).
References
Boardman, J. 2006. Soil erosion science: Reflections on the limitations of current approaches. Catena 68, pp.73-86.
Castillo, C. & Gómez, J.A. 2016. A century of gully erosion research: Urgency, complexity and study approaches. Earth- Science Reviews 160, 300-319.
CGIAR. 2013. The Nebraska Declaration on Conservation Agriculture. Independent Science and Partnership Council, CGIAR. p. 2.
Derpsch, R., Friedrich, T., Kassam, A. & Hongwen, L. 2010. Current status of adoption of no-till farming in the world and some of its main benefits. International Journal of Agricultural and Biological Engineering 3, pp. 1-26.
FAO. 2016. Voluntary Guidelines for Sustainable Soil Management, Food and Agriculture Organization of the United Nations, Rome, Italy. pp. 1-15.
FAO and ITPS. 2015. Status of the World’s Soil Resources (SWSR) - Technical Summary, Food and Agriculture Organization of the United Nations and Intergovernmental Technical Panel on Soils, Rome, Italy. pp. 1-77.
Lundy, M.E., Pittelkow, C.M., Linquist, B.A., Liang, X., van Groenigen, K.J., Lee, J., Six, J., Venterea, R.T. & van Kessel, C. 2015. Nitrogen fertilization reduces yield declines following no-till adoption. Field Crops Research 183, pp. 204-210.
Mangalassery, S., SjÖGersten, S., Sparkes, D.L. & Mooney, S.J., 2015. Examining the potential for climate change mitigation from zero tillage. The Journal of Agricultural Science 153, pp. 1151-1173.
Mhazo, N., Chivenge, P. & Chaplot, V., 2016. Tillage impact on soil erosion by water: Discrepancies due to climate and soil characteristics. Agriculture, Ecosystems & Environment 230, pp. 231-241.
Montgomery, D.R. 2007. Soil erosion and agricultural sustainability. Proc Natl Acad Sci U S A 104, pp. 13268-13272.
Oldeman, L.R., Hakkeling, R.T.A. & Sombroek, W.G., 1991. World map of the status of human-induced soil degradation: an explanatory note., ISRIC, Wageningen, The Netherlands.
Palm, C., Blanco-Canqui, H., DeClerck, F., Gatere, L. & Grace, P., 2014. Conservation agriculture and ecosystem services: An overview. Agriculture, Ecosystems & Environment 187, pp. 87-105.
FAO-IPCC Expert meeting on climate change, land use and food security