Author: Soil Health Institute

CEPHaS is interested in a broad perspective on conservation agriculture, in the context of the farming system, the constraints farmers face and the ways in which they are adapting to climate change. For this reason we have engaged with a range of partners, and in this series we invite them to respond to some questions.

The Indaba Agricultural Policy Research Institute (IAPRI) is a private company in Zambia with a board of directors drawn from stakeholders across the public and private sector. Its principal mandate is to conduct research in agricultural policy and to undertake outreach activities, supporting the agricultural sector in Zambia and pursuing agricultural development which is sustainable and pro-poor. More information can be found at their website https:// www.iapri.org.zm/ 

Dr Hambulo Ngoma (pictured above) answers our questions.

CEPHaS 4

Conservation Agriculture Perspectives

1. What are the main ways in which you have seen smallholder farmers adapting to climate change in southern and central Africa in recent years?

Farmers in Southern Africa adapt to climate change mainly through staggered planting, planting early maturing and drought-tolerant varieties, and the adoption of conservation agriculture practices. Farmers have diversified their livelihoods by venturing into non-farm enterprises like trading. More about farmer responses to climate change in Zambia has been published by Mulenga et al. (2017). Climate Trends and Farmers’ Perceptions of Climate Change in Zambia. Environmental Management 59, 291–306.

2. In what sets of circumstances (biophysical, socio-economic etc) are conservation agriculture practices most likely to be beneficial to rural communities, and in what circumstances are they least likely to be useful?

Biophysical
CA would be most likely to be beneficial under semi-dry conditions with low rainfall, I am not sure that it would be beneficial in under very dry and wet conditions.
Socio-economic
CA is most beneficial for those with finance to hire in labour and, more importantly, to afford herbicides and to finance other CA activities. Secure tenure might help the uptake of CA and make it more feasible to retain crop residues.

3. What components of conservation agriculture systems are most problematic from the perspective of farmers? 

Making planting basins under minimum tillage with hand hoes is challenging for farmers because of the drudgery, as is weeding, where they do not have access to herbicides. Retaining residues is difficult given competing uses, and on communal open grazing land. Limited market access for legumes makes full rotation an issue for some farmers.

4. What do you think are the main research questions that need to be addressed to support food security in sub-Saharan Africa under climate change?

An overarching area of interest is to understand how best smallholder farming systems can best become resilient to climate change while meeting a rising demand for food. A top priority should be to identify instruments to enhance resilience, and to test these out. It would also be interesting to understand how markets can enhance food security and help support the uptake of CA amidst climate change.

Biography of Dr Hambulo Ngoma (pictured overleaf)

Dr Hambulo Ngoma was a research fellow at IAPRI and lead, climate change and natural resource management thematic area at the time of this interview. He is now Agricultural Economist, International Maize and Wheat Improvement Center (CIMMYT), Southern Africa Regional Office in Harare, Zimbabwe.

Dr Hambulo Ngoma is a Development Economist with research interests spanning the development-environment nexus. His current research applies various methods to understand the connections among land use, agricultural practices, and livelihoods of smallholder farmers in the context of climate change in Southern Africa. He is particularly interested in factors influencing the adoption of new technologies and the impacts of these practices on livelihoods and welfare of smallholder farmers.

To find out more, visit our web pages at www2.bgs.ac.uk/CEPHaS and follow us on twitter @CEPHaS_Soil

Professor Emanoel Gomes de Moura is professor in the Agroecology Post- Graduate programme at Maranhão State University in Brazil. He is a specialist in tropical agriculture with particular interest in low-fertility soils and the stabilization of soil organic carbon. Alana das Chagas Ferreira Aguiar is also a professor at Maranhão State University where she works on ecological intensification and nutrient cycling, working with family farmers. They have both been collaborating with Professor Sacha Mooney (University of Nottingham, and CEPHaS project) to examine and demonstrate the benefits for soil quality and crop production of systems which combine grazing livestock, trees and crops as an adaptation to climate change. Here they tell us more about the systems they are studying, an interesting contrast with the conservation agriculture methods which CEPHaS is examining in Africa, but with some common features.

1. What are the main ways in which you have seen farmers adapting to climate change in Brazil in recent years?

• The principal strategy used by large-scale farmers to adapt to climate change in Brazil is the integrated agri-silvo-pastoral system also named low- carbon agriculture. This system comprises planting eucalyptus rows at wide spacings between crop strips intercropped with grass. This increases organic inputs to the soil, building the soil carbon stock and with it soil fertility and structural stability.
• At the family farm scale, we have recommended an integrated-alley-crop- livestock-system. This system takes advantage of fast-growing leguminous tropical trees which produce high quality biomass which is used to increase and maintain soil organic matter in soil. Zero till is almost always used, although farmers sometimes abandon it because of problems with weed control. Maize — Soybean rotations are used, mainly to reduce root diseases.

2.  In what sets of circumstances (biophysical, socio-economic etc) are conservation agriculture practices most likely to be beneficial to rural communities, and in what circumstances are they least likely to be useful?

Conservation agriculture practices are most likely to be beneficial to rural communities when family farmers have at their disposal, technologies, and systems to replace unsustainable models like shifting cultivation systems where land is brought into cultivation, and then abandoned to fallow after a few years. Establishing alternative and sustainable agricultural system

is heavily dependent on support of public decision makers and local government. Conservation agriculture practices fail in rural communities when they are not adequately supported through education and local technicians/agronomists.

3. What components of conservation agriculture systems are most problematic from the perspective of farmers?

We have found that many smallholder farmers in the Amazonian periphery view the greater complexity of the systems from conservation agriculture, like integrated-crop-livestock-systems, as a significant barrier to adoption. This highlights the need to improve how technicians and researchers engage with farmers. The substitution of simple low-cost systems like slash and burn with more complex and expensive ones such as no-tillage in alley cropping cannot succeed without efficient support by public agencies to overcome principal bottlenecks. Training in soil-crop management practices and increased understanding of the functioning of systems and their components, fertilizers, and soil amendments are needed urgently.

In addition to improving the dissemination of technology, efficient strategies to add value to the harvested product and to reduce the impact of costs of inputs on farmers’ evaluation of the system are needed.

4. What do you think should be priority research topics if agriculture in Brazil is to adapt to climate change and contribute to mitigation?

In tropical regions, climatic factors promote the loss of soil organic matter through fast decomposition, and the loss of fertility through leaching of nutrients. Unless this is countered by soil management, land degradation (and consequently shifting

cultivation) will occur. The continuous management of soil in the humid tropics requires soil organic matter accumulation and stabilization, increased retention of base cations in the root zone, and improvements to the soil structure. This requires approaches which do more than promote crop productivity in any one season, but which increase the stabilization of soil organic matter, and improve the cycling of nutrients to maintain fertility. The alley cropping system using leguminous trees that we have been using is one such option, but we need future research to consider others.