Innovative research methods show that fertilizer trees improve food security for smallholder farmers in Malawi

Agroforestry is getting more and more attention as the land management system is an important mitigation and adaption strategy to climate change. When combining agricultural crops with nitrogen fixing trees, soil fertility is improved which results in higher crop yields. However, very few studies have addressed the actual effects of fertilizer trees on livelihoods and instead focused on yields and biophysical parameters.
 
A new article published in Agricultural Systems aims to give realistic policy insights and improve research designs in rural development by studying how agroforestry affects food security under actual farming conditions. The study used data from over 300 maize farmers in Malawi of which around half had adopted agroforestry practises with fertilizer trees. What makes this study unique is the extensive analysis of the data to avoid biases affecting the result. For example adopters of new practises are usually better educate than non-adopters. Comparing yields between adopters and non-adopters will therefore not give a realistic estimate of the potential of agroforestry. Instead the potential could be overestimated as the well-educated adopters of agroforestry is much more likely to be successful with a new technology compared to an average farmer. Biases such as this requires careful correlation analyses when comparing agricultural productivity between agroforestry farmers and farmers without trees. Otherwise heterogeneities between the two groups can affect the result.
 
The study found that using fertilizer trees significantly improve food security for smallholder farmers in Malawi. Adopting fertilizer trees increased the value of the produced food with 35%. By disaggregating the results, i.e. separating them with regard to farmer conditions, the study found that agroforestry farmers with smaller plots improved their food security more than farmers with larger plots. Farmers with less that 1 acre of land increased their food crops value with 82% when adopting agroforestry by planting fertilizer trees. However, it is important to remember that farmers with limited plots are less likely to break-even on an investment in a new technology. This because a new investment requires some fixed costs in terms of time and money. The study therefore concluded that it is essential to lower the barriers to adoption of new technologies.
 
At Agroforestry Network we believe that this type of research, addressing actual farming conditions, is important when estimating the potential of agroforestry. We believe that researchers in agroforestry need to develop more holistic approaches and study livelihood impacts combined with biophysical parameters rather than focusing on results from research station or controlled on-farm trials.
 
You can read the working paper on the website of the World Agroforestry Centre if you don’t have access to the journal Agricultural Systems.
 
The picture shows root nodules in which rhizobia-bacteria live. The bacteria live in symbioses with a the tree and capture nitrogen from the atmosphere. The captured nitrogen is converted to different amino acids before transfered to the tree in return for carbohydrates. Picture Credit: Dave Whitinger, published under the license of CC BY-SA 3.0.