Building on Fertile Ground in Burundi
Duration: January 2014 – April 2017. This project has been finalized.
Aim: Optimize the dosage of organic and inorganic fertilizers. The best assessed propositions – in terms of improved access to food/income, improved land and labour productivity, sustainability and adaptation to climate change – will be embedded in ZOA’s agricultural programs and in the government rural extension services. Embed innovations in local rural agriculture extension services.
Objective: Contribute to food security of vulnerable smallholder farmer communities.
Method: Identify different areas of soil fertility as identified by local farmers. Understand traditional methods for assessing soil fertility. Trial fertilizer recommendations combined with conservation agriculture as applied in normal local farmer practices. Provide tailored advice on dosage of fertilizers and conservation agriculture to farmers and extension services.
Dutch policy goal: Increase sustainable food production.
Year 1: An increasing population, the lack of additional land to cultivate and poor food security all demand an increase in productivity which can be achieved by improving soil fertility. But this must be both profitable and sustainable. This research tests the efficacy and profitability of advised fertiliser applications based on standardised advice or tailored advice based on a soil analysis.
Year 2: To improve soil fertility management in South Burundi, the researchers first produced a detailed map of fifteen agro-ecological zones in the two districts Mabanda and Vugizo. Different soil and vegetation types were classified via a visual interpretation of Google Earth satellite images. The map, also showing suitability zones for certain crops, was validated by farmers in the region. Based on this map and on an inventory of existing farming practices, the researchers developed innovations for vulnerable smallholder farmers to improve their income and soil fertility.
In 2015, the team compared the effects of different fertilization recommendations in different agro-ecological zones. The trials were conducted with maize and beans in Mabanda (medium altitude) and with maize in Vugizo (high altitude). The innovations were tested, refined and evaluated by smallholder farmers from each agro-ecological zone.
All fertilizer applications resulted in significant yield improvements. The recommendations of the Dutch company Soil Cares, based on plot-specific soil analyses, resulted in higher yields for beans and maize in Mabanda compared to the recommendations of the Burundian National Fertilizer Subsidy Programme, but no significant differences were detected in Vugizo. Other observations included that the application of manure is the most important contributor to improved yields, that the application of micronutrients is not cost efficient and that spot applications of fertilizer and manure or compost result in better yields than broadcast treatment. These and other innovations have been communicated to the farmers and embedded in local agricultural extension services.
Summary of the results: An improved crop cultivation method which reduced labour inputs was rapidly adopted by farming households in Burundi, including the most vulnerable. The method consists of 1) use of herbicides to control perennial and persistent weeds and eliminating manual hoeing to prepare the ground for sowing 2) the application of low doses of organic and inorganic fertilizers and 3) the use of green manure (ground cover) so that herbicide are phased out. Farming households saved money and time needed for land preparation and weeding, yields increased and the resilience to climate extremes improved. Government and non-government agricultural extension services are integrating the method in their advice to farming communities, in planning and in funding proposals. Instead of intensive manual cultivation and weeding which leaves soils bare for part of the year, soils now remain undisturbed, covered and fertilized. Soil erosion is reduced or prevented and soil quality gradually improves.
Undergraduate studies indicated that the amount of fertiliser used by farmers is strongly influenced by distance from the collection point and that the most effective way of communicating new information to isolated and illiterate farmers is probably by radio broadcasts.