By Gildas Assogba and Rohit Pawar, Wageningen University; Anthony Malunga, CARE Malawi 
July 2, 2024 

In a previous post (March 2024), we had reported our experiences and lessons learnt while setting up field trials in southern Malawi (Mangochi and Zomba districts). In the trials, intercropping of maize with pigeon pea, groundnut, and soybean are being compared with maize-only cropping under different fertilization regimes; in terms of yields (grain and biomass), inputs (seeds and nutrients), nutrient uptake by crops, labour requirement and profitability. The broad objective is to ascertain the best modalities of integrating legumes within maize-centric production systems that dominate southern Africa. 

As of May 2024, harvest at the trial plots has begun: all the maize has already been harvested, and the harvest of groundnut was expected to be completed in early June is underway. Pigeon pea will be harvested in July.

malawi trials
A selection of the trial plots

Across plots, the following are being monitored, with data being recorded daily/weekly/biweekly: 

  • Soil moisture 
  • Daily rainfall 
  • Incidence of water logging 
  • Labour input 
  • Incidence of weed, and weeding requirements 
  • Plant density 
  • Fertilization requirements 
  • Insecticide requirements 

Also being monitored are some ‘confounding variables’- currently not part of the analysis, but will be taken into account if they are found to have a significant effect on the outcomes of the trial. These include: slope, presence of legume trees in the vicinity of the plots, and field-level soil water management by farmers (e.g. bunds).  

As happens during most field trials, we encountered unforeseen issues which were problems to solve and opportunities to learn. For starters, there was a Fall Armyworm outbreak in Zomba and Mangochi districts (where the field trials are located). This affected the trial plots as well, leading some of the farmers to request that we support them to procure insecticides. Based on national recommendations, insecticides were bought and applied to the plots in both districts. Treating crops with the recommended insecticides is not problematic to the experiments as it has been a common response in most districts and this was done as one way of responding to the unforeseen challenge of the Fall Armyworm.  

fall armyworm and poor germination in malawi(Above) Seed quality led to poor germination rates in some of the trial plots
(Below, left) Farmers measuring soil moisture at a flooded trial plot
(Below, right) Worm infestation during sowing and germination stages at a trial plot

The other, more significant issue we have encountered is the El Niño- induced dry spell. From November 2023 until March 2024, Malawi experienced a delay in the onset of its customary rainy season, typically spanning from mid-November to April, bringing about prolonged dry spells.  

Mangochi and Zomba were affected too, although the impact was different across the two districts. Mangochi did receive some rains in January which could have favored early crop establishment. Besides, the topography around the trial plots enables a relatively high degree of moisture retention in the soil. Zomba, on the other hand, received rains mainly in March, while January here was drier than in Mangochi. Overall, there were two key factors determining how well crops in the trial plots did: 

  • Date of planting: While designing the experiment, we did take into account the fact that Malawi is prone to dry spells, and had therefore used early-maturing varieties of maize instead of local varieties. However, we had not foreseen the extent of the drought this growing season. There were often germination problems, and seeds needed to be resown. When that happened during a dry spell, plant development was sub-optimal. In some cases, we were able to manage this by applying fertilizers. According to the farmers, the application of fertilizer later on  may have also affected the quality of harvests, as the fertilizers did not deliver nutrients to the crops as expected, due to the lack of rains and limited moisture availability. Farmers in Mangochi felt that plots with fertilizers had poor harvest.   
  • Location within the landscape: In Zomba, the trial plots are far apart from each other and fall under considerably different topographies. Some were located close to streams and lakes, which made for higher soil moisture availability, but led to legume seeds washing away during floods. The effect of fertilzers in in Zomba seemed largely positive due to the higher availability of moisture, in contrast to the plots in Mangochi where harvest was much worse.

As is often the case, the El Niño weather pattern is forecast to be followed by an onset of La Niña later this year, which means the next cropping season (April-June 2025) will likely be unusually wet. The FoSTA-Health test beds will be planted and harvested for a second and final time then, and we are looking forward to the possibility of testing our experiment design and assumptions in opposite weather conditions. 

In the field trials, we have been able to engage a large number of farmers (50) actively, productively, and within a short period of time. We had the opportunity to tap into network of farmers cultivated by CARE Malawi’s Titukulane project which involved them in Farmer Field and Business Schools- a learning-by-doing extension approach. The project helped develop an understanding of incentives and disincentives farmers must consider when it comes to participating in such field trials. As much as monetary incentives, they value trainings and experiential learning they could derive through the process. They also take into account whether the technology/ technique being tested is relevant to them, and how much they could potentially benefit from adopting them in the future. 

Based on these insights, local farmers have been closely involved in the FoSTA-Health field trials—the trials are set up on their land, they will keep the produce they harvest, and they are closely involved in the day-to-day monitoring of the crops along with local extension workers. Besides, they have provided valuable inputs to the experiment design at various stages based on their knowledge of local micro-climates, agronomic, and economic realities.  

Currently, we are keeping busy collecting and analysing the data from the field trial. Later this year, we will also begin participatory modelling of the farming system in Zomba and Mangochi districts. Along with evidence from the field trials, the scenarios proposed in the previous mental mapping will be used in participatory modelling sessions using a spatial model and a ‘serious game’- an interactive tool including options such as fertilization, livestock production, market opportunities, policy decisions, and exchange of resources and information among various stakeholders at the district level. (More details in this blogpost: https://tinyurl.com/2fykve8c

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