Wetenschap - 1 januari 1970

Patchwork precision

Patchwork precision

Patchwork precision: the fields in Niger

Farmers in Niger practise precision agriculture without the modern technology available to western farmers. Instead they use their own expertise, according to PhD student Mohamadou Gandah, who will graduate on 8 September. Gandah carried out research under Professor Johan Bouma (Soil Science and Geology) on spatial variability and farmer resource allocation in millet production in west Niger. Gandah's aim was to better understand the relation between soil characteristics and crop yields. He also examined how farmers judge soil quality and make management choices

Farming families in Niger do not necessarily make crop yield maximisation their highest priority. Minimising the risk of total crop failure is more important. Niger suffers from frequent droughts and poor soil fertility, causing low yields and repeated food shortages. Crop yields fluctuate enormously, not only from year to year, but also within one field. These differences are not only due to soil characteristics, but also topographical differences. For instance, water ponding resulted in a harvest loss of fifty percent on test plots in Sadoro. According to Gandah, farmers take these differences into account in their strategies. They use soil texture, colour and vegetation criteria to select field areas for cropping or leaving fallow. When sowing they apply their knowledge of topographical variability by planting denser hills around termite and ant mounds to make more efficient use of run-off water and nutrients from the mound. They plant millet hills at the four corners of a cut-down shrub site to make use of the nutrients accumulated there. Farmers also influence the variability themselves, through the way in which they distribute manure. Fields in Niger are fertilised by letting cattle graze on them overnight. Gandah discovered that farmers could use the manure much more efficiently by spreading it over an area twice as large. Very often manure is just left where it is deposited, and the nutrients are washed away

Gandah believes that further research on yield variability will lead to useful recommendations for farmers. These must however take into account farmer expertise and motivation. He warns that traditions can hinder innovation. For example, technologies for crop yield improvement may be advocated, such as inter-cropping millet with longer growing cowpea varieties to reduce competition for soil moisture. However, harvesting the legume late in the season prevents livestock from returning to the fields as soon as the millet is harvested to feed on the residues, and this is unacceptable to farmers. L.K

bij foto:All work and no play makes Jack a dull boy. Fortunately there is no risk of this being the fate of the international MSc students here in Wageningen. Last Saturday they had the opportunity to sample the sports on offer at the University Sports Centre De Bongerd and enjoy a Dutch lunch. Photos: Rita van Biesbergen