Farmers in smallholder agricultural systems rely on rudimentary tools for most farm practices (Nin-Pratt et al., 2011). From land preparation to harvesting, there is generally minimal mechanization in place (Mrema et al., 2008).
In some regions, the majority of farmers use bullocks for land preparation at the beginning of the crop season. Owing to the practice of an integrated crop-livestock system, farmers who own cattle use the bullocks for land preparation (Figure 2.1). Farmers who do not own cattle either rent the bullocks from their neighbors or prepare their lands with cutlasses and hoes. In recent years, smallholder farmers’ access to tractors is improving due to the efforts of farmer cooperatives (Amanor, 2013). These usually consist of a group of farmers who pull their resources together to realize shared objectives (Ortmann and King, 2007). In some instances, farmers who are not members of the cooperative can use the tractor for land preparation or weeding by renting.
Smallholder farmers normally reserve part of their harvest (of the previous year) for sowing (planting) in the next season (McGuire and Sperling, 2016). Those who do not have seeds ask for some from family and friends or through their networks (e.g., cooperatives or groups). Others may also contact the extension agents for advice concerning new and improved varieties. Farmers who have the financial capacity purchase seeds (e.g., new and improved varieties) from commercial seed companies, government sources (e.g., agricultural ministries) or relief providers (McGuire and Sperling, 2016). Planting is done after the first few rains of the season, at a time when farmers become convinced the rains will continue. Recent evidence of a gradual shift of the onset of the rainy season (Lacombe et al., 2012; Laux et al., 2008) has led farmers to plant late in the season.
Weeding is mostly done with hoes and cutlasses on smallholder farms. Labor is predominantly provided by women and children of a household (AGRA, 2013). A larger number of children in a household makes it easier to complete the weeding on the farm. Bullocks, and very occasionally tractors, are also used for weeding by farmers who have the means and can afford, but these are a minority. Farmers may also get their neighbors or members in their network (e.g., cooperatives) to provide labor on their farms; which they often reciprocate. Due to the predominantly manual weeding, farmers are unable to keep up with the weeds especially in the early stages of the season. Consequently, farms are often left weedy (pix), which can affect yields.
The execution of farming practice does not necessarily fall between day limits, and satellite overpass (of the type relevant for agriculture) is often around noon. This means that image acquisition often takes place while farm field work is ongoing. The image analyst/engineer should teherfore expect fields sometimes to show up as bipartite: some part ploughed, for instance, and the other part not yet so.
As rainfed agriculture dominates most smallholder agricultural systems, (supplemental) irrigation is often minimal (Oweis and Hachum, 2009). First, most farmers do not have water harvesting facilities on-farm to allow them to store water for irrigation during in-season dry spells. Irrigation is mainly practiced during the dry season around small reservoirs (de Fraiture et al., 2014), when the rains have stopped. Farmers use irrigation water that flows by gravity or they pump water from a nearby reservoir or stream. In other instances, farmers irrigate their crops using watering cans and buckets (Barry et al., 2010). To improve soil water availability, various management strategies have been employed and tested across smallholder agricultural systems. These include in-field techniques such as tied ridges (Fosu et al., 2008), rock bunds/stone rows (Barry et al., 2008), zai (or pits) (Barry et al., 2008) and straw mulching (Hauchart, 2007; Mando et al., 1999). These have been used successfully by a number of farmers to improve water availability and to maintain soil fertility.
Harvesting is mostly done manually. Some farmers will harvest their produce soon after maturity, while others may keep their crops in the field for a longer period before harvesting. Cereals such as maize, sorghum and millet and cotton, rice, yam, groundnuts, and beans are all mostly harvested manually. The stalks of sorghum and millet are sometimes transported home as fuel or fencing material (Karbo and Agyare, 2002) (Figure 2.2). Other crops such as groundnut and beans are sometimes transported home to serve as fodder. These various techniques may occasionally show up in satellite images as specific texture that can be exploited for cerop identification purposes.