Feasibility and Acceptability (based on Degrande 2001)

The feasibility of a technology can be assessed through the ability of farmers to manage this technology. Therefore, feedback about constraints in the establishment and maintenance of the improved practice is important. Furthermore, farmers’ perceptions of the advantages, disadvantages, requirements and benefits of the technology will eventually determine adoption.

Benefits

After the 1998 cropping season, a formal survey was conducted in the sites of Abondo and Nkolfep with 28 farmers who had been conducting researcher-designed/farmer-managed (type II) shrub fallow trials (see also 3.3.2). Half of the respondents mentioned increased yields as a reason for expanding cajanus fallows and 35% reported it as main benefit of shrub fallows. In fact, 92 % of the farmers who tried the technology noted a positive impact of cajanus fallow on crop yields, while only two farmers did not see a change in yield. Farmers’ second most important reason for expansion was soil fertility improvement, mentioned by 39 % of the farmers. In the same line of thinking, more than half of the experimenting farmers deliberately planted cajanus on their poorest soils. They said they did so because, after hearing about the benefits of cajanus, they wanted to test its potential to improve soil fertility there where they needed it most. The third main benefit, considered by 32 % of the respondents was the potential of cajanus to suppress weeds during the fallow period. Ngobo et al. (2004) identified the following species as dominant on soils with high

clay, N and C contents: Chromolaena odorata, Cyathyla prostrata, Mariscus alternifolius, Mikania cordata, Musanga cecropioides and Trema orientalis, whereas Ageratum conyzoides, Cyperus sp., Haumania danckelmaniana, Paspalum conjugatum, Pouzolzia guineensis, Richardia brasiliensis, Sida rhombifolia, Stachytarpheta cayennensis, Talinum trainulare and Triumfetta cordifolia were preponderant on sandier soils with high pH, P and Mg content. A survey in southern Cameroon (ASB 1996) indicated that grass and broadleaf weeds were reported as the major constraint to agricultural production by 70 % and 55 % of the respondents, respectively. The same survey revealed weed incidence as a major reason for fallowing. Thirty percent of farmers interviewed heard about the potential use of cajanus grains as food, but no one had actually eaten cajanus grains so far because their shrubs had not yet produced seed. Eighteen percent noted the shortening of the fallow period and the ease of clearing and ploughing following the fallow period as benefit. The fact that only 1 farmer mentioned the use of cajanus for firewood could be explained by the availability of other sources in the humid forest zone.

Problems

Thirty-five percent of farmers interviewed did not experience any problems in planting and managing cajanus fallow. Storing cajanus seeds was cited as a problem by 23 % of trial farmers. However, the biggest problem reported by adopters was that cajanus did not produce seeds, thereby limiting expansion of the technology. The cajanus variety promoted by ICRAF produces a lot of biomass, thereby enabling good nutrient recycling for soil fertility improvement, but does not flower nor seed well. On the other hand, farmers in the western highlands of Cameroon use varieties that seed profusely. A good balance between biomass and seed production should be sought since provision of good quality seed in adequate quantities is crucial for the promotion of shrub fallows on a large scale.

Expansion

The monitoring and evaluation results of cajanus fallows after four years indicate a strong interest in the technology shown by farmers. The number of shrub fallows increased from 40 in 1996 to 95 in 1997 and 282 in 1998. There was also considerable expansion within farms. In ICRAF’s pilot villages (Nkolfep and Abondo), 56 % of the farmers expanded their shrub fallows in 1998. In 71 % of the cases, the second shrub field farmers established was larger than the first one. When asked what proportion of their farm land they would like to plant with shrubs, 64 % reported to be willing to plant more than half of their crop fields with cajanus. Two major modifications in shrub management were recorded. First, a few farmers preferred broadcasting cajanus instead of planting it in lines. Second, some farmers extended the cajanus fallow for two or three years for better soil coverage and hoping for seed production.

Interest of Women

Thirty percent of the farmers testing shrub fallows were female. The interest of women in cajanus fallows can be explained by the following reasons.

1. Clearing of a cajanus fallow is much easier compared to natural fallow. This is an important factor, given recent changes in division of tasks between men and women in rural areas of Southern Cameroon. Traditionally, men were responsible for clearing of fields, but with the intensification and commercialisation of food cropping, men also got involved in food cropping, especially in areas with relative good market access (Kumar 1987; Guyer 1989). Therefore, women can no longer rely on male family labour to do land clearing. Hiring of labour would be another option, but would increase costs substantially.

2. After slashing cajanus shrubs and spot burning of woody residues, the field is clean and can easily be ploughed for groundnut planting. Groundnut is the main crop in the mixed food crop fields and is generally managed by women.

3. Cajanus is established through direct seeding, a less labour-intensive technique than nursing and transplanting seedlings, as is the case for trees such as calliandra. Given the high demand for women labour in rural areas, there exist incentives to adopt low labour-intensive technologies.

4. Yield response to shrub fallows is relatively quick compared to tree fallows. This is an important incentive for poor households that cannot afford to wait several years for their investment to yield benefits.

Incorporation of Shrub Fallows in Farming Systems

Farmers’ main intention in using cajanus fallows is to increase yield, improve soil fertility and suppress weeds, but it is not clear how they will actually incorporate the technology into their farming system. For example, in the farmer survey of 1998, 64 % reported to be willing to plant more than half of their cropland with cajanus. But so far, trial farmers preferred rotating the improved fallows around their farms. There is a need to find out what percentage of their land farmers are willing and able to cover with shrub fallows.