Some improved forage legumes like Mucuna pruriens were identified by farmers as a forage option, but were not ranked highly as important forage. This is because Mucuna pruriens is not yet disseminated in many areas of Rwanda and farmers do not know much about it. However, the importance of Mucuna pruriens has been reported by Peters et al.
(2001) who stated that it is adapted to various ranges of climatic conditions (e.g. humid and wet-sub humid tropics, central America and west Africa), it is a good forage and can improve soil fertility. Its seeds (beans) can be used as human food and it provides a high level of resources for poor smallholder farmers. Juma et al. (2006) stated that Mucuna spp. could increase daily milk up to 32% from Jersey cows in the period of lactation, when it was mixed with Napier grass. The biases of farmers on Mucuna sp. (lowest score for increase milk yield) (Table 4.5) can be attributed to the lack of extension services. The new fodder options (Mucuna and other fodder legumes) were brought to farmers, but there was inadequate technology transfer and evaluation together with the farmers. The low rating of these fodder species may be because the perception of issues is often different between farmers and scientists. In many areas of semi-arid Africa, drought is perceived by farmers as the major constraint reducing their farm production, whereas for scientists, soil depletion is identified as the main constraint (Slegers 2008). However, in our case, the two factors (low rainfall and soil depletion) were identified in the Bugesera and Nyamagabe districts respectively as the major factors affecting the availability of livestock feeds. Forage species adapted to these factors which limit animal feed availability are highly recommended in the low rainfall and acidic soil areas of the study.
boys. This could potentially block the development of livestock production in stalling because a household that does not have a boy or husband may not raise cows for milk production.
In addition, wealth ranking has an impact on livestock management. For example, of the five wealth categories the top two (the „very rich‟ and the „rich‟) were characterized by the possession of cows and land. These two characteristics are important in the areas where there are dense populations like in the Bugesera and Nyamagabe districts. This is because where small plots are over-exploited agricultural production can only be increased if there is addition of manure. Thus, „very poor‟ to „moderately poor‟
households will have plots prone to low production.
Furthermore, animal feed resources identified in the Bugesera and Nyamagabe districts showed that they were scarce. Although farmers identified thirteen feed resources in the Bugesera district and twenty-one in the Nyamagabe district, their availability during the year was limited. For example, in the Nyamagabe district low quality feed such as Commelina benghalensis and banana stems were fed to animals by up to 50% of the farmers during the rainy and dry seasons. In the Bugesera district, low quality banana stems were used by 80% of farmers for forage for cows during the dry season. The grasses like Napier grass that should constitute most of the ruminant diet were used at 25% in the diet during the dry season in the Nyamagabe district. In addition, the use of low nutritive value feeds (e.g. banana stems, leaves of trees like Albizia spp., Ficus spp.) confirmed the need for intervention in the forage options in the study areas. Fodder crops that are of good quality and can adapt to the particular climate constraints found in each district will be important. For example, in the Bugesera district the fodder crops could be tolerant to the long dry period whereas in the Nyamagabe district, they might be tolerant to the combination of soil acidity and aluminium toxicity.
CHAPTER FIVE–ON-FARM EVALUATION OF IMPROVED BRACHIARIA GRASSES IN LOW RAINFALL AND ALUMINIUM TOXICITY PRONE AREAS OF RWANDA
Abstract
One of the major limitations of livestock production in Rwanda, in particular in the areas constrained by low rainfall and acidic soils is the scarcity of quality forage year round.
The International Centre for Tropical Agriculture (CIAT) initiated a breeding programme to develop high quality forage species to overcome these limitations. The aim of this study was to determine the production of improved Brachiaria grass in comparison with indigenous Brachiaria under low rainfall and aluminium toxicity areas of Rwanda. The specific objectives were (i) to assess the on-farm production of improved Brachiaria grasses (varieties and hybrids) and (ii) to determine the criteria by which farmers selected the new Brachiaria species in the study areas. Three varieties and five hybrids of Brachiaria grass from CIAT and two local grasses (control) were used for on-farm participatory trials without fertiliser application. Twelve farmers were selected in each study area and on each farm ten grasses were established in 2 m x 3 m plots. Biomass was harvested six times during the year at two monthly intervals. For each cut, dry matter (DM) was measured. The crude protein (CP), calcium (Ca) and phosphorus (P) were also measured once in the wet season and once in the dry season. In the low rainfall area, Brachiaria brizantha cv. Toledo and Brachiaria decumbens (local) had the highest DM yields (5.71and 5.61 t ha-1 respectively), while DM of the rest of the grasses ranged from 1.2 to 5.13 t ha-1. In the acidic soil area, Brachiaria hybrid Bro2/1485 had higher DM (5.95 t ha-1) than the rest of the grasses (1–4.47 t ha-1). The highest quality grass was Brachiaria hybrid Bro2/1485 which obtained a CP value of 12.15% in the low rainfall area, whereas in the acidic soil area hybrid cv. Mulato II obtained the highest CP value of 11.6%. In the low rainfall area the Brachiaria hybrid cv. Mulato obtained a high mean Ca value of 2.15% while in the acidic soil area, cv. Marandu obtained a high Ca value of 2.41% during the wet and dry seasons. The cv. Toledo had high P (0.28%) compared to the other grasses (0.07–0.11%) in the low rainfall area. In the acidic soil area, the
Brachiaria hybrid Bro2/1485 had high P of 0.53% compared to other grasses in which P varied between 0.16 and 0.47%. Local control grasses had lower nutrients than the improved Brachiaria grass in the low rainfall and acidic soil area. Although Brachiaria hybrid cv. Mulato II was not the most productive grass, it was selected by farmers as the preferred cultivar at both sites because of its adaptability to low rainfall and acidic soil stress, and its production of green forage year round without any input of fertilizer.