James B. Kung’u

Improving food production using ‘best bet’ soil fertility technologies in the Central highlands of Kenya

Declining crop productivity is a major challenge facing smallholder farmers in central highlands of Kenya. This decline is caused by continuous cultivation of soils without adequate addition of external inputs in form of manures and fertilizers. With this background, an on-station trial was initiated at Embu in 1992 to evaluate the feasibility of using two leguminous shrubs; Calliandra calothyrsus and Leucaena leucocephala for improving food production. In 2000, an off-station farmers’ participatory trial aimed at offering farmers soil enhancing technologies for replenishing soil fertility was established in Meru South District. The results from the Embu on-station trial indicate that, over the 11 years of study, calliandra and leucaena biomass transfer with half recommended rate of inorganic fertilizer treatments gave the best average maize grain yields of 3.3 Mg ha-1. Treatment where calliandra was alley cropped with maize but the prunings removed recorded the lowest maize yield of 1.2 Mg ha-1. Treatments with calliandra and leucana biomass transfer had similar yields but treatments that were alley cropped with leucaena did better than those that were alley cropped with calliandra. On the other hand, results from the off-station trial in Meru South indicate that, on average, across the seven seasons, sole tithonia gave the highest maize grain yield followed closely by tithonia with half recommended rate of inorganic fertilizer with 6.4 and 6.3 Mg ha-1 respectively. Control gave the lowest yield of 2.2 Mg ha-1 across the seasons. On average, integration of organic an inorganic sources of nutrients gave higher yields compared to all the other treatments.

Food Security in Africa: The Challenges of Researchers in the 21st Century

Food production in most of Sub-Saharan Africa (SSA) has not kept pace with the population increase over the past three decades. In many countries, food security remains a serious problem. It contributes both to high rates of under- and malnutrition, poorer learning in school, and lack of development in general. In Africa as a whole, food consumption exceeded domestic production by 50% in the mid-1980s and more than 30% in the mid-1990s. Food aid constitutes a major proportion of net food trade and in many countries it constitutes more than half of net imports. Despite food imports, per capita dietary energy supply (DES) remains relatively low; with about one-third of the countries having per capita DES of less than 2,000 kcal day−1 which is lower than the minimum recommended intake.

Economic evaluation of local inputs in Meru South District, Kenya

Declining land productivity is a major problem facing smallholder farmers in Kenya today. This decline is as a result of reduced soil fertility caused by continuous cultivation without adequate addition of manures and fertilizers. Low soil fertility is one of the greatest challenges facing farmers in the central highlands of Kenya. A farmers’ participatory trial was established in Meru South District, Kenya in 2000 to investigate feasible soil nutrient replenishment technologies for poor resource smallholder farmers. Results across seven seasons indicate that sole tithonia gave the highest grain yield followed closely by tithonia with half recommended rate of inorganic fertilizer with 6.4 and 6.3 Mg ha-1respectively. The control treatment gave the lowest yield of 2.2 Mg ha-1 across the seasons. The integration of organic and inorganic nutrient sources of N gave higher maize grain yield as compared to the sole organic materials in all seven seasons. Economic analyses indicate that on average tithonia with half the recommended rate of inorganic fertilizer recorded the highest net benefit (US

Growing common plantation tree species in Kenya for sale of carbon and wood supply: what is the best bet?

787.2) whereas the control treatment gave the lowest benefit (US

Effects of organic and mineral fertilizer inputs on maize yield and soil chemical properties in a maize cropping system in Meru South District, Kenya

271.7). On the other hand the recommended rate of inorganic fertilizer gave the highest (US

Combining napier grass with leguminous shrubs in contour hedgerows controls soil erosion without competing with crops

12.5) return to labour while sole tithonia gave the lowest (US

Adoption potential of selected organic resources for improving soil fertility in the central highlands of Kenya

4.0). On average in the farmers’ fields, manure alone gave the highest return to labour of US

Improved food production by use of soil fertility amendment strategies in the central highlands of Kenya

3.6, while the control treatment gave the lowest return to labour US

Regeneration of the East African timber tree Ocotea usambarensis in relation to historical logging

–0.2.

Soil Carbon Sequestration Differentials among Key Forest Plantation Species in Kenya: Promising Opportunities for Sustainable Development Mechanism

The introduction of carbon finance as an incentive in forestry farming has a potential of increasing the amount of carbon sequestered. However, this has created a daunting task among investors in forestry to optimise the joint production of wood and carbon sequestration. For instance, investors might find it profitable to give up some timber returns in exchange for carbon credits. This study evaluated expected income from growing Cupressus lusitanica Mill., Pinus patula Schiede ex Schltdl. & Cham., Eucalyptus saligna Sm. and Juniperus procera Hochst. ex Endl. for wood and/or the carbon market in central Kenya. The global average unit price of carbon and stumpage royalty were used to estimate expected returns from sale of carbon credits and wood, respectively. There were significant differences (p < 0.01) in the expected amount of income from sale of carbon and wood among the four species. Specifically, at economic rotation of 30 years with stand density of 532 trees ha−1 P. patula and C. lusitanica yielded US