Enhancement of Grassland Production Through Integration of Forage Legumes in Semi-Arid Rangelands of Kenya

Livestock production in semi-arid rangelands of Kenya is limited by the seasonal quantity and quality of fodder. Kirkman & Carvalho (2003) stated that these inter- and intra-seasonal quality and quantity fluctuations result in nutrient deficits that severely limit livestock production potential. The objective of this experiment was to study the effect of three forage legumes on the production of natural pastures in semi-arid rangelands of Kenya

Adapting Nyando smallholder farming systems to climate change and variability through modeling

This study was done in Nyando, Kenya to model maize production under different climate scenarios and project the yields up to 2030 and 2050 using Decision Support System for Agrotechnology Transfer (DSSAT) under rain fed conditions. Three maize varieties were used; Katumani Comp B as early maturing variety, Hybrid 511 as a medium maturing variety and Hybrid 614 as a late maturing variety. Global coupled model Hadley Centre Global Environment Model version 2 (HadGEM2-ES) under representative concentration pathways (RCP) 4.5 and 8.5 was used to downscale Nyando’s climate data for the years 2030 and 2050. Past climate data for 53 years and current data was obtained from Kisumu Meteorological station while crop growth and farm management data was obtained from 70 farmers in Nyando. Results showed a decrease in yields across the years from 2015, 2030 and 2050 under both RCP 4.5 and 8.5. Average simulated yields for 2015 were 2519 kg ha-1 while projected yields under RCP 4.5 were 2212 and 2081 kg ha-1 in 2030 and 2050 respectively. Average yield projections under RCP 8.5 were 2184 and 1806 kg ha-1 for the years 2030 and 2050 consecutively. The study found out that temperatures will increase and rainfall duration will reduce. In addition, Katumani Comp B maize variety was not very much affected by these changes in temperatures and rainfall compared to H511 and H614

Sustainable development of crop-livestock farms in Africa

Crop-livestock farms across Africa are highly variable due to in agroecological and socioeconomic factors, the latter shaping the demand and supply of livestock products. Crop-livestock farms in Africa in the 20-first century are very different from most mixed farms elsewhere in the world. African crop-livestock farms are smaller in size, have fewer livestock, lower productivity and less dependency on imported feed than farms in most countries of Europe, the Americas and the intensive agricultural systems of Asia. This paper discusses the role African crop-livestock farms have in the broader socio-agricultural economy, and how these are likely to change adapting to pressures brought on by the intensification of food systems. This intensification implies increasing land productivity (more food per hectare), often leading to more livestock heads per farm, producing fertilized feeds in croplands and importing feed supplements from the market. This discussion includes (1) the links between crop yields, soil fertility and crop-livestock integration, (2) the increasing demand for livestock products and the land resources required to meet to this demand, and (3) the opportunities to integrate broader societal goals into the development of crop-livestock farms. There is ample room for development of crop-livestock farms in Africa, and keeping integration as part of the development will help prevent many of the mistakes and environmental problems related to the intensification of livestock production observed elsewhere in the world. This development can integrate biodiversity, climate change adaptation and mitigation to the current goals of increasing productivity and food security. The inclusion of broader goals could help farmers access the level of finance required to implement changes

Maize yield reduction due to erosion in a high potential area of Central Kenya Highlands

(African Crop Science Journal, 1998 6(1): 29-38

Effect of rangeland rehabilitation on the herbaceous species composition and diversity in Suswa catchment, Narok County, Kenya

Abstract Introduction Land degradation is a serious environmental problem of our time. In Kenya, it is estimated that 30% of the total land mass is severely degraded. Suswa catchment within Narok County is a good example with gullies of over 25 m deep and 30 m wide. In response to the increasing land degradation in the area, the Sustainable Land Management (SLM) project rehabilitated the catchment through establishment of soil and water conservation structures such as cutoff drains, semicircular bunds, and water retention ditches. Despite the various rehabilitation approaches carried out, little research has been done to ascertain their effect on successful vegetation recovery. This coupled with the fact that many restoration approaches have failed in East Africa and Kenya in particular gave drive to the study. The objective of this study was to determine the effects of rangeland rehabilitation on herbaceous species composition and diversity in a severely degraded rangeland. Methods To assess the diversity of aboveground herbaceous layer in the rehabilitated and degraded areas along a slope (upper, middle, and lower), line transect and quadrat count methods were used. Within each slope position, three 100-m-long transects were placed across the hill parallel to one another 30 m apart using a tape. The species hit, the closest species to the hit, and hits on bare ground were recorded. Along the same transects, 1-m2 quadrats were placed 25 m apart and aboveground biomass determined by the use of the destructive method. In the determination of species richness, diversity, relative abundance, percentage cover, and species composition, the Shannon-Wiener diversity index was used. Data collected on vegetation attributes was subjected to analysis of variance (ANOVA) using Genstat and Tukey’s HSD post hoc used in means separation where F values were significant. Results The results showed that percent cover (74.67%), aboveground biomass (1459 kg/ha), relative abundance, richness, composition, and diversity of perennial grasses significantly (P ≤ 0.05) increased downslope and were higher in the rehabilitated area than in the degraded area. On the contrary, forbs and annual grasses were significantly (P ≤ 0.05) higher within the degraded area compared to the rehabilitated area and increased upslope. Conclusions In general, herbaceous species diversity, species richness, relative abundance, percent composition, biomass production, and percent cover of perennial grasses significantly increased downslope and were higher in the rehabilitated area compared to the degraded area. On the contrary, the same attributes for forbs and annual grasses were higher in the degraded area and increased upslope. The study concluded that effective rangeland rehabilitation has the potential to enhance vegetation regeneration and hence forage productivity

Soil acidity management by farmers in the Kenya highlands

Declining soil fertility attributed to soil acidity is a major soil productivity problem in sub-Saharan Africa. A study was carried out in nine counties across the Kenya highlands, namely Meru, Embu, Kerugoya, Nyeri, Kiambu, Kinangop, Siaya, Busia and Eldoret, where the problems associated with soil acidity are prominent. The study aimed at assessing farmers' awareness of soil acidity, and establishment of common acidity management practices following administration of structured questionnaires. From the information gathered through personal interviews via questionnaires, <37% of the farmers were attached to a farmers training group in all study sites; among them, <4% were aware of soil acidity problems and <8% had carried out chemical analysis of their soils. The farmers who had applied lime at least once on their farms were <3% in all sites. Most farmers (>80%) used both inorganic fertilizers and manure on their farms, with the majority using DAP, CAN and farmyard manure. On cultural soil fertility management, choice of subsequent crop was dictated by sustainability rather than cropping system like rotation. There was a significant (P<0.05) negative relationship between livestock keeping and soil fertility management, with <30% of the farmers returning crop residues back to the farm. Most of them fed crop residues to their livestock. Only 8% of the farmers incorporated crop residues into the soil. There was a significant (Ps 0.05) positive correlation between education level and inorganic fertilizer use in crop production. Farmer's age and maize yields correlated negatively with each other. Additionally, farmers' training programmes and frequencies positively influenced choice of inorganic fertilizers and levels of application. Training is therefore one of the most significant issues affecting soil fertility management in the Kenya highlands. To further enhance the understanding of soil acidity and fertility management in Kenya highlands, farmers training should be prioritized

Phosphorus Adsorption and Its Relation with Soil Properties in Acid Soils of Western Kenya

Low available phosphorus (P) is one of the major hindrances to crop production in acid soils of western Kenya. Although considerable work has been done to establish P levels in the region, there is paucity of information on which to base fertilizer recommendations due to potential crop production differences caused by different soil types and climate. Phosphorus adsorption capacity and its relationship with some soil properties were evaluated in acid soils from nine locations of western Kenya. Adsorption data was obtained by equilibrating the nine soil samples with 30ml of KH2PO4 in 0.01 M CaCl2, containing 0, 80, 150 and 300 µg ml-1 for 48 hours with shaking for 30 minutes at intervals of 8 hours. Langmuir, Freundlich and Tempkin adsorption models were fitted to the test results and relationship between P adsorption and soil properties determined by correlations. The result of this study showed that the soils were strongly to extremely acidic (pH 4.83 - 3.76), had high exchangeable Al3+ (&gt;2 cmol Al kg-1), Al saturation of (&gt; 20% Al) and calculated maximal phosphorous adsorption varied from 770.83 to 1795.83 mg kg-1 soil. Comparing the models, Freundlich linear model showed a better fit to the tested soils compared to Langmuir and Tempkin models. The regression coefficients (R2) for the fitted Freundlich P adsorption isotherms was highly significant ranging from (0.995- 1.000) for all tested soils. Analysis of relationship between adsorption maximum and soil attributes revealed that adsorption maximum positively correlated with clay content, exchangeable P, exchangeable acidity and Aluminium saturation and negatively correlation with organic matter and electrical conductivity. Due to differences in maximal P sorption capacities within the tested area, blanket P fertilizer recommendation may affect crop productivity in some sites. There is therefore need for further research to determine optimal Phosphorus requirements for soils in each research site

Soil acidity management by farmers in the Kenya highlands

Declining soil fertility attributed to soil acidity is a major soil productivity problem in sub-Saharan Africa. A study was carried out in nine counties across the Kenya highlands, namely Meru, Embu, Kerugoya, Nyeri, Kiambu, Kinangop, Siaya, Busia and Eldoret, where the problems associated with soil acidity are prominent. The study aimed at assessing farmers' awareness of soil acidity, and establishment of common acidity management practices following administration of structured questionnaires. From the information gathered through personal interviews via questionnaires, <37% of the farmers were attached to a farmers training group in all study sites; among them, <4% were aware of soil acidity problems and <8% had carried out chemical analysis of their soils. The farmers who had applied lime at least once on their farms were <3% in all sites. Most farmers (>80%) used both inorganic fertilizers and manure on their farms, with the majority using DAP, CAN and farmyard manure. On cultural soil fertility management, choice of subsequent crop was dictated by sustainability rather than cropping system like rotation. There was a significant (P<0.05) negative relationship between livestock keeping and soil fertility management, with <30% of the farmers returning crop residues back to the farm. Most of them fed crop residues to their livestock. Only 8% of the farmers incorporated crop residues into the soil. There was a significant (Ps 0.05) positive correlation between education level and inorganic fertilizer use in crop production. Farmer's age and maize yields correlated negatively with each other. Additionally, farmers' training programmes and frequencies positively influenced choice of inorganic fertilizers and levels of application. Training is therefore one of the most significant issues affecting soil fertility management in the Kenya highlands. To further enhance the understanding of soil acidity and fertility management in Kenya highlands, farmers training should be prioritized