Adapting Agriculture to Climate Change: An Evaluation of Yield Potential of Maize, Sorghum, Common Bean and Pigeon Pea Varieties in a Very Cool-Wet Region of Nyandarua County, Central Kenya

Three experiments were conducted to evaluate the performance of maize, sorghum, common bean and pigeon pea varieties under different water management in a cool and wet region of Central Kenya, as a part of the studies at analogue sites. The first experiment evaluated the growth and performance of three varieties (early maturing: EM, medium maturing: MM and late maturing: LM) of maize (Zea mays L), sorghum (Sorghum bicolor L.), pigeon pea (Cajanus cajan) and common bean (Phaseolus vulgaris L.). The second experiment evaluated maize and sorghum response to water conservation and three fertiliser rates (0, 20 and 40 kg N/ha). The third experiment assessed the effect of water conservation measures on crop yields of common bean and pigeon pea grown under three plant densities (low, medium and high). Tied ridge tillage was used as the water conservation measure and disc plough as the control in the second and third experiments. Maize, sorghum, pigeon pea and common bean took more than 180, 245, 217 and 95 days respectively, to reach physiological maturity. The MM maize variety (DK8031), EM pigeon pea variety (ICPL 84091) and LM common bean variety (GLP 24) yielded the greatest grain of 4,938, 881 and 620 kg/ha respectively, among the respective crop varieties. The sorghum varieties were attacked by fungal and rust diseases leading to yield losses in all seasons. Soil water conservation in general did not have a significant effect on crop yield though there were yield improvements. In the plant density trial, the medium plant densities of pigeon pea (33,333 pl/ha) and common bean (148,148 pl/ha) resulted in the greatest grain yields. The highest grain yield of maize (4,184 kg/ha) and sorghum (47 kg/ha) was obtained in plots with 20 kg/ha of nitrogen fertilizer. Based on the results of this study, pigeon pea and common bean can be introduced in the farming systems to improve crop diversity. The production of the tested sorghum varieties should be discouraged in this region because they are prone to fungal and rust diseases due to the cold and wet weather conditions

Adapting agriculture to climate change - An evaluation of yield potential of maize, sorghum, common bean and pigeon pea varieties in a very cool-wet region of Nayandarua County

Soil and water conservation, use of more adaptive crop genotypes and crop diversification are widely accepted as some of the management practices that can help reduce agriculture vulnerability to impacts of climate change. A study was conducted to evaluate the yield potential of maize, sorghum, common bean and pigeon pea varieties under different water management, plant densities and fertility levels in Nyahururu, Central Kenya. The study involved three experiments. The first experiment evaluated the growth and performance of three varieties (early maturing, medium maturing and late maturing) of maize, sorghum, pigeon pea and common bean. The experimental design was a completely randomized block design (RCBD) replicated three times. The second experiment evaluated maize and sorghum yield response to water conservation and three fertiliser rates (0, 20 and 40 kg N/ha). The third experiment assessed the effect of water conservation measures on crop yields of common bean and pigeon pea grown under three plant densities (low, medium and high). Tied ridge tillage was used as the water conservation measure and disc plough as the control in the second and third experiments. Results showed that water conservation in general did not have a significant effect on crop yield though they were improved. The medium density pigeon pea gave the highest grain (719 kg/ha) followed by low (688 kg/ha) and high plant density (687 kg/ha), though not significant at 0.95 confidence level. Similar trends were observed with common bean grain and dry matter yield. Tied ridges tended to lower maize yield compared to flat tillage while it increased sorghum yields but the difference was insignificant. When average across the tillage systems, the highest maize grain (5553 kg/ha) and dry matter (14298 kg/ha) yield was obtained in plots without N fertilizer. Sorghum dry matter was highest (11333 kg/ha) in plots with 40 kg N/ha and lowest (7903 kg/ha) in plots with 20 kg/ha N. In the variety experiment, the EM pigeon pea variety (ICPL 84091) yielded the greatest grain (881 kg/ha) while the late maturing variety (ICEAP 00040) gave the least (565 kg/ha). The LM maize variety (DK8031) yielded the highest grain (5701 kg/ha) and dry matter (18843 kg/ha). The LM sorghum variety (Macia) had 47% and 49% dry matter yield advantage over MM (Kari Mtama 1) and EM (Gadam) varieties, respectively. The yields for common bean varieties tended to vary with seasons. So what are the conclusions

Costs and benefits of livestock systems and the role of market and nonmarket relationships

In developing countries livestock are kept not only for their physical products, but also for insurance, financing, and to display status. Though this range of purposes is acknowledged, livestock policies nevertheless often emphasize physical production: a limited perspective that hampers the formulation and implementation of effective livestock policies. This article presents a comprehensive appraisal of costs and benefits of livestock systems that takes into account the institutional environment of livestock keepers. Indicators are developed that capture, quantify, and organize not only the benefits resulting from the physical production, but also those from the intangible functions. The method is illustrated by an analysis of cattle in the Western Province of Zambia. The results indicate that the perspective on livestock systems developed more closely reflects the observed decisions of the livestock keepers. Copyright 2005 International Association of Agricultural Economics.

EFFECT OF MULCHING CABBAGE WITH BANANA RESIDUES ON CABBAGE YIELD, SOIL NUTRIENT AND MOISTURE SUPPLY, SOIL BIOTA AND WEED BIOMASS

Banana (Musa   spp.) residues were examined as organic inputs for cabbage (Brassica oleracea   L.) production in Uganda with respect to yield and soil biological activities. Cabbage, cultivar Copenhagen, was cultivated on a Ferralsol of low inherent fertility, with (15 t ha-1 dw) or without banana residues and hand-weeding. Two additional treatments included application of fertiliser (100 kg N, 50 kg P and 100 kg K ha-1) with weeding and surface mulching with black polythene (no nutrient inputs). Rankings of cabbage yields by management practice were consistent in both seasons, following the order of fertilised + weeded > banana mulched + weeded > plastic mulched > weeded > banana mulched > unmulched + unweeded. Hand-weeding increased yields by 9.3 t ha-1 (fresh weight). Combined banana mulching and hand-weeding resulted in an additional 12.5 t ha-1, but this increase was 15.1 t ha-1 less than that from application of fertiliser. Surface mulching with banana residues was not effective in weed suppression or moisture conservation but increased earthworm population densities. Banana pseudostems decayed more rapidly than leaves, and excluding soil macrofauna from both decaying tissues delayed decomposition. Plastic mulching increased cabbage yields by 14.9 t ha-1 over the unweeded treatment and improved soil moisture status, but this material is not widely available to smallholder farmers in Uganda. Farmers who seek to improve vegetable production can utilise banana residues as nutrient inputs only in combination with effective weeding; although the nutrients applied through banana mulch may not be utilised effectively compared to chemical fertilisers

Reducing uncertainty in nitrogen budgets for African livestock systems

Livestock is poorly represented in N budgets for the African continent although some studies have examined livestock-related N flows at different levels. Livestock plays an important role in N cycling and therefore on N budgets including livestock-related flows. This study reviews the literature on N budgets for Africa to identify factors contributing to uncertainties. Livestock densities are usually modelled because of the lack of observational spatial data. Even though feed availability and quality varies across seasons, most studies use constant livestock excretion rates, and excreta are usually assumed to be uniformly distributed onto the land. Major uncertainties originate in the fraction of manure managed, and emission factors which may not reflect the situation of Africa. N budgets use coarse assumptions on production, availability, and use of crop residues as livestock feed. No flows between croplands-livestock and rangelands reflect the lack of data. Joint efforts are needed for spatial data collection of livestock data, crowdsourcing appears to be a promising option. The focus of the assessment of N budgets must go beyond croplands to include livestock and crop-livestock flows. We propose a nested systems definition of livestock systems to link local, regional level, and continental level and to increase the usefulness of point measurements of N losses. Scientists working at all levels should generate data to calibrate process-based models. Measurements in the field should not only concentrate on greenhouse gas emissions, but need to include crop and livestock production measurements, soil stock changes and other N loss pathways such as leaching, run-off and volatilization to assess management practices and trade-offs. Compared to the research done in other continents on N flows in livestock systems, there are few data for Africa, and therefore concerted effort will be needed to generate sufficient data for modelling