RP-Department of Agricultural Resources Management (ARM)

Permanent URI for this collection

https://repository.ku.ac.ke/handle/123456789/5392

Browse

Now showing 1 - 20 of 64

Assessment of erosion damage in Ndome and Ghazi, Taita Taveta, Kenya: Towards an integrated erosion management approach
(GeoJournal, 2002-01-02) Waswa, F.; Gachene, C.K.K.; Eggers, Helmut
Aerial photograph interpretation on erosion trends from 1961 to 1998 showed that by 1998, approximately 17 and 50% of agricultural land in Ndome and Ghazi respectively had been permanently lost due to the combined effect of rill, inter-rill, and gully erosion, and sand deposition. Although abnormally heavy rains received between 1996–98 caused much of the present land damage, the severity of the damage was enhanced by inappropriate and persistent human perturbations in the land-system notably through vegetative degradation and destruction of soil structure through inappropriate tillage practices. With soil organic matter contents of 1.6 and 1.9%, and clay ratios of 10.1 and 10.6 for Ndome and Ghazi, respectively, the areas inherent erodibility was considered as high thus pointing to the need for careful use and management of the soil resource. That farmers appreciated only land quality indicators that were visible to the naked eye and that directly affected their subsistence, revealed a knowledge gap that saw damages from intrinsic processes like rill and inter-rill erosion proceed unnoticed. This paper argues that the spread of erosion damage in rural agro-ecosystems is survival-driven. And as a remedy to this problem, there is need for the diversification of livelihood endeavours to alternative off-farm income sources to reduce pressure on the already fragile land resource. Further, being the ultimate implementers of conservation technologies and by virtue of the multiplicity and inter-relation of rural household needs, adoption of an integrated erosion management approach with food security as paramount presents the most practical entry point for sustainable land management in such rural agro-ecosystems.
Indigenous soil and water conservation techniques in smallholder farms in Africa.
(Springer, 2007) Danga, B. O.; Ben-Hur, M.; Wakindiki, I.I.C.
Runoff and soil erosion are responsible for about 83% of the land degradation worldwide. Many smallholder farmers in arid and semi-arid areas of Africa often use inexpensive indigenous soil and water conservation (ISWC) techniques to control runoff and erosion. This paper is a review of the ISWC methods and categorizes them into three: those suitable for semi-arid areas, those suitable for wet areas and those suitable for both semi-arid and wet areas. The usefulness of ISWC is generally appreciated but literature on the subject is scarce. A case study that investigated effects of 2-m spaced trash lines on runoff, erosion and crop yield in a cowpea – maize rotation is presented. Trash lines reduced runoff and soil loss and increased crop biomass yield three-fold. We conclude that ISWC like close-spaced trash lines are beneficial soil and water conservation methods and should be incorporated in future land resource conservation programmes
Pollen longevity in ecologically different zones of western Kenya
(African Journals Online, 2007) Muui, C. W.; Muasya, R.M.; Rao, N; Anjichi, V.E
Maize (Zea mays L.) is the most important staple crop in Kenya with the small holder farming systems accounting for about 75-80% of the total production. Most of the small-scale farmers plant locally adapted landraces and there are concerns about the possible contamination of these through geneflow from novel varieties, including the transgenics. The survival of pollen after dehiscence is an important factor affecting the geneflow. Studies were conducted to investigate the duration of pollen viability in two locations in western Kenya - Eldoret and Kakamega, representing the highland tropical and moist mid-altitude/transitional zones, respectively. Pollen was collected at dehiscence and exposed as a thin layer in the open air for 0 (control), 15, 30, 60, 120 and 240 minutes. Pollen viability was assessed by measuring the seed set after pollination, scoring percentage pollen color change and percentage pollen germination. Pollen maintained viability for 120 minutes after dehiscence in Eldoret (T=23-240C; RH=45-55%; Ø=-109 to -82 MPa) and for 240 minutes in Kakamega (T=25-270C; RH=68-83%; Ø=-53 to -26 MPa). The differences in pollen longevity were attributed to the differences in atmospheric water potential between the two locations. The results suggest that the likelihood of genetic contamination of the landraces through geneflow from novel varieties is higher in the moist mid-altitude zones than in the highland tropical zones of Kenya.
Potential nutritive value and tannin bioassay of selected Acacia species from Kenya
(Wiley, 2007-04-24) Osuga, I. M; Maindi, C. N.; Abdulrazak, S. A.; Nishino, N.; Ichinohe, T.; Fujihara, T.
Six Acacia forage species–A. brevispica, A. elatior, A. mellifera, A. nilotica, A. senegal and A. seyal—were analysed for their chemical composition, including phenolics and rumen fermentation characteristics. In vitro gas production technique was used to study the rumen fermentation characteristics and the effect of tannins present in the browse forages on in vitro fermentation by including polyethylene glycol (PEG-6000) in the incubation. The forages had high crude protein content (145.7–270.1 g kg−1 DM) and low to moderate content of neutral detergent fibre (220.2–442.8 g kg−1 DM). The forages had variable content of total extractable phenolics ranging from 18.4 to 384.2 g kg−1 DM and total extractable tannins ranging from 7.1 to 364.8 g kg−1 DM (tannic acid equivalent). Fractionation of the condensed tannin flavonoids showed that the delphinidin/cyanidin ratio ranged from not detected:100 to 71:29. The gas production potential ranged from 28.4 to 40.8 mL gas 0.2 g−1 DM. The rate of gas production was highest in A. elatior and lowest in A. nilotica. Addition of PEG-6000 increased gas production significantly (P < 0.05) in all species except A. mellifera. PEG-6000 addition did not have any significant effect on in vitro true dry matter and organic matter degradability but decreased the partitioning factor in all the species. Gas production and degradability parameters correlated positively with the CP content and negatively with the fibre and phenolics contents. Based on chemical composition, gas production and degradability, the forages have high potential nutritive value, especially as supplements to low-quality feeds in the tropics and particularly during the dry season. However, the presence of tannins in terms of high levels and biological antinutritive activity may limit the nutritive potential of some of the forages, such as A. seyal and A. nilotica. Copyright © 2007 Society of Chemical Industry
Evaluation of nutritive value and palatability by goats and sheep of selected browse foliages from semiarid area of Kenya
(Wiley, 2008-08-22) Osuga, I. M.; Wambui, C. C.; Abdulrazak, S. A.; Ichinohe, T.; Fujihara, T.
The feeding value of five browse foliages (Acacia brevispica, Acacia mellifera, Berchemia discolor, Zizyphus mucronata and Maerua angolensis) grown in semiarid area of Kenya were evaluated. Their chemical composition including polyphenolics and in vitro gas production characteristics were determined. The biological activity of the polyphenolics was assessed as the increases in gas production profiles and in vitro true dry matter (DM) and organic matter (OM) digestibility after in vitro incubation with or without addition of polyethylene glycol (PEG) as a tannin binding reagent. The intake and palatability ranking of the browse foliages by goats and sheep were also investigated. The browse foliages had variable crude protein content (149.5–248.6 g/kg DM) and variable content of neutral detergent fiber (205.1–424.0 g/kg DM). The content of total extractable tannins was generally low (2.4–34.8 g/kg DM). At 24 h of incubation, Z. mucronata produced the highest gas volume, while after 48 h of incubation, B. discolor produced the highest gas volume. M. angolensis had the least gas production potential within the browse foliages. Addition of PEG increased gas production except in A. mellifera and M. angolensis. However, PEG addition did not have any significant effect on in vitro true DM and OM digestibility except in B. discolor, which decreased. The rank order of preference (highest to least) for goats was A. brevispica, Z. mucronata, B. discolor, A. mellifera and M. angolensis while the rank order of preference for sheep was A. brevispica, B. discolor, A. mellifera, Z. mucronata and M. angolensis. The goats had higher intakes of all the browse foliages than sheep. The result of this study highlights the higher feeding value of the browse species as supplemental feed with low quality basal diet with both of animal species except M. angolensis.
How weather during development of common bean (Phaseolus vulgaris L.) affects the crop's maximum attainable seed quality
(Science Direct, 2008-10) Muasya, R. M.; Lommen, W. J. M.; Muui, C. W.; Struik, P. C.
Weather conditions affect the seed quality of major crops including common bean. This study aimed to evaluate whether seed quality is affected through weather effects on the quality achievable at the end of seed filling (PM) or through changes in quality during maturation drying in the period between PM and harvest maturity (HM). The research also aimed to establish relationships between seed yield and seed quality. Twenty-four common bean (Phaseolus vulgaris L.) crops from two cultivars were sown on different dates in Eldoret and Kitui, Kenya. Seed quality was quantified as the percentage of viable seeds determined with a tetrazolium test, and as vigour measured by electrical conductivity (EC). Over the range of weather conditions during our study, high temperatures were more detrimental to seed quality than little rainfall. The two cultivars differed in susceptibility to high temperatures. High temperatures and little rainfall seemed to reduce seed quality mainly through reducing maximum quality attainable during the course of crop development. The quality in general did not change significantly between PM and HM, but in some cases the proportion of viable seeds increased between PM and HM, especially when ambient temperatures were relatively low. For seed samples free from mechanical damage, EC appeared to be an unsuitable criterion to detect quality differences at HM, because in almost all seed lots quality was indiscriminately classified as ‘good’, whereas viability varied between 69 and 100%. Production conditions leading to low seed yields or seeds of low weight resulted in a low percentage of viable seeds but conditions resulting in fairly high yields or heavy seeds did not guarantee a high percentage of viable seeds.
Effect of placement of straw mulch on soil conservation, nutrient accumulation, and wheat yield in a humid Kenyan highland
(Kerala Agricultural University, 2009) Danga, B. O.; Wakindiki, I. I. C.
Mulching affects soil nutrient dynamics and crop yields. The effects of quantity and method of application of wheat straw mulch on soil loss, nutrient accumulation, nutrient loss, and wheat yield were evaluated in a field experiment in the acidic, d ark red, Rhodic Ferralsols of Kenya. The experiment involved three levels of wheat straw mulch (0, 3, and 5 Mg · ha –1 ) either incorporated in the soil (0 to 0.2 m) or surface applied. Surface application at 5 Mg · ha –1 decreased annual soil loss to 1.82 Mg · ha –1 from 14 Mg · ha –1 in the control. Deep placement of 5 Mg · ha –1 of straw, however, increased soil organic matter content by 23%. Annual losses of NH 4 –N, NO 3 –N, PO 4 –P, and available K in the sediments were 0.02, 0.04, 0.06, and 0.44 kg · ha –1 , respectively in the 5 Mg · ha –1 surface treatment. Straw mulch treatments also enriched NO 3 –N concentration in the 0 to 0.4 m soil layer. Surface application of 3 Mg · ha –1 straw gave the highest grain yield of wheat and the highest net returns (US$ 747), which was 30% more than that of the control.
Enhancing household food and income security through crop diversification in the Nzoia and Mumias sugarbelts in Kenya
(F.a.C.T Ltd, 2009) Waswa, F.; Mcharo, M.; Netondo, G.
Objective: Competition for land use among crops in the Nzoia and Mumias sugar belts has tended to favour sugarcane and maize at the expense of indigenous food crops such as onions, tomatoes, cassava and sweet potatoes. This in part explains the persistent food insecurity situation in these regions. This study investigated the income potential of diverse crops as a basis of encouraging farmers in the area to diversify their sources of livelihoods. Methodology and results: An income analysis based on a social survey research was conducted in Webuye and Matungu - Mumias areas in western Kenya. The survey involved45farmers from Nzoia and 43 from Matungu. In both sites respondents were selected randomly from farmers lists obtained from the local ministry of agriculture offices. Data were collected the through use of questionnaires, interviews and Participatory Rural Appraisals targeting the selected sugarcane farmers and key respondents, mainly the local ministry of agriculture officers. The results indicated that sugarcane and maize have less potential to contribute to increased household incomes as compared to other ecologically suitable crops. This is particularly true for smallholder farmers. Crops with potentially high income included onions, tomatoes, indigenous vegetables, cassava, sweet potatoes, pineapples and ground nuts. To enhance household food and income security, farmers need to invest in these high in come crops based on an entrepreneurial culture with institutionalised value -addition practices along the value-chain. Sustainability of such crop production systems is however hinged upon farmers’ competences in agricultural entrepreneurship, availability of ready markets for their products, and ready access to value-addition technology and infrastructure. Conclusion and application of findings: Opportunities for crop diversification in the Nzoia and Mumias sugar belts are enormous. To maximise benefits from these opportunities requires an attitude change on the part of farmers away from sugarcane and maize. This calls for the implementation of aggressive farmer - centred integrated extension services, involving strategic partnership with government, private sector and civil society organisations working within the agricultural sector in the sugar belt.
Determinants of the decision to adopt integrated soil fertility management practices by smallholder farmers in the central highlands of Kenya
(Cambridge University Press, 2009-01) Mugwe, J. N.; Mugendi, D.N.; Mucheru-Muna, M.; Merckx, R.; Chianu, Jonas; Vanlauwe, B.
Declining soil fertility is a major cause of low per capita food production on smallholder farms of sub-Saharan Africa. This study attempted to provide an empirical explanation of the factors associated with farmers' decisions to adopt or not to adopt newly introduced integrated soil fertility management (ISFM) technologies consisting of combinations of organics and mineral fertilizer in Meru South district of the central highlands of Kenya. Out of 106 households interviewed, 46% were ‘adopters’ while 54% were ‘non-adopters’. A logistic regression model showed that the factors that significantly influenced adoption positively were farm management, ability to hire labour and months in a year households bought food for their families, while age of household head and number of mature cattle negatively influenced adoption. The implication of these results is that the adoption of ISFM practices could be enhanced through targeting of younger families where both spouses work on the farm full-time and food insecure households. It is also important to target farmers that lack access to other sources of soil fertility improvement. Examples include farmers that do not own cattle or those owning few and who, therefore, have limited access to animal manure.
Biophysical and Socio-economic Frame Conditions for the Sustainable Management of Natural Resources
(2009-10-06) Bekele, N.A.; Mithöfer, D.; Amudavi, D.; Obare, G.
Horticulture is a key sector of the Kenyan economy. It improves household welfare through providing income, satisfying domestic food needs and improving human nutrition. Next to market access pests and diseases are the major constraints. With the adoption of Farmer Field Schools (FFS) and Common Interest Groups (CIG) as information sources in horticultural production, it is not yet understood how effective the two approaches en- hance environmentally and health friendly production practices such as integrated pest management (IPM). It is expected that IPM information is to a greater extent communicated among farmers belonging to farmer groups because of the enhanced interaction among group members. This paper presents findings of farmer preferences in the choice of information sources and assesses factors that influence IPM information reception and sharing. The analysis applies a bivariate probit regression model for reception and sharing of IPM information to survey data from a random sample of 487 smallholder horticultural producers who are either FFS members, CIG members or non-group based farmers. IPM information and knowledge in this paper is defined as a range of practices including scouting, sanitation, crop rotation, mixed cropping, hand picking, solarisation, planting resistant varieties, applying plant extracts and selective pesticide application. Findings show that government extension staff, NGOs, friends, and neighbours are the three most important information sources for horticulture production and IPM. FFS farmers have more knowledge on IPM practices than CIG and non-group based farmers. Regression results show that membership in farmer groups, gender, education, locality, household size, landper capita, distance to extension service, frequency of listening to radio and literate hou- sehold members significantly influence information flow. FFS farmers are more likely to receive IPM information than individual farmers whereas CIG farmers are not distinguishable from individual farmers with respect to receiving IPM information. Unlike FFS and non group based framers, CIG farmers are more likely to share IPM information. Implications may be that the intensive training of FFS farmers promotes information reception and knowledge accumulation but promotes close knit interaction in the group which prevents information leaving the group. This is being further tested.
Effects of Low Nitrogen and Drought on Genetic Parameters of Grain Yield and Endosperm Hardness of Quality Protein Maize
(2010) Kirubi, D.; Njoroge, Kiarie; Ngaboyisonga, Claver; Githiri, S. M.
The aim of this study was to assess how low nitrogen and drought stresses affect genetic parameters of grain yield and endosperm hardness of QPM. Twelve inbred lines were acquired from CIMMYT and used to generate 36 single cross hybrids with North Carolina Design II procedures. The single crosses were evaluated at Kiboko in Kenya and Rubona in Rwanda in 2005 and 2006 cropping seasons under optimum, low nitrogen and drought conditions. Observations were performed on grain yield and endosperm hardness. The results showed that gene action on the grain yield was predominantly non-additive and maternal, whereas that of the endosperm hardness was predominantly additive and maternal. Low nitrogen and drought changed the proportions of different genetic effects. They changed as well the magnitudes and direction of General Combining Abilities (GCAs) of lines and Specific Combining Abilities (SCAs) of crosses. It was possible to have together, significant and positive SCAs for grain yield and significant and negative SCAs for endosperm hardness. Crosses with significant and positive SCAs for grain yield and significant and negative SCAs for endosperm hardness are candidates to use in QPM production, especially in drought and low nitrogen prone areas.
Temporal variability of two contrasting transient pollution events in a pastoral stream
(IWA Publishing, 2010) Mwetu, Kennedy K.; Yillia, PT; Kreuzinger, N.
Two transient pollution events were monitored in a pastoral stream in southwestern Kenya to evaluate their relative contribution to diffuse pollution. Peak loads of pollutants during storm-induced transients were within 3-4 orders of magnitude higher than the short-lived (30-60 minutes) diurnal episodes provoked by in-stream activities of people and livestock. Transient yields were striking during storm-induced events; 778,000, 8,400, 550 and 100 kg day(-1) for suspended solids, BOD(5), total P and total N, respectively, compared to wet weather base flow (150, 30, 0.8 and 1.4 kg day(-1), for the same parameters, respectively). Two forms of concentration-discharge relationships were observed: increases in concentration for turbidity, suspended solids, BOD(5), total P and the faecal indicator bacteria at the peak of the stream hydrograph, and concurrent decreases in concentration for conductivity and total N. Following each storm-induced transient event, a marked improvement in water quality was observed within 48-72 hrs of the receding limb of the stream hydrograph before the next base low was established. It was concluded that storm-induced transients are exceedingly important for the mobilization of pollutants from diffuse sources but both transient events affect stream-channel processes, especially water quality, with the possibility of attendant consequences on the health of riparian inhabitants.
Wheat Rotation for Higher Production in a Humid Tropical Region
(Association of Official Seed Analysts, 2010-03) Danga, B. O.; Ouma, J. P.; Wakindiki, I. I. C.; Bar-Tal, A.
Stagnation in grain production in the developing world has contributed to the current worldwide food crisis. The principle objective of this study was to evaluate the possibility of improving grain production in the tropical humid region by chickpea (Cicer arietinum L.) in rotation with wheat (Triticum aestivum L). A 3-yr field experiment in Kenya included four short-rain-season (SRS) management practices (chickpea green manure [GM], mature chickpea grain crop [CG], tilled fallow [TF], and weedy fallow [WF]), and inorganic N fertilizer at three rates (0, 30, and 60 kg N ha−1). The chickpea treatments decreased SRS water storage at wheat planting by 14 to 16% compared with TF, but this did not affect yield of subsequent wheat. The GM accumulated 77 kg N ha−1 yr−1, compared with 42 kg N ha−1 yr−1 for the CG. The chickpea treatments increased soil available N by 19% and N uptake by wheat by 39% compared with the fallow methods. Inorganic N applications of 60 kg N ha−1 increased soil-available N at 30 d after sowing by 21.4% and N uptake by wheat by 47%. The CG and GM increased the average annual wheat grain yield by 14 and 31% compared with the WF and TF. Inorganic N applications of 30 and 60 kg N ha−1 increased wheat grain yield by 20 and 7%, respectively. The combination of GM with 30 kg N ha−1 gave the highest wheat grain yield, but CG with 30 kg N ha−1 fertilizer was the most profitable practice.
Agrobiodiversity Endangered by Sugarcane Farming in Mumias and Nzoia Sugarbelts of Western Kenya.
(2010-07) Waswa, F.; Maina, L.; Netondo, G.W.; Naisiko, T.; Masayi, N.; Ngaira, J.K.
Commercial sugarcane farming has been practised in western Kenya for nearly forty years. This monocultural land use is associated with loss of natural vegetation and cropland, thus undermining food security status of a place. Further, sugarcane farming is a major contributor to loss of biodiversity in western Kenya. This study was therefore aimed at determining the long-term effects of sugarcane farming on indigenous food crops and vegetables in Mumias and Nzoia sugarbelts of western Kenya. Up to 188 respondents in three divisions of Mumias and 178 respondents of three divisions in Nzoia were purposively selected. These included small-scale and large-scale farmers. Data were collected using questionnaires, Participatory Rural Appraisal tool, interviews and field observations. Secondary data were obtained from documented materials. Land under indigenous food crops and vegetable has been declining since the introduction of sugarcane. Indigenous food crops and vegetable cultivation by farmers in the sugarbelts has been declining. Furthermore, some farmers have abandoned the growing of these crops altogether. Our results imply that sugarcane farming is a major contributor to agrobiodiversity erosion, but that there are also other important reasons such as change of consumer preference, land fragmentation, climate variability among others. In order to curb further loss of biodiversity, efforts should particularly focus on food crops and livelihood diversification and adoption of farming technologies such as agroforestry.
Soil Inorganic N and N Uptake by Maize Following Application of Legume Biomass, Tithonia, Manure and Mineral Fertilizer in Central Kenya
(Springer Science+Business Media B.V., 2011) Mugwe, J. N.; Mugendi, D.N.; Mucheru-Muna, M.; Kung'u, J.B.
In the smallholder farms of central Kenya soils suffer from nitrogen (N) deficiency due to inability to replenish it through application of chemical fertilizers and/or manure. This study evaluated the effect of some organic materials such as Mucuna pruriens, Crotalaria ochroleuca, Calliandra calothyr-sus, Leucaena trichandra, cattle manure and Tithonia diversifolia applied solely or combined with inorganic fertilizer on soil mineral N dynamics and N uptake by maize. Soils and maize samples were taken at 0, 2, 4, 6, 8, 12, 16 and 20 weeks after planting maize (WAP) during 2002 long rain (LR) and 2004 LR seasons and analysed. The study showed that amounts of soil inorganic N and uptake of N by maize varied among the different sampling dates, treatments and between seasons. There was a general increase of mineral N after the start of the season followed by a drastic reduction during 6 and 4 WAP during 2002 and 2004 LR, respectively. This trend was attributed to the decomposition of organic materials at the beginning of the season followed by leaching due to intense rainfall during this period. Treatments that had tithonia, leucaena and calliandra applied recorded the highest amounts of soil inorganic N and also the highest N uptake by maize. Poor rainfall in 2004 LR restricted N uptake and was responsible for lower N uptake by maize in 2002 LR than in 2004 LR. At the end of the growing season, there were high amounts of mineral N at 100–150 cm soil depth that was probably due to leaching. This mineral N is below the rooting zone of most maize plants, consequently not available to maize crop and is therefore of concern.
Impact of Agricultural Market Liberalization on Food Security in developing countries: a Comparative Study of Kenya and Zambia
(University of Helsinki, 2011) Nyairo, N.M.
This research investigates the impact of agricultural market liberalization on food security in developing countries and it evaluates the supply perspective of food security. This research theme is applied on the agricultural sector in Kenya and in Zambia by studying the role policies played in the maize sub-sector. An evaluation of selected policies introduced at the beginning of the 1980s is made, as well as an assessment of whether those policies influenced maize output. A theoretical model of agricultural production is then formulated to reflect cereal production in a developing country setting. This study begins with a review of the general framework and the aims of the structural adjustment programs and proceeds to their application in the maize sub-sector in Kenya and Zambia. A literature review of the supply and demand synthesis of food security is presented with examples from various developing countries. Contrary to previous studies on food security, this study assesses two countries with divergent economic orientations. Agricultural sector response to economic and institutional policies in different settings is also evaluated. Finally, a dynamic time series econometric model is applied to assess the effects of policy on maize output. The empirical findings suggest a weak policy influence on maize output, but the precipitation and acreage variables stand out as core determinants of maize output. The policy dimension of acreage and how markets influence it is not discussed at length in this study. Due to weak land rights and tenure structures in these countries, the direct impact of policy change on land markets cannot be precisely measured. Recurring government intervention during the structural policy implementation period impeded efficient functioning of input and output markets, particularly in Zambia. Input and output prices of maize and fertilizer responded more strongly in Kenya than in Zambia, where the state often ceded to public pressure by revoking pertinent policy measures. These policy interpretations are based on the response of policy variables which are more responsive in Kenya than in Zambia. According to the obtained regression results, agricultural markets in general, and the maize sub-sector in particular, responded more positively to implemented policies in Kenya, than in Zambia, which supported a more socialist economic system. It is observed in these results that in order for policies to be effective, sector and regional dimensions need to be considered. The regional and sector dimensions were not taken into account in the formulation and implementation of structural adjustment policies in the 1980s. It can be noted that countries with vibrant economic structures and institutions fared better than those which had a firm, socially founded system.
Effect of Planting Dates on Maize Yield under Rainfed Conditions in the Central Highlands of Kenya
(2011) Ngetich, K. F.; Mugwe, J. N.; Mucheru-Muna, M.; Shisanya, C.A.; Mugendi, D.N.; Diels, J.
Raifed farming systems in the Central Highlands of Kenya have beer agricultural productivity. high temporal variability of rainfall recurrent droughts is among the most important factors affecting agriculture study was set up with the objective of evaluating the effects of planting dates and rainfall variability on observed and simulated maize performance and to assess AquaCrop model performance and efficiency. The study was carried out in Mbeere District in Kenya, representing a low potential area in terms of agricultural productivity due to low and erratic rainfall. The trial followed a 3 x 2 split-plot design replicated thrice in randomized complete blocks. The main factors were three staggered planting dates (dry planting, wet planting and late planting) while the sub factors were two maize varieties. Phenological stages' durations, daily rainfall, maximum & minimum temperature, grain and biomass yields were key parameters. An AquaCrop model simulation exercise was carried out after model parameterization and calibration using crop, soil and climatic data collected from the trial site. Analysis of variance was used for analysis of the experimental data and the differences between treatment means were examined using least square difference at 5% level of significance. The performance and efficiency of the model was evaluated using root mean square error and correlation coefficients. The trial results showed that, relative to late planting, dry planting increased maize stover yields by 53% (significance p=0.05) during the long rains season of 2009 (LR09), followed by wet planting that led to a 19% increase. During the short rains season of2009 (SR09), there was 27% increase in the stover of dry planted maize while wet planting effect was not significant. There was no observed significant effect of planting dates on maize stover in long rains season of 2010 (LRIO) probably due to relatively high amounts of rainfall. Due to early rainfall cessation in LR 2009, no grain yields were realized. In SR 09, dry planting increased grain yields by 77% compared to late planting while wet planting effect was negligible (significance p=0.05). In LRI0, dry planting increased grain yields by 26% while wet planting led to 24% decrease probably due to the rainfall pattern during the onset of the season. Simulated results using AquaCrop model followed the same trend as the observed yields. The observed effects of planting dates were mainly caused by rainfall patterns and amounts. The study highlighted the importance of planting dates in relation to rainfall onset, pattern and amounts as a key farm management practice that has a direct impact on maize productivity.
Effect of straw mulch application on nutrient concentration in runoff and sediment in a humid region in Kenya
(African Journal of Agricultural Research, 2011-02) Danga, B. O.; Wakindiki, I. I. C.
Straw mulch use has been studied extensively especially for soil erosion and runoff control in arid and semi-arid regions but few studies have been done with regard to nutrient loss and accumulation in humid climate regions in Africa. The objective of the present study was to investigate the effects of straw mulch application using different methods on nutrient loss and accumulation in a humid region in Kenya. Straw mulch was applied to runoff plots at 0, 3 and 5 Mg ha-1, either incorporated into the 0 to 0.2 m soil layer or placed on the soil surface. The concentration of NH4–N, NO3–N, and PO4–P in the runoff decreased exponentially and significantly with advancing time. The K concentration in the runoff followed a hyperbolic pattern with a minimum value between 33 and 55 days after planting. In all the treatments, the concentrations of the NH4–Nassociated with the sediments decreased, in general, with advancing time. However, no corresponding progressive increases of the NO3–N concentration in the sediments were observed. The concentrations of the sediments-associated NH4–N, NO3–N, PO4–P and K in the mulch treatments were higher than those in the control, although these differences were not significant in all the rainstorms. Under this humid climate, either surface placement or incorporation of straw mulch at 3 or 5 Mg ha-1 enriched the soil with NO3–N, PO4–P and K. The soil was enriched with NH4–N after incorporating straw mulch at 3 Mg ha-1 and or surface application at 3 and 5 Mg ha-1. Key words: Erosion, nutrient accumulation, nutrient loss, sediment enrichment, water quality.
Effect of Supplementing Rhodes Grass Hay (Chloris gayana) with Berchemia Discolor or Zizyphus Mucronata on the Performance of Growing Goats in Kenya.
(Journal of Animal Physiology and Animal Nutrition, 2011-06) Osuga, Isaac M.; Abdulrazak, S. A.; Muleke, C. I.; Fujihara, T.
Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5 g/kg DM, while Z. mucronata had CP content of 169.5 g/kg DM. The grass hay had the lowest CP content of 50.9 g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5 g/kg DM], while the grass hay had high fibre content (NDF; 713.1 g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals.
Socioeconomic factors influencing levels of knowledge in soil fertility management in the central highlands of Kenya
(2012) Mugendi, D.N.; Mugwe, J. N.; Mucheru-Muna, M.; Macharia, J. M.; Mairura, S. F.; Kimani, S. K.
This study aimed at identifying the knowledge levels of the farmers and the socioeconomic factors influencing the levels of knowledge on use of animal manure, inorganic fertilizers and combination of animal manure and inorganic fertilizers for effective and enhanced uptake and utilization of these technologies in Meru South, Maara and Mbeere South districts of the central highlands of Kenya where 300 farmers were randomly selected. Logistic regression models were used to predict the socioeconomic factors influencing the levels of knowledge in the use of manure, fertilizers and manure + fertilizers. Age of the household head (HHH), training in the use of animal manure and group membership significantly influenced household levels of knowledge in use of animal manure. Group membership, age of the HHH and total farm size significantly influenced the levels of knowledge in inorganic fertilizers. Gender of the HHH, household size, training on manure + fertilizers, group membership and total farm size significantly influenced the levels of knowledge in use of manure + fertilizers at P<0.05. The implication of these results is that in order to improve knowledge levels, trainings should be enhanced and targeted to the farmers belonging to farmer groups considering their gender, age and total farms size.

Browse

Browsing RP-Department of Agricultural Resources Management (ARM) by Issue Date

Results Per Page

Sort Options