MST-Department of Agricultural Resources Management (ARM)

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Assessing the Status of Crop Farming and Strategies Used to Scaleup Yields for Enhanced Food Security in Turkana County, Kenya
(Kenyatta University, 2020) Mutai, Philip
Despite being a culture-centred livelihood activity, pastoralism alone has not guaranteed food and nutrition security for households in Turkana, Kenya. The frequency of droughts and their negative impact on livestock production in the County translate into reduced purchasing power of the pastoral households; causing perennial food insecurity and consequent human indignity. As a growing response to this perennial situation, rain-fed crop production has been introduced in the County at subsistence level. Most pastoralists however still tend to shy away from crop farming largely due to cultural factors and not their technical feasibility. This study assessed the current status of crop farming and analyzed factors limiting diversification to crop farming. Further it appraised measures towards increased adoption of viable crop production systems within households in five locations purposively selected from two Sub-counties of Turkana Central and Loima. A cross-sectional descriptive survey design targeting 357 respondents was used in this study. In addition data was collected from a few key respondents from sub-County Agricultural Extension Offices. Primary data was collected using questionnaires and interview schedules. On farm experimentation on crop performance under different treatments (drip & bucket irrigation methods) was done in order to demonstrate the potential inherent in crop farming under appropriate crop and land husbandry practices. Data was analyzed using descriptive statistics. Experimental data was subjected to analysis of variance. Results showed that an increasing number of pastoralists are now venturing into crop farming for survival purposes; of which seventy three percent (73%) of the respondents were agro-pastoralists. With a change in attitude away from cultural pastoralism, this percentage can increase with more deliberate and targeted extension service at the County level. Annual average yield of maize in Turkana County was twelve 90kg-bags per acre, while its annual cost of production was Ksh 12,600/acre and the annual revenue was Ksh 32,400/acre. The annual average yield of sorghum in the County was relatively the same as that of maize, and its annual cost of production was Ksh 6,800/acre, while the annual revenue was Ksh 43,200/acre. The study concluded that there is potential and opportunity to improve crop farming under proper land and crop husbandry practices including water use efficiency in Turkana County. Currently, there is a shift from pastoralism to agro-pastoralism. However, this shift is still slow and adoption levels low leading to poor crop yields. The main challenges that constrain crop farming include general lack of knowledge in crop farming and low adoption levels of modern agricultural practices such as use of manure and fertilizer. The study established that drip irrigation had good crop yields, though not used due to high initial costs. Where irrigation is being used, increasing salinity problem was noted. On farm trials with spinach (Spinacia oleracea) as the test crop demonstrated the superiority of water use efficiency under drip irrigation than under bucket method of irrigation. The use of inorganic fertilizers is not common in Turkana County because of the combined reasons of costs and knowledge on fertilizer use under water scarcity conditions. Some farmers use farmyard manure, which readily available from the large herds and flocks kept, but the level of use is low. The study recommended a more deliberate and targeted extension service to introduce improved crop agriculture which can be integrated with the cultural way of life of pastoralists which would ensure improved livelihoods and food security
Assessment of Vertical Price Transmission in Rice Markets in Nairobi City County, Kenya
(kenyatta University, 2020-06) Letting, Irene Cherono; Bernard Njehia; Lucy Ngare
Sub-Saharan Africa (SSA) agricultural commodity markets have been liberalised since the 1980s through Structural Adjustment Programs (SAPs). The aim was to foster market integration and efficiency. Liberalisation of markets allows free flow of goods and services from areas with excesses to those with a deficit. But most Sub-Saharan countries, Kenya included, has associated liberalisation with failure and unsustainable food markets though agriculture is the mainstay of the economy. Price information is a conduit connecting and integrating different market locations and levels. Thus, this study assessed the degree of market integration and direction of price influence between the wholesale and retail rice market levels in Nairobi City County. Besides, the research examined the role of market structure and conduct in vertical market integration and Granger causality. The Eastern African Grain Council (EAGC) provided the weekly wholesale and retail price data from January to December of the year 2016. Data analysis was done in E-views 9. Primary data were randomly gathered from 80 rice traders in Nyamakima and Toi markets through questionnaires. The data consisted of socioeconomic aspects, market structure, and market conduct of rice wholesalers and retailers. This data was analysed using SPSS 20. Johansen cointegration method revealed the absence of cointegration between the wholesale and retail rice markets. Further, wholesale and retail prices exhibited independent Granger causality. The assessment of socioeconomic characteristics showed the dominance of female retailers. Further, most retailers were in their productive ages while most wholesalers were old. Also, wholesalers were more educated than retailers, and retailers possessed more experience than wholesalers. The assessment of market structure showed a high concentration in the wholesale market (HHI of 0.33) while the retail market had a moderate concentration (HHI 0.21). The examination of market conduct showed a majority of both wholesalers and retailers shared a similar source of rice supplies (brokers). Besides, the word of mouth provided most of the market information. The study concluded the rice market in Nairobi City County were not integrated and inefficient. It links this to the presence of market power at wholesale and retail market levels, minimal price interaction, and unreliable market information. Policies that favour a formal centralised information system can improve market integration. Adoption of Information and Communication Technologies (ICTs) can also enhance reliability of information and access to formal financial services.
Assessment of water quality and soil properties for irigation in the horticultural crops producing areas of Alhegaina, North Kordofan State Sudan
(2014-08-26) Adam, hamed mohammed ibrahim
Sudan is a large country with a great diversity of climatic and agro-ecological zones. The horticultural acreage in the Sudan is estimated at 273,000 hectares, representing about 3% of the total crop area. The area under horticultural crops is on the increasing for it is fetching good money for the farmers. Horticultural crops comprise the groups of vegetables,fresh legumes, fruit trees, ornamental plants, plantation crops, medicinal and aromatic plants and spices. The present study was conducted in Alhegaina area, North Kordofan-Sudan,with an aim of assessing the quality of water used for irrigation and soil properties for the production of horticultural crops mainly onions and tomatoes. The data of the study were obtained from two sources, from soil and water samples analysis, and from a questionnaire which was prepared to assess the farmers’ perception on the factors affecting horticultural crops production in Alhegaina. Soil samples were taken from depths 0-15, 15-30 and 30-40 cm and were collected from 10 small scale farms, in which 5 farms used surface water while the other 5 farms used ground water for irrigation. Six water samples were collected during dry and wet seasons, three from surface sources (dams) and the other three from sub-surface normal wells. The sampled soil and water were analyzed for various parameters in the laboratory. Using the questionnaire, fifty six small garden holders (10%)were interviewed randomly. For data analysis, statistical mean comparisons based on T-test using Excel and SPSS packages were used. The results of the study indicated that water sources, that is from sub-surface and surface sources did not differ significantly and that their chemical values were within the limits acceptable for irrigation and crop production. However, the concentrations of the bi-carbonates were somewhat high (between 50-135mg/L) while for other chemicals, the concentrations (Na, Ca ,Mg, K and even EC and TDS) were fairly within the permissive limits for use. For example, EC of water and that of soil extracts were between 0.03-0.1 for water and 0.38-0.01 dS/m for soil extracts. Surface water pH was slightly alkaline (7.38 – 7.68) while that from sub-surface was slightly acidic (6.98-6.69). The soils generally were of low soil fertility with very low values of N and P, and in some cases K. With the farmers’ perception on horticultural crops production, farmers were generally poorly informed, have low education and rarely use fertilizer inputs in crop production. There is need therefore to improve their knowledge on crop management and production. The Government has to come up with a policies on farmers’ education,on inputs usage especially fertilizers and on credit facilitation to farmers.
Characterization of Soil Mineralogy in Relation to Soil Fertility Functional Properties for Selected Countries in Africa
(2013-08-13) Kamau, Mercy Nyambura
Africa’s development depends heavily on soil ecosystem services. However current soil degradation coupled with increasing pressure on land is threatening the soil resource base. There is an urgent need to establish soil health surveillance systems to guide investments and monitor trends in soil health status and impacts of interventions. Surveillance systems require appropriate and rapid, low cost methods that directly measure soil functional properties and can be applied at larger scale. Spectroscopic methods that directly measure organic and mineral composition hold promise for fulfilling this role. Infrared molecular spectroscopy (IR) is one method that has shown promise for predicting many soil functional properties. Xray diffraction spectroscopy (XRD) is another promising method, which directly determines soil mineral composition, but has been little researched as a tool for quantitative prediction of soil functional properties. However a comprehensive knowledge of soil mineralogy in Africa is lacking due to poorly and fragmentally coordinated scientific investigations coupled with the limitations in the traditional analytical techniques. The aim of this study was to develop a rapid XRD measurement protocol and evaluate the ability of X-ray diffraction technique to rapidly predict soil functional properties based on mineral composition. Geo-referenced samples associated with the Africa Soil Information Service (AfSIS), taken from a set of 10 sentinel sites randomized over sub-Saharan Africa, were used for characterization. A total of 160 topsoil samples taken from 16 randomized points of ten 100-km2 sites: Tanzania (3 sites), Malawi (2 sites), Mali (1 site), Burkina Faso (1 site), Kenya (2 sites) and Ghana (1 site) were characterized for chemical properties, particle size distribution, engineering properties and bulk mineralogy. Variation of the mineralogy within and between sites was explored using principal component analysis using the R statistical software, as a precursor to exploring relationships with directly measured soil properties and soil fertility diagnostics. The clustering of individual minerals and the distributions of the soil fertility variables identified across the sites appeared to relate to differences in mineralogical functional groups, supporting the hypothesis that mineralogical data could be used to predict functional properties. The findings therefore suggest opportunity for improving soil assessment using information on soil mineralogy. For instance XRD information on mineralogy can be combined with information from soil physico-chemical properties, to provide powerful diagnostic capabilities, for low cost and rapid prediction of soil functional properties. Further work should aim to develop direct quantitative predictive relationships between soil functional properties and mineralogical composition using the full set of AfSIS reference samples.
Characterization of soils using infrared scanning in South kivu province, Democratic Republic of Congo
(Kenyatta University, 2014) Bigabwa, Janvier Bashagaluke
Understanding soil properties is an essential pre-requisite for sustainable land management. Assessment of soil properties has long been done through conventional laboratory analysis, which is costly and time consuming. Therefore, there is a need to develop alternative cheaper and faster techniques for soil analysis. In recent years, special attention has been given to Infrared Reflectance Spectroscopy and chemometrics. ear Infrared Reflectance (NIR) and mid-infrared (MIR) spectroscopy techniques are rapid, convenient and simple non-destructive techniques for quantifying several soil properties. This study aims to characterized soil based on based on infrared spectroscopy. This method were to predict soil pH, soil organic C, total N, exchangeable AI, Ca, Mg, and K, CEC and soil texture for soil samples collected in Sud-Kivu province, Democratic Republic of Congo. A total of 530 composite soil samples were taken from two locations (Burhale and Luhihi) at two depths (0-20 and 20-40 ern) using a spatially-stratified random sampling design within an area of 100 km2. After minimal sample preparation, the MIR spectrum of a soil takes about two minutes for the analyses. Ddifferences in characteristics were evaluated between the two locations, land use (cultivated vs. non-agricultural land) and soil depth. A random subset of the samples (10%) were analyzed using standard wet chemistry methods, and calibration models developed using MIR data to estimate soil properties for the full soil sample set. Partial least squares regression (PLS) method gave acceptable coefficients of determination between 0.71 and 0.93 for all parameters hence good prediction. Soil organic matter levels were higher in cultivated plots in Luhihi (3.9% C) than in Burhale (3.0% C), suggesting lower levels of soil fertility in the latter area. For both sites, soil pH (water) was generally very low (less than 4.8) This indicates high levels of acidity, which is likely to limit crop production in the area. Phosphorus deficiency was acute for both locations but more for Burhale (2.4 mg P kg') than Luhihi (5.4 mg P kg"). Aluminium toxicity was prevalent in both sites which is attributed to low pH values. The recommended soil management strategies therefore involve liming with dolomite material since Ca/Mg > 4. In both locations, low levels. of Ca and Mg indicate that soils may be susceptible to " deficiencies of both elements. No risk ofK deficiency was observed in the area. These findings suggest new opportunities for monitoring soil quality in the region which can benefit multiple actors in the agricultural and environmental sectors. More efforts are needed to improve the use of these new technologies of monitoring soil and land degradation across developing countries.
The contribution of rainwater harvesting from roof catchments in increasing water resources for Nairobi City County residents
(Kenyatta University, 2017-03) Ombuna, Christine
Nairobi City County is faced with acute water scarcity. The daily deficit is currently 170,000 m3/day which accounts for about 23%. This deficit will escalate as population increases. However, streets are often flooded during heavy rains and water harvesting has been neglected. The County relies mainly on surface water sources from Athi River basin, Tana River basin and over 3000 boreholes. The objectives of this study were to assess volumes of rainwater that can be harvested from roof catchments, sizes of storage capacity required, water quality and adoption of rainwater harvesting from roof catchments. Five rainfall Thiessen polygons that covered the entire County were created using ArcGIS version 9.2. Samples of 10 maisonettes and multi-story buildings were obtained from each Polygon. More samples of 25 industries and 25 institutions were collected making a total of 150 samples. Data used included rainfall depths, roof surface area, size of tanks, physical, bacteriological and chemical properties of rainwater from roof catchments. Microsoft Excel, SPSS, descriptive analysis, regression and correlation analysis were appropriately used in the study. The result indicated that Kabete receives highest annual rainfall followed by Dagoretti, Eastleigh Moi Airbase, Wilson and J.K.I.A. Over 90% of buildings would have rainwater supplements of above 23% thus filling the current deficit. The size of storage tanks for maisonettes ranged from 5, 126 to 60, 840 litres while multi story buildings it ranged from 32, 400 to 344, 250 litres. A regression model for storage capacities and their cost were generated. The quality of rainwater from different roofing materials was not suitable for potable purposes but, it would be used for nonpotable purposes. Majority (93%) of residents depended on city council piped water, private boreholes (7%) and only 16% harvested rainwater as supplement to City council or private borehole sources. Institutions are leading in roof catchment rainwater harvesting (44%), followed by maisonettes( 20%), Multi-story buildings 6% and industries have least adopted rainwater harvesting(4%). The result indicates that if roof top rainwater catchment is done, water deficit that has been estimated in Nairobi County will be definitely offset. Industries and institutions will benefit more from roof catchment rainwater harvesting followed by maisonettes and multi-story residential buildings. Residents should be encouraged to adopt roof catchment rainwater harvesting by enforcing policies and by laws for roof catchment rainwater harvesting in Nairobi City County.
Demand for tractor services in Trans-Nzoia district
(2012-05-17) Obilo, Jeremiah Abok
The current study was formulated to investigate into the factors that affect the demand for tractor services among smallholders in Trans-Nzoia district. Questionnaire was used to collect data and about 113 small farm holders were interviewed. Multiple regression analysis was then used to determine the association between the use of tractors and the various postulated independent variables. The empirical findings of the study indicate that there is a strong correlation between use of tractors and the following: land acreage, the tractor hire charges; though contrary to a priority expectations, empirical evidence of this study show apparently a weak relationship between income variations and the demand for tractor services. The researcher suggests that this might be a reflection of low-income levels of small farm holders. Other variables like age of the farmer; education levels, and their main occupation were statistically insignificant at the 5 per cent level. The study also revealed several tractor services, which small farm holders utilize. Among these, ploughing activity was the most used tractor service; and 92.5 per cent of the respondents had used tractors for ploughing during the period of data collection. Other tractor services, which were identified, were re-ploughing, harvesting, planting shelling and transport. Finally, based on the statistical results various policy implications were suggested.
Effect of Cattle Manure, Mineral Fertilizer and Rhizobium Inoculation on Climbing Beans Production and Soil Properties in Burera District, Rwanda.
(2014-02-24) Musaninkindi, Nadia; Mochoge, B. O.; Muhinda, Jean Jacques Mbonigaba
Agriculture is the major engine of Rwandese economy, accounting for about 40% of the GDP, 85% of employment and 80% of exports. Known as “meat for the poor”, beans constitute a predominant source of proteins in Rwandese diet since they supply 65% of national dietary proteins compared to 4% from animal sources. However, the on-farm bean productivity is about 0.8 – 1.0 tons/ hectare which is quite low compared to 5 tons/hectare that is achieved under optimal management conditions. The aim of this study was therefore to determine the effect of cattle manure, mineral fertilizer and Rhizobium inoculation on production of climbing beans and subsequently the soil properties in Burera District. The experimental design was a split plot in completely randomized design (CRD) with two main plots (with and without Rhizobium inoculum); four sub-plots (Cattle Manure, DAP, Cattle manure + DAP, untreated control) with quantities applied at single level for each treatment, i.e. 20t/ha for Cattle manure, 50 kg/ha for DAP and 100 g of inoculum which was mixed with 15 kg of beans. The experiment involved 8 treatments which were replicated three times to give 24 plots. The mean bean grain yields from inoculated treatments and non-inoculated treatments showed statistically significant difference (P< 0.0001), that is 3900 kg/ha from inoculated plots and 2946 kg/ha from non-inoculated. Statistical significant differences were also found among treatments (P<0.0001) with the highest mean yield of 4782 kg/ha obtained from treatment Inoculum + DAP + Cattle Manure against 2640 kg/ha from untreated (control) plots. The mean number of nodules was significantly different (P< 0.0001) between inoculated (60 nodules) and non-inoculated (15 nodules) plots. The highest number of nodules (95) was recorded from plots that were treated with Inoculum + DAP + Cattle Manure and the lowest (14) in the untreated control plots (P<0.0001). Regression analysis between yield and nodule number showed a coefficient of determination R2 of 0.8 and a p value of < 0.0001, which confirmed the dependence of the yield on nodules number. In terms of cost-benefit analysis, in the highest yielding treatment (I+FYM+DAP) scenario, a farmer is likely to earn around 1,330 USD per season per hectare; while in the middle and lowest yielding treatment (I and UNTREATED CONTROL), the farmer is likely to lose 43.8 USD and 388 USD per season per hectare, respectively. On the effect of treatments on soil chemical properties, no tangible changes were observed in pH, CEC and organic matter at the end of season. According to these results a combination of mineral fertilizer, inoculum and cattle manure application gave the best results in terms of bean yield, nodulation and nitrogen uptake and therefore could be better considered for recommendation to climbing bean growers in the region.
Effect of Combining Cattle Manure and Inorganic P-fertilizer on Soil Properties and Maize Yield in Acidic Soils in Beira Corridor, Mozambique
(2014-02-19) Muambole, Arlindo; Danga, B. O.; MIGUEL, MAGALHÃES A. MIGUEL
Mozambique lags behind all other Southern and Eastern African countries in maize production leading to maize imports. Soil nutrient depletion, lack of combination of organic resources with mineral resources coupled with high soil acidity has been identified as the main causes of the declining crop yields. Maize yield in smallholder systems in central Mozambique can be increased by optimum utilization of mineral fertilizers combined with cattle manure and other locally available organic resources. The aim of this study was to evaluate the effect of combining cattle manure and inorganic P-fertilizer on soil properties and maize yield in acidic soils along Beira Corridor, Mozambique. The objectives were to evaluate the effect of combined incorporation of cattle manure and mineral fertilisers on soil properties and maize yield; to determine the optimum rate of manure-inorganic fertiliser interactions for increased fertilizer use efficiency and to assess the profitability of combined application of cattle manure and mineral fertilisers for small scale farmers. The experiment consisted of combination of three levels of inorganic P-fertilizers (TSP) at 0; 25 and 50 kg ha-1 (P2O5) with three levels of cattle manure (0, 5 Mg/ha and 10 Mg/ha). The total treatments tested were nine and arranged in RCBD with four replications. Analysis of variance (ANOVA) was used for data analysis, and treatment means were compared at probability (p<0.05) using Least Significant Difference (LSD). Cattle manure at 10 Mg/ha combined with TSP at rate of 50 kg/ha gave higher maize grain yield of 4.87 Mgha-1 compared to 0.55 Mgha-1 of the control. Combination of mineral fertilizers with manure significantly increased phosphorus use efficiency by 98%; phosphorus agronomic efficiency by 87%; phosphorus recovery efficiency by 0.46 g kg-1 and utilization efficiency by 98%. Inorganic P-fertilizer use was cheapest when TSP as source of P was combined with manure at rate of 5 Mg ha-1 having Value Cost Ratio of 8.12 but P-fertilizer (as TSP) was most expensive when applied without manure, having VCR of 3.40. Advocacy on combination of cattle manure that is locally available with TSP should be increased to improve soil properties, crop yield, fertilizers use efficiency, income and profit to farmers.
Effect of farmyard manure and mineral fertilizers on maize yield and soil properties in Huye and Bugesera Districts of Rwanda
(2014) Munyabarenzi, Innocent
Agriculture in Rwanda is today characterized by low agricultural productivity due to soil fertility decline. This is mainly attributed to the mining of nutrients due to continuous cropping without adequate external addition of inputs. The adoption of Integrated Soil Fertility Management (ISFM) technologies such as the combination of organic manure and mineral fertilizers is being taken as one of solutions to this situation. A study was therefore, conducted to investigate the effects of farmyard manure and mineral fertilizers on maize yield response, crop nutrient uptake, nutrient use efficiency and to evaluate changes of bio-chemical soil properties brought about by the treatments applied. The study was conducted at the Research Stations of Rwanda Agriculture Board (RAB), namely, at Rubona in Huye and at Karama in Bugesera Districts in Southern and Eastern provinces of Rwanda,respectively. The experiment was arranged in a randomized complete block design (RCBD) with three factors : nitrogen, phosphorus fertilizers and farmyard manure. Nitrogen and phosphorus fertilizers were applied at three levels, 0, 50 and 100 Kg/ha for nitrogen and 0, 25 and 50 kg/ha for phosphorus while Manure levels were two (0 and 10 tons/ha). Maize was the test crop and was planted in plots measuring 4.5 x 4.5 m with a spacing of 75 x 30 cm. The experiments were replicated three times. Soils samples were analyzed for soil pH, soil organic Carbon, total N, available phosphorus,Potassium, CEC, ECEC, Exchangeable acidity and microbial status of the soil. Maize grains were dried after harvest and weighed at 12.5% moisture content. The data was analyzed by ANOVA using general linear model of SAS software. Regression and correlation were used to establish relationships between measured parameters. The results showed that maize grain yield,1000 grain weight and stover biomass were influenced significantly (P<0.05) by the application of farmyard manure and inorganic fertilizers. The combined applications produced yields which were significantly higher than organic or inorganic alone and the control. The highest grain yields of 8.92 tons ha-1 and 7.11 tons ha-1 were obtained in the combined treatments of farmyard manure with mineral fertilizer at a rate of 100 kg ha-1 N, 50kg ha-1 P mineral fertilizer and 10 tons ha-1 manure at both sites (Rubona and Karama), while the controls recorded the lowest grain yields of 4.61 tons ha-1 and 3.23 tons ha-1 for Rubona and Karama sites,respectively. The combined treatments generally showed significantly higher nutrient uptake and nutrient use efficiency than the sole organic and inorganic fertilizers. In the evaluation of soil properties, total nitrogen, K and pH significantly decreased in plots treated with organic and inorganic fertilizers while soil organic C, available P, Ca, Mg and CEC increased generally in treatments under inorganic plus organic fertilizers. In the case of microbial biomass, there were slight increase for both bacteria and fungi after NP fertilizers and manure combined treatments. In both sites, maize yields responded more to nitrogen fertilizer than P fertilizer, an indication of low nitrogen content in the soils of Rubona and Karama.
The effect of method, rate and time of urea application on nitrogen use efficiency and yield of wetland rice in Rwamagana district of Rwanda
(2014-09-08) Nyampinga, Immaculee
Rice is the staple food for more than half of the world population and for most low income people especially in Asia. In Africa, over 50 million people depend on rice farming. In Rwanda, the livelihood of nearly half a million individuals is rice-based. Rice is often very responsive to nitrogen fertilization and the high yield potential of modern varieties cannot be realized without adequate nitrogen supply to the plant during the entire growing period. The purpose of this study was to evaluate the effect of mode of application, rates, and timing of urea on rice productivity in Rwamagana marshland, Rwanda. IRRI28 variety was used in the experiment. Two separate experiments were conducted. The first one assessed the effect of fertilizer at different rates and at two modes of application i.e deep and surface placement. The N fertilizer rates were at 4 levels (0, 40, 80 and 120kg N/ha) resulting into a total of 8 treatments. The experiment was factorial and was arranged in a Completely Randomized Design (CRD).The second experiment assessed the effect of time and rates of nitrogen fertilizer applied in splits to the surface only. This second experiment was also arranged in a CRD with 11 treatments. All the treatments were replicated three times. For data analysis, JMP package statistical software was used to analyse data, and for means of separation, Fischer's protected LSD at the 5% significance level was used. Results of Grain yield components and grain rice yields were affected by different application methods but not significantly. Deep placement method appeared to be more effective and superior in rice performance, with grain yield of 5.6t/ha realized when 120kg/ha N was applied compared to 5.3tkg/ha with surface method, a difference of about 6%. Application of N in splits also influenced the rice yield components and grain yield but not significantly in relation to that of deep placement. In terms ofNUE (Nitrogen Use Efficiency), deep placement ofN again exhibited higher values than both surface and split methods which ranged between 7.5 and 13.5 kg grain/kg N applied. Nitrogen content in plant tissues and grain was generally low and less than 2% which is the recommended value in plant tissues. Again, deep placement exhibited higher % N content in plant tissues especially in Panicle Initiation where the content was more than 2 % than surface and split modes of application. In overall, deep method ofN application appeared more promising in rice productivity than surface and split modes of application in this study at Rwamagana, Rwanda.
Effect of rhizobia inoculant on soybean nodulation and arbuscular mycorrhizal fungi colonization under greenhouse and field conditions.
(Kenyatta University, 2015-06) Bahati, Liliane Shukuru
In the highland of South-Kivu, DR.Congo, soybean farming is increasingly practiced by smallholder farmers but it productivity remains low. Both productivity and N2-fixing abilities of legumes can be enhanced not only by Rhizobium spp but also by colonization of their roots by Arbuscular Mycorrhizal Fungi (AMF). The objectives of this study were:- to evaluate symbiotic effectiveness of bradyrhizobia isolates for soybean inoculant production, their effect on indigenous AMF root colonization, and the suitability of Walungu peat/DR. Congo for inoculants production. The study was carried out in the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Nine strains of B. Japonicum from IITA collection and two reference strains (USDA110 and USDA532c) used in commercial inoculant, two controls (Urea and un-inoculated, non fertilized plots), Walungu peat from D.R Congo and the commercial standards America Peat Technology (APT) were investigated. Strains effectiveness for soybean nodulation was evaluated in both screenhouse and field conditions. In the field experiment the study also evaluated the effect of each individual strain on indigenous AMF colonization with soybean roots. The experimental design used was a randomized complete block design (RCBD) replicated 4 times giving a total of 52 plots in the experiment. Data were recorded on leave chlorophyll content, nodulation parameters (number and dry weight of nodules) above ground biomass parameters (dry weight, nitrogen and phosphorus content), and AMF colonization (presence or absence of hyphae, arbuscular and vesicular).In the laboratory experiment, the suitability of Walungu peat as carrier material for inoculant production was assessed under sterile and unsterile conditions and at three different temperatures (4°C, 15°C and laboratory temperature), as compared to the standards APT, using plate count method. The results showed that RANI22, RACA6 and IRJ2180A were effective in improving most of the parameters under study (chlorophyll, above ground dry weight, above ground nitrogen and phosphorus content, nodule number and dry weight) in both screenhouse and field experiment. At 8WAP leaf chlorophyll content increased by 27, 25, and 23% for RANI22, RACA6, and IRJ2180A respectively in the screenhouse experiment and 40-47% in the field experiment as compared to the control (uninoculated- no fertilized plots). On another hand, nitrogen fertilizer also showed increase in some of the parameters especially chlorophyll and nitrogen content but not significantly different from one or another of the three strains. In screenhouse conditions for instance, nitrogen fertilizer, RANI22 and RACA6 increased the above ground nitrogen content by 43-51% (p˂.001) as compared to the control, and in the field experiment the same parameter was increased by 69-66% (p˂.001) by RANI22, RACA6, IRJ2180A, and nitrogen fertilizer relative to the control. None of B. japonicum strains used in the current study or nitrogen addition affected significantly the infection rate of indigenous AMF as indicated by 100% (p˃0.05) hyphae in all the treatments. Walungu peat limed and APT were equally effective in increasing the growth and survival of the initial B. japonicum (USDA110) population (5x 108) over a period of 2 months. Higher population density (3.9 x109 and 3.5x 109) (p˂0.05) was recorded in sterile condition at 4°C and 15°C respectively. RANI22, RACA6, IRJ2180A and Walungu peat amended are alternative inputs for high quality inoculant production and soybean performance.
Effect of Tithonia Biomass and Mineral Fertilizer Application on Soybean Perfomance in Degraded Technosols from Tantalum Mining in Gatumba, Rwanda
(2014-02-26) Ndoli, Alain; Mochoge, B. O.; Naramabuye, F.
Large areas of the Gatumba Mining District (GMD) in Rwanda are covered by Technosols (pegmatite or pegmatite-soil mixtures) resulting from coltan mining activities. These substrates are poor in soil plant nutrient contents and are low in soil productivity. Due to agricultural land shortage in Rwanda, almost all the available land is farmed. The present study was conducted to evaluate the effect of tithonia and inorganic fertilizers on plant nutrient uptake and biomass production of soybean grown in Gatumba soils that are affected by the previous coltan mining activities. A greenhouse pot experiment and a field trial were conducted using pegmatite substrate alone and pegmatite-Lixisol Bt mixture in a completely randomized design (CRD). Another experiment was set on cambisol in a farmer’s field to compare the treatments from the technosols (affected by mining). Tithonia biomass (T) was applied at 5 tonnes (t) dry matter (DM) ha-1 alone and combined with triple superphosphate (TSP), Matongo rock phosphate (MtRP) (for the greenhouse), Minjingu rock phosphate (for the field trials) and ammonium sulphate (AS). Soybean biomass, grain yield as well as its total N, P and K were measured at harvest while soil total nitrogen (N), available phosphorus (P), potassium (K) and carbon (C) were analyzed before and after the trials. The results demonstrate that soybean DM, grain yield, N, P and K accumulation were higher on pegmatite than on the mixture, The combination of T, MtRP and TSP also gave higher grain yields on both pegmatite (2.1t ha-1) and mixture (1.7 t ha-1) in the greenhouse. In the field, T+MRP and AS treatments, compared to other treatments, gave highest grain yields (1.5 ha-1) followed closely by T+MRP+TSP (1.49ha-1) on pegmatite while on the mixture, T+MRP+AS gave highest grain yields (0.87 ha-1) followed closely by T+MRP+TSP (0.7 ha-1). At the end of the greenhouse experiment, all treatments on both pegmatite and the mixture showed a general increase in pH, total N, exchangeable K and total organic C with the exception of the available P in the mixture which had declined. The same increase in soil nutrients was observed also in the field trial with the exception of total N that declined in all soil types and treatments. The combination of tithonia green manure and different inorganic fertilizers significantly (<0.05) increased the N, P and K accumulation of soybean grain, shoot and root biomass over tithonia alone. The results indicate that soil plant nutrients generally increased in all treatments in both greenhouse and field trials which is a good indication that these technosols can be reclaimed for agricultural use.
Effects of conservation agriculture on bean and maize yield, soil properties and water productivity in Bugesera District, Rwanda
(Kenyatta University, 2015-10) Kabirigi, Michel
Land degradation is a major threat to food security and natural resources management in Rwanda as well as in SSA. The major objective of this study was to evaluate the effects of tillage methods, residue management and fertilizer application on bean and maize yield, soil properties and water productivity in Bugesera District, Rwanda. Experiment was established in Bugesera district located in Eastern province of Rwanda. The experimental design was Split Plot with 4 replications. The main plots were conventional tillage (CT) and no tillage (NT), while sub plots were control, Residues applied (RA), RA with inorganic fertilizers and sole inorganic fertilizers (IF). Experiment was carried out for two seasons; A2014 and B 2014.Soil properties assessed were Organic carbon, total Nitrogen, CEC, available P and soil pH. Calibrated parameterized and validated APSIM model was used for scenario analysis to assess the long term effect of Residues application on maize yield, water productivity and organic carbon with a scenario of 10% reduced rainfall. Data were subjected to analysis of variance (ANOVA) using Genstat Dicovery Edition 3. Residues application with inorganic fertilizers had 103% higher bean grain yield than the control, conventional tillage had 23% higher bean grain yield than no tillage. Residues application increased maize grain and biomass yield by 68% in conventional tillage while in no tillage, inorganic fertilizers treatment had higher maize grain and biomass. Residues application resulted in increase of organic carbon Available P was significantly increased in RA and in residues applied with inorganic fertilizers. The increase in soil pH was observed in inorganic fertilizers treatment and in, respectively, for conventional and no tillage. Residues applied with inorganic fertilizers had 103% higher bean water productivity and 78% higher maize water productivity than the control. Conventional tillage had 23% higher beans water productivity compared to no tillage. Long term simulation of the effect of residues and fertilizer shows no significant effect of reduced rainfall on maize productivity. However residues applied with inorganic fertilizers had higher grain yield, higher maize water productivity and 10.6% higher organic carbon than the control. The study concluded that the combination of Residue application and inorganic fertilizers should be considered as the engine for the success of conservation agriculture implementation in Rwanda.
Effects of Different Limes on Soil Properties and Yield of Irish Potatoes (Solanum tuberosum. L) in Burera District, Rwanda
(2014-02-19) Nduwumuremyi, Athanase; Mugwe, J. N.; Ruganzu, V.
The problem of acidic soils is complex and threatens food production in many parts of Africa and Rwanda in particular. Rwanda is a small land locked country in sub-Saharan Africa and its population density is currently the highest in the region and continues to grow. Agriculture supports 82% of the population and hence it is the most important sector that needs to be explored in order to enhance food security. The major objective of this study was to evaluate the quality of agricultural and local liming materials, their effects on selected soil physical and chemical properties and yield of Irish potatoes in Burera district. This was achieved through a laboratory based quality analysis and a field experiment. The field trial followed a randomized complete block design (RCBD) with three replications and it was established in September, 2011. The treatments comprised of the four lime materials (Agricultural lime, Karongi, Musanze and Rusizi liming materials) applied at three levels (1.4, 2.8 and 4.2 t ha-1 of CaCO3 equivalent) and control. Soil properties were monitored over a period of 16 weeks (112 days) after limes application. The data collected were subjected to analysis of variance (ANOVA) and t-test. The findings showed that, agricultural and Rusizi limes had the highest CCE (86.36 % and 85.46%, respectively). In terms of fineness factor (FF), agricultural lime and Musanze lime had higher FF compared to other limes. Lime rate of 2.8 t ha-1 of Musanze and agricultural limes had similar and highest effects in increasing soil pH. At the rate of 2.8 t ha-1 they increased the soil pH by 0.65 and 0.64 units, respectively. On the other hand, at a rate of 4.2 t ha-1, Rusizi lime had a higher Lime Efficiency (LE) (102.3%) in increasing soil pH than Musanze and agricultural lime (LE of 100% respectively). Lime rate of 4.2 t ha-1 of agricultural, Rusizi and Musanze limes reduced exchangeable Al. The effectiveness of Musanze lime at the rate of 2.8 t ha-1 had the highest LE (100.8%) among all the limes making it the best in reducing exchangeable Al, while Karongi lime was the poorest. Lime rate of 4.2 t ha-1 of agricultural lime had the highest effect in increasing available phosphorus compared to other limes while Karongi lime had the lowest effects in increasing available phosphorus. Lime application rate of 1.4 and 4.2 t ha-1of agricultural lime significantly (p<0.001) reduced the ECEC. At the rate of 2.8 t ha-1, agricultural and Musanze limes increased 0.24% and 0.21% of total nitrogen, respectively. Notably, all lime rates of Karongi lime were the lowest in increasing total nitrogen. Musanze lime had higher Relative Agronomic Efficient (RAE) than other local limes. At a rate of 1.4 t ha-1, Musanze lime had 113.04% of RAE, an indication of yield increase by 13.03%. Economically, lime rates of 1.4t ha-1 of Musanze lime had the highest economical efficiency (121.81%), which makes it to be more economically efficient than other limes and rates. Therefore, this study recommends the use of Musanze lime applied at a rate of 2 to 4 t ha-1 in acidic soils of Burera district.
Effects of different organic residues on carbon sequestration, nutrient availability in soil and maize yields at Katumani, Machakos county Kenya
(Kenyatta University, 2015-01) Mbaluka, Titus Luta; Danga, B. O.; Mugwe, J. N.
Reduced farm productivity in smallholder farms is the principal cause of food insecurity in semi-arid parts of Kenya. This is mainly attributed to soil fertility depletion, land degradation, low soil moisture and climate change. Climate change due to increased carbon dioxideemission into the atmosphere has impacted negatively on the food productivity in Africa.The objectives of this study were: 1) to determine the effect of different organic residues on soil carbon accumulation in soil. 2) to determine the effect of organic residues on the availability of nutrients into the soil, and 3) to determine the effect of different organic residues on maize growth and yields. Field studies were carried out in two seasons (2011/2012 short rains and 2012 long rains) at Kenya Agricultural Research Institute (KARI) – Katumani Dry land Research Centre in Machakos County. Maize residues and compost manure were used, under different application methods and a control where no organic residue was applied. This constituted seven treatment combinations as follows; 1) Control, no organic residue application; 2) 10 ton/ha compost, surface application; 3) 10 ton/ha compost, incorporated application; 4) 5 ton/ha maize stover, surface application; 5) 5 ton/ha maize stover, incorporated application; 6) 5 ton/ha maize stover, 10 ton/ha compost, surface application; 7) 5ton/ha Maize stover, 10 ton/ha compost, incorporated application). The seven treatments were laid out in a randomized complete block (RCBD) design with 3 replications. Soil samples were collected from 0-20cm and 20-40cm depths before planting, at six weeks after planting and at harvest. The soil samples were analyzed for total C, total N, soil pH, available P, Mg, Ca, Na, K and CEC. Maize grain yield and total dry matter was measured. Statistical analysis of data was done using analysis of variance (ANOVA) and means separated using LSD at p=0.05. Results of this study showed that total soil organic carbon increased with application of organic residues. Treatments that had 5ton/ha maize stover and 10 ton/ha compost, incorporated recorded the highest soil carbon accumulation of 0.36 Mg C/ha and 0.39 Mg C/ha at the end of season one and two, respectively while the control decreased by 0.02 Mg C/ha in season 1 and 0.03 Mg C/ha in season two. Nutrients concentrations in the soil were found to increase with application of organic residues where by incorporated 5 ton/ha maize stover and 10 ton/ha compost treatment recorded the highest concentrations of most nutrients in the soil. Maize yields increased with the application of organic residues. Treatments that had 5 ton/ha maize stover and 10 ton/ha compost under incorporated application gave the highest maize grains which was 145% more, compared to the control in season one and 248% in season two. In conclusion combining 5 ton/ha maize stover and 10 ton/ha compost under incorporated application could be a promising soil fertility management strategy for improved carbon storage in soils and for increased maize productivity.
Effects of intergrated soil fertility management and ridging on maize-soybeans yields and selected soil properties in Tharaka-Nithi County, Kenya
(2016-08) Sibomana, Jean Damascene
Constraints to soil productivity include reduction in soil fertility and lack of adequate soil water conservation techniques due to erratic rainfall in central highlands of Kenya. This study evaluated effects of combining integrated soil fertility management options and tied- ridging on maize-soybean yields and selected soil properties during short rains in 2014 and long rains in 2015 seasons. The study was carried out in Kigogo primary school in Tharaka- Nithi County. The experimental layout was a randomized complete block design replicated 4 times. The treatments were: manure+fertilizer, tithonia+fertilizer, inorganic fertilizer, sole and control under tied ridging or conventional tillage. To evaluate effect of rotation on maize grain yield, 2 test crops: maize and soybean were alternated every season except sole maize treatment which was maintained throughout the trial period. Soil was sampled at 0-20 cm and 20-40 cm depths at the start and end of the study, and analyzed for soil pH, total N, available P, organic C and exchangeable bases. The data was subjected to analysis of variance using Genstat program and means were separated using Fishers’ LSD at p=0.05. Integrated soil fertility management technologies under soil water conservation tillage significantly increased both maize and soybean grain yields during short rains in 2014 (p≤0.037 and p≤0.039 respectively) and only maize grain yield during long rains in 2015 (p≤0.005). Further, tithonia+fertilizer and manure+fertilizer treatments under tied ridging significantly increased maize grain yields and soybean grain yields by 34.8% and 43.5% respectively compared to the control in long rains in 2015. Only tithonia+fertilizer under tied ridging increased significantly soybean grain yields by 57.1% over control in short rains in 2014. Maize grain yield also has increased under maize-soybean rotation by 35.5% over sole maize. The results showed significant decrease in soil pH, available P and total N in mineral fertilizer under tied ridging (p0.05). Soil exchangeable K + , Ca 2+ and Mg 2+ generally increased in most treatments. This study recommends use of combination of either tithonia biomass or manure with inorganic fertilizer under conventional tillage as well as crop rotation to enhance soil fertility and maize-soybean yields in the region.
Effects of Lime, inorganic P and inoculation on Soil Chemical properties and Grain Yields of Maize and Soybean in Western Kenya
(2013-10-17) Onyango, Maurine Akinyi; Danga, B. O.; Odendo, Martins
Low crop responses to fertilizer application among small holder farms are common phenomena in degraded acidic soils of western Kenya. Continuous growing of maize without commensurate soil nutrient replenishment coupled with application of soil acidifying fertilizers, especially Di-ammonium Phosphate (DAP) and Sulphate of ammonia (SA) have aggravated the soil acidity problem. An on-farm trial was sited in Shianda sub-location, East Wanga division in Mumias district, Western province, Kenya during the 2011 long rain (LR) and short rain (SR) seasons to determine the effect of lime, inorganic P, inoculation on soil chemical properties and yields of soybean (Glycine max L.) and maize (Zea mays L.). The treatments included, 2 lime rates (0, 2.5 t/ha), 2 inorganic Prates (0, 30 kg P/ha) with or without inoculation (Rhizobium japonicum) of soybean. The eight treatments were arranged as factorial in RCBD with four replicates. All data were analyzed with the ANOV A procedure of the GENST AT statistical software and treatment means separated using least significance difference at (P < 0.05). Regression analysis was performed to examine relationships between plant and soil parameters. Benefit-cost analysis was performed on maize and soybean grain yields to determine the treatments with the most profitable returns. A combination of Lime + P + inoculation recorded the highest maize (4490 kg/ha, 3470 kg/ha) and soybean (970kglha, 830kglha) grain yields during the first and second seasons, respectively. Sole P treatment gave a higher average nodule number per plant and plant biomass (g), respectively (8 and 21.8) than sole inoculation (4 and 19.2) and sole lime treatments (2 and 16.8) during the first season. Lime application at Z.5 t/ha increased soil pH from 4.9 to 5.58. Increase in soil available P was in the order' of lime> P > inoculation (9.35 > 6.50 > 5.10) mg/kg. Sole lime treatment proved 'to be a more profitable investment for the farmers as it gave. a net benefit of Ksh 89,015.20 with a benefit-cost ratio (BCR) of 2.2. Therefore, integration of lime, inorganic P and inoculation needs to be disseminated among small-scale farmers in western Kenya for improved maize and legume production.
Effects of maize (zea mays l.) – soybean (glycine max (l.) merrill) intercropping patterns on yields and soil properties in two contrasting sites of Embu and Meru counties, Kenya
(Kenyatta University, 2015-01) Matusso, Jossias Mateus Materusse; Mugwe, J. N.; Mucheru-Muna, M.
In the central highlands of Kenya, the adoption of integrated soil fertility management technologies such as maize-soybean intercropping system is being promoted as one of the options to address low crop productivity and soil fertility depletion among the farmers of this region. This study aimed to: (i) determine the effects of maize-soybean intercropping patterns on yields, N uptake, and soil properties; (ii) determine the effects of different maize-soybean intercropping patterns on light interception and leaf area index; (iii) quantify the land equivalent ratio of various maize soybean intercropping patterns. The study areas were Embu – Agriculture Training Centre in Embu district (Embu County) and Kamujine in Tigania East district (Meru County). The main treatments were four maize – soybean intercropping patterns (conventional-1maize:1soya; MBILI-2maize:2soya; 2maize:4soya; 2maize:6soya) and two sole crops of maize and soybean, respectively. The experimental design was a randomized complete block design with four replications, and plot size of 7.0 m by 4.5 m. The study was carried out in two seasons (long rain 2012 and short rain 2012). The soil was sampled at 15 cm depth. All biophysical data were subjected to Analysis of Variance and means separated using Least Significant Difference of mean at 95% (p ≤ 0.05). The results showed that, the maize-soybean intercropping patterns had significant effect on maize stover and grain yields during both seasons at Embu site. During the long rain 2012, the soybean yields were reduced by 60 and 81% due to the intercropping with maize, at Embu and Kamujine, respectively; whereas during the 2012 SR, the yields were reduced by 52 and 78% as effect of intercropping with maize at Embu and Kamujine sites, respectively. In general, the soil nitrate-N was reduced due to intercropping patterns. The soil organic matter was significantly (p≤0.05) affected by the treatments at Kamujine site. The intercropping patterns affected significantly (p≤0.0001) the photosynthetically active radiation intercepted and the leaf area index at both sites. During both seasons at both localities, the total land equivalent ratio values greater than unit. From the results of this study, the use of MBILI maize-soybean intercropping pattern can be recommended to the farmers of central highlands of Kenya because of more efficient resources use and higher yields
Effects of manure, lime and phosphorus fertilizer on soil Properties and soybean (glycine max l.) yields in Embu County, Kenya
(2014-08-26) Benvindo, Serafim Manuel Mário Verde
Agricultural sector in Kenya, contributes with 25% on GDP, yet this sector is far to supply adequate food for an increasing population due to declining soil productivity. Soybean (Glycine max L. Merrill) is relatively new crop being introduced in smallholders farming system in the Central Highlands of Kenya as source of nutrition, income generation and soil fertility improvement. However, the crop yields are below the national average. Soil acidity and depletion of nutrients affect negatively performance and yields of soybean in the region. The study was carried out for two seasons in Embu County to determine the effects of manure, lime and phosphorus (P) fertilizer on: (i) soil chemical properties and soybean yields; (ii) nitrogen (N) and phosphorus (P) uptake, and biological nitrogen fixation (BNF) by soybean; (iii) soil microbial biomass. The treatments included goat manure (0, 5 and 10 ton ha-1), lime (0 and 2 ton ha-1), and P fertilizer (0, 30 and 60 kg P2O5 ha-1). The experiment was laid out in a Randomized Complete Block Design (RCBD) with 4 replicates. Soils samples collected before and after the experiment were analyzed for soil chemical properties and microbial biomass (MB). Soybean N and P uptake, N fixation and yields were determined. Data generated was subjected to Analysis of Variance (ANOVA) and means were separated using Least Significant Difference (LSD) at 95% significance level (p<0.05). The results showed that lime alone (2 ton ha-1) increased significantly soil pH (15.9%), extractable Ca (64.4%) and Mg (23.1%), and reduced exchangeable acidity by 3.5 times. Goat manure alone (10 ton ha-1) increased significantly extractable K by 6.8 times, CEC (55.8%), available P (37.9%), N and P uptake (98.2% for N and 120.8% for P) and microbial biomass (73.5%). Integrated application of 5 ton ha-1 of goat manure with 2 ton ha-1 of lime plus 30 kg ha-1 P2O5 increased significantly soil pH (14.1%), Ca (87.7%), Mg (30.8%), K (3.7 times) CEC (73.7%) available P (38.0%) and 59.3% on microbial biomass. The integrated application of 5 ton ha-1 of goat manure with 30 kg ha-1 P2O5 increased significantly the uptake of N (99.2%) and P (153.2%). Soybean grain yields were significantly increased by 2.5 and 2.3 times under sole application of goat manure (10 ton ha-1) and integrated application of 5 ton.ha-1 of goat manure with 2 ton.ha-1 of lime plus 30 kg P2O5 ha-1, respectively. Goat manure proved to be an important soil amendment by providing nutrients, increasing soil pH, which in turn enhanced nutrient uptake, N fixation, microbial biomass, and increased soybean yields. Integrated application of manure with lime and P fertilizer contributed to improved soil chemical properties and soybean yields. Therefore, manure can substitute or supplement the inorganic fertilizers and could be recommended for the smallholder farmers of Embu County, Central Highlands of Kenya