MST-Department of Agricultural Resources Management (ARM)

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Browsing MST-Department of Agricultural Resources Management (ARM) by Author "Mugwe, J. N."

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    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.
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    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.
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    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
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    Effects of Phosphorus Sources and Starter Nitrogen on Soybean Yield and Selected Soil Properties in Tharaka Nithi and Meru Counties of Kenya
    (2014-02-24) Abuli, Jackson Sianje; Mugwe, J. N.; Mucheru-Muna, M.
    Integration of legumes into farming systems is one of the Integrated Soil Fertility Management (ISFM) options for improving soil fertility. Farmers can save their cost of production by using legumes, which, in association with rhizobia, can fix atmospheric nitrogen. Soybean is an important legume compatible with the smallholder farming systems in Tharaka Nithi and Meru counties. However, low P and N, a situation prevalent in the two counties can limit its performance. The study was carried out in Kigogo in Tharaka Nithi County and Kamujine in Meru County. Sources of P, with or without starter N application were evaluated while pursuing the following objectives: (1) to determine the effects of different phosphorus sources and starter N on soybean yield and selected soil chemical properties, (2) to evaluate the effects of different phosphorus sources and starter N on nodule numbers and soybean growth parameters. Finally, the study assessed the effects of different phosphorus sources and starter N on the amount of N fixed by soybean and their economic suitability. A trial was laid out in a randomized complete block design (RCBD), having 13 treatments with four replications each on a 4.0 m by 4.5 m plot size. The P sources were Triple Super Phosphate (TSP), Minjingu rock phosphate, Mavuno fertilizer, diammonium phosphate (DAP), animal manure and fortified manure (animal manure with Minjingu fertilizer at 1:1 ratio) all providing 30 kg P ha-1. Diammonium phosphate (DAP) was reference input as it has both P and N and was the farmers’ choice in the study area. Data collected were soybean growth parameters, biomass and grain yields, soil chemical characteristics and soybean and fertilizer market prices. Data was analyzed using analysis of variance (ANOVA) and means separated using t-test and Least Significant Difference (LSD) (P<0.05). The use of Mavuno fertilizer in combination with CAN as nitrogen source significantly (P<0.01) improved soybean yield and significantly (P<0.05) enhanced BNF compared to the control and ranked higher than TSP, DAP, Minjingu and animal manure. Addition of CAN alone as starter N restricted BNF in N rich Kigogo but enhanced it in N deficient Kamujine, giving 56.32 kg ha-1yr-1. This increase was however not significant. Starter N did not enhance soybean nodulation but increased yield in combination with other P sources by 14.95% in Kamujine and 14.28% in Kigogo. The least costly source of P was DAP and therefore recommended for use in soybean production with consideration for liming to address possible reduction in soil pH. Farmers may also improve soybean yield and enhance their incomes while sustaining their soil fertility by using Mavuno fertilizer suppliments or Minjingu phosphate rock.