Browsing by Author "Kihara, Job"

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    Effect of Application of Different Nutrients on Growth and Yield Parameters of Maize (Zea Mays), Case of Kandara Murang’a County
    (Asian Research Publishing Network (ARPN), 2017) Muthaura, Chrispaul; Mucheru-Muna, Monicah; Zingore, Shamie; Kihara, Job; Muthamia, Joses
    Soil fertility is a major challenge depressing yields in small hold farms of Sub-Saharan Africa. Growth and yield parameters are key indicators of soil fertility status in most agro ecosystems. A study was conducted in Murang’a County Kandara Sub-County in Kenya. This was to determine the effects of applying different nutrients on growth and yield of maize. The study was done in 2013 during the long rains season (LR13) and the short rains season (SR13). Twenty-three farmers were randomly selected for the study. The experiment was laid out in randomized complete block design (RCBD) with 8 treatments (control, NPK+ CaMgS micronutrient fertilizer (Ca, Mg, S, B, Mn, Cu, Zn,), NPK+ Manure, NPK+ Lime, NPK, NP, NK, and PK). Soil was sampled before establishment of the trials at a depth of 0–20 cm. The soil samples were analyzed for pH, total carbon, macro, and secondary nutrients. Treatment inputs were applied at rates of 100 kg ha-1 N, 30 kg ha-1 P, 60 kg ha-1 K, 10 kg ha-1 Ca, 10 kg ha-1 Mg, 5 kg ha-1 S, 10 t ha-1 manure and 1 t ha-1 lime. Data on maize plant height, leaf number, and basal diameter was collected at 14, 28, 42, 56 and 70 days after planting (DAP). Grain and stover yield was collected at physiological maturity. The results showed that control, PK and NK treatment achieved means that were significantly different (p<0.05) for leaf number and bio-volume during the 2 cropping seasons. The grain and stover yields for control, NK and PK showed significant differences (p<0.05) during the two cropping seasons. Simple linear regression analysis between grain yield and leaf number achieved a coefficient of determination (R2 ) of 0.9 during both seasons. The coefficient of determination (R2 ) between bio-volume and grain yield at 42 DAP was 0.8 for LR13 season and 0.9 for SR1, respectively. The yield response to nitrogen application was 1.87 Mg ha-1 in the LR13 season and 1.90 Mg ha-1 during the SR13 season. The yield response (yield loss) for phosphorus was 0.84 Mg ha-1 in the LR13 season and 0.81 Mg ha-1 during the SR13 season. It was concluded that absence of N and P nutrients significantly affects maize leaf number and bio-volume and eventually these effects influence the achieved grain yield. The results of the study show the need to adopt specific nutrient application instead of the former use of blanket recommendation for whole regions.
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    Effects of tree nursery growing media and farmers' management techniques on seedling quality in mount Kenya region
    (2012-01-30) Kihara, Job; Kung'u, J.B.; Mugendi, D.N.; Jaenicke, Hannah
    Low survival and slow growth rate of trees as result of poor quality tree seedlings hamper effort by small-scale farmers in development of agroforestry systems. These may be attributed to the chemical and physical properties of the growing media used and the management practices adopted. With the growing demand for quality agroforestry trees, farmers have increasingly attempted to raise planting stock on-farm. However, insufficient technical knowledge has often hindered success. Insufficient growth medium quality has been identified as one of the factors contributing to low seedling qualities. Such growing medium contributes to physical and chemical conditions that may be inappropriate for quality seedling development. Slow growth rate and survival rate lead to extra costs in replacement planting as well as delayed benefits. With this knowledge, this study attempted to find out the effect of growing media chemical and physical properties used by farmers to raise seedlings of Tamarindus indica on-farm and the management practices adopted. This was necessitated by the need to determine parameters that make a good tree nursery growing medium that can be used by farmers on their on-farm nurseries for appropriate seedlings quality. The study also monitored the quality of the seedlings during the nursery period. On-farm tree nurseries in two agro-ecological zones in mount Kenya region-main coffee and marginal coffee zones were studied. Samples of the growing media used were analyzed for chemical and physical properties. Seedlings were produced in the media and their root diameter and seedling height measured periodically. Data collected were analyzed for variance (ANOVA) and tested for correlation. Aeration pore volume, total pore volume and wet bulk density were the physical properties that had greatest influence on seedling quality parameters. These had more effect at initial period of growth. Chemical properties affected seedling growth and quality parameters at later stages of growth. Important nutrients were observed to be nitrogen, organic carbon, magnesium and calcium. From the findings of this study, farmers can curtail nursery period from 130 days to as little as 75 days. There is need for further research to determine the cause of too much phosphorus concentration in the growing media tested and understand ways of ameliorating its negative effect on seedling development.
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    Plant Spatial Configurations and their Influences on Phenological Traits of Cereal and Legume Crops under Maize‐Based Intercropping Systems
    (Journal of Sustainable Agriculture and Environment published by Global Initiative of Sustainable Agriculture and Environment and John Wiley & Sons Australia, Ltd., 2024-06) Kinyua, Michael W.; Mucheru‐Muna, Monicah W.; Bolo, Peter; Kihara, Job
    Introduction: Intercropping systems have a great potential for crop diversification thus increasing smallholder systems' resilience to climate change while improving soil health. However, optimal benefits associated with intercropping systems are rarely realised because of the interspecific competition for growth resources among the intercropped species. Methodology: Six trials were established in the high and low rainfall agroecological zones of Babati district in Tanzania to assess how promising cropping systems with different plant spatial configurations would influence the phenological development of intercropped maize, bean and pigeonpea. Cropping systems under study included a sole maize system rotated with a pigeonpea‐bean intercrop dubbed Doubled‐up legume (DUL), maize‐pigeonpea system both with and without de‐topping, an innovation comprising double maize rows alternated with pigeonpea and beans (Mbili‐Mbili), maize‐ pigeonpea system with two maize seeds sown within a 50 cm intra‐row space, a vertical‐ architecture Meru H513‐pigeonpea system and a farmer practice. Results: Branch formation was significantly higher in DUL than in maize‐based systems (p ≤ 0.05). Seasonal weather had upto 30% influence on pigeonpea flowering, with DUL having highest (p ≤ 0.05) flower production. The rate of pigeonpea branch and flower production in Mbili‐Mbili was stable across seasons relative to other maize‐pigeonpea systems. Doubled‐up legume and farmer practice had pigeonpea litter yield of between 1 and 2 t ha−1 which was at least 0.5 t ha−1 higher than in maize‐based systems (p ≤ 0.05). During the period preceding early maize reproductive stages, Mbili‐Mbili increased light interception by 30% and 63% compared to maize‐based systems and DUL, respectively. Maize toppings had higher (94%) P content than stover biomass that remained until harvest. Conclusion: Overall, maize‐legume systems had higher intercropping efficacy than sole maize system, both in interception use efficiency, soil mulch cover, among other soil health benefits. Mbili‐Mbili and DUL also had increased phenological benefits on intercropped legumes however, the latter was prone to seasonal weather variability.