Effect of different cover crop residue management practices on soil moisture content under a tomato crop (Lycopersicon esculentum)

Water relations are among the most important physical phenomena that affect the use of soils for agricultural, ecological, environmental, and engineering purposes. In sub-Saharan African, water is most critical in limiting crop production and yields especially in the Arid and Sub-arid regions. The soil water storage, available water content and soil water balance under various cover crop residue management practices in a Nitisol were evaluated in a field experiment at the Kabete Field Station, University of Nairobi. The effects of surface mulching, above and below ground biomass and roots only incorporated of velvet bean (Mucuna pruriens), Tanzanian sunhemp (Crotalaria ochroleuca) and purple vetch (Vicia benghalensis) cover crops, fertilizer and non fertilized plots on soil water balance were studied. The experimental design was a split plot and tomato (Lycopersicon esculentum) was the test crop. Since water content was close to field capacity, the drainage component at 100 cm soil depth was negligible and evapotranspiration was therefore derived from the change in soil moisture storage and precipitation. Residue management showed that above and below ground biomass incorporated optimized the partitioning of the water balance components, increasing moisture storage, leading to increased tomato yields and water use efficiency (WUE). Furthermore, vetch above and below ground biomass incorporated significantly improved the quantity and frequency of deep percolation. Soil fertilization (F) and non fertilization (NF) caused the most unfavourable partitioning of water balance, leading to the lowest yield and WUE. Tomato yields ranged from 4.1 in NF to 7.4 Mg ha-1 in vetch treated plots. Vetch above and belowground biomass incorporated had significant (p ≤ 0.1) yields of 11.4 Mg ha-1 compared to all other residue management systems. Vetch residue treatment had the highest WUE (22.7 kg mm-1 ha-1) followed by mucuna treated plots (20.7 kg mm-1 ha-1) and both were significantly different (p ≤ 0.05) compared to the others irrespective of residue management practices

Soil hydraulic properties of a Nitisol in Kabete, Kenya

Water relations are among the most important physical phenomena that affect the use of soils for agricultural, ecological, environmental, and engineering purposes. To formulate soil-water relationships, soil hydraulic properties are required as essential inputs. The most important hydraulic properties are the soil-water retention curve and the hydraulic conductivity. The objective of this study was to determine the soil hydraulic properties of a Nitisol, at Kabete Campus Field Station. Use of an internal drainage procedure to characterize the hydraulic properties and soil and water retention curves allowed for the establishment of the moisture and matric potential at field capacity and permanent wilting point. The Bt2 (84 -115) and Bt3 (115 - 143 cm) had the highest clay contents of 619 compared to Ap, AB and Bt1 horizons. The PWP was attained at soil moisture contents of 0.223, 0.284, 0277, 0.307 and 0.314 m3m-3 in the Ap, AB, Bt1, Bt2, and Bt3 horizons, respectively. Horizontal saturated hydraulic conductivity (Ksat) was high at 6.0 cm hr-1 in Ap horizon and decreased to 0.4 cm hr-1 in the subsurface horizon (Bt3). Ksat in the vertical direction was higher than horizontal and ranged from 8.3 cm hr-1 in surface layer to 0.6 cm hr-1 in Bt3 horizon, with exception of Bt1 and Bt2 where horizontal Ksat was greater than vertical. The Ap horizon also had the highest crop extractable water. Though the AB and Bt1 had the same water content at low matric suction, the variation was very wide as the SWRC approached saturation point. Bt1 and Bt2 also had similar water contents at suction range of – 7kPa after which Bt1, tended towards Bt3. Bt3 had the narrowest range of crop extractable water and thus was attributed to texture. The Bt3 retained the most amount of water at 0.314 m3m-3concluding that θPWP increased with depth. The total available water capacity between FC and PWP in the profile was 79.2 mm m-1. The study observed that the field capacity, crop available water contents and hydraulic conductivities were influenced positively by soil organic matter. The Van Genuchten parameters of air entry value (α) and pore size distribution (n) indicated that pore size distribution was not even in the AP and AB horizons. The field capacity was attained at higher matric potential at -5kPa for Bt1 while Bt2 and AP, AB, Bt2 and Bt3 was at -10kPa.The functional relationship, K(θ) = aθb that deals with water redistribution as a result of soil hydraulic properties and evaporative demand of the atmosphere was highly correlated to soil moisture content and texture with R2 values > 0.85

Effectiveness and Safety of 2-Hourly 20 MCG Oral Misoprostol Solution Compared to Standard Intravenous Oxytocin in Labour Induction Due to Pre-Labour Rupture of Membranes at Term: A Randomised Clinical Trial at Kenyatta National Hospital

Background: Pre-labour rupture of membranes (PROM) at term is a common event whose management varies from centre to centre. The practice at the Kenyatta National Hospital (KNH) for patients with PROM at term is to initiate delivery of the patient soon on admission with intravenous oxytocin, if there are no contraindications to vaginal delivery. However, in PROM at term, if the cervix is not ripe,vaginal administration of prostaglandin pessaries for cervical ripening is not possible when there is active draining of liquor, thus use of intravenous oxytocin may take a very long time or fail all together. Oral misoprostol at low doses has been found to be a safe and effective agent for labour induction in numerous studies carried out in the developed world, where there are better resources for monitoring of labour. None of the studies has been carried out in Kenya,a limited resource country. Therefore, there is a need to determine the effectiveness and safety of oral misoprostol solution at the KNH, a limited resource set up.Objective: To determine the effectiveness and safety of 2-hourly 20 mcg oral misoprostol solution compared to the standard intravenous oxytocinin labour induction in mothers with pre-labour rupture of membranes at term at the Kenyatta National Hospital.Design: An unblinded randomised clinical trial.Setting: Kenyatta National Hospital Labour Ward Unit.Participants: Eighty three pregnant women with pre-labour rupture of membranes at term without an indication for Caeserian section were consented and randomised for labour induction with either oral misoprostol at a dose of 20mcg 2-hourly up to a maximum of 4-doses, or with  intravenous oxytocin according to the WHO protocol.Main outcome measures: Induction to delivery interval; maternal  complications and early neonatal outcomes.Results: The overall induction success rates in the misoprostol arm was 81% versus 83% in the oxytocin arm (P=0.447). The mean induction to vaginal delivery interval in the misoprostol arm was 8.4 hours as compared to 9.45 hours in the oxytocin arm (P=0.116). The induction to active labour interval was similar in the two study arms. The mean induction to active labour in the misoprostol arm was 4.02 hours as versus 4.51 hours in the oxytocin arm (P=0.223 ). Two women who had failed induction with misoprostol were augmented with oxytocin and delivered vaginally. The Caesarean section rates were 19% in the misoprostol arm and 17% in the oxytocin arm (P=0.447), which was not statistically significant. The maternal outcomes were similar in the two study arms. Four women had tachysystole in the misoprostol arm, compared to three  in the oxytocin arm (P=0.253). In the misoprostol arm two women had hypertonus compared to three in the oxytocin arm (P=0.322).There was one case of hyperstimulation in the misoprostol arm and two in in the oxytocin arm. There were no differences in the foetal/ neonatal outcomes. No baby had an Apgar score of less than seven at one or five minutes. No baby was admitted to the New Born Unit in either of the two arms. There was no case of a still birth in either of the study arms. There was no significant difference in the passage of meconium between the two arms, 39% in the misoprostol arm and 35.7% in the oxytocin arm (P=0.755). The passage of meconium did not impact on the neonatal outcomes.Conclusion: Oral misoprostol solution 20mcg 2-hourly is as safe and effective as the standard intravenous oxytocin for labour induction in women presenting with prelabour rupture of membranes at term at the Kenyatta National Hospital

Identification and Evaluation of Cost Optimal Technology Options for Improvement of Electricity Access in Rural Kenya

With around 12% of Kenya’s rural population having access to electricity in 2014, rural electrification’s progress has been conspicuously slow over the years. The purpose of this study is to identify and evaluate cost optimal technology options for improvement of electricity access in rural Kenya, on a geographical information system platform. Based on a one-year scenario, the study uses site suitability and cost distance analysis to conduct a mapping exercise based on four pre-chosen technologies. The results indicate that these technologies have the potential to reach around 2.1 million households increasing the national electrification rate by 28 percentage points to stand at around 94% from the current reported figures of 66%. Grid extension has the potential to reach 1.6 million households, followed by the solar photovoltaics and solar photovoltaics/wind hybrid mini-grids reaching 167,925 households while solar home systems extends to 315,844 households. Geographical information systems can be useful to energy planners, regulators, investors and users, as they aid in decision-making through the intersection and integration of information on multiple levels. Further research is also identified

Response of cowpea genotypes to Alectra vogelii parasitism in Kenya

Cowpea is popular in Eastern Kenya where it is attractive to farmers because of its high economic value and the belief that it does not require many external inputs. Farmers are however discouraged to grow the crop in this region due to massive attack by a parasitic weed Alectra vogelii (Benth). Yield losses due to A. vogelii have being estimated to range from 50 to 100% in Mbeere, Kitui and Makueni districts. No single method however is available to farmers in these regions in control of the parasitic weed. Combining several control methods, as in the management of Striga spp in Western Kenya should be a sustainable option. Field studies were conducted in 2010 and 2011 at Kenya Agricultural Research Institute (KARI), Kiboko farm to determine the response of 143 cowpea genotypes to Alectra infestation. The aim for the study was to identify resistant genotypes that could be used in breeding programme. Significant differences were observed amongst cowpea genotypes in days to first Alectra emergence, number of Alectra shoots emerged at 6, 8, 10 and 12 week after planting and grain yield. Cowpea genotypes Kir/Nya-005 and Mbe/Mach-022 showed complete resistance to  Alectra while Ken-Kunde, M66 and K80 (all commercial varieties) supported the highest number of Alectra shoots. Grain yield loss in the three susceptible varieties was 80, 79 and 50% respectively. On the other hand, Sia/Cia-004, Mbe/Mach-014 and Kib-006 had high grain yields despite the high number of Alectra shoots present. There was a strong correlation (r = -0.57) between grain yield and number of Alectra shoots emerged at 12 weeks after planting. A significant negative (r = -0.37) correlation was also obtained between pod number per plant and number of emerged Alectra shoots at 12 weeks after planting. This negative correlation proves the high accumulation dry matter in the cowpea roots at the expense of the pods thus decreasing grain yield. This information showed that there is sufficient genetic variability in the cowpea genotypes studied, which can be exploited in breeding improved cowpea varieties for resistance to A. vogelii in Kenya. A great progress towards developing improved cowpea variety that meets farmer’s preferences with durable resistance to A. vogelii can be achieved if the genes from the resistant and tolerant local cowpea cultivars identified in this study could be introgressed into the adapted susceptible improved varieties. This will increase the potential impact of adoption of resistant cowpea varieties in the zones.Key words: Cowpea, Alectra vogelii, Resistance/tolerance and grain yield

Impact of Enclosures on Range Productivity in Chepareria West Pokot County Kenya

In the semi-arid areas of West Pokot particularly Chepareria, majority of the people live semi sedentary lives while others are nomadic pastoralists. In the last three decades, there have been concerted efforts to restore and improve rangeland in this area. Use of enclosures, which is one of the key interventions, by the Vi Agro- forestry a Non-Governmental Organisation, enhancing with many ecological processes such as disturbance, is a method of rehabilitating degraded rangeland, which in turn affects vegetation dynamics. Adoption of these strategies by farmers has been gradual and some areas are still open and degraded. The aim of this study was to evaluate the effects of enclosures on range productivity in the semi-arid rangeland in West Pokot. Plant productivity, diversity and density were assessed in enclosures of different ages and in adjacent open land used for communal grazing. Questionnaires were also used to assess local community perception of the range restoration and improvement. Modified Whittaker plot was used for sampling in the selected enclosures and open areas. Herbaceous biomass and plant cover were greater in enclosures than in open areas. The average herbaceous cover in the enclosed area was 76% while that in the open it was 55% which was significantly different, P \u3c 0.001. The average herbaceous biomass in the enclosure was 137.2kg/ha while in the open it was 37.8kg/ha respectively. Enclosed areas are more productive than open areas and should be adopted in other dry areas as a method of rehabilitating degraded grazing lands

Curing reduces postharvest deterioration of biozyme® produced potatoes ( Solanum tuberosum L.)

Potato is among food crops that are heavily relied upon for food security assurance worldwide. Potato tubers are consumed in their fresh form and therefore require proper storage to prolong their life after harvest. Being succulent, massive losses result if bruised, exposed to light and low relative humidity. The present experiment was conducted to find optimal conductions that prolong the shelf-life of potato tubers grown using the biomass and succulence enhancing Biozyme® Potatoes were grown in a split plot experiment, arranged in a randomized complete block design. The experiment was replicated three times and repeated once. Main plots were assigned to potato cultivar (Tigoni and Asante), while subplots were assigned to Biozyme® foliar feed rate (0, 125, 250, 500 and 750 ml/ha). Each subplot was planted with 28 seed potato tubers spaced at 30 cm x 70 cm in four rows. A distance of 1 m separated adjacent subplots and main plots. After harvesting, ware potato tubers, from each treatment, were divided into four groups for four postharvest handling regimes (Cured + Dark, Cured + Room, Not Cured + Dark, and Not Cured + Room Storage). Each postharvest regime had 20 tubers, replicated four times. Weight loss, shrinkage and rotting percentages increased, but firmness decreased with increase in Biozyme® rate. The deterioration was counteracted by Curing and Dark Storage of the potato tubers that reduced weight loss, shrinkage and rotting, but increased firmness. Thus, foliar-feeding potato plants with 500 ml/ha Biozyme® followed by Curing and Dark Storage of harvested tubers are recommended to ensure high potato tuber yields and effective reduction of premature postharvest deterioration of the tubers during storage. KEYWORDS : Firmness, Rotting, Shelf-life, Shrinkage, Tuber handling, Weight loss

Kiswahili Dialects Endangered: The Case of Kiamu and Kimvita

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Soil Nitrous Oxide (N\u3csub\u3e2\u3c/sub\u3eO) Emission from Integrated Soil Fertility Management in Maize (\u3ci\u3eZea mays\u3c/i\u3e L.) Cropping Systems

Integrated Soil Fertility Management (ISFM) has been recommended to address challenges of low soil fertility by incorporating locally available organic resources (ORs) together with inorganic nitrogen (N) fertilizers. Despite ISFM success in field trials, there is limited information on ORs contribution to atmospheric greenhouse gas concentrations through N2O emission. A short-term field study was conducted at two sites with different soil types; silt loam (Aludeka) and silty-clay soil (Sidada) to assess the influence of selected ORs on soil N2O emissions. The ORs treatments included; Calliandra carothyrsus (CL), farmyard manure (FYM) and maize stover (MS) with (+N) and without (-N) inorganic N fertilizer. The study also evaluated the relationship between N2O emissions and soil organic carbon, mineral N, total nitrogen, soil temperature, moisture content, soil nitrate (NO3-) and ammonium (NH4+). Relative to the control (0.19±0.1 Kg N2O-N ha-1), cumulative N2O emissions were significantly (P= 0.01) higher by 6, 9 and 13 fold under MS +N (1.05±0.8 Kg N2O-N ha-1), FYM +N (1.74±0.8 Kg N2O-N ha-1) and CL +N (2.54±1.2 Kg N2O-N ha-1), respectively at the Aludeka site. At Sidada, cumulative N2O emissions were similar across all the treatments (P = 0.149). Approximately 240% and 411% of increase in cumulative N2O emissions across treatments at Sidada and Aludeka, respectively, was related to inorganic N fertilizer application. At Aludeka, cumulative N2O emissions exhibited significant positive relationship with soil NO3-(r = 0.894, P = 0.03) and NH4+ (r = 0.817, P = 0.013), and negatively correlated with soil C: N ratio (r = -0.710, P = 0.049). While at Sidada soil properties did not exhibit significant relationship with cumulative N2O emissions. The study suggests that influence of OR on N2O emissions in maize based-cropping system vary depending on the type of soil and increases when OR are applied in combination with inorganic N fertilizers