and Gliricidia sepium (Jacq.) Walp. growing in association with maize (Zea mays L.) were examined in semiarid Kenya during the long rains of 1996 and 1997. Even although tree roots penetrated more deeply than maize roots, maximum root length densities for both tree species and maize occurred in the top 200 mm of the soil profile where soil moisture was frequently recharged by rains. Populations of roots in plots containing trees were dominated by tree roots at the beginning of the growing season but because tree roots died and maize root length increased during the cropping season, amounts of tree and maize roots were similar at the end of the season. Thus, there was evidence of temporal separation of root activity between species, but there was no spatial separation of the rooting zones of the trees and crops within that part of the soil profile occupied by crop roots. Tree root length density declined with increasing distances from rows of trees and with depth in the soil profile.Although Grevillea trees were largest, plots containing G. sepium trees always contained more tree roots than plots containing G. robusta trees and Gliricidia was more competitive with maize than Grevillea. Overall, Gliricidia reduced crop yield by about 50% andGrevillea by about 40% relative to crop yield in control plots lacking trees and reductions of crop yield were greatest close to trees. There was less soil moisture in plots containing trees than in control plots. Such difference between control plots and plots containing trees were maximal at the end of the dry season and there was always less soil moisture close to trees than elsewhere in the plots. Plots containing Gliricidia trees contained less soil water than plots containing Grevillea trees.

The widespread poor agricultural practices and ancient technologies continuously aggravate erosion of sediments and soil nutrients from delicate terrains at the major catchments of water shades. The ongoing study is assessing soil and nutrient losses in the four major land use covers (forest, pasture, tea and maize farms) in the upper catchment of Nyondo River Basin. The study sites in the upper catchment of Nyondo River Basin are densely populated and receive bimodal rains that support agriculture which is the main economic activity supporting livelihoods of the communities in the region. The experiment is laid in a randomized complete block design (RCBD) with each of the land use covers replicated 3 times with erosion traps mounted on 150 m2 plots. First data set was collected during the short rainy season of 2019 and long rainy season of 2020, with subsequent data collection continuing up to the short rainy season of 2021. Preliminary results showed that soil and nutrients were significantly lost in maize fields (p=0.05), forest cover was the least vulnerable while pasture cover had the highest surface runoff. Nutrient concentrations in the eroded sediments (p=0.05) were significantly higher than those that remained in maize plot while forest and tea fields registered comparable effectiveness in reducing both soil and nutrient losses, seasons notwithstanding. Pasture and maize fields had the highest water loss due to low infiltration rate and were also vulnerable to sediment and nutrients loss through surface runoff. The information will be used to inform and advise stake holders on land use policies geared towards attainment of sustainable agriculture and water quality in Nyondo and areas with similar landscapes and agricultural practices. Keywords: Erosion; Sediment; Nutrients; Land use

With the rising global human population, decreasing mass of arable land, increasing demand for food and the emergence of biotic and abiotic constrains to crop production in the advent of climate change, the future of food security stares at intensified production under controlled environments such as greenhouses. Cowpea [Vigna unguiculata (L.) Walp.], is an economically and nutritionally important vegetable crop widely cultivated by smallholder farmers both for subsistence and income generation. Uprooting the entire plant as a form of harvest is common in open-field subsistence farming systems. However, little is known about the effect of harvesting regimes on total productivity of cowpea under greenhouse conditions. This study was conducted in a greenhouse at Mundika Boys' High School farm, Busia County with an objective of evaluating growth and yield of cowpea (M66 variety) in response to different harvest regimes under controlled (greenhouse) conditions. Plots of cowpea stands/clusters each with four plants were subjected to three different treatments, i.e., harvest 1 (H1), harvest 2 (H2), harvest 3 (H3) and a control (no harvest or H0) in a randomized complete block design. Overall crop yield was measured by the number of trifoliate leaves (NTL) and plant height (PH) at 7-day intervals. Data collection was initiated at week 1 (for PH) and week 2 (for NTL) after emergence. The results revealed significant differences in both PH and NTL between H0 and H1, H2, or H3 (p≤0.05), implying that cowpea yields can be significantly improved by applying harvesting regimes to vegetable-only production systems. For PH, maximum values were obtained for H1 and H3. Thus, farmers can obtain higher vegetable productivity by harvesting cowpea for consumption or sale at intervals, as opposed to a one-time mass harvesting.

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A study was carried out at the Busia Agricultural Training Center (A.T.C), Western Kenya in 2019 to compare the fruit yields of two capsicum varieties from Syngenta seed company at the physiological maturity stages of red and yellow colors. Commandant F1 (red) and Admiral F1 (yellow) capsicum varieties were established under greenhouse conditions in two experimental beds measuring 0.7m by 13.5m. No controls were planted. Drip irrigation system was used with a plant-to-plant and inter-row spacing of 30cm and 40cm, respectively. Both of the two varieties were planted at the same time and subjected the same fertilizer treatments, pest and disease control measures, cultural practices and moisture supply. Data was collected on growth parameters (number of vegetative branches, flower buds and flowers) and yield components (number of fruits and harvest weight). Independent sample t-test was used to compare parameters (number of flowers, flower buds, fruits and the number of branches) for the two colored capsicum varieties, at a probability of p≤0.05. Further analysis involved finding weight and harvest averages for the two varieties. All analyses were performed in IBM SPSS Statistics, version 23. The red-coloured variety produced an average of 9.36 buds per plant compared to 5.2 for the yellow cultivar (p=0.01). Significant differences in the average yield potential of the yellow and red varieties (calculated as flowers, buds, and young fruits) were found between the red and yellow varieties (p=0.02). The red variety had a higher yield potential (19.52) than the yellow one (13.46). Within-variety weight comparison showed that the yellow variety lost a significant amount of fruit mass between the second and third harvest (0.122kg or 61%) compared to the red variety which lost 0.099kg or 58%. Keywords: Capsicum; Fruit yield; Physiological maturity; Variety; Red; Yellow