Abstract To attain agricultural sustainability, use of soil resources and tillage requires equal consideration for chemical and physical components of soil fertility. We assessed responses of selected soil physical and chemical properties to tillage and soil fertility amending resources. The study was carried out in Meru South and Kandara sub-counties located in the Central Highlands of Kenya for four cropping seasons. The experimental design was split-plot with tillage as the main factor - ...
Abstract Soil acidity and phosphorus deficiency are some of the constraints hampering agricultural production in tropical regions. The prevalence of soil acidity is associated with phosphorus (P) insufficiency and aluminum saturation. We conducted a two-seasons experiment to evaluate soil phosphorus availability and exchangeable aluminum in response to phosphate rock and organic inputs in acidic humic nitisols. The field experiment was installed in Tharaka Nithi County in the Central Highlan...
Abstract Planting pits are rain water harvesting structures that trap water and nutrients in surface runoff and rain water falling directly into the pits. Planting pits have been promoted for improving crop yields without considering the nutrient dynamics. To contribute to this knowledge, a study was conducted to determine the soil nutrient content after four seasons of growing sorghum and pigeon pea in rotation in “Chololo” and “Five by Nine” pits. Two planting pits; “Five by Nine...
Abstract Soil Collembola communities were sampled along a gradient of land use intensification in Taita-Taveta, Wundanyi division, Coast Province during the wet season (October-November 2007) and dry season (February- March 2008). This gradient ranged from Natural undisturbed land use to intensively cultivated (disturbed) horticulture fields. The eight land use types (LUTs) were stands of (1) Pinus patula, (2) Cypress lusitanica, (3) Indigenous forest, (4) Fallow, (5) Pennisetum purpureum, (...
Abstract Populations of soil-dwelling Collembola were monitored on a land use gradient ranging from Natural forests to intensively cultivated land during the wet season October-November, 2007 and dry season February-March, 2008. Eight land use types (LUTs) which included stands of; Eucalyptus saligna, Vitex keniensis, Pennisetum purpureum, indigenous forest, fallow fields, Cammelia sinensis, Coffea africana and Zea mays intercropped with Phaseolus vulgaris were sampled for Collembola in Embu...
Abstract The study aimed at identifying soil fertility management practices that promote the Collembola population, diversity and survival in the soil. Soil samples were randomly collected from on farm plots amended with: 1-Mavuno ((Ma)-is a compound fertilizer containing 26% Potassium, 10% Nitrogen, 10% Calcium, 4% Sulphur, 4% Magnesium and trace elements like Zinc, Copper, Boron, Molybdenum and Manganese)), 2-Manure (Mn), 3-Trichoderna (Tr) inoculant (is a soil and compost-borne antagonist...
Abstract tillage practices on runoff amounts, sediment yield and maize yields under semi-arid and sub-humid environments. Field trials were set in Kigogo primary school in Meru South Sub-County, Tharaka Nithi County, representing the sub-humid conditions, and Machang'a secondary in Mbeere South Sub-County, Embu County (semi-arid) in the central highlands of Kenya. The experiment layout was a randomized complete block design and the treatments were implemented in runoff plots. Tied ridging (T...
Abstract Mitigating nutrient loss is a prerequisite of sustainable agriculture in the tropics. We evaluated three soil and water conservation technologies (mulching, minimum tillage and tied ridging) for two cropping seasons (long rains 2011, short rains 2011) at two sites in the central highlands of Kenya. The objectives were: to determine effects of the technologies on runoff, sediment yield and nutrient loads in sediment, and to assess influence of the technologies on maize yields. Experi...
Abstract An experiment in the Blue Mountains of Jamaica investigated the consequences of three land-use treatments applied following forest clearance on soil fertility and resulting crop growth over a five year period. The treatments were: maintained weed-free without cultivation (bare); cultivated with herbaceous crops (agriculture); and cultivated with herbaceous crops and intercropped with Calliandra calothyrsus contour hedges (agroforestry) and compared with an uncleared secondary forest...
Abstract Four proximal soil sensors were tested at four smallholder farms in Embu County, Kenya: a portable X-ray fluorescence sensor (PXRF), a mobile phone application for soil color determination by photography, a dual-depth electromagnetic induction (EMI) sensor, and a LED-based soil optical reflectance sensor. Measurements were made at 32–43 locations at each site. Topsoil samples were analyzed for plant-available nutrients (N, P, K, Mg, Ca, S, B, Mn, Zn, Cu, and Fe), pH, total nitroge...
Abstract Biological control of plant diseases through the addition of microbial biocontrol agents and the promotion of earthworms can be an environmentally friendly alternative to the chemical control of plant diseases. However, possible risks with biocontrol agents and their interactions with earthworms and other soil biota have not been well studied. The aim of this study was to assess whether the beneficial bacterium Bacillus amyloliquefaciens and the earthworms Aporrectodea caliginosa or...
Abstract Kenya’s Vision 2030 identifies agriculture as one of the key sectors to deliver sustainable economic growth and improved livelihoods for the poor in the rural areas. However, the sector continues to face several endemic and emerging constraints that require special attention. During the first two decades after independence, Kenya’s economy grew at an average rate of 6 percent per year and this was substantially driven by a robust agriculture sector. However, until about five yea...
Abstract Roundup degrading bacteria were isolated from the soil and gut of fungus cultivating termites Macrotermes michaelseni using MM7 media supplemented with the pesticide as the sole source of carbon and energy. The isolates were gram negative rods the isolate from the soil was designated GS1 while that from termite gut was designated GT2. The 16S rRNA gene sequence of the isolates revealed that isolates Both isolates GS1 and GT2 are closely related to Enterobacter sp AY 0822447 with 99%...
Abstract Smallholder farmers in sub-Saharan Africa (SSA) face several challenges that include pests and diseases. Plant-parasitic nematodes (PPN) reduce crop yields and affect their quality. They are an emerging threat to smallholder agriculture with several species attacking economically important crops. In SSA, most PPN control strategies are therapeutic and therefore unsustainable. Cost-effective nematode management strategies that promote soil health and enhance soil suppressiveness agai...
Abstract: Integrated soil fertility management (ISFM) technologies hold potential to protect against climate risks, reduce nutrient depletion and enhance food security. In this paper, we study how exposure to dry spells influences use and use intensity of ISFM technologies, specifically focusing on maize-legume intercropping and organic manure. We use a four-round panel dataset collected from households in six Malawi districts over a period of nine years and merged with daily rainfall data f...