Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Royaume-Uni → 1992 → Soil and water conservation for improved soil moisture and crop production : an empirical and modelling study in semi-arid Kenya.

University of East Anglia (1992)

Soil and water conservation for improved soil moisture and crop production : an empirical and modelling study in semi-arid Kenya.

Kiome, Romano Mungiiria

Titre : Soil and water conservation for improved soil moisture and crop production : an empirical and modelling study in semi-arid Kenya.

Auteur : Kiome, Romano Mungiiria.

Université de soutenance : University of East Anglia

Grade : Doctor of Philosophy (Ph.D.) : 1992

Résumé
In Semi-arid Kenya, soil and water conservation (S&#38 WC) is intended to address one of the most limiting factors of crop production, the availability of soil moisture. In this study, the effect of S&#38 WC methods on soil loss, soil moisture and the yield of a test crop on three soils is investigated using experimental and modelling approaches. A Soil and Water Conservation Assessment Model (SWCAM) incorporating erosion, water-limited and erosion-productivity components was developed. Over two growing seasons, in 1990/91, field experiments on a monocrop of maize ( Zea mays L) with five S&#38 WC treatments, fertilized and nonfertiized levels, were conducted. Although labour and capital intensive methods such as terraces and tied ridges controlled soil erosion effectively, simple and cheap methods such as trashlines and contour tillage reduced soil loss significantly. Fertilizer application reduced soil loss because of better crop cover. A soil erosion submodel, was validated and shown to be suitable for prediction of relative soil loss in the area. The predictions indicate that soil erosion in the cultivated land is a serious problem, leading to soil loss of over 18 tons/ha at all the trial sites. Hence soil conservation is essential. Soil moisture content in the growing period was not significantly different between S&#38 WC methods in both fertilized and nonfertilized treatments but differences occur between fertility levels. Evapotranspiration (consumptive water use) over the growing season did differ significantly between both soil fertility and conservation treatments and indicated that S&#38 WC improves soil moisture availability. A water balance submodel, with functions to calculate surface storage of water for different S&#38 WC methods, simulated the soil moisture balance components and indicated which S&#38 WC improved the availability of soil moisture. The simulations indicate that S&#38 WC methods significantly improve soil moisture availability especially in soils with poor physical properties

Mots clés : Agronomy Agronomy Plant diseases Horticulture Soil science Geography Agronomy

Présentation : EThOS (UK)

Proquest Dissertations & Theses

Page publiée le 26 mai 2009, mise à jour le 31 octobre 2019