Ngugi, Lucy Wangui2015-10-012015-10-012014-08http://ir-library.ku.ac.ke/handle/123456789/13724Department of Agricultural Resources Management (ARM), 85p. 2014, S 625 .K4N48Soil degradation and moisture stress remain the major constraints and environmental threat to agricultural productivity in the semi-arids of Kenya, which account for more than 80% of the total land mass. Government development partners and donor institutions have been promoting soil and water conservation technologies aimed at reducing soil erosion and in making more water available for agricultural production. Investments in soil and water conservation technologies can be undertaken when sufficient returns are guaranteed and the risks thereof are known. This study assessed soil and water conservation technology investment by farmers, examined factors that influence investment into soil and water conservation technologies, quantified the costs and the benefits of short term investments in soil and water conservation technologies and finally, it identified the potential opportunities to reduce risks of investments in soil and water conservation technologies under variable climatic conditions. The study was carried out in Mwania and Kalii watersheds in Machakos and Makueni Counties of Eastern Kenya. Two stage sampling method was used to obtain the sample size of farmers used for the household surveys. First the watersheds were delineated, and the number of HHs picked from sub locations depending on the sampling frame of that sub location to obtain a sample size of 380 households. Purposive sampling method was later used to obtain total of 120 households based on the SWC technologies invested by the farmers. Descriptive statistics were conducted using Statistical Package for Social Sciences (SPSS). The crop simulation model APSIM was used to generate yield data under irrigation, tied ridges and terraces which were subjected to analysis of variance (ANOV A) using R-statistical software. Results indicated that terraces were the most used SWC technology in both sites while tied ridges and mulching the least invested technology in Mwania and Kalii respectively. High cost and input unavailability locally were the key factors constraining investments in SWC technologies. On the other hand, benefit accrued after investing in SWC technologies was the significant factor promoting the investments. Benefit-cost analysis (BCA) during 2010/2011 SR season indicated that irrigation and tied ridges yielded the highest benefit-cost ratio (BCR) of 1.3 and 2.5 in Mwania and Kalii respectively in maize production. Terraces gave the highest BCR (1.5) in Kalii under bean production. ANOV A results indicated that the technology used, fertilizer rate applied and the season type were significant in both maize and bean production. Modeling results indicated that investing during above normal seasons was risky in all technologies but beneficial during normal seasons. Model simulations further indicated that fertilizer application led to up to 73% and 61% yield gains in maize and beans production when up to 30kg Nlha fertilizer was applied. The study recommends development of strategies that will ensure reduction of prices of farm inputs and their availability in the study area, farmers' economic empowerment to enhance investment in irrigation and tied ridges to ensure food security in semi-arid Eastern Kenya.enThesis