Assessing and Monitoring Agriculture Crop Production for Improved Food Security in Machakos County

Agriculture productivity has been a challenge to food security in Machakos County, Kenya. The area is semi-arid with scanty rainfall amounts irregularly distributed. Population pressure in high agriculture potential areas has pushed human settlement to fragile ecosystems. The objective of this study was to assess state of land cover and land use with keen interest on agriculture land use. Eco-climatic variables are known to influence agriculture crop production, thus crop condition was assessed using normalized difference vegetation index. Rainfall amounts and distribution was analyzed to show its impact on crop production. The methodology was based on satellite data processing. Land use and land cover was derived from Landsat satellite imagery while normalized difference vegetation index was computed from SPOT vegetation satellite data; time series analysis of biomass health and vigor for 2010 and 2011 cropping season in Machakos was analyzed. FEWSNET rainfall data was used to compute cumulative rainfall amount and average for the growing season. The Analysis revealed that Agriculture occupies 64 % of the total land mass, and most land in high potential areas of the district is under agricultural production. During March 2011- September 2011 the region received total rainfall of 81-250 mm. Crop condition in 2010 was better than 2011 season, this can be attributed to decline in soil moisture content and nutrients. Agriculture assessment using earth observation data is a viable technology especially when working in a relatively large area with limited resources (time/finances) or when you need to study change over time as with the normalized difference vegetation index. This study proposes use of very high resolution data to capture detailed land use for crop production assessment. Long term change analysis of land cover using Geo information and Remote Sensing would further help in current and future analysis of agriculture crop production in Machakos.