Spatiotemporal information on crops and cropping systems can provide useful insights into disease outbreak mechanisms in croplands. In September 2011, a severe outbreak of Maize Lethal Necrosis (MLN) disease was reported in Bomet County, Kenya. We aimed to detect severely MLN-infected fields and discriminate mono, inter, and continuous maize cropping systems. We collected in-situ MLN severity observations and acquired multi-date and multisensor data viz., RapidEye (RE), Sentinel-1 (S1), digital elevation model (DEM), and Landsat-8 (L8) imagery. A hierarchical classification approach was used to map the cropping systems and severely MLN-infected fields during the short rainy season (September 2014-February 2015) using the random forest (RF), one-class support vector machine (OCSVM) and biased SVM (BSVM) classifiers. RF showed better performance when a balanced multi-class dataset was available. Both OCSVM and BSVM did not lead to an accurate high severity MLN class separation. Moreover, the BSVM classifier was able to separate the mono and intercropping systems. During the long rainy season (March-August 2015), only maize crop data were available, hence the BSVM as one class classifiers (OCC) was used and maize fields were successfully mapped even with high confusion rate. Furthermore, the distribution of maize intercropping system increased in low rainfall sites, and the continuous cropping system limited to only 31% of total maize cropland.

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Introduction Total population of the Kenya at 2014 was 45.5 Million individuals that the share of rural and urban area was 74.4% and 25.6% respectively. Within the crop income category, maize with horticultural crops, covering 14% of total household income in Kenya. At the same time, coffee and tea account for a combined 5.6% of total gross income. In the mid-1970s maize accounted for about 35% of the value of total crop production in Kenya while in the late 1990s, it reduced to 28% of the value of total crop production (Olwande, Sikei et al. 2009). Since 2008 the area under cereal production increased ~ 647,762 ha and the cereal production reached 1,446,328 tonnes. Maize farming is the backbone of food