Assessing gaps in irrigated agricultural productivity through satellite earth observations—A case study of the Fergana Valley, Central Asia

Abstract

tImproving crop area and/or crop yields in agricultural regions is one of the foremost scientific challengesfor the next decades. This is especially true in irrigated areas because sustainable intensification of irri-gated crop production is virtually the sole means to enhance food supply and contribute to meetingfood demands of a growing population. Yet, irrigated crop production worldwide is suffering from soildegradation and salinity, reduced soil fertility, and water scarcity rendering the performance of irriga-tion schemes often below potential. On the other hand, the scope for improving irrigated agriculturalproductivity remains obscure also due to the lack of spatial data on agricultural production (e.g. cropacreage and yield). To fill this gap, satellite earth observations and a replicable methodology were usedto estimate crop yields at the field level for the period 2010/2014 in the Fergana Valley, Central Asia,to understand the response of agricultural productivity to factors related to the irrigation and drainageinfrastructure and environment. The results showed that cropping pattern, i.e. the presence or absence ofmulti-annual crop rotations, and spatial diversity of crops had the most persistent effects on crop yieldsacross observation years suggesting the need for introducing sustainable cropping systems. On the otherhand, areas with a lower crop diversity or abundance of crop rotation tended to have lower crop yields,with differences of partly more than one t/ha yield. It is argued that factors related to the infrastructure,for example, the distance of farms to the next settlement or the density of roads, had a persistent effect oncrop yield dynamics over time. The improvement potential of cotton and wheat yields were estimated at5%, compared to crop yields of farms in the direct vicinity of settlements or roads. In this study it is high-lighted how remotely sensed estimates of crop production in combination with geospatial technologiesprovide a unique perspective that, when combined with field surveys, can support planners to identifymanagement priorities for improving regional production and/or reducing environmental impacts.