Infocommunication environments of extended agro-industrial enterprises in the context of precision farming strategy provide various types of information and telecommunication services. External factors change leads to reconfiguring such system to new operational requirements. There are different types of resources needed to maintain process of system modernization. At the same time, it is a typical situation of many resources vendors with different characteristics. The problem of multiple source control for reconfiguration of infocommunication environments under uncertainty is considered in the article. The proposed algorithm allows to evaluate the quality of modernization plans and source control according to the value of the potential effect and characteristics of sources. The basic foundations of the algorithm are sources flow monitoring and modernized firstmost timeliness (FMT) method for alternative selection and resource flow control. To estimate the effect of the alternatives, the special cost function is used. It is expected that the proposed source control method will help to improve the IT systems resource provision and increase their suitability in the case of uncertainty.