Nowadays, there are various methods of plant biomass assessment available for the purposes of plant growth analysis. Visual plant coverage assessment is often subjective; the other methods are destructive or require purchasing some special devices. This paper presents the assessment of the possibilities and limitations of using digital images made by conventional digital cameras for the purposes of monitoring of the plant canopy development and weed distribution during a vegetation period using the example from the field experiment established on agricultural land in Malanta at the experimental site of the Slovak University of Agriculture. The study is focused on assessment of the effect of biochar application on gas emission, hydrophysical soil properties as well as plant response and yields and it was established in the spring of 2014. Downward images of corn (