IMPACT OF THE BIOCHAR APPPLICATION ON CORN GROWTH ASSESSED BY VEGETATION INDEX.

Due to the growing world population, there is an increasing demand on agricultural production. Moreover, climate change and related changes in the environment force scientists to seek new solutions. This contribution presents the partial results of the field study conducted in experimental area of the Slovak University of Agriculture in Nitra, Slovakia where biochar as a potentially sustainable soil amendment was incorporated at different application rates (0, 10 and 20 t ha^-1) in the loamy soil in Spring 2014. In 2015, the soil was either fertilized by ammonium nitrate at dosage of 160 kg ha^-1 or left without fertilizing. To assess biochar impact on plant density development of corn (Zea mays), non-destructive method of taking digital imagery by conventional digital camera was used in 2015. In total, four imagery sessions were realized during the vegetation season in May-June 2015, during which 3 replicate images were taken on each plot per session. Images were processed in Breedpix software. Vegetation index was calculated according to the estimates of the amount of green pixels present in the image. By comparing the vegetation indices obtained for different dates it was possible to determine the percentage of the plant mass development according to the increasing amount of green pixels representing the plant bodies. Application of biochar at the end of the experiment resulted at 10 t ha^-1 in increase of the plant vegetation index by 7 % when not fertilized, resp. by 11 % when fertilized, thus the biochar amendment improved the vegetative growth of corn, although this improvement was not significant. Estimating vegetation indices from digital imagery is a method easy to use, is repeatable on the same group of plants, but is limited only to early stages of vegetation season. [ABSTRACT FROM AUTHOR]