Evaluation of soil bacteria treatments on some physiological parameters of crops by spectral vegetation indices

The effects of soil bacteria treatments on barley and wheat (1. treatment: stubble decomposers + soil inoculators; 2. stubble decomposers + soil regenerators; 3. control) were studied at the Agricultural Research Institute in Kompolt on spectral vegetation indices which are closely related to photochemical processes and photosynthetic pigments in barley and wheat leaves. We applied in vivo field measurements: SPAD 502 relative chlorophyll meter and ASD Field Spec Pro 3 spectroradiometer. This work presents the results of the experiments in 2019, moreover, we compared them with our previously published investigations on several other crops (maize, sunflower, rape, barley) carried out in 2017 and 2018. In 2019 despite the significant level of the standard deviation of data in field conditions, treated (mainly with stubble decomposers + soil inoculators) wheat leaves could be characterized by significantly higher chlorophyll and water content, higher photochemical efficiency, and lower carotenoid content. In the case of barley due to the large standard deviation of data, we couldn’t reveal the beneficial effects of treatments by these methods. Due to the very rainy spring in 2019 some experimental plots - like K9 with barley – wre covered by inland water, which negatively influenced living conditions of soil bacteria. Despite this unfavourable conditions, the first treatment resulted in an 18.9% higher yield of barley and 27.8% higher yield of wheat, while the second treatment increased barley yield with 28.9% and wheat yield with 27.7%. In the case of wheat, spectral vegetation indices could indicate beneficial effects of soil bacteria treatments at the beginning of flowering, similarly to our results in 2017 and 2018 in case of maize, sunflower, rape, and barley