CONTAMINATION MONITORING OF AGROPHYTOCENOSIS OF GRAIN CULTURES BY WEED SEEDS

Abstract

Contamination monitoring of agrocenosis is main is a basis for successful protection of agricultural crops. Global climatic changes and weather changes effect on weed’s component of agrophytocenosis. During the last years we can see the tendency of spreading and appearing more weeds. Agrothechnical measures, soil peculiarities, locations, density of plants, condition the adapting of the weeds in the agrophytocenosis, which decreases the effect of adding fertilizers, increases the material spending and methods of plants protections. Thus, the soil agrocenosis contamination by big amount of weeds is actual problem for the whole agricultural production. Looking at the results of our research, we can say that the biggest amount of seeds in the soil accumulated Spergula avensis L. – 48.7 seeds in 0–20 cm layer of soil per the 40 square centimeters. The population of Polygonum convolvulus L., Polygonum lapathifolium L. and Chenopodium album L. are contaminating the soil slightly 9.9–10.1 seeds per the 40 square centimeters. In the agrophytocenosis of winter cereals the biggest population was C. album – 61.5 seeds. The seeds of S. arvensis 21.2 seeds per the 40 square centimeters was the second biggest population. In the crops of spring cereals we could see the tendency of decreasing weeds in the deeper layers of soil from 49.9 seeds/at the 40 square centimeters up to 12.3 seeds/ per the 40 square centimeters, while under the crops of the winter cereals the most contaminated was 15–20 cm layer – 41,5 seeds/per the 40 square centimeters. From the main reserve the weeds 79.5–81.7% are the seeds of minor weeds and 10.8–7.1% are the seeds of perennial types. From the group of minor weeds the biggest amount of seeds in the soil were characterized the populations of C. album – 45.8%. The amount of perennial weeds in the general structure of the crops contamination of the grain cultures was not big from 1 to 5 seeds per the 40 square centimeters. Thus, big amount of the weeds in the agrophytocenosis – 265.3–335.5 millions per hectare, is very dynamic at the same time- it constantly refreshes by means of fructification of the weeds, but at the same time the part of the seeds is used for germination, the other part dies, the other plants exude in the process of crops care. That’s why the on time made complex of agrotechnical measures determines the level of actual agrocenosis contamination.