THE METHOD OF STUDYING WATER CONSUMPTION OF CROPS IN FIELD VEGETATION EXPERIMENTS
Authors: Kolomiets S. S. , Nechaj O. M. , Turaieva O. V. , Hnelytsia O. V. 
Published: February 2020

Facing the global climate change, the study of the water consumption of new varieties and hybrids of crops becomes an urgent problem because of the need for economical use of available water resources in the production process and adaptation of agro-technologies to climate change. The purpose of the research is to study the patterns of water consumption of new varieties of crops on the basis of instrumental daily measurement of the dynamics of components of the total water consumption of crops – evaporation and transpiration under different systems of their fertilizers and different levels of soil moisture. The developed method of instrumental measurement of the components of total water consumption is based on the use of ceramic membranes to automatically maintain different levels of soil moisture in the field vegetation experience under the influence of natural climatic factors. A two-factor vegetation experiment allows a comparative analysis of the structure of water consumption of crops at different levels of soil moisture and different fertilizer systems. The constructive decisions and history of creation and formation of field vegetation experiments with controlled level of soil moisture supply, their advantages and disadvantages are presented. Since 2017, the field of vegetation field experiments has functioned on a permanent basis in the village of Gora, Boryspil district, Kiev region. The advantage of these experiments is the high reliability of the obtained patterns, which provides a sufficient number of replicates in each variant; instrumental measurement of constituents of water consumption – evaporation from soil, total water consumption and, by difference, transpiration of plants that can be monitored on a daily basis, and even on an hourly basis; the dual action of the moisture supply device allows both to supply water to the soil and to divert excess water after precipitation to the storage tanks, which prevents anaerobiosis in the soil. According to the results of the conducted experiments, regularities of fundamental character were established: the ratio of evaporation and transpiration during the period of vegetation of crops was quantified; the influence of different fertilizer systems on the components of total water consumption of crops has been reliably established, in particular the influence of microbiological preparations and the participation of soil biota in the water consumption have been proved; factor analysis proved the equivalence of moisture supply factors (38 %) and fertilizer (36 %) on buckwheat grain productivity; under conditions of guaranteed moisture supply, soil biota improves soil fertility parameters. Conclusions. The fundamental result of vegetation experiments is the reliable establishment of the influence of different fertilizer systems on the components of water consumption of crops and in particular microbiological preparations, the participation of soil biota in soil moisture consumption, as well as its positive effect on the growth of the parameters of soil fertility substance, most likely due to the development of micro- and mesobiota (algae, moss, etc.) under conditions of guaranteed soil moisture. The method of conducting field vegetation experiments with regulation of soil moisture level developed at the Institute of Water Problems and Land Reclamation is indispensable for instrumental study of the patterns of evaporation and transpiration during the growing season of agricultural crops, which are further used in the scenario modeling of agrotechnological technologies. also rainfed agriculture for long-term forecasts of security and the growing season, which is aimed at the economical use of moisture in the production process.The possibility of a direct comparative assessment of water consumption of different new varieties and hybrids of crops at different levels of soil moisture in the field vegetation experiment remains unrealized.Field vegetation experiment has a high demonstration and educational potential for teaching undergraduate and graduate students.