SEASONAL REGULARITIES OF MICRORELIEF ELEMENTS INFLUENCE ON THE STATE OF WINTER WHEAT CROPS

Abstract

 It is established that the microdepressions are the most widespread phenomena of zonal soil combinations in the Forest-Steppe zone of Ukraine. They are represented by rather large combinations of zonal soils: different subtypes of gray forest soils and chernozem.  It is revealed that fairly common heterogeneities of various forms and depths have become the cause of the variegated field crop rotation of the research farm. Borders of microdepressions indicate a change in the soil properties , the nature of the state of plants and their yields.

The main factor of influence is the hydrological regime of microdepressions, which differs significantly from the water regime of the plains. Depending on the redistribution of moisture across the field, varies the physiological state of plants, biological activity of the soil and grain quality indicators changes.

The article deals with the distribution of microdepressions in the fields of RF "Velikosnitinske" in the Fastovsky district of the Kiev region and analyzes the seasonal regularities of the influence of these microscales on winter wheat sowing state. The studies were carried out using ground-based field and laboratory methods, as well as aerovisual observations of the quadrocopter.

The basis for the study was a preliminary familiarization with the soil maps of the economy and additional field studies, during which numerous microdepressions of various shapes and depths were identified. The area of the agro-research field is 32 hectares. The territory is represented by a large variegated cover in flat areas, is caused by nanorelief and very slightly pronounced depressions with a depth of up to 20-30 cm. Key factor in the formation of heterogeneities here is the specific water regime of the elements of the relief. This is due to the uneven redistribution of atmospheric precipitation over the surface of the territories, which in turn leads to a concentration of moisture in barely noticeable nanoscales and microscales, its filtration deep into the soil profile, washing out the products of soil formation to a noticeable depth.

The spatial heterogeneity of the water regime of such territories leads to the same heterogeneity of soil fertility and crop yields. Using ground-based field research and laboratory methods of analysis with the involvement of robotics, namely quadrocopter, it was possible to analyze seasonally  patterns of the microscales influence on the state of winter wheat «Merlena» variety.

In the course of the research, the yields of wheat within the  microdepression border and on the plain, the quality and quantity of gluten were compared, and the soil was analyzed for biological activity.

At the end of March 2017 the physiological state of wheat within the microdepression was generally suppressed. The situation changed in summer, when because of  relatively dry weather conditions , agroecological state of the vegetation and soil state of the microdepressions was even in better condition than on the plain (control plot). This increased the productivity of wheat within the microdepressions, in comparison with the control plains area.

A complex approach to the study  of fields productivity problem with available microdepressions of the relief, made it possible to establish a interconnection between the water regime features of experimental field and the agroecological state of vegetation and the individual elements of microdepression soil. It is necessary to continue the research to find new approaches for conducting accurate farming and increasing the productivity of agricultural production.