ASSESSMENT OF CALCULATION ACCURACY OF BUCKWHEAT WATER CONSUMPTION BY BIOCLIMATIC METHODS

Abstract

The accuracy of determining the total water consumption in buckwheat crop sowing was estimated using bioclimatic methods taking into account the sum of daily average temperatures and air humidity deficit (control - water balance method). Field experiments were carried out in 2010 - 2014 on the irrigated plot of DalGAU in the village of Gribsky, Blagoveshchensk district, Amur region. The water regime of the active layer (0.4 m) was maintained by irrigation of at least 70% HB. The fertilizers dose (N40P80K20) is determined to obtain a yield of 1.5 t / ha of grain. The Amurskaya mestnaya variety buckwheat was sown with 0.15 m row-spacings under winter ploughing with a focus on the maximum use of monsoon rains in the first two years of June 15 and 14, and the third and fourth on June 19. Comparison of soil moisture consumption by the sum of daily average temperatures and air humidity deficit during the growing and interphase periods was in favor of the temperature method. Deviations of water consumption, determined by the temperature indicator, did not exceed 10% of the control, while by the sum of air humidity deficits in the interphase periods they exceeded 20%, and in some years even 50%. It has been established that in the conditions of the southern agricultural zone of the Amur Region, the bioclimatic method based on the correlation of soil moisture consumption with the sum of average daily air temperatures gives closer to the control measurement of this indicator by the method of water balance. The temperature bioclimatic coefficient of evaporation is less variable over the years than the coefficient of correlation of soil moisture consumption with the sum of air humidity deficits. The use of short- and medium-term weather forecasts to determine the water consumption flow by cultivated plants makes it possible to plan irrigation dates and program the management of soil water regime.