ASSESSMENT OF INFLUENCE OF METEOROLOGICAL FACTORS ON THE YIELD OF BLUE LUPINE IN THE POLISSIA ZONE OF UKRAINE

Abstract

Each component of a coherent range of weather conditions is reflected on growth and development indexes of plants during the relevant time period and, in the end, determines the level of crop yield.

The purpose of this article is to identify the influence of meteorological factors on yield of blue lupine in the conditions of Ukrainian Polissia. Task of research is to determine the dependence of the lupine yield from the complex of meteorological factors in the areas of Polissia zone of Ukraine.

Polissia area in contrast to other soil-climatic zones is characterized by significant heterogeneity in meteorological conditions, for example lower indexes of temperature regime of the vegetation period (14,1-16,0 ^°С), near to the forest-steppe area values of the average temperatures (6,6-9,1 ^°С) and more amplitude of their variations across the regions (from 6,6 ^°С – in Chernihiv to 9,1 ^°С – in the Transcarpathia). This regularity is mostly evident in autumn and winter and is less visible in spring and summer during the active vegetation of agricultural crops.

As to the level of moisture keeping during the calendar year (596-759 mm) and warm period (413-579 mm) the area has advantages over other regions, forming more favourable conditions for the growth and development of plants in most years. The Transcarpathian (852 mm, including warm period – 527 mm), Ivano-Frankivsk (759 and 579 mm) and Lviv (704 and 501 mm) regions have the greatest number of rainfalls, Volyn region has the lowest one (596 mm on the average annually, and 414 mm in the warm period).

Weather conditions in 2005-2015 were mainly determined by the level of influence of the main hydrothermal factors that had a specific differentiation depending on the intensity of each of them. In general, over the research years in the districts of Polissia area the multiplicity of manifestations of unfavourable weather conditions during the vegetation period, which were caused by low or high temperature, ranged from 35 cases in Chernihiv region to 50 – in Ivano-Frankivsk, and were caused by the insufficient and excess rainfalls – from 18 in Volyn and Chernihiv regions to 24 cases in Ivano-Frankivsk region.

The territory of Polissia is characterized by favourable agro-climatic potential for the cultivation of blue lupine of modern varieties. This feature, as well as a large economic value of forage crop and an important replenishment factor of the nitrogen fund of soil stipulated the placement of lupine on large areas in Polissia and forest-steppe zones of our country.

At the present time, particularly in the period 2005–2015, the total area of lupine in the state has varied from 5.4 thousand hectares to 42.7 thousand hectares, including in the Polissia area from 3.6 thousand hectares to 25.2 thousand hectares. At the average country yield in these years (at a level of 10.6–18.3 centner/hectare), including Polissia – 9.5-16.8 centner/hectare, the gross grain harvest of lupine reached the level of 6.58-60,96 thousand of tones in the state and 3,79-of 34.76 thousand of tones in Polissia region. This fact had a positive effect on the stabilization of the production of vegetable protein for feed purposes in the country.

The results of the dependence of yields on weather conditions during 11 years (2005-2015,) cycle in Polissia indicate that in some areas of the zone the lupine yield formation was determined by the weather conditions of April, May, June and July; their level of correlation (R) with yields exceeded a value of 0,667. In General the result is the following: the low level of correlation of weather with culture productivity in the period 2005-2015 was noted in no region. Almost half of the indicators of the correlation coefficient were respectively in the range R = 0,355-0,591 and participation index – 12.6–34.9 %; these facts indicate the presence of trend and average (0,334<R<0,666) communication, but only in some circumstances.

The results about the lupine yield dependence on the actions of individual components of the weather conditions complex (air temperature, rainfall) are confirmed by the differentiation of their effects in accordance with the regions, the observation period and individual months of the growing season. In Polissia the productivity of lupine is largely determined by the effect of the temperature factor during 2005-2015, and by the rainfall factor – to a lesser extent.

Regarding the effect of individual components of the complex of weather conditions on the lupine yield in Polissia, it should be noted that the highest level of responsiveness of the crop to the temperature and humidity in the period 2005-2015. was only in the Transcarpathian region, where the coefficient of correlation between yield and temperature was in the range R=0,838-0,908; D=70,2-82,4%, and rainfall R=0,712-0,897; D=50,7-80,5%. Due to analysis of other areas, in the same period only the conditions of temperature of June in Rivne region (R=0,702; D=49,3%) and April in Chernihiv (R=0,812; D=65,9%) had a significant influence on the yield formation of lupine.

According to the lupine yield dependence on the moisture conditions in 2005–2015 years, the highest rate was noted between productivity and conditions of May in Volyn, Zhytomyr and Lviv regions (R=0,864; 0,796; 0,681, D=74,6; 63,4; 46,4%). In general we can say that the level of correlation of temperature and moisture with yield was observed only in 4 and 6 cases, respectively, and the correlation value (R) exceeded the value of 0,667. The average level of correlation (0,334<R<0,666) between weather factors and crop productivity on the temperature regime was observed in 18 cases, and on water supply – in 12 cases.

According to the criteria of basic meteorological parameters (air temperature, rainfall), according to their deviations from the average multiyear values, the intensity, duration and frequency of unfavourable conditions which are caused by high or low temperatures, in all regions the soil and climatic zone of Polissia of Ukraine during 2005-2015 the increase in the number of cases of their manifestations is observed, which is caused by high air temperatures and excess rainfalls; this fact indicates the existence of a trend of certain change of climatic characteristics in the direction of greater warming and humidification.

Thus, the acreage of crops and their yields depend on the climatic conditions of the year and area of cultivation. That is why it is necessary to create varieties, resistant to adverse weather conditions, which would provide the necessary level of production in conditions of fluctuations of their parameters by maximizing the potential of appropriate cultivation technology in specific soil-climatic zone.