In recent years, the structure of sown areas has undergone significant changes in the Rivne region. The areas under warm-season crops such as soy and corn are rapidly growing. Soy accounts for the largest share in the structure of crops – 21%, corn accounts for 14%.
This phenomenon has become possible due to the processes of global climate change. Therefore, the question of assessing climate change and adapting to agriculture in the region is extremely relevant.
Climate change is taking place today, which affects the productivity of agricultural industry and makes it rapidly change its specialization.
Climate change causes changes in agroclimatic conditions of growth, development, and productivity of crops. It manifests in a significant increase in the air temperature in winter months, time displacement of the development of natural processes, the extension of the frost-free period and the duration of the vegetation period of crops, an increase in the heat supply of the growing season, and some changes in moisture) content.
During the last 25 years, a steady increase in the average annual air temperature has been observed. The analysis of climatic changes that took place in the region shows that during this period, the average annual air temperature increased from 7,0оС to 8,5оС. Moreover, the highest temperature rises (2,0-2,3оС) are characteristic of the summer period.
Observations of rainопадівs and their annual dynamics indicate that although their total number for the past 30 years has increased by 8%, their total number in June-July has significantly decreased.
In June, a rapid decrease in the moisture of the soil begins. For example, in this period, the reserves of productive moisture under winter wheat, in the meter-thick layer of soil in the last five years were two times less than 20 years ago. It should also be taken to account that sand and loamy soils, which are characterized by low moisture content, dominate in the region, and therefore zero reserves of productive moisture not only in the arable land but also in the meter-thick layers of soil are common for Polisia.
The improvement of the heat supply in the region has significant positive effects. In particular, the sowing areas of corn and soy are expanding, and there is a possibility of growing sunflowers. It also became possible to grow their more advanced varieties and hybrids, which are more productive.
Scientists at the Institute of Agriculture of Western Polesia began to consider the problem of climate change from the angle of diversification of the plants, that is, adaptation to new weather conditions and growing new non-typical for the region crops. A demonstration ground was created to compare the productivity of typical for the region crops and new crops. Peas, soybeans, corn, sunflower, sorghum, pickles, lentils, chickpeas, as well as peanuts and sesame seeds, are grown there.
The complete maturation for any plant is conditioned by the sum of the effective temperatures during the period of its vegetation. For cold-resistant plants – this is the sum of effective temperatures > 50С. The main condition for the successful cultivation of heat-loving crops is the amount of effective air temperatures > 100С (Table 1), as well as seeding in well-heated soil (soil temperature at a depth of 10 cm should not be less than 100С). The need for warmth for crop maturation also depends on the type of the plant. It should be mentioned, that the more time a plant requires for maturation, the more heat it needs. To sum up, in order to adapt to the conditions of insufficient heat supply, thermophilic plants that become mature early or fast are grown.
As you can see from the Table 1, the most heat-loving crops are sesame seeds and peanuts, they need 3000-35000С. However, despite the fact that millet is also a heat-loving culture, due to a very short vegetative period (60-100 days), this plant’s biological need for heat is 1120-15700С, which is the same as for peas, a rather cold-resistant plant.
To grow new, non-typical for the region plants, we should pay the utmost attention to chickpea and lentil. These are legumes; their grain contains 25-34% of protein, which determines their high nutritional value.
Chickpea is a cold resistant crop. Seeds sprout at a temperature of 2-50С. Seeds withstand frosts up to 8-100С below zero. However, during the processes of blooming and formation of the beans chickpeas demand warm weather conditions.
Chickpea is very drought-and heat-resistant. Can withstand air and soil drought, but reacts negatively to excessive moisture, cause, in this case, plants are damaged by diseases. This plant is unpretentious to the soil. Its vegetation period lasts 80-120 days.
Lentil is a more heat-loving plant than a chickpea. Despite the fact that the seed germination temperature is the same as chickpea’s, its plants die at a temperature of 2-30С below zero. Lentil needs a lot of water during the period of germination of seeds and at the beginning of the vegetation. During the period of maturation of the seeds, excessive moisture is harmful, as under such conditions small beans and large vegetative mass are formed.
Chickpea and lentil are cultures that are traditionally grown under dry conditions. Since in recent years, such weather conditions during the period of summer vegetation are observed in the Rivne region, and now it is entirely possible to grow these crops in our country. However, it should be noted that the distribution of crops in agricultural production depends not only on the ability to meet their biological needs but above all on the market conjuncture. Therefore, for today, there no competition between these crops and peas and soybeans traditionally grown in the region.
As for the productivity of new crops in our region, the results will be visible only in the fall, after the harvest. Even a negative result is considered a result by scientists.
Lukashchuk Lyudmila, Deputy Head of Scientific Research at the Institute of Agriculture of Western Polisia, Ph.D. in Agricultural Sciences.
Bratsenuk Volodymyr, the junior researcher at the laboratory for fodder production and bioenergy raw materials at the Institute of Agriculture of Western Polisia.