Changes in the agrochemical indices of Luvic Greyzemic Phaeozems under the impact of west Ukraine climate aridization

Abstract

Modern agriculture has not been so strongly affected by the climate change we are seeing today. There are no systematic studies and predictions regarding the response of soils to rising air temperatures and changes in the water supply of landscape ecosystems. Ultimately, it is unknown how climate fl uctuations affect the balance of nutrients and humus in soil depending on the crops grown. There is not enough scientifi c data to indicate that warming or aridization affect the effi ciency of plant fertilizers. Our aim is to fi nd out how changes in the climate of the Western Ukrainian mesoclimate interacts with the trends in soil processes and crop yields in the Northwestern Forest-Steppe. We analysed the weather data from 1945–2018 provided by the Rivne State Weather Station (Ukraine) and the crop yields of the Main Directorate of Statistics of Ukraine in Rivne region. Field studies were conducted in the conditions of the Northwestern Forest-Steppe of Ukraine during 1960–2018 at the stationary fi eld experiments of the Luvic Greyzemic Phaeozems (WRB. 2015) of the Institute of Agriculture of the Western Polissia of NAAS (Ukraine). Laboratory analyses were performed using standard techniques. Observations of climatic processes have allowed us to offer polynomial models that confi rm, with high degree of certainty, the steady trend of regional climate change towards warming in the Northwestern Forest Steppe of Ukraine (an average annual temperature R2 = 0.76; the sum of T >5°C R2 = 0.91 and the sum T >10°C R2 = 0.90. Rainfall has declined sharply in the last fi ve years, signifi cantly limiting soil moisture resources. There was a steady tendency towards aridization of the agrolandscape mezoclimate. We cannot say that climate warming has had a signifi cant impact on increasing the nutrient content of soils to contribute to a signifi cant increase in crop yields in the absence of fi eld fertilization. However, crop production of Rivne region (Ukraine), N, P and K application rates have increased periodically over the whole observed period of 1960–2001. There has been a steady upward trend in fertilizer application rates since 2000 and agricultural harvests have been steadily growing together with the warming of the climate zone of the Northwestern Forest Steppe of Ukraine in this period.