It was established that there are significant changes in hydrothermal indicators over the past thirty years in the south of the Steppe. During the growing seasons of 1963/64–1989/90, the average annual air temperature was 9.6 °С, in 1990/91–2019/20 – 11.3 °C. Average annual precipitation in 1957/58–1989/90 was 456.1 mm, 1990/91–2019/20 – 400.5 mm. Thus, the increase in climate aridity over the last thirty years is obvious: the average annual precipitation has decreased by 55.6 mm, and the average annual air temperature has increased by 1.7 °C. During the growing seasons of 1990/91–2019/20, scientific research found that water consumption by wheat plants after black fallow during the growing season decreased to 2536–2811 m3/ha in the Steppe zone. Moisture was most efficiently consumed by crops at sowing on September 25 (background N40P40K40, seed rate – 4.5 million germinable seeds/ha): total water consumption was 2605 m3/ha, water consumption coefficient – 428 m3/t, grain yield – 6,08 t/ha. According to 28-year-old data, it was found that the available moisture reserves in the 0-10 cm soil layer on black fallow, as the most stable predecessor on water availability of soil, equaled 10.2 mm and ensured almost annual obtainment of full winter wheat seedlings. It was found that the winter wheat plants did not evenly consume moisture during the growing season: in the autumn period – 8.0–19.2 % of the total water consumption, resumption of spring growing season – beginning of stem elongation – 28.3–30.9 %, stem elongation – beginning of heading – 22.1–24.2 %, heading – full ripeness – 30.0–36.9 %. According to the research results, it was proposed the measures to minimize the negative impact of further climate aridity increase by an increase in the autumn-winter precipitation absorption by soil, an improvement of the agrophysical soil properties and its water permeability, the introduction of varieties with a more pronounced xeromorphic structure and an increased level of adaptation to arid conditions of the Steppe zone and resistance to abiotic stress factors. Key words: predecessors, sowing dates, productive moisture reserves in the soil, water consumption, yield, winter wheat, water consumption coefficient.

During 2000–2018, the results of the application of organic and mineral fertilizers in dynamics and their effect on the content of humus and nutrients in the soils of the Zaporizhzhya region were reviewed. To control the state of soil fertility use the calculation of the balance of humus and nutrients. This makes it possible to determine the extent to which the application of nutrients with fertilizers covers their removal by crop yields. Negative tendencies have been identified, which have led to the deterioration of soil fertility in the Zaporizhia region. Measures are proposed to achieve a deficit-free balance of humus and nutrients. On average, in 2000–2018, the level of mineral fertilizer application in the Zaporizhia region remained low – 38 kg/ha (nitrogen – 28 kg, phosphorus – 7, potassium – 3 kg), and manure – only 0.2 t/ha. According to the results of agrochemical certification of agricultural lands, the dynamics of changes in the content of humus, easily hydrolyzed nitrogen, mobile compounds of phosphorus and potassium over the past 18 years has been determined. The average weighted content of humus in the soils in the VIII round was 3.44 %, IX – 3.52, X – 3.40, XI (2016–2018) – 3.57 %, which indicates the stability of this indicator. The weighted average nitrogen content, which is easily hydrolyzed during all rounds, has close values (83.6–90.3 mg/kg) and corresponds to a low level of its supply. The content of mobile phosphorus compounds during the VIII – IX rounds was quite stable (97.1–101.6 mg/kg), and in the X–XI rounds there was even an increase to 123.3–123.4 mg/kg. The phosphorus regime of soils is stable and corresponds to the increased level of security, except for the ninth round (average). Potassium regime of the soil for eighteen years also remains stable and refers to a high level of security (159.6–176.8 mg/kg). The balance of humus and nutrients in the soils of the region remains negative. There is a tendency of positive changes if we compare the results for the first (2003–2014) and second (2003–2018) periods. Thus, to achieve a positive balance of humus it is necessary to apply 2 t/ha of straw (+400 kg/ha), 20 kg/ha of nitrogen fertilizers and 6.4 t/ha of manure, and in 2003–2018 – respectively 2 t / ha straw (+400 kg/ha), 20 kg/ha of nitrogen, 5.8 t/ha of manure. Key words: soil, balance, dynamics, humus, fertility, organic and mineral fertilizers.