Plant nutrition conditions are limited in naturally acidic soil due to harmful hydrogen and aluminium ions. More favourable conditions for plant nutrition (soil liming) will affect root qualitative and quantitative parameters and influence ecosystem stability. Four legume–grass swards were cultivated. The swards were a combination of one species of legume and two species of grasses: Trifolium pratense L., Trifolium repens L., Trifolium hybridum L., Medicago sativa L. (each of 50%) with Phleum pratense L. (35%) and Poa pratensis L. (15%). The aim of this study is to evaluate the root morphological and soil biological indicators of legume–grass swards under the first two years of development in soils with different pH levels. Sward ecosystem development depends on the pH of the soil, sward species composition and soil biota. During the first year of sward development, soil pH had a significant influence on the morphology of root system. Sward‘s root mass and total root length was 2.4 and 2.2 times bigger in naturally acidic soil. This resulted in a change of biological parameters. In the second year of sward development, soil pH had no significant influence on sward‘s root mass. However, under the impact of different soil pH, various sward‘s root systems were formed and the root C:N ratio had changed. It is observed that, regardless of the sward species composition and the year of development, at higher root C:N ratio soil microbial biomass was higher and CO₂ emissions were lower in swards in naturally acidic soils. Regardless of soil pH, different types of clover–grass swards promoted organic carbon immobilization in microbial biomass and, at the same time, stabilized the sward ecosystem in the top soil layer (soil respiration in 0–10 and 10–20 cm layers was lower) more effectively than the alfalfa–grass sward.

For the prevention of hilly soils from erosion, a smart selection of crop rotations is very important. The aim of this study was to investigate the influence of different agrophytocenoses on seed numbers in the soil runoff sediments and soil seed banks’ relations to soil properties in hilly landscapes. This study analyzes long-term monitoring data from three different agrophytocenoses (permanent grassland, cereal–grass crop rotation and crop rotation with a row crop) set up on slopes of 9–11° steepness with collectors for soil and water installed. The soil of the southern exposition slope was a slightly eroded Eutric Retisol. In the soil of permanent grassland, the number of seeds was 4036 seeds m⁻², 6.0 and 3.2 times smaller compared to cereal–grass crop rotation and crop rotation with a row crop. The seeds found in the soil runoff sediments composed, on average, 0.9% of the soil seed bank, and the number of seeds depended on the number of days with heavy precipitation during the plant vegetation period, as well as on the plant communities grown in a particular rotation. Correlation analysis showed the seed numbers’ dependence on the soil’s chemical and physical properties. Hill slopes were not affected by water erosion, when agrophytocenoses were based on perennial grassland and also cereal–grass crop rotation, where reduced soil tillage was applied.

Soil erosion by water is a serious environmental problem. It is very important to form agrophytocenosis, which is productive on hilly terrain and could effectively protect the soil from erosion. The aim of the study was to examine the impact of a hilly relief on the changes of seeds in a soil of pre-erosion cereal-grass crop rotation. The study included different parts of the hill (summit, midslope, and footslope). The southern exposition slope’s soil was slightly eroded Eutric Retisol (loamic) (RT-eu.lo), and the steepness of the slope was 9–11°. The seed bank was investigated at the depths of 0–5 and 5–15 cm. The number of seeds in the soil seed bank during autumn was 20.4% higher than in the spring. The highest number of seeds in the autumn was determined on the summit (40.6 thousand seeds m^–2). The highest count during the spring was determined on the midslope of the hill (36.4 thousand seeds m^–2). In general, in the soil seed bank of the midslope of the hill, the number of seeds was by 7.8% and 42.4% higher compared to the summit and footslope parts. The highest seed reserve was found in the soil at a 0–5 cm depth (59.4% of the total seed number).