MOSCOW, May 29. /TASS/. A scientific team led by Doctor of Geographic Sciences Yury Chendev from Belgorod State University (BelSU) determined the changes that flat black soils had undergone in the Belgorod Region in more than two centuries of landowning and agricultural activities, Belgorod State University’s press office said. The researchers established various facts on black soil degradation and its fertility, as well as factors bringing about an improvement in the soil’s structure.
"Our multi-year research on the transformation of black soil as a result of plowing makes it possible not only for a better understanding of soil formation and the mechanisms of changes in cultivating black soil, but also for formulating the basis and working out a strategy to protect and regenerate this valuable Russian natural resource," Chendev commented.
During the course of their research, four flat black earth plots in the forest steppe in the south of the Belgorod Region were studied. Each plot had included plowed lands of various ages as well as natural soil of similar composition in close proximity to fields untouched by plowing for the sake of comparison. For each area examined, broad and deep soil profile cuts (1.2 cm over 2 meters) were made.
The timelines of land utilizations of all the fields under examination were obtained using various cartographic materials and by questioning local citizens.
"From an agrotechnical point of view, all fields studied took the same path, starting from shallow (up to 15 cm) plowing with the horse-drawn wooden cultivators (until 1930) to tilling with tractors bringing about an increase in the depth of plowing," Chendev noted. "In recent years, various soil-saving techniques were introduced to all the fields."
The outcome of the investigation established the peculiarities of soil evolution for more than 200 years of cultivation. For example, the already-known fact than the losses of nutritious humus in the upper half-meter of plowed black earth soils slow down with time has been proven once again. Moreover, the scientists found out that in the first hundred years of plowing, these losses can be partially compensated with the accumulation of humus in the under-plowing strata.
Together with the signs of degradation in old plowing black soils, the researchers disclosed some points on the improvement of the soil’s properties. For example, the agricultural usage of the field leads to more intensive processing of these areas by subterranean animals, primarily by Spalax. This improves the soil aeration and benefits the germinating power of plants’ root systems.
"The changes uncovered in the various features of black soil’s long-term usage proves that black soil belongs to sophisticated and self-regulating systems. One should take it into account to regulate its yield," Chendev concluded.
The scientists’ work has been published in the May issue of Soil Sciences.