Effect of various tillage systems on the agrophysical properties of black soils of the right-bank forest-steppe of Ukraine

Abstract

The article deals with the changes of the basic agrophysical properties of the arable layer of typical black soil (chernozems) within ten-year basic cultivation and fertilization in the five-field grazing crop rotation. The aim of the research was to optimally combine the systems of basic cultivation and fertilization of typical chernozem, which provides the best agrophysical state of the soil and the productivity of field crop rotation at 5.5 t ha-1 of dry matter. We studied four basic cultivating systems and four levels of fertilization of chernozems. The levels of annual fertilization per hectare of arable crop rotation were zero level - without fertilizers; the first level – 8 t ha-1 of cattle manure+N76P64K57; the second – 12 t ha-1 of cattle manure+N95P82K72; the third – 16 t ha-1 of cattle manure+N112P100K86. The research was carried out on the experimental field of the Bila Tserkva National Agrarian University (Ukraine) during 2007- 2017. All the experiments were dealed with typical, black soil with loamy granulometric composition and low cattle manure contamination on a carbonate deposits. The annual introduction of 12 tons of cattle manure+N95P82K72 per 1 hectare of crop ensured a significant improvement in soil structural under moldboard and beardless tillage for 10 years. The arable layer has been substantially compacted only at in uncooled fields with moldboard tillage, while a substantial increase in bulk mass was recorded in all plots with beardless tillage. We obtained the best results on fields with combined tillage with introduction of 12 t ha-1 of cattle manure+N95P82K72 and on the fields with mulching disk tillage with 16 t ha-1 of cattle manure+N112P100K86. The total porosity decreased significantly in all the plots with beardless tillage, in the plots with moldboard and combined tillage fertilized by 8.0 t ha-1 of cattle manure+N76P64K57, and in the no-till plots with introduction of 12 t ha-1 of cattle manure+N95P82K72. We fixed the slight increase of capillary porosity of the arable layer on the plots with moldboard and combined tillage and highest fertilizer rate on the last year of experiments. We observed the stabilization of the least moisture content in the plots with moldboard, mulching, and beardless tillage under the highest fertilizer rate; this was also typical for the plots with combined tillage at introduction of eight t ha-1 of cattle manure+N76P64K57. We estimated a significant decrease in soil permeability in 2017 compared to 2007 in non-fertilized areas and fertilized by 8 t ha-1 of cattle manure+N76P64K57 under beardless and disk tillage. Application of 16 t ha-1 of cattle manure+N112 P100K86 caused the insignificant increase of the soil permeability on the plots with combined and moldboard tillage. We suggested that the productivity of crop rotation was almost equal at the fields with moldboard and combined tillage, but the latter is more energetically effective. We could recommend the combined tillage with a deep plowing in one field and disk (10-12 cm) with beardless (16-18 and 25-27 cm) plowing with application of 12 t ha-1 of cattle manure+N95P82K72.