Humus state of chernozem at different ways of tillage in the agrosystems of the left-bank forest steppe of Ukraine
Agricultural science and practice
Aim. To demonstrate the long-term effect of different ways of tillage of typical low-humus chernozem on the change in humus content and composition and the direction of transformation processes of organic fertilizers. To study the changes in the structure of energy reserves in group and fractional composition of humus in typical low-humus light-loamy chernozem of the Forest-Steppe of Ukraine. Methods. Field, laboratory, microbiological, computational, mathematical and statistical. Results. It
... s determined that in conditions of long-term subsurface tillage the most ef cient humus accumulation occurs in the 0-20 cm layer of chernozem with simultaneous increase in its content in the lower part of the processed layer without any accumulation differentiation. Surface tillage leads to expressed differentiation in humus accumulation in the 0-20 cm layer of soil (0.005 % per year). When 6 t/ha of humus are replaced by 7 t/ha of by-products the intensity of humus accumulation is decreasing regardless of the way of tillage, but humus accumulation was found to be the most ef cient for subsurface tillage. The application of subsurface tillage leads to the increase in the ratio of C HA : C FA , which is conditioned by the increase in the humi cation of plant remains of by-products in the 0 20 cm layer of soil by 110-112 % -for subsurface tillage, and by 105 % -for surface tillage. Conclusions. It was established that systematic subsurface tillage of typical chernozem of the Left-Bank Forest-Steppe of Ukraine leads to the structuring both of the total reserves of energy org , and its quality content, aimed at the increase in the intensity of the processes of humi cation and accumulation of organic carbon, and the decrease in mineralization. The ratio of energy reserves org of humic acids to fulvic acids in the 0 30 cm layer of chernozem is 1.85 1.87 regardless of the way of tillage, which testi es to the repeatability of humus accumulation, but the total reserves of energy org was higher for subsurface tillage (+ 31 Teracalorie/ha) compared to deep ploughing. As for the surface tillage, the energy enrichment was at the level of deep ploughing.