Структурно-агрегатний склад чорнозему типового за різних систем обробітку ґрунту

Abstract

It has been noticed the improvement of soil macro-aggregates and soil structure rating of typical chernozem under minimum deep and shallow tillage in comparison with plowing. A long-term field experiment of Soil science and Soil conservation Department NUBiP of Ukraine was conducted on typical chernozem in the Forest-Steppe zone of Ukraine near town of Vekykosnyatinskiy, Kyiv region. Soil type was determined according to FAO soil classification as Haplic Chernozem (Typical Chernozem – in Ukrainian Soil Classification) or Mollisol. Plots were 8 by 30 m and fertilized annually with 87 kg N ha-1 , 68 kg P2O5 ha-1 and 68 kg K2O ha-1 on the background of winter wheat straw 1,2 t ha-1 yr -1 + green manure. Tillage treatments included conventional technology, based on deep plowing (25-30 cm), the deep minimum soil tillage to the depth of 25-30 cm, reduced minimum soil tillage to the depth of 10–12 cm. A plant was corn for grain.Tillage practices impacted on soil aggregates distribution in different layers of typical chernozem. Soil aggregates larger than 10 mm in upper horizon were crashed by field machinery in the spring-summer period. By this reason the content of macroaggregates in 0–5 cm soil layer was minimal but increased downwards the soil profile. At the same time the amount of the smallest <0,25 mm fraction taken from that soil horizon was the greatest. Variants from minimum tillage and deep minimum tillage formed the most valuable 10–0,25 mm mesoaggregates on a large quantity versus to plowing: 77,04 %, 79,71 % versus 74,83 % in 0–5 cm layer; 72,94 %, 76,81 % versus 70,73 % in 5–10 cm layer, 73,82 %, 62,69 % versus 66,38 % in 10–20 cm layer and 75,64 %, 71,1 % versus 64,81 % in 20–40 cm soil layer. The amount of deflation proof aggregates larger than 1 mm from 0–10 cm soil layer was the greatest under deep minimum tillage – 76,57 %. Soil organic matter content was greater under minimum tillage in 0–10 cm layer and deep minimum tillage in 10–20 cm layer. Corn yield was similar on variants without fertilizers and greater under deep tillage on fertilizer variant. Our findings demonstrate that the use of tillage practices strongly influences on the soil aggregates distribution in different layers of typical chernozem. Agronomical valuable 10–0,25 mm were formed much better under minimum tillage. The difference in soil aggregates distribution among tillage treatments did not significantly affect the level of structural coefficient.

Установлено улучшение макроагрегатного состава и коэффициента структурности чернозема типичного при глубокой и мелкой плоскорезной обработке почвы в сравнении со вспашкой.

Установлено покращення макроагрегатного складу і коефіцієнта структурності чорнозему типового за глибокого і мілкого плоскорізного обробітку ґрунту порівняно з оранкою.