Hot water extractable organic carbon of chernozem under the system of cover crop incorporation and subsequent sowing of spring crops

In the agroecological conditions of Vojvodina, there is not enough research on the influence of plowing cover crops as a green manure on the content of labile organic carbon soluble in hot water (HWOC). The aim of the study was to determine the influence of crop rotation of different species of winter cover crops (CC) and spring crops in the subsequent sowing period (corn, soybeans and Sudan grass) on the content of organic matter (OM) levels as well as the dynamic of labile OM. Research was carried out at the Rimski Šančevi experimental station under Chernozem soil type. The winter CC consisted of the combined intercrops: winter pea (Pisum sativum ssp. Arvense L.) + triticale (×Triticosecale Wittm. ex A. Camus) (PT) and single-species CC winter pea (P) and control (without CC). Plowing of CC and control plots was carried out at a depth of 27 cm in the last decades of May 2018, and the sowing of maize, soybean and Sudan grass in early June with addition of 50 kg N ha-1 . Sampled was done in October at depth of: 0-20 cm, 20-40 cm. The analysis of variance determined a significant effect of cultivated crops (maize, soybeans and Sudan grass) in the subsequent sowing period on the changes of the HWOC content, as well as the interaction of cover crops and fertilization. The highest value of HWOC was measured in maize (658 µg g-1 ) on the variant P N0 (0-20 cm), and the lowest in the Sudan grass P N50 (20-40 cm). The highest share of HWOC in the total OM content was found in maize (2.56%), while the lowest share was measured in Sudan grass (1.87%).