THE EFFECT OF SPRING WHEAT CULTIVATION METHODS ON SOME FERTILITY INDICATORS OF SOUTHERN CARBONATE CHERNOZEM IN NORTHERN KAZAKHSTANNadezhda Filippova, Galina Churkina, Maral Utebayev, Irina Rukavitsina and Kairat Kunanbayev
The long-term stationary data about the reserves of humus and its group composition in the southern carbonate Haplic Chernozems Pachic (WRB, 2014) in Northern Kazakhstan have been presented. Southern carbonate chernozems are characterized by low humus reserves of 97 t/ha in their natural state. Turning virgin land to arable land has significantly reduced the reserves of organic matter (49.1 â 66.6 t/ha). It has been found that the type of humus in the topsoil of southern carbonate chernozems is fulvate-humate. A two or more times decrease has been found in the content of the labile part of organic matter and humic acids on arable land, compared to virgin land. Of the considered variants, the most optimal one for increasing the yields (0.158 t/ha) and preserving soil fertility (3.26 % of humus) is continuous wheat cultivation with the introduction of fertilizers and herbicides. The use of two-field grain-fallow crop rotation causes irreplaceable loss of organic matter (2.48 %).