1. Adaptive Landscape Agricultural Systems of Novosibirsk Oblast (Siberian Scientific Research Institute of Agrochemistry, Novosibirsk, 2002) [in Russian].
2. L. I. Aksent’eva and M. S. Chizhova, “Change of humus formation in chernozem after long-term surface tillage,” Pochvovedenie, No. 2, 69–74 (1986).
3. H. P. Allen, Direct Drilling and Reduced Cultivations (Farming Press, Ipswich, Suffolk, 1981; Agropromizdat, Moscow, 1985).
4. A. I. Baraev, Soil-Protective Agriculture (Agropromizdat, Moscow, 1988) [in Russian].
5. A. F. Viter and A. M. Novichikhin, “Changes in the fertility of ordinary chernozem in the central chernozemic region under the impact of traditional ploughing,” Vestn. S-kh. Nauki, No. 1, 77–84 (1984).