Effects of various fertilizations on soil organic carbon and total nitrogen in winter wheat-summer corn rotation in the Huang-Huai-Hai Plain of China.

摘要

We analyzed the dynamics of grain yields and soil organic carbon and total nitrogen in a long-term fertilization experiment (1991-2008) in winter wheat (Triticum aestivium L.)-summer corn (Zea mays L.) rotation systems in the Huang-Huai-Hai Plain of China. The treatments were inorganic fertilization (N, NK, NP, PK and NPK), inorganic NPK fertilizers and manure combination (MNPK), 150% of the MNPK (1.5MNPK), inorganic NPK fertilizers and straw combination (SNPK), and no fertilization as control (CK). The results showed that almost all the fertilization practices (except N and PK) contributed to increasing trend for the soil organic carbon and the total nitrogen contents over 18 years. Moreover, balance-fertilization (NPK) and NPK fertilizer combined with organic fertilizer continuously lead to high wheat grain yields (6,031-6,700 kg ha-1 for 1991-1999; 5,682-6,226 kg ha-1 for 2000-2008) and corn grain yields (5,895-6,715 kg ha-1 for 1991-1999; 7,344-7,588 kg ha-1 for 2000-2008), and maintain sustainable higher yield increasing rates. Correlation analysis indicated that grain yields have significant (P<0.05) correlations with soil organic carbon, total nitrogen and other soil properties. In addition, application of organic fertilizer combined with inorganic fertilizers greatly improved soil organic carbon and total nitrogen concentrations over the years. Therefore, mixed application of organic and inorganic fertilizers is a suitable practice for food security and soil carbon sequestration in the Huang-Huai-Hai Plain.