Hawkins J A, Sawyer J E, Barker D W, et al. Using relative chlorophyll meter values to determine nitrogen application rates for corn. Agronomy Journal, 2007, 99: 1034-1040.
[2]
Zhang J, Alfred M B, Jason W. Sensitivity of chlorophyll meters for diagnosing nitrogen deficiencies of corn in production agriculture. Agronomy Journal, 2008, 100: 543-550.
[3]
Alexandratos N. World Agriculture, Towards 2010, An FAO Study. New York: FAO, Rome, John Wiley& Sons, 1995: 190.
[4]
Dale N. Ingredient analysis table. Feedstuffs, 1997, 69(30): 24-31.
Raun W R, Johnson G V, Westerman R L. Fertilizer nitrogen recovery in long-term continuous winter wheat. Soil Science Society America Journal, 1999, 63(4): 645-650.
Trenton F S, Joseph G L. Corn grain yield response to crop rotation and nitrogen over 35 years. Agronomy Journal, 2008, 100: 643-650.
[10]
Sheri C, Deanna O, Carl C, et al. Winter wheat and maize response to urea ammonium nitrate and a new urea formaldehyde polymer fertilizer. Agronomy Journal, 2007, 99: 1645-1653.
[11]
Anonym. Fertilized to death. Nature, 2003, 425: 894-895.
[12]
Raun W R, Johnson G V. Improving nitrogen use efficiency for cereal production. Agronomy Journal, 1999, 91: 357-363.