7Tully K L, Weil R. Ion-selective electrode offers accurate, inexpensive method for analyzing soil solution nitrate in remote regions [J]. Communications in Soil Science and Plant Analysis, 2014, 45(14) : 1974 -1980.
8Lima J L F C, Rangel A O S S, Souto M R S. Flow injection determination of nitrate in vegetables using a tubular potentiometric detector[ J ]. Journal of Agricultural and Food Chemistry, 1995, 43 (3) : 704 - 707.
9Sibley K J, Astatkie T, Brewster G, et al. Field-scale validation of an automated soil nitrate extraction and measurement system [J3. Precision Agriculture, 2009, 10(2): 162-174.
