7Goh K M, Malakouti M J. Preliminary nitrogen, phos- phorus, calcium and magnesium DRIS norms and indices for apple orchards in Canterbury, Newland[J]. Commu- nications in Soil Science and Plant Analysis, 1992,23 (13/14) : 1375 - 1385.
8Cerdd A, Nieves M, Marttnez V. An evaluation of mineralanalysis of ' Vema' Lemons by DRIS [ J ]. Communications in Soil Science and Plant Analysis, 1995, 26 (11/12): 1697 - 1707.
9Nachtigall G R, Dechen A R. DRIS use on apple orchard nutritional evaluation in response to potassium fertiliza- tion[J. Communications in Soil Science and Plant A- nalysis,2007,38(17/18) :2557 - 2566.