7Cerrato M E and Blackmer h M. Comparision of mldels for describing com yield response to nitrogen fertilizer[J], hgron.j. , 1990,82(1) :138-143.
8Hamer, P. J. C., A semi-mechanistic model of the phtential growth and yield of Brussets sprouts[J] ,J. Hort. Sci., 1992,67(2):111-169.
9Greenwood, D. J., Kenichi, K., Bums. I. G. and Draycott, A.. Apparent recovery of fertilizer N by vegetable crops[J]. Soil Sci. Plant Nutr., 1989,35 (3) :367-381.
