5Drew M C, Saker L R. Nutrient supply and the growth of the seminal root system in barley: I. The effect of nitrate concentration on the growth of axes and laterals. Journal of Experimental Botany, 1973,24:1 189-1202.
6Anderson E L. Corn root growth and distribution as influenced by tillage and nitrogen fertilization. Agronomy Journal, 1987, 79:544- 549.
7Newman E I. A method for estimating the total length of roots in a sample. Journal of Applied Ecology, 1966, 3: 139-145.
8Shenk M K, Baber S A. Root characteristics of corn genotypes as related to P uptake. Agronomy Journal, 1979, 71: 921 - 924.
9Egbhall B, Maranville J W. Root development and nitrogen influx of corn genotypes grown under combined drought and nitrogen stresses.Agronomy Journal, 1993, 85(1): 147- 152.
10Robert P, DurieuxRP, Kamprath E J, JakcksonWA, Mol1RH.Root distribution of corn: the effect of nitrogen fertilization. Agronomy Journal, 1994, 86: 958-962.
