Quantitative observation on the root system of various crops growing in the field

Abstract

Abstract 1. Rice (flooded), wheat, maize, soybean, potato, and sugarbeet were grown in fields with and without nitrogen application, and various traits of the root system were quantitatively measured at the growth stage when the root system had fully developed. 2. The total length of the whole root system per unit field area ranged from 21 (potato) to 86 (wheat) km-m−2. The total surface area was only 22 m2-m−2 in potato and about 90 m2-m−2 in rice, wheat, and maize. The total volume was in the range of 1.8 (potato) to 13 (maize) liters -m−2. The mean diameter was 0.56 mm in maize and 0.33-0.39 mm in the other crops. These values generally increased when nitrogen was applied. 3. The root system was shallower in rice, and deeper in maize than in the other crops. Soil depth where 90% of the roots were distributed was 23 cm in rice, 35-38 cm in potato and soybean, 48-51 cm in sugarbeet and wheat, and 59 cm in maize. 4. The root density (value of various root traits per unit soil volume) in the upper soil lay...