中国北方主要作物根系生长的研究

Study on Root Growth of Main Crops in North China

本文对中国北方18种不同类型的作物及2种农田杂草的根系生长深度、生物量与地上部的关系进行了两年观察,所有18种作物及2种杂草根深分布在40～300cm之内,根系最浅的为芝麻,最深的为大麻.一般高秆作物根系相对较深,但矮秆作物也有根深者,如甜菜、花生、小麦等;一般生育期短、耐瘠抗旱喜欢冷凉的作物根系分布较浅.根系深浅与作物类型无关,不论各类、纤维类、豆类、甚至块根块茎类都有深浅之差.所有18种作物株高根深的根冠比平均为2.27,生物量的冠根比平均为7.25;根系垂直分布呈指数递减模式y=A.e^(bx),但不同作物b值不同.二种杂草不论根深及生物量都较大.

Relations of root depth and root biomass to shoot growth of 18 farm crops in North China and 2 weeds were studied in two years (1987-1988). Root depth of all the crops and weeds studied varied from 40 to 300 cm, the root system of sesame being the most shallow one, while that of hemp the deepest. Generally, tall-stemed crops had deeper root system, but some short-statured crops, such as sugarbeet、peanut、wheat etc. , also bear deeper roots. Those crops which were of short growing period, tolerant to poor soil and better adapted to cool environment usually gave shallow root system. However, the root depth was not related to crop types and difference of root depth of existed with in the crop type. The average ratio of root depth to shoot height of 18 farm crops was 2. 29, and the average ratio of shoot biomass to root biomass was 7. 25. The vertical distribution of root system fit a reduction of index model Y = A. e-bx, but the b value varied in different crops. Observation in the two weeds showed that both the depth of root system and root biomass were greater than those of farm crops.