我们在作共生固氮根瘤菌移植基础试验时发现,在黄砂中栽培的大豆根系,由原来的直根系变成了须根系。我们曾作了24次重复试验,结果在粘土、稻田土、河沙中栽培的大豆根系,主、侧根有区别;在黄沙中栽培其根系没有主、侧根区别,侧根长达20厘米。上述试验虽然简单,但却证实了植物的侧根在某种条件下可以抑制主根的生长。现在我们又根据水、肥、土质等条件对根顶端优势的影响;生长激素及其他激素浓度变化及地心引 As a basic experiment on transplantation of symbiotic nitrogen-fixing rhizobia, we found that the root system of soybean cultivated in yellow sand changed from straight root system to fibrous root system. We have made 24 repeated tests, the results in clay, paddy soil, river sand cultivation in soybean root, main, lateral root difference; cultivation in the yellow sand root system is not the main difference between the lateral roots, lateral roots up to 20 cm. Although the above experiment is simple, it confirms that the lateral root of the plant can inhibit the growth of the main root under certain conditions. Now we also according to the water, fertilizer, soil and other conditions on the root tip of the advantages; growth hormone and other hormone concentrations and geocentric