土壤中风沙土含量对甜叶菊(Stevia rebaudiana)生长的影响

Effect of Farmland Sediment Concentration on Stevia Rebaudiana Growth

农田土壤中风沙土的含量影响土壤机械组成、养分水分含量、离子交换等土壤性质和植物的生长。通过在耕种多年的农田土壤中添加不同比例的风沙土（风沙土/（风沙土＋壤土）=0、20%、40%、60%、80%、100%）,研究土壤含沙量对甜叶菊（Stevia rebaudiana）生长的影响。结果表明：甜叶菊在沙土环境下具有较好的适应性,长势良好,产量较高,是较为理想的沙土环境经济作物。随土壤含沙量的增加,土壤含水量逐渐减少;甜叶菊株高,叶、茎生物量先升高后减少;根系长度逐渐变长,但基径逐渐变细,根部生物量逐渐减少;因此,土壤含沙量对甜叶菊生长的影响可概括为＂低促高抑＂,即存在一个最佳土壤含沙量范围,使得甜叶菊获得最大增产,当土壤含沙量为20%~40%（即沙粒含量68%~77%）时,甜叶菊长势最好,干叶产量显著增长5.7%。

The sediment concentration affects the soil mechanical composition,nutrients,moisture content,ion exchange and plant growth,but the current research on the impact of soil sediment concentration on plant growth are rare.Stevia transplanting seedlings were used in the present study to explore the effect of different sand/soil ratio（clay with no sand;sand/soil=20%,40%,60%,80%;pure-sand）on Stevia growth.Results showed that Stevia was the ideal sand environment economic crops and had a good adaptability,good shape and high yield in sandy soil environment;With the increasing of soil sediment concentration,soil moisture reduced gradually;stevia plant height,leaf and stem biomass increased first after reduction;root length gradually became longer,but base diameter became smaller gradually,root biomass reduced gradually;Therefore,the effect of soil sediment concentration on the growth of stevia can be summarized as ＂low to promote high suppression＂ effect,namely,there was an optimum soil sediment concentration range making Stevia obtain maximum yield,when soil sediment concentration was 20%-40%（that is,the grains of sand content is 68%-77%）can significantly increase yield of Stevia dry leaves by 5.7%.