绿肥植物田菁的化感效应及对土壤肥力的影响

实验研究了自然条件下原位提取的田菁(Sesbania cannabina)淋溶液和田菁秸秆模拟还田对不同类型受体植物三叶鬼针草(Bidens pilosa)、稗草(Echinochloa crusgalli)和萝卜(Raphanus sativus)的生长及土壤性质的影响,旨在从化感作用角度综合评价田菁作为绿肥栽培时的生态效应。结果表明:原位提取的田菁淋溶液和模拟还田的田菁秸秆(根、茎、叶)对发育初期的受体植物三叶鬼针草、稗草和萝卜的生长具有一定的抑制作用,尤其对于稗草的抑制效果表现最强;然而对于受体植物生长的土壤,其土壤微生物数量和土壤酶活性显著增加,此外田间野外调查进一步证实了田菁对提高土壤肥力具有显著的促进效果。因此,合理利用田菁秸秆资源不仅能抑制杂草生长,还增加了土壤酶活性和土壤微生物量,促进了土壤的代谢,显著提高了土壤肥力水平。

Allelopathic Effect of Green Manure Sesbania and Its Impact on Soil Fertility

A natural in-situ extraction was conducted to study the effects of exudates and returning residue to field from sesbania(Sesbania cannabina) on growth of Bidens pilosa, Echinochloa crusgalli, Raphanus sativus and soil environment. We focus on allelopathic perspective to evaluate the ecological effects of Sesbania which was applied to green manure cultivation. The results showed that a natural in-situ exudates and returning residue of sesbania inhibited plant growth, especially in Echinochloa crusgalli. However, increased significantly of soil microbial and enzfyme activities were better by exudates and returning residue of sesbania than control. The positive impact caused by improve soil fertility (confirmed by field investigation) was demonstrated to be highly ef?cient not only for soil microbial, but also for soil enzfyme activities. That is a known precursor for sesbania residues resources apply to inhibit weed growth and improved soil fertility.