施用蚯蚓粪对杨树苗根际土壤生物学特征的影响

通过盆栽试验,研究了CF(单施化肥)、VC(蚯蚓粪)和VC+CF(蚯蚓粪和化肥各提供50%的氮)处理对一年生欧美I-107杨根际土壤微生物数量、酶活性、根系建造水平及理化性状的影响。结果表明,VC+CF处理有利于协调土壤C/N比,并且化肥的施入补充了土壤中氮的消耗,从而明显提高了根际土壤中微生物数量及脲酶、过氧化氢酶、多酚氧化酶和蔗糖酶活性,其中细菌数量分别比CK,CF和VC处理提高165.99%,67.34%和31.73%,蔗糖酶活性分别提高90.37%,45.31%和32.34%。施用蚯蚓粪有利于杨树苗细根的生长,但对地上部的增长速度显著快于地下部。此外,VC+CF处理使根际土壤pH值明显降低,显著增加了根际土壤中养分离子的有效性。与VC+CF处理相比,VC处理对根际土壤生物学特征的影响较小。因此,蚯蚓粪与化肥配施更好地改善了杨树苗根际区域的微生态环境。

Effects of Vermicompost on Biological Characteristics in Rhizosphere Soil of Poplar Seedlings

A pot experiment was conducted to determine the effects of four treatments, i.e., CK (neither urea nor vermicompost was applied), CF (100% of nitrogen was provided by urea), VC (100% of nitrogen was provided by vermicompost), and VC+CF (two 50% of nitrogen were provided by vermicompost and urea, respectively), on the soil microorganism population, enzyme activities, root construction and physiochemical properties in rhizosphere soil of poplar seedlings. Results showed that the VC+CF treatment was beneficial to coordinate the soil C/N ratio, and the application of inorganic fertilizer could supplement the consumption of nitrogen in the soil. Besides, the microorganism population and the activities of urease enzyme, catalase enzyme, polyphenol oxidase enzyme and invertase enzyme significantly increased. As compared with the CK, CF and VC treatments, the bacteria population in the VC+CF treatment increased by 165.99%, 67.34% and 31.73%, and the invertase enzyme increased by 90.37%, 45.31% and 32.34%, respectively. Vermicompost application had a beneficial effect on the fine root growth, and the aerial part was influenced by vermicompost greater than the under-ground part. Additionally, the VC+CF treatment obviously reduced soil pH value and significantly enhanced the efficiency of nutrient ions in the rhizosphere soil. Compared with the VC+CF treatment, the VC treatment had little effect on soil biological characteristics of one-year poplar seedlings. vermicompost co-applied with inorganic fertilizer had better effect on ecological environment in rhizosphere soil of poplar seedlings.