生姜水浸液对生姜幼苗根际土壤酶活性、微生物群落结构及土壤养分的影响

Abstract

Ginger(Zingiber officinale) is an important horticultural crop in tropical Southeast Asia.However,the main problem for ginger culture is that ginger is not suitable for continuous cropping and ginger yields are low when this species is cultivated consecutively for years on the same land and rotated with other crops for not more than three years.Ginger aqueous extract can inhibit seed germination and seedling growth of soybean and chive,it also can depress the growth of ginger seedlings.However,allelochemicals in this plant species are unclear,and the effects of ginger aqueous extracts on soil enzyme activity,soil nutrient content and microbial numbers are not well-understood.Therefore,the objectives of the paper were to(1) study the effects of rhizome,stem and leaf aqueous extracts of ginger at different concentrations(10、20、40 and 80 g/L) on microbe number,enzyme activities and nutrient content in the rhizosphere soil of ginger seedlings using a potted planting experiment,and(2) reveal allelochemicals in the rhizome,stem and leaf of the ginger aqueous extracts by HPLC.The results indicated that the rhizome,stem and leaf ginger aqueous extracts had different effect on six soil enzyme activities(urease,denitrifying,acid phosphatase,proteinase,polyphenol oxidase,invertase).Acid phosphatase and invertase were impacted most strongly,and significantly stimulated when the aqueous extract concentration over 10 g/L.Six soil enzyme activities increased with the concentration of the aqueous extracts.Bacterial and fungi numbers increased,while antinomyces decreased with the concentration of the aqueous extracts of the identical ginger parts.The ginger aqueous extracts reduced soil organic matter content,and promoted NO-3-N accumulation in the soil.Rhizome aqueous extract had similar effects on available P,available K and NH+4-N in the soil,i.e.,nutrient content were increased at the lower concentrations,and decreased at the higher concentration.The main allelopathic components of three types of the aqueous extracts were as follows: syringic acid and vmbelliferone were mainly contained in the rhizome extract,while frulic acid was mainly in the stem extract where whose content was the highest(73.4 μg/g).The other six substances were detected,except for frulic acid in the ginger aqueous extracts,but the contents of syringic acid,vmbelliferone and p-coumaric acid were relatively higher.The result suggested that allelochemicals released from the ginger deteriorated chemical and biological properties in the soils of ginger land and resulted in the continuous cropping obstacle of ginger plants.The study could benefit for the development of sustainable management in the ginger planting.