【摘要】 【目的】探究不同区域草莓连作障碍的发生原因。【方法】用典型调查法调查并统计江苏省邳州港上镇、东海石榴镇和溧水白马镇草莓连作土壤的养分含量及微生物区系,并采集当地连作土与非连作土盆栽草莓,观察植株茎粗、鲜质量、株高、根长和根质量的生长状况。【结果】港上镇和石榴镇的草莓连作土壤有机质和碱解氮含量缺乏;港上镇0～10 cm土层的土壤有机质,有效钙、镁、铁和硼含量比10～20 cm土层低10.50%～54.65%,根际土壤养分流失严重;港上镇土壤有效锰含量缺乏,白马镇的土壤硼含量很缺乏;港上镇和白马镇的草莓连作土壤已发生轻度盐渍化,石榴镇土壤已发生中度盐渍化;各地连作土壤微生物均以细菌为主,真菌的数量最低;连作会给植株茎粗、鲜质量、株高、根质量和根长带来显著的负影响。【结论】草莓连作会使土壤理化性质改变、养分失衡以及微生物群落结构失衡,影响植株生长。生产上应尽可能采取措施避免连作,并及时对连作土壤进行修复改良。更多还原

【Abstract】 【Objective】In recent years,different levels of continuous cropping obstacles have occurred in strawberry production in China.Continuous cropping reduces the content of soil organic matter and leads to increasing shortage of trace elements.It may also cause imbalance of microbial structure in the soil.As a result,strawberry plants become susceptible to pests and diseases that cause huge losses for strawberry producers.In our study,soils of continuous cropping of strawberry were collected from Gangshang town,Shiliu town,and Baima town,which are the main strawberry producing areas in Jiangsu province.By investigating the nutrient contents and microflora status of the continuous cropping soils at different depths in these areas,we planned to analyze the effect of continuous cropping on strawberry plants,understand the mechanisms of continuous cropping obstacles,find countermeasures,as well as provide a theoretical basis for overcoming continuous cropping obstacles in strawberry.【Methods】Soil samples were collected from strawberry greenhouses in Gangshang town,Shiliu town,and Baima town in Jiangsu province at the end of May 2016,and these areas have been continuously cropping strawberries for more than seven years.The greenhouses at different locations in each region were used and the soils of 0 to 10 cm,10 to 20 cm,and 20 to 30 cm in depths were collected using a five-point sampling method.The soil samples were divided into two equal parts,one of which was used to detect soil microorganisms,and the other was used to determine soil physical and chemical properties.On September 5 th of the same year,20 strawberry plants were planted in continuous cropping soils collected from each area in a potted manner,and the non-continuous cropping soils in the same area were used as the experimental control.Three replicates were conducted in this experiment.On the 57 th day after planting(November 1 st),the status of plant growth was investigated.【Results】The organic matter content(g · kg-1) of the surface soils(0 to 20 cm) in Gangshang town,Shiliu town,and Baima town was18.40±5.42,18.26±1.28,and 28.63±8.04,respectively,and the organic matter in Gangshang town and Shiliu town is in shortage.As the depth of the soil increased,the organic matter content in Shiliu town and Baima town showed a decreasing trend,while it increased first and then decreased in Gangshang town.The content of available nitrogen(mg · kg-1) in the surface of Gangshang town,Shiliu town,and Baima town was 75.37±1.24,81.25±3.09,and 113.75±14.21,respectively,and the available nitrogen in Gangshang town and Shiliu town is relatively in shortage,and the content of available nitrogen in Baima town is moderate.The available soil nitrogen in the three regions was mainly concentrated in the 0 to 20 cm soil layer,and the available nitrogen content in the deeper soil layer decreased by 33%-45%.The available manganese content(mg · kg-1) in the surface of Gangshang town,Shiliu town,and Baima town was 3.76±0.56,44.15±3.20,and 13.06±0.85,respectively,corresponding to lacking,abundant,and moderate,respectively.The boron concentration(mg · kg-1) in continuous cropping soil in Gangshang town,Shiliu town,and Baima town was 0.63±0.27,0.51±0.03 and 0.25±0.03,respectively.The soil boron was moderate in Gangshang town and Shiliu town,but lacking in Baima town.The contents of available potassium,phosphorus,magnesium,iron and zinc were very high in the three regions.The result of soil electrical conductivity(EC) showed that the continuous cropping soils in Gangshang town and Baima town had mild salinization,and the soils in Shiliu town had moderate salinization.Soils in Gangshang town and Shiliu town were neutral in pH,while soils in Baima town belonged to the slightly alkaline soil.As the depth of soil increased,the abundance of soil actinomycetes in Gangshang town,Shiliu town and Baima town showed a decreasing trend;the abundance of soil bacteria in Gangshang town and Shiliu town tended to decrease;while that in Baima town increased.Interestingly,with the deepening of the soils,the abundance of fungi in Gangshang town first decreased and then increased;that in the Shiliu town showed a decreasing trend,while soils in Baima town showed an increasing trend.【Conclusion】Continuous cropping results in the loss of soil nutrients and the imbalance of microbial community structure,which will have a significant impact on strawberry production.As long as possible,continuous cropping should be avoided in the production,and soil improvement should be conducted in time.更多还原