不同农业措施对草莓连作土壤状况的影响

Effects of Different Agronomic Measures on Strawberry Continuous Cropping Soil

为探究不同农业措施对土壤环境的影响,本研究以北京昌平连作多年的草莓土壤为研究对象,通过设置田间试验,以夏季闲置为对照,选用草莓与水稻轮作和氯化苦消毒两种农业措施,研究其对草莓连作土壤理化性质、酶活性及微生物群落的影响,以期为改善温室草莓土壤连作障碍,筛选出适宜的农业措施。结果表明:与夏季闲置相比,草莓-水稻轮作后,表层土壤(0~20 cm)的理化性质发生了改变,其中pH提高3.18%,铵态氮含量增加44.3%,盐分积累降低33%,硝态氮降低21.23%;同时土壤脲酶活性提高6.1%、过氧化氢酶活性提高23.4%;此外土壤细菌数量增加9.86%,细菌/真菌比值提高1倍,促进菌群由“真菌型”向“细菌型”转变,有效降低土传病害发生。而草莓-氯化苦消毒,可有效杀灭96.7%真菌,防止土传病害发生,但对酶活性具有一定抑制作用,对其他菌群也具有较强杀灭作用,影响土壤生态平衡。因此,草莓与水稻轮作作为一种非化学土壤消毒方法,在改良土壤、连作地土传病原菌的防治具有较大的潜力,为实现连作草莓土传病害的绿色防控提供了新途径。

To explore the impact of different agronomic measures on soil environment,the strawberry field in Changping of Beijing,which has continuous cropping of strawberry for many years,was taken as research object.Field experiment with summer fallowing as control was established to investigate the impact of two different agronomic measures,which were strawberry-rice rotation and soil disinfection with chloropicrin fumigation,on the soil physical and chemical properties,enzyme activities and microbial flora.The results showed that:compared with those under summer fallowing,soil pH and ammonium nitrogen of topsoil(0-20 cm)under strawberry-rice rotation increased by 3.18%and 44.3%,respectively,but salt accumulation and nitrate nitrogen decreased by 33%and 21.23%,respectively.Both the peroxidase and urease activity increased by 23.4%and 6.1%,respectively,while the number of soil bacteria and the ratio of bacteria/fungi increased by 9.86%and 100%,respectively,indicating that the soil changed from fungi type to bacteria type,and soil-borne diseases were reduced.Soil disinfection with chloropicrin fumigation could effectively kill 96.7%of fungi and prevent soil diseases.But soil disinfection could kill other soil microbes and disturb soil balance.Therefore,strawberry-rice rotation has great potential to control soil-borne pathogens in continuous cropping soil and could improve soil condition as a non-chemical method of agriculture,and it will be a new way of green control of soil-borne diseases.