土壤熏蒸－微生物有机肥联用对连作马铃薯生长和土壤生化性质的影响

摘要

The yellow river irrigation areas in the central Gansu Province are the main potato growing and pro-cessing regions in China.However,continuous cropping has resulted in production losses and impaired the de- velopment of the potato industry in the region.A field experiment was conducted to evaluate the effectiveness of a combination of soil fumigation and bio-organic fertilizer application to increase yields through increased crop growth and suppression of soil-borne pathogens.Five treatment combinations including control (CK),soil fumigation using aqueous ammonia (SFA),soil fumigation plus lime and ammonium bicarbonate (SFB),a combination of SFA and bio-organic fertilizer application (SFA+BOF),and a combination of SFB and bio-or-ganic fertilizer application (SFB+BOF),were utilised.Compared with CK,SFA+BOF and SFB+BOF treat-ments significantly increased tuber yield by 13.62% and 20.36%,decreased the incidence of diseased plants by 54.9% and 72.8%,and decreased the ratio of diseased tuber by 66.15% and 64.76%,respectively.Addition-ally,SFA+BOF and SFB+BOF treatments significantly increased leaf chlorophyll content and improved the morphological characteristics of potato roots.Compared with CK,SFA+BOF and SFB+BOF treatments in-creased soil bacteria and actinomycetes and decreased fungi populations.In particular,these treatments signifi-cantly decreased Fusarium sp.which reduced the incidence of diseased plants during crop growth and increased tuber yields.Neither treatment influenced soil enzyme activity but both treatments significantly increased soil phosphatase activity.Our results indicated that a combination of soil fumigation and bio-organic fertilizer appli-cation may potentially be used to control soil borne fungal diseases in potatoes.%甘肃省中部沿黄灌区是全国重要的加工型马铃薯生产基地，但因集约化种植带来的连作障碍问题已严重影响到产业的健康发展，因而寻求能够缓解或克服马铃薯连作障碍的有效措施。本研究评估了土壤熏蒸和微生物有机肥联用的方法对马铃薯连作障碍的防控效果，特别是对植株生长发育、土传病害抑制以及微生物区系和酶活性等土壤生化性质的影响。田间试验共设置5个处理：对照（CK）、氨水熏蒸（SFA）、石灰＋碳铵熏蒸（SFB）、氨水熏蒸与微生物有机肥联用（SFA＋BOF）、石灰＋碳铵熏蒸与微生物有机肥联用（SFB＋BOF）。结果表明，SFA＋BOF和 SFB＋BOF 处理较 CK 均显著增加连作马铃薯的块茎产量，增幅分别达到13．62％和20．36％，也显著降低植株的发病率（54．92％和72．82％）和收获后的病薯率（66．15％和64．76％），并且提高叶绿素含量和改善根系形态结构。SFA＋BOF 和 SFB＋BOF 处理显著影响土壤可培养微生物的数量，表现为增加马铃薯生育后期土壤细菌和放线菌的数量，降低真菌的数量，在土壤中维持一个更高的细菌／真菌。与 CK、SFA 和 SFB 处理相比，SFA＋BOF 和SFB＋BOF 处理大幅度降低了连作马铃薯生育期内主要土传致病菌———镰刀菌的数量，使植株发病率降低且块茎产量显著增加。SFA＋BOF 和 SFB＋BOF 处理对连作土壤脲酶、蔗糖酶、脱氢酶和过氧化氢酶的活性无显著影响，但显著提高磷酸酶的活性。因此，土壤熏蒸和微生物有机肥联用的方法在克服甘肃省中部沿黄灌区的马铃薯连作障碍上具有较大的应用潜力，且石灰＋碳铵熏蒸与微生物有机肥联用的效果优于氨水熏蒸与微生物有机肥联用。