大棚蔬菜轮/连作系统土壤肥力与微生物因子综合评价

从土壤肥力与微生物因子探索连茬障碍机理,以期为其提供科学依据。研究草莓番茄轮作(RST)、番茄连作4年(CT4)和番茄连作10年(CT10)3种蔬菜种植模式根际与非根际土壤微生物区系及生理菌群,并对土壤肥力与微生物生物因子进行主成分分析。结果表明根际土壤微生物三大类群和生理菌群数量均高于非根际,根际效应显著。番茄连作根际与非根际土壤细菌和放线菌数量呈现先增加后减少趋势;真菌数量呈线型增加趋势,CT4和CT10在根际与非根际较RST分别增加9.09%和2.11%、75.48%和57.72%。番茄连作根际土壤硝化细菌和好气性自生固氮菌数量的减少,氨化细菌与好气性纤维素分解菌在短期连作表现为增加长期减少的变化趋势;解钾菌、无机磷和有机磷细菌数量在根际与非根际土壤均减少。在6种研究的种植模式中,RST根际土壤状况最好,其次为CT4的根际与RST非根际土壤,CT10的根际土壤、CT4与CT10非根际土壤状况最差。结论是蔬菜连作造成土壤质量下降,连作年限越长下降越显著。

Comprehensive evaluation of soil fertility and microorganisms factors for vegetables rotation and continuous systems in greenhouse

In this study, we analyzed the affect of soil fertility and microorganism on continuous cropping obstacles and these results may provided scientific evidence for mechanism of continuous cropping obstacles. Soil fertility, soil micro flora and microbial physiologic flora from the rhizosphere and bulk soil of strawberry and tomatoes rotation (RST), 4 years continuous tomatoes cropping (CT4) and 10 years continuous tomato cropping (CT10) were analyzed respectively. Several main factors were ana-lyzed by the principal component analysis (PCA). The results showed that the number of micro flora and microbial physiologic flora in rhizosphere were higher than bulk soils, which showed a signifi-cantly rhizosphere effect. The number of bacteria and actinomycetes decreased firstly and then in-creased as continuous cropping years increasing, while the number of fungi showed a linear increase trendency. Compare with RST, the CT4 and CT10 increased by 9.09% and 2.11%, 74.58% and 57.72% in rhizosphere and bulk soils respectively. The number of nitrobacteria and aerobic nitrogen-fixing bacteria decreased as continuous cropping years increasing, while the ammonifying bacteria and aerobic cellulose degrading bacteria increased firstly and then decreased. Solution potassium bacterium, inor-ganic phosphor-bacteria and organic phosphor-bacteria decreased in rhizosphere and bulk soil. Among the three planting systems, RST in the rhizosphere soil is best, follow by CT4 in rhizosphere soil and RST in bulk soil, CT10 in rhizosphere and CT4, CT10 in bulk soils were the worst. Continuous vegeta-ble cropping can cause reduction of the soil quality, the longer the continuous cropping is and the more reduction of soil quality.