Studies on the sensitive limiting factors of soil fertility for continuous cropping fruits and vegetables in greenhouse | 大棚果蔬连作土壤肥力限制性因子研究

Chinese. 揭示大棚果蔬连作的土壤肥力限制性因子，为大棚果蔬的连作经营提供参考。以草莓番茄轮作(RST)为对照，研究草莓连作2年(CS2)、草莓连作3年(CS3)、番茄连作4年(CT4)和番茄连作10年（CT10）4种果蔬种植模式对其根际与非根际土壤养分与酶活性的影响。与RST相比，连作土壤pH呈酸化趋势，其土壤硝态氮含量有所增加，但也会造成有机质、速效磷的耗竭以及有效态微量元素（锌和铁）的缺失。与轮作相比，连作种植时果蔬根际和非根际土壤的硝态氮含量分别增加了10.3%~30.0%和2.4%~23.2%；有机质减少了4.4%~8.8%和2.8%~7.4%；土壤速效磷降低了5.5%~24.4%和8.7%~25.5%。与轮作相比，CS2处理根际与非根际土壤的有效态锌含量分别减少了36.8%和35.2%；有效态锰有所减少但变化不大；CT4处理有效态铜含量分别减少了43.0%和34.8%；CT10处理有效态锌、锰和铁含量严重缺乏，连作年限越长，土壤质量下降越显著。CS2与CS3处理土壤的过氧化氢酶、脲酶和纤维素酶活性均表现为非根际土壤根际土壤，而CS2、CS3与CT4处理土壤的蔗糖酶活性则与之相反，均表现为根际土壤非根际土壤。随连作年限的增加，非根际土壤的过氧化氢酶、磷酸酶和蔗糖酶活性均表现出降低趋势；纤维素酶活性在非根际土壤中表现出增加趋势。微量元素分别与土壤pH和有机质含量有很好的相关性，但与土壤速效氮、磷和钾的相关性不显著。土壤有效态锌和铁元素的亏缺是土壤肥力的限制性因子。

English. Soil fertility was measured in order to study the mechanisation, clarify the most sensitive limiting factors of soil nutrients and provide reference for continuous cropping in greenhouse. To evaluate these influences, we analyzed the rhizosphere and non-rhizosphere soil of strawberry and tomatoes rotation (RST), 2 years continuous strawberry cropping (CS2), 3 years continuous strawberry cropping (CS3), 4 years continuous tomatoes cropping (CT4) and 10 years continuous tomato cropping (CT10), respectively. The result showed that all the soil samples in our study were alkali at the beginning,but finally were seriously acidified. Compared with rotation cropping, the nitrate nitrogen content of rhizosphere and non-rhizosphere soils in continuous cropping-increased by 10.3%-30.0% and 2.4%-23.2%, organic matter -declined by 4.4%-8.8% and 2.8%-7.4%, and extractable P declined by 5.5%-24.4% and 8.7%-25.5%, respectively. These led to some trace element deficiency (such as Zn2+ and Fe2+) in soil, which was essential for plant growth after a long period of continuous cropping. The extractable Zn2+, Mn2+ and Fe2+ in CT10, appeared to be seriously deficient, while the extractable Zn2+ content in rhizosphere and non-rhizophere soils of CS2 respectively decreased by 36.8% and 35.2% comparing with RST. The decline of extractable Mn2+ was not so significant in CT4 and CS2. It had a significant correlation between trace elements and soil orgnic matter, but not significant with soil nitrate and extractable P. The activity activtitys of catalase, urease and cellulase in non-rhizosphere soil of CS2 and CS3 was higher than that of rhizosphere soil, while saccharase in CS2, CS3 and CT4 showed a contrary trend. The deficiency of soil extractable Zn2+ and Fe2+ is the most sensitive limiting factor of soil fertility.