低湖田生态系统特点及开发利用研究

阐述了低湖田生态系统中的生物系统、土壤系统同水土体系的相互作用，分析了低湖田生态系统中的土壤特性及资源优势潜力。主要表现为：水温、泥温低，土壤通透性能差，结构不良；土壤处于强还原状态，有毒还原性物质含量高，不利于作物的正常生长；土壤微生物活动弱，微生物生物量显著低于正常土壤；土壤有机质矿化慢，土壤供氮能力弱，缺磷、缺锌严重。而水生经济植物莲藕的生物学特性决定其地下茎具有发达的通气组织，保证了植株在水中的正常呼吸和新陈代谢的需要，同时还能改善土壤通气性能和土壤氧化还原状态，增强土壤微生物活力，加快土壤有机质矿化状况。着重从低湖田生态系统所具备的优势入手，对低湖田的作物系统、土壤系统和水土体系进行了比较和分析，其作物生物量排序为：莲藕＞茭白＞菱＞水稻， 其作物产量排序为：莲藕＞茭白＞菱＞水稻；对作物系统的主体作物进行了优化，对土壤系统的关键营养元素进行了调控（N:P:K:16:16:16），合理利用水土体系的特点构建生物共生的模式，提出了合理利用低湖田资源优势的措施和开发模式（鱼藕共生模式），提高低湖田生态系统综合开发效益的整体水平。

ECOLOGY SYSTEM CHARACTERS OF LOWLAND LAKE FIELDS AND THEIR DEVELOPMENT AND UTILIZATION

In this article , the interaction among biosystem, soil system and water system in the whole ecologic system of lowland lake field are described. And in the mean time, the soil characters, potential resource dominance about lowland lake field are analysed. Lower water and soil temperature, bad aerate penetrability and worse structure cause soil presenting strong reducibility. Containing large amount of toxic reducing substance, the soil went against growth of crops such as rice. The amount of microorganism lower than normal soil observably, organism in the soil mineralization is very slowly, the nitrogen supplying is weakness too, lack of phosphorus and zinc fearfully. The bio character of aquatic economical plant nelubo nucifera possesses dominance of upgrowth spiracle which assuring the need of respiration and metabolization for the plant in the water, in the mean while, improving aerate penetrability and estate of reduce oxidation, enhancing activity of the soil microorganism accerlerating mineralization of the organism. In terms of ecosystem advantages in lowland, cropsystem, soilsystem and water soil system was compared and analysised,with the results of crop biomass: Nelumbo nucifera﹥Zizania caduciflora﹥Trapa bispinosa﹥Oryza sativa,and crop yields: Nelumbo nucifera﹥Zizania caduciflora ﹥Trapa bispinosa﹥Oryza sativa.Dominant in crop system was optimized,and the key nutrient elements were regulated (N:P:K 16:16:16).According to the characyeristics of water soil system, biological coexistence model was constructed, and the measures to make fall use of resource advantages in lowland lake as well as the developmental model were put forword. These would help improve the whole level of the ecosystem′s integrative developmental benefit in lowland lake.