Nutrient Mineralization Of Compost Of Aquatic Plants And Its Agricultural Utilization Approaches

Waterborne raw materials used as fertilizer and substrate not only make it possible for the reuse of the nitrogen and phosphorus pollutants and the recycle of waste resources, but have an effect of protecting environment and high-effective utilization of resources. It is of vital theoretical and practical importance to land and water nutrients cycle. Elodea nuttallii, Water Hyacinth, sludge and straw were chosen as raw materials to compost. The rules of nutrient releasing in different compost applied soil were studied by indoor culture. Effects of fruit body yield; quality and biological efficiency of agaricus bisporus planted in different compost were studied by plot experiment. Impacts of different compost on soil nutrients condition, the yield, quality and the nutrient absorption of greengrocery were studied by field plot experiment. Thus, we could inaugurate new application ways of compost and provide a reference for decision making in application of compost. Main results are as follows:1. The amounts of the nitrogen mineralized by applying different waterborne raw material composts under flooding condition were higher than that of chicken manure fertilizer (control). Organic material contained in aquatic plant composts decomposed more easily, which caused a faster rate of carbon mineralization. The quantity and the rate of the mineralized nitrogen of aquatic plant composts were higher than that of sludge compost. Nitrogen mineralization of Elodea nuttallii compost composed of more nitrate nitrogen while the sludge compost composed of more ammonium nitrogen. The organic matter contained in Water Hyacinth compost was easier to decompose that improved the carbon content. It had the fastest carbon mineralization rate under both flooding and aerobic conditions and the largest amount of the nitrogen mineralized under flooding condition.2. Both the biological efficiency and the nitrogen use efficiency of agaricus bisporus of water borne material composts were higher than that of control. The nitrogen use efficiency of Elodea nuttallii+sludge treatment was6.8times, while the biologic efficiency6.7times, as control. The Elodea nuttallii+sludge treatment was a cultivation pattern of efficient conversion and reuse of waste. The biologic efficiency of sludge treatment was2.5times as control. The nitrogen use efficiency of Water Hyacinth+sludge treatment was1.78times as control. They were practicable materials in resource recycling. Both the yield and the quality of button mushroom of water borne material composts were higher than that of control, increase production rates ranging19.8%-383%, and differed from each treatment.3. Applying composting in condition of equal N can effectively increase P and K in soil. After continuously planting3stubbles, soil TP contents of all treatments were higher than chemical fertilizer applied with P. With the increasing number of stubble, these treatments, water hyacinth, and elodea and added with sludge respectively, enhanced nitrogen supply capacity. Applying water hyacinth compost, the content of available nutrients in soil was higher than other treatments and had a sustainable increase in yield. It contributed to crop yield and had the highest nitrogen dry matter production efficiency of20.16%. Applying organic fertilizers had no impact on the nitrate and VC content of greengrocery.