【作者】 胡国平；

【导师】 曹靖；

【作者基本信息】 兰州大学 ， 生态学， 2012， 硕士

【摘要】 蔬菜废弃物作为一种特殊的秸秆资源,含有大量的有机物及丰富的营养物质,将其通过综合利用作为肥料返还农田,能够改良土壤,培肥地力,是农业生产重要的有机肥源之一。论文针对榆中县高原夏菜发展迅速,大量蔬菜剩余物资源不能有效利用,根据目前我国循环农业发展趋势与科技方向,因地制宜地充分利用这种特殊秸秆资源作为肥料,使其利用效率最大化,以实现生态的良性循环和农业的可持续发展。本研究采用田间试验和室内试验相结合的方法,探明高原夏菜剩余物资源状况及其还田效应,以期了解蔬菜废弃物还田后分解周期、土壤养分变化以及化肥减量化施用,为蔬菜废弃物直接还田提供理论依据。主要结果表明：(1)调查显示,蔬菜种植过程中,随着品种的差异会产生32～66%的剩余物,娃娃菜最多,达65.6%,芹菜最小,为32.1%,其中干物质含钾4～12%,含氮2.7-4.5%,含磷0.16～1.65%。丢弃时不仅浪费资源,而且污染环境；蔬菜收获后11月初到来年4月初,农田休闲,蔬菜废弃叶还田成为可能。(2)2010年9月14日到来年3月10日的大田分解试验表明,还田初期,新鲜蔬菜废弃物分解迅速,重残留率的指数分解模型曲线拟合效果较好(R2为0.49～0.71),可知新鲜芹菜废弃物还田后经过31-57天其50%干物质被分解,新鲜花椰菜废弃物还田后经过6-12天其50%干物质被分解,同时发现对数拟合结果优于指数拟合。(3)无机氮与蔬菜废弃物耦合试验结果表明,和对照(CK)相比,蔬菜废弃物添加土壤肥力显著增加,土壤有机质、全氮、速效磷、速效钾分别是对照下的1.28-1.39倍、1.20-1.46倍、1.36-1.82倍、1.81-2.60倍,pH值显著降低。各氮处理下土壤净累积氮矿化量是对照(CK)的4-5倍,N1水平下土壤净累积氮矿化量显著高于其它氮水平。随甘蓝废弃叶添加量的增加,土壤净累积氮矿化量是CK下的3-5倍不等,且B2添加量下土壤净累积氮矿化量显著高于B1和B3的。统计分析表明,氮处理和甘蓝废弃叶添加量之间的交互效应不显著(P=0.275),废弃菜叶的添加是影响氮矿化的主要因素(Eta2=0.16),而供氮水平为次要因素(Eta2=0.07)。B1添加量下,培养前期(0-20天)土壤净累计矿化量逐渐升高,后期保持稳定水平,但B2和B3添加量下,培养前期(30天)呈现矿化、固持、再矿化现象,后期逐渐升高。氮矿化速率说明,甘蓝后氮素矿化主要发生在前30天；对培养期间土壤净累积氮矿化量随时间变化作了一级动力方程模拟,拟合效果良好(R2从0.62到0.89)。(4)蔬菜废弃物直接还田试验结果显示,和对照(CK)相比,蔬菜废弃叶直接还田能显著降低田间速效氮,对不同土层来说,蔬菜废弃物直接还田可以降低下层土壤速效氮,相对减小氮淋失风险；甘蓝产量表明蔬菜废弃物直接还田(还田量为37500kg·ha-1)时,常规磷肥减施600kg·ha-1,不施钾肥(常规用量为375kg·ha-1可以稳产,同时可知,本试验中蔬菜废弃物还田可以减少农家肥用量。(5)本研究结果表明,蔬菜废弃物还田具有可行性,不仅快捷处理了废弃菜叶,增加了土壤养分含量,可使氮肥用量减半,替代钾肥和农家肥用量,而且减少了环境污染。大田试验表明,菜地土壤速效氮和速效钾淋失风险较大,蔬菜废弃叶还田时应适当增加C/N比较高的秸秆以减少氮素损失风险。田间管理应根据实际需要确定蔬菜废弃叶还田时间及肥料氮素施用量。更多还原

【Abstract】 The disposal of vegetable waste in the process of vegetable planting is a problem. Our research is based on vegetable waste cycle agriculture and main object is reduce the use of fertilizer. Laboratory incubation experiment and field experiment of vegetables waste of plateau summer vegetable were conducted in Lanzhou City in order to understand the decomposition cycle of vegetable waste and nutrients change in soil and fertilizer reduction after applied vegetable waste, provide a basis theory for vegetable waste return to field. The results showed as follows:(1) Large amounts of waste leaves was produced through vegetable growing, and waste leaves not only waste resources, but also pollute the environment as which contain nitrogen, phosphorus, and other nutrients, especially potassium. Vegetable waste return field become possible, because of farmland leisure during vegetable harvested in October until early April next year.(2) The result of decomposition experiment from mid-September to mid-March show that celery decompose more rapidly than cauliflower waste. The decomposition pattern which was characterized by using an exponential regression equation fit well except for H3(R2=0.49-0.71), and predict the half of celery and cauliflower waste dry matter decomposed need31-57and6-12days. Luckily, we noticed that logarithmic equation is better than the exponential equation.(3) Comparing with CK, soil fertility increased significantly when vegetable waste is added. Soil organic matter, total nitrogen, available phosphorus and potassium were1.28to1.39times,1.20to1.46times,1.36to1.82times,2.60-1.81times higher than the CK, respectively. pH decreased significantly.The result showed that the net accumulated nitrogen mineralization in amended soil under inorganic nitrogen supply level was4-5times higher than the CK, moreover, the net accumulated N mineralization under N1level was significantly higher than under other nitrogen levels. Net accumulated nitrogen mineralization in amended soil with wasted cabbage leaves was3-5times higher than the CK, and the net accumulated nitrogen mineralization under B2treatment was significantly higher than that under Bland B3treatments. No significant interactive effect was found (.P=0.275) between the inorganic nitrogen level and the addition of wasted cabbage leaves by statistical analysis. The addition of wasted cabbage leaves influence nitrogen mineralization in amended soil was the dominated factor(Eta2=0.16), while the inorganic nitrogen supply level was the secondary (Eta2=0.07). In the early period(0-20d) of incubation the net accumulated nitrogen mineralization gradually increased under B1treatment, and then maintained a steady tendency in the later period of incubation. But nitrogen mineralization, immobilization and re-mineralization occurred in the early period of incubation (30d) and the net accumulated nitrogen mineralization increased gradually in the later period of incubation under B2and B3treatments. The result showed nitrogen mineralization mainly occurred in the first30days of incubation according to mineralization rate after wasted cabbage leaves added. In addition, during the period of incubation, a first-order kinetics equation of net accumulated nitrogen mineralization in amended soil fits well with the extension of incubation days (R2=0.62-0.89).(4) Available N in lower layer and different fields decreased and vegetable yield kept steady after applying half P(600kg-ha-1) and no K(375kg-ha-1) compare with tradition and farmyard manure reduced when incorporate vegetable waste.(5) In summary, Vegetable waste return field not only making use of waste leaves efficiently, but also increasing the soil nutrient content, moreover, that can reduce environmental pollution based on the above analysis.更多还原