Investigation on an effective index for introducing biodiversity into agricultural site and application to co-existent cropping systems at paddy field

我们在2008年将关于这项研究的两篇论文贡献给了相关的科学杂志。在2007年的试验中，我们设计了一个新的试验，包括两个因素，包括养分短缺和过剩的影响，在稻田环境负荷和水稻产量的相互关联的因素进行整体评估。在2007年的实验中，我们最终集中在稻田甲烷产生和水质的环境负荷发生的变化。在2007年的试验中，全氮（TN）浓度在一次底肥和两次追肥的3个时期都有显著增加，而磷（TP）浓度仅在一次底肥时期有增加。生长季甲烷累积量与水稻产量呈线性相关，相关性大小依次为：不施肥区<标准三要素区<标准三要素+有机肥区<氮肥重复区。在此基础上，以指标值为100的标准三要素图为基础，绘制了单位水稻产量MP、单位水稻产量TN、TP的雷达图，并进行了比较，探讨了它们在满足环境和生产要求下的综合效益。本研究中最重要的关键词是“可持续性”。针对目前我国农业生产中单一栽培模式效率低下的现状，引进包括混养在内的新系统，还存在一些亟待解决的问题。但我们必须努力为后代提出各种合理的选择，克服一些障碍。

We contributed our two papers on this research to the related Scientific Journal in 2008. In the 2007 experiment to evaluate holistically the mutually-related factors with environmental loads and rice grain yield, we designed the new experiment with two factors including nutrient shortage and excess fertilizing effects at a paddy field. In the 2007 experiment, we eventually focused on the changes of environmental loads of methane production and water quality occurred at a paddy field. In the 2007 experiment, concentration of total nitrogen (TN) increased noticeably at the three periods including a basal fertilization with pudding and two top dressings, but concentration of phosphorus (TP) increased only at the period of a basal fertilization. The linear correlation was observed between accumulated methane production during growing season (MP) and rice grain yield, and the order were as follows, no-fertilizer plot<the standard three elements plot<the standard three elements + manure plot<duplicated nitrogen plot. Then we drew a radar chart for MP per unit rice grain yield, TN and TP per unit rice grain yield based on the standard three elements plot with index value of 100 for their comparison, and discussed their holistic fertilizing efficiency to satisfy both environmental and productive requirements. The most important keyword is "sustainability" in this research. In regard to present situation of monoculture with a shortsighted efficiency at agricultural site, an introduction of new systems including polyculture leaves some unsolved problems. But we must try to propose various and sound options for future generation beyond some obstacles.