【作者】 胡飞龙；

【导师】 胡锋；

【作者基本信息】 南京农业大学 ， 生态学， 2011， 硕士

【摘要】 通过田间试验研究了木薯花生间作模式对生态系统稳定性的影响,兼顾土壤其他指标,研究间作模式下作物对光合、土壤、水分等因子的响应,多角度、全方位探讨木薯花生间作系统内部稳定性问题。结果表明：(1)木薯、花生的生长环境因子的日变化均为“单峰”型曲线,其中光合有效辐射(PAR)、田间CO2浓度(Ca)为向下抛物线,大气相对湿度(RH)、大气温度(Ta)的日变化则为向上曲线。(2)受日全食影响,大气温度(Ta)、光合有效辐射(PAR)、田间CO2浓度(Ca)明显降低,大气相对湿度(RH)则有升高现象。日全食发生时,间作措施下花生对环境变化抵抗力要优于单作措施；日全食结束后,单作措施下花生的光合有效速率(Pn)恢复能力则更强。借助叶温模型的构建,创建间作优势度(Intercropping Dominance)这一概念,进而得出木薯花生间作模式的ID为+0.83%,说明木薯花生间作存有间作优势。(3)不同间作措施中,间作窄行并无绝对优势；间作宽行可保证作物产量,但其瞬时水分利用效率(WUE)和气孔限制值(Ls)均最低,不利于在缺水环境下推广间作双行的WUE和CO2利用效率最高,这在严重水分胁迫条件无疑是最优选择。方差分析表明,间作措施下木薯花生间作,距离木薯第1、3、5列的土壤理化性质均无显著性差异(p>0.05),因此间作措施下土壤各项理化性质不受距离影响。(4)不同土壤深度,单作措施下线虫数量都要高于间作措施,但差异并不显著；间作措施降低了表层土壤(0-15 cm)和深层土壤(30-45 cm)的微生物量氮水平,但显著提高了中层土壤(15-30 cm)微生物量碳氮水平(p<0.05)。(5)受间作措施影响,土壤碱解氮和速效磷含量均显著降低,而钾的含量则相对稳定；间作模式显著降低了表层和中层土壤中有机质含量(p<0.05),而深层土壤(30-45 cm)有机质含量则受干扰较小(6)对生态环境的影响方面,木薯花生间作提高了水分保持效能,但从一定程度上加剧了红壤的酸化。更多还原

【Abstract】 A field experimental was conducted to investigate the effect of cassava-peanut intercropping on the stability of ecosystem functioning, and also integrating other analyses to study the response of intercropping system to photosynthesis, soil, water and so on. We discussed the internal stability of cassava-peanut intercropping from multiple perspectives. Our results showed that:(1) The diurnal variation of photosynthesis of both cassava and peanut had a single peak:the curves of photosynthetic active radiation (PAR) and atmospheric relative humidity (RH) open downward when the curves of field CO2 concentration (Ca) and atmospheric temperature (Ta) open to an opposite direction.(1) Impacted by the solar eclipse, the diurnal variation of atmospheric temperature (Ta), photosynthetic active radiation (PAR) and field CO2 concentration (Ca) were all significantly reduced, while atmospheric relative humidity (RH) was increased.When total solar eclipse occurred, peanuts under intercropping showed a higher resistance to the disturbance than single system, reflecting the advantage of intercropping. Following the total solar eclipse, the restoration of net photosynthetic efficiency (Pn) of peanut under single system became greater, reflecting the single advantage. With the model based on leaf temperature, we created a model named intercropping dominance (ID). The ID of cassava-peanut intercropping derived+0.83% which verified that cassava-peanut intercropping had indeed advantages under normal weather conditions.(2) Among the several intercropping systems, narrow-intercropping had no apparent advantage while wide-intercropping seems to be an optimal one. However, the WUE and Ls of wide-intercropping were the lowest which would make it not appropriate in the drought prone region; Double-intercropping had a high efficient use of water and CO2 which would play an important role in the area subjected to periodical shortage of water. Analysis of variance showed that the soil physico-chemical properties in the line of 1.3.5 from cassava had no significant difference(p> 0.05). That means that soil properties under intercropping practices not influenced by distance.(3) Under different depth of soil, the number of nematodes from intercropping system was higher than that from the single one, but the difference did not reach significant level. Intercropping measures reduced the MBN level of the surface soil (0-15 cm) and deep soil (30-45 cm) but significantly increased MBC, MBN content (p<0.05) of the middle soil (15-30 cm).(4) Compared to monoculture, intercropping models can significantly lower content of nitrogen and available phosphorus (p<0.05), while the potassium content is relatively stable. The intercropping models significantly reduced the soil organic matter content in the surface and middle soil (p<0.05), while organic matter in the deep soil (30-45cm) was not affected.(5)While promoting the performance of water retention undoubtedly, cassava-peanut intercropping also exacerbated the red soil acidification.更多还原