不同作物组合间作优势和时空稳定性的生态机制

发布时间：2018-04-24 08:37

本文选题：选择效应 + 补偿效应　；参考：《中国农业大学》2017年博士论文

【摘要】：间作广泛应用于农业生产中,且种植模式多样。以往的研究多关注间作体系中资源高效利用,但对间作系统生产力的时空稳定性、植物种间互作动态等问题很少涉及。本研究以西北一熟制地区19种不同间作体系为研究对象,通过在甘肃省武威市、张掖市和靖远县三地设置为期三年(2012-2014)的田间试验,分析种间相互作用对作物生产力和养分吸收优势及其时空稳定性的影响,并利用Logistic models模拟不同竞争强度间作体系作物生长和养分获取的动态过程,完善种间相互作用的动力学机制,为间作模式的合理配置设计和可持续生产提供理论依据。主要研究结果如下:(1)玉米参与的间作模式大多数具有产量优势和养分吸收优势,比相应单作提高了14.6%～46.0%。短生育期作物(油菜、胡麻和豌豆)/油葵间作体系基于生产力计算的土地当量比(LER)为1.18～1.54。间作体系(尤其是高杆/矮杆间作体系)基于生产力计算的LER随着时间生态位分离度(TND)的增加而显著增加(P0.01)。(2)当高产作物在间作时对体系产量和养分吸收量相对单作的增加(减少)的影响占主导地位时,生物多样性净效应、补偿效应和选择效应均表现为正(负)效应;当低产作物在间作时对体系产量和养分吸收量相对单作的增加(减少)的影响程度更大时,生物多样性净效应和补偿效应表现为正(负)效应,选择效应表现为负(正)效应。无论生物多样性净效应为正还是负,间作体系(尤其是高杆/矮杆间作体系)基于生产力和养分吸收量计算的补偿效应随着TND的增加而显著增加(P0.05),选择效应则与TND呈显著的负相关(P0.05)。(3)在玉米/蚕豆、玉米/豌豆和玉米/小麦间作体系中,与相应单作相比,间作蚕豆、豌豆和小麦的干物质和养分吸收的最大累积量(Ymax)分别提高了 34.5%～49.5%、8.6%～38.1%和34.9%～62.4%;最大日生长速率(Imax-Y)分别增加了 1.6～2.1倍、1.3～1.6倍和1.7～2.4倍。与单作玉米相比,与蚕豆和小麦间作玉米的Ymax和Imax-Y均无显著性差异,而与豌豆间作的玉米的Ymax和Imax-Y则分别显著提高了 25.5%～38.9%和24.3%～60.7%;与蚕豆、豌豆和小麦间作玉米获得干物质和养分吸收最大瞬时生长速率的时间(TImax-Y)分别比单作玉米分别延迟了 10～13d、11～20d和3～12 d。间作强化了作物之间的生态位分离。(4)无论是以作物还是体系为研究对象,间作生产力和养分吸收量的时空稳定性与相应单作相比无显著差异。当短生育期作物胡麻、油菜与长生育期高杆作物玉米或油葵间作时,其时间稳定性系数比相应单作体系增加了 35.2%～256.8%;豆科作物大豆、豌豆与玉米间作时基于生产力和养分吸收量计算的时间稳定性系数均等于或高于相应单作体系。综上所述,大部分间作体系在具有产量优势和养分吸收优势的同时,能够维持时空稳定性。
[Abstract]:Intercropping is widely used in agricultural production, and the planting patterns are diverse. Previous studies have focused on the efficient utilization of resources in intercropping systems, but little attention has been paid to the spatio-temporal stability of intercropping system productivity and the dynamics of plant interspecific interactions. In this study, 19 different intercropping systems in a cooked area of northwest China were studied. Field experiments were conducted in Wuwei, Zhangye and Jingyuan counties in Gansu Province for a period of three years (2012-2014). The effects of interspecific interactions on crop productivity, nutrient absorption advantage and spatiotemporal stability were analyzed. Logistic models was used to simulate the dynamic process of crop growth and nutrient acquisition in intercropping systems with different competitive intensities. The dynamic mechanism of interspecific interaction is improved to provide theoretical basis for rational allocation design and sustainable production of intercropping mode. The main results were as follows: (1) most of the intercropping patterns of maize had yield advantage and nutrient absorption advantage, which were 14.6m 46.0g higher than the corresponding monoculture. The land equivalent ratio (Ler) of short growing period crops (rapeseed, flax and pea / sunflower intercropping system based on productivity) was 1.18 ~ 1.54. LER calculated based on productivity in intercropping systems (especially high-stem / dwarf intercropping systems) increased significantly with the increase of niche separation degree in time (P 0.01N. M). When high yield crops were intercropping, the yield and nutrient uptake of the system were relatively single. When the effect of the increase (decrease) is dominant, The net effects of biodiversity, compensatory effects and selective effects were positive (negative) effects, and the effects of low yield crops on the yield and nutrient uptake of the system were greater than those of monoculture. The net and compensatory effects of biodiversity are positive (negative) effects, and the selection effects are negative (positive) effects. Whether the net effect of biodiversity is positive or negative, The compensatory effect of intercropping system (especially high-stem / dwarf intercropping system) based on productivity and nutrient uptake increased significantly with the increase of TND, while the selective effect was negatively correlated with TND. In maize / pea and maize / wheat intercropping systems, compared with the corresponding monoculture, the intercropping of broad bean, The maximum accumulative amount of dry matter and nutrient uptake of pea and wheat increased by 38.5%, 38.1% and 34.4%, respectively, and the maximum daily growth rate (Imax-YX) increased by 1.61 times and 1.72.4 times, respectively. Compared with monoculture maize, the Ymax and Imax-Y of maize intercropping with broad bean and wheat had no significant difference, but the Ymax and Imax-Y of maize intercropping with pea were significantly increased by 38.9% and 24.30.7%, respectively, compared with the intercropping of broad bean and wheat, the Ymax and Imax-Y of maize intercropping with pea were increased by 25.5% and 24.30.7%, respectively. The time of obtaining the maximum instantaneous growth rate of dry matter and nutrient uptake by pea and wheat intercropping maize was 10 ~ 13d ~ 1120d and 3n ~ 12d later than that of monoculture maize, respectively. The spatial and temporal stability of intercropping productivity and nutrient uptake was not significantly different from that of monoculture. When short growing period crop flax, rapeseed and long growing period high stem crop corn or oil sunflower were intercropping, the time stability coefficient increased 35.2256.8% than the corresponding monoculture system, soybean, leguminous crop, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, soybean, The time stability coefficient of pea and maize intercropping based on productivity and nutrient uptake was equal to or higher than that of the corresponding monoculture system. In conclusion, most intercropping systems have the advantage of yield and nutrient absorption, while maintaining space-time stability.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S344.2

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