Arbuscular mycorrhizal effects on plant water relations and soil greenhouse gas emissions under changing moisture regimes
Arbuscular mycorrhizal effects on plant water relations and soil greenhouse gas emissions under changing moisture regimes
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DOI：
10.1016/j.soilbio.2014.03.010
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发表时间：
2014-07-01
影响因子：
9.7
通讯作者：
Jackson, Louise E.
中科院分区：
文献类型：
--
作者：
Lazcano, Cristina;Barrios-Masias, Felipe H.;Jackson, Louise E.
丛枝菌根（AM）共生所增加的养分和/或水分吸收可能会影响土壤生化特性以及温室气体（GHG）排放。进行了一项温室实验，以比较菌根化番茄（76R MYC）及其非菌根突变体（rmc）对有机管理土壤中二氧化碳（CO₂）和氧化亚氮（N₂O）排放的影响。植株在装有堆肥改良土壤的花盆中生长10周，并经历两个连续的干旱周期以模拟田间水分状况的变化。通过控制浇水处理逐渐施加干旱。在花盆中安装的根内生聚氯乙烯（PVC）圆筒中评估了丛枝菌根和土壤水分对温室气体排放的影响。每次浇水事件4小时后，使用静态气室从圆筒中采集气体样本。浇水后使用便携式开放式红外气体分析仪评估植株的光合速率和气孔导度。在整个实验过程中监测土壤水分。在收获时评估植株生物量以及地上部分总氮、磷和钾含量，以及土壤中溶解性有机氮（DON）、溶解性有机碳（DOC）、铵态氮（NH₄⁺ - N）、硝态氮（NO₃⁻ - N）和微生物生物量碳含量。对于相同的地上部分生长和养分含量，rmc植株比菌根化植株将更多资源分配给根系生物量。丛枝菌根共生提高了植株适应土壤水分变化的能力，在高土壤水分时提高光合速率和气孔导度，而在土壤水分较低时降低它们。此外，丛枝菌根共生有助于在高土壤水分时调节氧化亚氮排放。丛枝菌根植株对氧化亚氮排放的控制似乎是由更高的土壤水分利用驱动的，而非由增加的氮吸收驱动。（C）2014爱思唯尔有限公司。保留所有权利。
Increased nutrient and/or water uptake by AM symbiosis may affect soil biochemical properties and greenhouse gas (GHG) emissions. A greenhouse experiment was carried out to compare mycorrhizal tomato (76R MYC) and its non-mycorrhizal mutant (rmc) on the CO2 and N2O emissions from an organically-managed soil. Plants were grown for 10 weeks in pots with compost amended soil and subjected to two consecutive dry down cycles to simulate changing moisture regimes in the field. Dry downs were applied gradually through controlled watering treatments. The effects of AM and soil moisture in GHG emissions were assessed in root in-growth PVC cylinders installed in the pots. Gas samples were taken from the cylinders using static chambers 4 h after each watering event. Photosynthetic rates and stomatal conductance of the plants were assessed after watering using a field portable open flow infra-red gas analyzer. Soil moisture was monitored throughout the experiment. Plant biomass and total shoot N, P and K as well as soil content of DON, DOC, NH4+-N, NO3--N and microbial biomass C, were assessed at harvest. For the same shoot growth and nutrient content, rmc plants allocated more resources to root biomass than mycorrhizal plants. AM symbiosis improved the capacity of the plants to adapt to changing soil moisture, increasing photosynthetic rates and stomatal conductance at high soil moisture but decreasing them when soil moisture was lower. In addition AM symbiosis helped to regulate N2O emissions at high soil moisture. Control over N2O emissions by AM plants seemed to be driven by a higher use of soil water and not by increased N uptake. (C) 2014 Elsevier Ltd. All rights reserved.