The effect of tillage management on microbial functions in a maize crop at different slope positions
The effect of tillage management on microbial functions in a maize crop at different slope positions
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DOI：
10.1016/j.geoderma.2021.115171
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发表时间：
2021
期刊：
影响因子：
6.1
通讯作者：
Meng Xu;L. Cárdenas;C. Horrocks;M. López‐Aizpún;Junling Zhang;Fusuo Zhang;J. Dungait
中科院分区：
文献类型：
--
作者：
Meng Xu;L. Cárdenas;C. Horrocks;M. López‐Aizpún;Junling Zhang;Fusuo Zhang;J. Dungait
确定农业土壤是否充当温室气体（GHG）的汇或源，需要量化土壤有机碳（SOC）和养分（如氮（N））的库和通量的变化，以及相关的土壤微生物反应。在这项研究中，土壤收集的玉米（玉米）在传统的，最少或带状耕作处理建立在坡地（约10%）的壤土在英格兰西南部，英国，玉米已被传统种植12年的试验田。分别在坡顶、坡中、坡底和坡脚4个位置采集0-10 cm土层的土样，研究土壤C、N和微生物特性。通过培养从常规处理的顶部、中部和底部斜坡位置收集的土壤，评估了常规管理对潜在温室气体排放的影响。各处理土壤有机碳和全氮含量均以坡顶最高，而矿质氮（NO3--N和NH 4 +-N）含量以坡底和坡脚最高。生物标志物磷脂脂肪酸（PLFA）的革兰氏阳性细菌和真菌相对富集13 C在每个斜坡位置，无论处理，表明优先利用的有机质从玉米（C4），而不是SOC（C3）。约70%的碳纳入总PLFA来自C3-SOC在坡脚，表明更多的SOC年龄超过12年被矿化的沉积位置。流出的N2 O和CO2，和温室气体排放总量是最大的孵化土壤采样从底部的斜坡位置，这表明在沉积位置的条件下，定期翻耕倾斜耕地可能增加了矿化和反硝化的潜力。我们的结论是C汇的潜力的沉积位置的斜坡可能会减少巧合的温室气体排放。
Determining whether agricultural soils act as sinks or sources of greenhouse gases (GHGs) requires the quantification of variations in the pools and fluxes of soil organic carbon (SOC) and nutrients, e.g. nitrogen (N), as well as the associated soil microbial responses. In this study, soil was collected from experimental plots of maize (Zea mays) under conventional, minimum or strip tillage treatments established in a sloping field (~10%) of loamy soil in SW England, UK, where maize had been cultivated conventionally for 12 years. Topsoil (0–10 cm) cores were collected from the top, mid, bottom and foot slope positions to investigate soil C, N and microbial properties. The impact of conventional management on potential GHG emissions was assessed by incubating soils collected from the top, mid and bottom slope positions from the conventional treatment. Contents of SOC and total N were greatest at the top slope position and soil mineral N (NO3−-N and NH4+-N) concentrations were greater at the bottom and foot slope positions in all treatments. Biomarker phospholipid fatty acids (PLFA) for Gram positive bacteria and fungi were relatively13C-enriched at each slope position regardless of treatment, indicating preferential utilization of organic matter from maize (C4) rather than SOC (C3). Around 70% of carbon incorporated into total PLFA was derived from C3-SOC at the slope foot, indicating that more SOC older than 12 years was being mineralized at the depositional position. Effluxes of N2O and CO2, and total GHG emission were greatest from the incubated soils sampled from the bottom slope position, suggesting that conditions in depositional positions of regularly ploughed sloping arable fields may have increased the potential for mineralization and denitrification. We conclude that the C sink potential of the depositional positions of slopes may be diminished by coincidental GHG emissions.