Impact of medium-term summer-planted cover crop (6-yrs) and crop residue retained (+R) or removed (-R) on soil labile and stable fractions of C and N from 0–15 cm depth in site-year 2016.

a-c For each fraction and effect, based on a protected LSD test, means followed by a different letter indicate statistical significant difference (P2d, cumulative 2d soil C mineralization; MBC, microbial biomass C; MBN, microbial biomass N; SLAN, Solvita labile amino N; OC, organic C; WAS, wet aggregate stability; WEOC, water extractable organic C; WEON, water extractable organic N. z SE, standard error of mean. (XLSX)

a至c小节中，针对每个组分与效应，基于保护性最小显著差数法（protected LSD test），标有不同字母的均值组间存在统计学显著差异。各缩写对应的指标如下：P2d为2天累积土壤碳矿化量（cumulative 2-day soil C mineralization）；MBC为微生物量碳（microbial biomass C）；MBN为微生物量氮（microbial biomass N）；SLAN为Solvita不稳定氨基氮（Solvita labile amino N）；OC为有机碳（organic C）；WAS为水稳性团聚体稳定性（wet aggregate stability）；WEOC为水溶性有机碳（water extractable organic C）；WEON为水溶性有机氮（water extractable organic N）。z SE 代表均值标准误（standard error of mean）。本数据集格式为XLSX。