Effects of subsurface organic ameliorant combined with film mulching on saline soil organic and inorganic carbon in Hetao Irrigation District
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摘要: 土壤有机碳(SOC)和无机碳(SIC)是参与全球碳循环的重要碳库。亚表层(10~30 cm)培肥结合地膜覆盖措施是干旱区优化盐碱土壤物理结构和调控土壤水盐环境的有效措施, 然而关于其如何调控0~60 cm土体SOC、SIC分布及其与土壤相关理化性状的关系尚不明确。本研究基于内蒙古河套灌区盐碱土壤6年的田间微区试验, 设置常规对照(CK)、亚表层(10~30 cm)有机培肥(OM)、地膜覆盖(PM)、亚表层有机培肥+地膜覆盖(OM+PM) 4个处理, 测定了2019—2020年0~60 cm剖面SOC、SIC、全碳(TC)含量以及土壤理化指标(土壤水分、盐分、pH和全氮), 分析了TC、SOC、SIC变化特征及其影响因素。结果表明: OM和OM+PM处理较CK和PM处理显著增加0~40 cm土层SOC含量31.9%~195.6% (P<0.05), 显著增加40~60 cm SOC含量33.7%~49.4% (P<0.05, 仅2020年), 但显著降低0~40 cm SIC含量9.9%~35.0% (P<0.05)。基于SOC和SIC的变化, OM+PM较CK处理显著增加2019年20~60 cm TC含量10.4%~39.4% (P<0.05), 并显著增加2020年0~20 cm TC含量13.0% (P<0.05)。回归分析结果进一步说明, 覆膜条件下补充亚表层培肥, 使总碳库变化的主导因素由SIC转变为SOC。冗余分析结果表明土壤理化性质是影响土壤碳库的主要因素(解释度为60.7%~91.9%), 其中全氮和pH是0~40 cm土壤碳库的主要影响因子, 而40~60 cm土壤碳库主要受盐分和pH影响。相关性分析结果表明SOC与SIC表现为完全相反的变化规律, 其中SOC与全氮极显著正相关, 与盐分和pH呈极显著负相关(P<0.01); SIC与全氮呈极显著负相关, 与pH呈极显著正相关(P<0.01)。因此, 亚表层培肥结合地膜覆盖可以通过增加SOC来弥补SIC的损失进而实现碳积累, 是该区域盐碱地增加固碳潜力的有效措施。Abstract: Soil organic carbon (SOC) and inorganic carbon (SIC) are important carbon pools involved in the global carbon cycle. Subsurface (10−30 cm) organic ameliorant (OM) combined with film mulching (PM) is an effective measure to optimize the physical structure and regulate water and salt movement of saline soil in arid areas. However, the distribution of SOC and SIC in the 0–60 cm soil layer and their relationship with soil physicochemical properties remain unclear. This study was based on a 6-year micro-field experiment of saline soil at the Yichang Experiment Station, which is located in the Hetao irrigation area of Inner Mongolia. Four treatments were set: conventional control (CK), OM, PM, and OM+PM. The levels of SOC, SIC, total carbon (TC), and soil physicochemical property indexes (soil moisture, salinity, pH, and total nitrogen) in the 0−60 cm (0−20 cm, 20−40 cm, and 40−60 cm) soil layer after the harvest of Helianthus annuus during 2019–2020 were measured, and the variation characteristics and influencing factors of TC, SOC, and SIC were analyzed. The results showed that the TC content in the 0−60 cm soil layer and SOC in the 0−40 cm soil layer were mainly affected by OM treatment compared with PM treatment (P<0.01). The SIC content in the 0−40 cm soil layer was affected by OM treatment (P<0.001), PM treatment (P<0.05, except for the 20−40 cm soil layer in 2019), and their interaction (P<0.001); however, the 40−60 cm soil layer was mainly affected by OM treatment (P<0.05). Compared to CK and PM treatments, OM and OM+PM treatments significantly increased SOC content in the 0−40 cm (0−20 cm and 20−40 cm) soil layer by 31.9%−195.6% (P<0.05), and significantly increased SOC content in the 40−60 cm soil layer by 33.7%−49.4% (P<0.05) only in 2020, but significantly decreased SIC content in the 0−40 cm (0−20 cm and 20−40 cm) by 9.9%−35.0% (P<0.05). Based on the changes in SOC and SIC, compared with CK treatment, OM+PM treatment significantly increased TC content in the 20−60 cm (20−40 cm and 40−60 cm) soil layer in 2019 by 10.4%−39.4% (P<0.05), and the TC content of the 0−20 cm layer in 2020 was significantly increased by 13.0% (P<0.05). The regression analysis results further indicated that the dominant factor of the total carbon pool changed from SIC to SOC with the OM+PM treatment. The results of redundancy analysis showed that soil physicochemical properties were the main factors affecting soil TC, SOC, and SIC (explaining 60.7%−91.9% of the variation), and total nitrogen and pH were the main factors affecting soil TC, SOC, and SIC in the 0−40 cm layer, whereas soil TC, SOC, and SIC in the 40−60 cm layer were mainly affected by salinity and pH. Correlation analysis showed that changes in SOC and SIC were completely opposite. Soil organic carbon was positively correlated with total nitrogen and negatively correlated with salinity and pH (P<0.01). Soil inorganic carbon was negatively correlated with total nitrogen and positively correlated with pH (P<0.01). Therefore, OM combined with PM (OM+PM) could compensate for the loss of SIC and realize carbon accumulation by increasing SOC, which is an effective strategy to increase the carbon sequestration potential of saline soil in this region.
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Keywords:
- Subsurface organic ameliorant /
- Film mulching /
- Saline soil /
- Organic carbon /
- Inorganic carbon
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土壤碳库主要包括有机碳库和无机碳库两部分, 全球1 m内土壤无机碳库约为有机碳库的2/3[1]。据估计, 我国土壤有机碳(SOC)储量为70.3 Pg C (1 m深度), 占全球碳储量的4.7%; 而土壤无机碳(SIC)储量为55.3 Pg C, 约占全球无机碳储量的5.8%[2-3]。由于SOC一直被认为是增加碳储量和固定的主要驱动者, 所以大部分研究都集中在SOC部分[4]。相比之下, 由于SIC一般被认为比较稳定且不易受农业措施影响而被忽视[5]。然而, 近期研究表明, 农业活动和土地利用变化等引起的土壤酸化和碳酸盐溶解等可以在几十年内迅速降低土壤SIC储量[6-8]。1980—2020年间, 我国农田中表层土壤无机碳库已损失145 Tg C (1.1 Mg∙hm−2)[9]。因此, 在评估整个土壤碳库和肥力变化时, SIC与SOC同等重要。并且, 与SOC相比, SIC的损失是不可逆转的, SIC的损失将严重影响土壤健康状况[10]。
SIC主要以碳酸盐形式存在, 可分为原生碳酸盐(主要来自母质)或次生碳酸盐(由原生碳酸盐的溶解和重结晶以及其土壤发生过程形成)[11]。我国约有30% (3.44×106 km2)的土壤中含有成土碳酸盐, 主要分布在我国西北干旱和半干旱地区[12]。干旱地区年蒸发量较大, 蒸发/降雨比高, 限制了碳酸盐从土壤中的溶解和浸出[1]。因此, 这些区域土壤SIC含量相对较高, 研究其SIC变化对了解土壤全碳状况十分重要。施肥和灌溉等土地管理措施也会显著影响农田SIC含量[6,9,13]。有研究表明, 有机肥和化肥结合施用可以通过向土壤中额外添加Ca2+和Mg2+, 以及通过增加土壤微生物和根系呼吸来促进SIC的形成, 增加SIC储量[14-16]。但也有研究认为, 有机肥和化肥的施用会降低盐碱土壤pH, 导致SIC发生溶解而损失[8,13]。
河套灌区地处西北干旱半干旱地区, 是我国大型自流灌区之一, 由于灌排不合理, 盐渍化耕地面积达 39.4万hm2, 占全区耕地面积的68.7%[17], 土壤盐分普遍较高、表聚速度快、积累强度大, 而且土壤水分和养分都极为匮乏。现有研究表明, 相对于表层培肥, 亚表层培肥(10~30 cm)可能更利于土壤保水蓄肥, 为作物生长创造了良好的环境条件, 增加土壤有机质积累, 同时提高作物产量[18-19]。课题组通过研究也发现, 采用亚表层培肥结合地表地膜覆盖一方面有利于优化土壤物理结构, 增强盐碱土水盐调控能力[20]; 另一方面可以通过物理保护和微生物调节增加土壤耕层SOC含量[21]。然而该措施对盐碱土壤SOC、SIC变化特征及其影响因素尚不清楚。我们假设: 1)亚表层培肥结合地膜覆盖措施除了直接增加碳输入外, 还可以通过改善土壤理化性质间接增加SOC含量; 2)土壤理化性质的改善(尤其是pH的降低)也会导致SIC发生一定损失; 3)在亚表层培肥结合地膜覆盖条件下, 土壤全碳(TC)受SOC的显著变化, 因此仍表现为显著提高。因此, 本研究基于内蒙古河套灌区连续6年的田间定位试验, 研究亚表层培肥结合地表覆膜对SOC、SIC及全碳含量和分布的影响及有机碳和无机碳之间的关系, 并分析土壤理化指标与有机碳、无机碳的相关性, 以期为揭示河套灌区肥沃亚表层构建措施对SOC和SIC的影响提供科学依据。
1. 材料和方法
1.1 试验地概况
试验地位于内蒙古自治区巴彦淖尔市五原县河套灌区义长灌域管理局试验站永联基地(41.07°N、108.00°E, 海拔 1022 m), 试验地地处中温带, 多年平均气温6.1 ℃, 年平均降雨量200 mm, 无霜期117~136 d。2019—2020年作物生育期间气象数据如图1所示。试验地土壤类型为粉砂壤土, 按盐土分类为氯化物−硫酸盐土, 土壤砂粒、粉粒、黏粒质量分数分别为35.9%、53.6%和10.5%。试验地土壤含盐量为3.4 g∙kg−1, 有机质9.2 g∙kg−1, 全氮0.5 g∙kg−1, 全磷0.6 g∙kg−1, 全钾19.4 g∙kg−1, pH (土水比1∶5) 8.5。
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图 1 研究区2019—2020年作物生长期月降雨(MP)和月平均气温(MAT)Figure 1. Monthly precipitation (MP) and mean air temperature (MAT) during crop growth seasons in 2019 and 2020 in the study area1.2 试验设计
田间微区(1.8 m×1.8 m)试验开始于2015年, 采用随机区组排列, 共设置4个处理: 常规对照(CK)、10~30 cm亚表层有机培肥(OM)、地膜覆盖(PM)、亚表层有机培肥+地膜覆盖(OM+PM), 每个处理3次重复。每个微区四周均用双层塑料布阻隔, 确保每个微区间相对独立。为保证处理间表层土壤基础理化性质保持一致, 在试验前, 将所有微区中0~10 cm土壤取出后拌匀。亚表层培肥处理(OM、OM+PM)中将34.60 kg有机肥与土壤10~30 cm土层的土壤混合并压实, 有机肥为牛粪、羊粪、鸡粪和草炭混合物(拌匀后的有机肥盐分含量为16.1 g∙kg−1, pH为7.1, 全氮、全磷、全钾以及有机碳含量分别为12.9 g∙kg−1、5.4 g∙kg−1、13.9 g∙kg−1和425.7 g∙kg−1), 有机肥仅第1年施用, 后续不再添加; 最后, 将混匀的0~10 cm土壤按原容重等质量回填。地膜覆盖处理(PM、OM+PM)采用70 cm宽的农用塑料薄膜覆盖, 微区铺设两条膜带, 膜间距20 cm。
所有微区统一沟施化肥, 施肥深度为10 cm, 用量分别是N 180 kg∙hm−2、P 53 kg∙hm−2和K 62 kg∙hm−2。灌溉采用引黄灌溉, 定额为1850 m3∙hm−2。供试作物为食葵(Helianthus annuus L.), 播种后穴口用细砂覆盖, 行距为60 cm, 株距为20 cm。其他管理方式与当地农户保持一致。2019年和2020年分别于5月23日和6月12日播种, 并于9月3日和10月2日收获。
1.3 土壤样品采集与测定
1.3.1 土壤含水率、盐分和pH测定
于2019—2020年作物收获后用土钻在地膜位置(无地膜处理与其取样方位保持一致), 按0~20 cm、20~40 cm和40~60 cm土层采集土壤样品, 将样品去除根系、地膜等杂质后, 一部分用于测定土壤含水率、盐分与pH, 另一部分用于后续测定土壤碳氮含量。其中土壤含水率采用烘干法测定, 烘干后土样粉碎过2 mm筛, 以1∶5土水比浸提土壤溶液, 采用DDS-307电导率仪和PHS-3B型pH计测定电导率和pH, 土壤盐分含量根据公式换算[22]:
$$ y=3.0111x/1000 $$ (1) 式中: y为土壤盐分含量(g∙kg−1), x为土壤提取液的电导率(μS∙cm−2)。
1.3.2 土壤全氮、全碳、有机碳与无机碳测定
取另一部分土壤样品, 自然风干, 过0.15 mm筛, 通过四分法将土样分为具有代表性的两部分, 一部分直接保存, 用于测定土壤全氮(TN)和TC含量; 另一部分通过酸洗法去除SIC来测定土壤SOC[23]。具体方法如下: 称取1.0 g土样, 加入10 mL 1 mol∙L−1的盐酸溶液, 200 r∙min−1震荡30 min使土壤样品和盐酸充分反应至无气泡产生, 再以3000 r∙min−1离心5 min, 离心后去除酸液后反复加入蒸馏水清洗, 至上清液为中性, 再将离心后的土壤放至60 ℃下烘干至恒重。上述土样均通过碳氮元素分析仪(vario MACRO cube)上机测定碳氮含量。SIC含量为TC含量与SOC含量的差值。
1.4 数据分析
数据统计分析采用DPS 9.01进行, 方差分析采用单因素方差分析(Two-Way ANOVA), 并用最小方差分析(LSD)进行多重比较来研究亚表层有机培肥、地膜覆盖及其交互作用对0~60 cm土壤全氮、全碳、有机碳和无机碳含量以及土壤含水率、盐分、pH的影响; 并采用线性回归分析来检验SOC与SIC之间的关系, 应用Origin 2021作图; 相关分析采用皮尔森(Pearson)双侧检验法, 应用TB tools绘制相关性热图; 采用Canoco 5.0进行冗余分析(RDA), 探讨土壤碳含量与土壤理化因子间关系。
2. 结果与分析
2.1 土壤全碳(TC)、有机碳(SOC)和无机碳(SIC)在不同土层的分布
OM+PM显著增加2019年20~40 cm TC含量, 较CK和PM处理分别增加3.9%和5.6% (P<0.05); 2019年, OM、PM和OM+PM处理40~60 cm土层TC含量较CK显著增加8.0%~10.4% (P<0.05) (图2a)。2020年, OM+PM和OM同时显著增加了0~20 cm TC含量, 较CK和PM分别增加13.0%~13.2%和17.5%~17.8% (P<0.05) (图2b)。两年结果的差异性可能与有机肥为第1年一次性施入, 随试验年限增加, 表层土壤TC变化可能更多取决于根系分泌和当年气象情况。此外, 亚表层培肥结合地膜覆盖0~60 cm剖面TC含量在不同土层间整体差异不大, 这可能与SOC和SIC含量随土层加深而呈现出不同趋势有关。
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图 2 2019—2020年不同亚表层培肥结合地膜覆盖处理下不同土层土壤全碳(a、b)、有机碳(c、d)和无机碳(e、f)含量CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。不同小写字母表示同一土层不同处理间差异显著(P<0.05)。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. Different lowercase letters mean significant differences (P<0.05) under different treatments for the same soil layer.Figure 2. Contents of soil total carbon (TC; a, b), organic carbon (SOC; c, d) and inorganic carbon (SIC; e, f) of different soil layers under different treatments of subsurface organic ameliorant and film mulching in 2019 and 2020亚表层培肥(OM和OM+PM)处理显著增加了SOC含量, 其中OM和OM+PM在2019—2020年较CK和PM处理显著增加0~20 cm SOC含量54.0%~195.6% (P<0.05), 显著增加20~40 cm SOC含量31.9%~162.6% (P<0.05); OM和OM+PM较CK和PM处理显著增加2020年40~60 cm SOC含量33.7%~49.4% (P<0.05)。同时, OM+PM较OM处理显著增加2019—2020年20~40 cm SOC含量20.1%~39.1% (P<0.05)。此外, 除OM+PM处理外, 2019— 2020年土壤SOC含量随土层深度增加整体呈下降趋势(图2c, d)。
由图2e, f可知, 与SOC含量变化不同, 0~60 cm土层SIC含量随土层加深整体呈增加趋势, 其中, 2019—2020年, 0~20 cm土层OM和OM+PM较CK和PM处理SIC含量显著降低12.3%~28.4% (P<0.05), 20~40 cm土层显著降低29.9%~35.0% (P<0.05); 然而, 2019年40~60 cm土层, OM较CK处理SIC含量显著增加9.65% (P<0.05)。
2.2 不同处理土壤有机碳、无机碳和全碳之间的关系
线性回归分析表明(图3), 在CK和OM+PM处理下, 土壤SOC与TC含量呈显著正相关关系(CK: R2=0.34, P<0.05; OM+PM: R2=0.22, P<0.05); 在PM处理下, 土壤SIC与TC含量呈显著正相关关系(R2=0.42, P<0.05)。此外, 在所有处理下, 土壤SOC与SIC含量均表现为负相关关系(CK: R2=0.28, P<0.05; OM: R2=0.80, P<0.01; PM: R2=0.39, P<0.05; OM+PM: R2=0.85, P<0.01)。
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图 3 不同亚表层培肥结合地膜覆盖处理下土壤有机碳(SOC)、无机碳(SIC)及全碳(TC)间相关性分析CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。实线和阴影区域分别表示线性模型拟合和95%置信区间。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. The dotted lines and shadow areas indicate linear model fits and 95% confidence intervals, respectively.Figure 3. Correlation analysis among soil organic carbon (SOC), inorganic carbon (SIC) and total carbon (TC) contents under different treatments of subsurface organic ameliorant and film mulching2.3 土壤理化性质
亚表层培肥显著增加了0~40 cm土层全氮含量(P<0.05), 对40~60 cm土层全氮含量无显著影响(表1)。2019—2020年, 相较于CK和PM, OM和OM+PM处理0~20 cm土层SOC含量显著增加21.7%~83.7% (P<0.05), 20~40 cm土层SOC含量显著增加35.3%~100.1% (P<0.05)。此外, OM+PM较OM处理20~40 cm土层全氮含量显著增加33.7%~38.3% (P<0.05)。
表 1 2019—2020年不同亚表层培肥结合地膜覆盖处理对不同土层土壤理化性质的影响Table 1. Soil physicochemical properties of different layers under different treatments of subsurface organic ameliorant and film mulching in 2019 and 2020理化性质
Physicochemical property处理
Treatment2019 2020 0~20 cm 20~40 cm 40~60 cm 0~20 cm 20~40 cm 40~60 cm 全氮
Total N
(g∙kg−1)CK 0.71±0.01b 0.61±0.03c 0.69±0.03a 0.69±0.06b 0.61±0.04c 0.55±0.05a OM 0.96±0.01a 0.88±0.06b 0.72±0.05a 1.18±0.03a 0.86±0.03b 0.56±0.05a PM 0.79±0.02b 0.65±0.03c 0.72±0.03a 0.69±0.04b 0.63±0.04c 0.56±0.05a OM+PM 0.96±0.05a 1.21±0.05a 0.72±0.05a 1.27±0.01a 1.15±0.03a 0.56±0.05a 含水率
Moisture
(%)CK 9.28±0.14b 13.27±0.06b 14.97±0.25c 13.83±0.36a 14.00±0.09b 14.47±0.44c OM 5.23±0.00c 13.81±0.43b 17.97±0.34a 10.97±0.56b 14.52±0.10b 16.89±0.16a PM 10.50±0.51a 15.80±0.22a 17.33±0.42a 13.19±0.50a 16.25±0.01a 17.51±0.29a OM+PM 4.93±0.14c 10.90±0.52c 16.11±0.36b 11.74±0.07b 10.55±0.31c 15.99±0.12b 含盐量
Salt content
(g∙kg−1)CK 4.43±0.22a 2.58±0.13a 2.13±0.33a 3.59±0.06a 2.28±0.15a 2.65±0.06a OM 3.73±0.12b 2.06±0.21b 2.18±0.12a 2.37±0.08b 2.20±0.11a 2.55±0.04a PM 3.97±0.06ab 2.69±0.12a 2.44±0.12a 3.49±0.00a 2.38±0.04a 2.69±0.10a OM+PM 2.98±0.19c 1.90±0.02b 2.31±0.29a 2.11±0.17b 2.06±0.02a 2.58±0.26a pH CK 8.03±0.04a 8.25±0.00a 8.21±0.05a 7.91±0.07a 8.21±0.11a 8.26±0.03ab OM 7.74±0.11bc 7.62±0.01b 7.90±0.02b 7.67±0.11b 7.55±0.03b 8.14±0.02b PM 7.96±0.08ab 8.12±0.08a 8.10±0.07a 7.98±0.02a 8.17±0.01a 8.29±0.01a OM+PM 7.70±0.03c 7.59±0.05b 7.91±0.03b 7.76±0.05ab 7.31±0.08c 7.97±0.08c CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。不同小写字母表示同一土层不同处理间差异显著(P<0.05)。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. Different lowercase letters mean significant differences (P<0.05) under different treatments for the same soil layer. 在0~20 cm土层, OM和OM+PM处理较CK和PM处理显著降低11.0%~53.1% (P<0.05), 并且在2019年PM较CK显著增加13.2% (P<0.05); 在20~40 cm土层, PM和OM+PM较CK处理显著增加16.1%~19.1%, 而OM+PM较CK处理显著降低17.8%~24.6% (P<0.05); 对于40~60 cm土层, OM、PM和OM+PM处理较CK显著增加7.7%~21.0% (P<0.05), 然而OM+PM较OM和PM处理显著降低5.3%~10.3% (P<0.05)。此外, 0~60 cm剖面土壤含水率随土层加深而增加(表1)。
OM和OM+PM较CK处理显著降低0~20 cm土层盐分含量15.8%~41.2%, 且OM+PM较CK显著降低25.1%~39.5% (P<0.05); OM和OM+PM较CK和PM处理显著降低2019年20~40 cm土层盐分含量20.2%~29.4% (P<0.05)。此外, 0~20 cm表层土壤盐分含量高于20~60 cm土层(表1)。
在0~20 cm土层, OM较CK处理显著降低3.0%~3.5%, OM+PM仅在2019年较CK和PM处理降低2.7%~4.1%; 20~40 cm土层, OM和OM+PM较CK和PM处理显著降低6.2%~11.0%, 且OM+PM在2020年较OM处理降低3.1%; 40~60 cm土层, OM和OM+PM较PM处理显著降低1.8%~3.9%, 且OM+PM较CK处理显著降低3.5%~3.7%。
2.4 土壤理化性质与土壤全碳、有机碳、无机碳的关系
为进一步分析亚表层培肥结合地膜覆盖下不同土层土壤碳(TC、SOC、SIC)含量变化的影响因素, 对试验期间(2019—2020年)土壤碳含量与理化性质进行了冗余分析(图4)。结果表明, 不同土层土壤碳含量变化的主要影响因素不同。在0~20 cm土层, RDA1和RDA2分别解释了81.9%和10.1%的变异, 前两轴共解释了土壤碳含量总变异的91.9% (图4a)。土壤理化性质对0~20 cm土壤碳含量变化的贡献从高到低为全氮>含水率>pH>盐分。其中土壤全氮(F=66.2, P=0.002)是影响0~20 cm土壤碳含量的最显著变量, 解释了75.1% 的变异; 其次是含水率(13.2%, F=23.7, P=0.002)、pH (2.6%, F=5.6, P=0.012)和盐分(1.4%, F=3.3, P=0.068)(图4b)。其中相关性热图表明(图4c), SOC与全氮含量呈极显著正相关(P<0.01), 而与盐分和pH呈极显著负相关关系(P<0.01); SIC与含水率、pH呈极显著正相关(P<0.01), 与盐分呈显著正相关(P<0.05), 而与全氮呈极显著负相关(P<0.01)。
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图 4 不同亚表层培肥结合地膜覆盖处理下不同土层理化性状与碳含量之间相关性的冗余分析(a, d, g)、土壤理化性状对土壤碳含量变化的解释率(b, e, h)及两者间相关性分析(c, f, i)CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。TC: 全碳; SOC: 有机碳; SIC: 无机碳; TN: 全氮; Moisture: 含水率; Salt: 盐分。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. TC: total carbon; SOC: organic carbon; SIC: inorganic carbon; TN: total nitrogen. *: P<0.05; **: P<0.01.Figure 4. Redundancy analyses (RDA) of the correlations between soil physicochemical properties and carbon content (a, d, g), and the explained rates of soil physicochemical properties on variance of soil carbon (b, e, h), and Pearson correlation among them (c, f, i) of different soil layers under different treatments of subsurface organic ameliorant and film mulching在20~40 cm土层, RDA1和RDA2分别解释了91.0%和3.3%的变异, 前两轴共解释了土壤碳含量总变异的94.2% (图4d)。土壤理化性质对20~40 cm土壤碳含量变化的贡献从高到低为pH>全氮>含水率>盐分。其中土壤pH (F=80.2, P=0.002)是影响20~40 cm土层土壤碳含量的最显著变量, 解释了78.5%的变异, 其次是全氮(9.5%, F=16.5, P=0.002)、含水率(3.6%, F=8.5, P=0.012)和盐分(2.7%, F=9.0, P=0.004)(图4e)。相关性热图表明(图4f), 土壤SOC与全氮含量呈极显著正相关(P<0.01), 而与含水率、盐分和pH呈极显著负相关关系(P<0.01)。SIC与全氮含量呈极显著负相关(P<0.01), 而与含水率、盐分和pH呈极显著正相关关系(P<0.01)。
在40~60 cm土层, RDA1和RDA2分别解释了52.2%和8.5%的变异, 前两轴共解释了土壤碳含量总变异的60.7% (图4g)。土壤理化性质对40~60 cm土壤碳含量变化的贡献从高到低为pH>盐分>含水率>全氮。其中土壤pH (F=12.8, P unknown)是影响40~60 cm土壤碳含量的最显著变量, 解释了29.2%的变异, 其次是盐分(23.1%, F=6.6, P=0.004)、含水率(5.7%, F=3.0, P=0.066)和全氮(5.4%, F=2.5, P=0.086)(图4h)。相关性热图表明(图4i), 土壤SOC与全氮含量呈极显著正相关(P<0.01), 而SIC与盐分呈极显著正相关(P<0.01), 与含水率呈显著正相关(P<0.05)。
3. 讨论
3.1 亚表层培肥对盐碱土壤全碳、有机碳、无机碳分布的影响
亚表层培肥结合地膜覆盖条件下, 0~60 cm土层SOC含量整体随土层加深而下降, 这与胡诚等[24]的研究结果大体一致, 但他们的研究认为0~20 cm表层SOC含量最高, 而本研究中, 0~20 cm和20~40 cm土层间SOC含量并无明显差异, 这可能是我们将有机肥施入亚表层(10~30 cm)的缘故。然而, 与SOC不同, 0~60 cm SIC含量随深度增加而增加, 这主要是由于微生物生物量在有机培肥措施下显著增加[20], 进而呼吸产生了更多的CO2, 土壤中CO2分压的增加会导致表层土壤中碳酸盐发生一定的溶解, 然后被转移到深层土壤中, 在含水量相对较低的深层土壤中重新结晶[25]。Pant等[26]研究表明土壤TC与SOC一样随着土层深度增加呈下降趋势, 0~15 cm表层土壤由于含有更多的作物残茬、根系生物量和根系分泌物等, 因此全碳含量最高; 而在我们的研究中0~60 cm土层TC含量在不同土层间并无明显差异, 这主要是由于0~40 cm土层SIC含量受pH和全氮含量变化影响发生损失的缘故(图4)。另外, 各土层SOC与SIC含量在不同处理间差异在试验期间基本保持一致, 这表明亚表层有机培肥结合地膜覆盖措施在6年后仍能显著影响土壤SOC和SIC含量。
3.2 亚表层培肥条件下土壤有机碳、无机碳与全碳间关系
土壤SOC与SIC间关系复杂, 会因土壤自身特性和管理措施(有机改良剂种类及种植系统等)的不同产生差异[9]。其中在我国华北平原黄河三角洲上游地区[27]和甘肃巴丹吉林沙漠[28]SOC和SIC存在显著正相关关系, 这可能是因为施肥等措施会增加土壤中有机碳含量, SOC分解会产生更多的CO2, 土壤CO2通常溶解在土壤水中, 产生CO32−或HCO3−有助于SIC的沉淀[16]。而在我国华北平原[29]和黄土高原西部[30]发现SIC与SOC呈负相关关系。本文研究也发现SIC与SOC呈显著负相关(图3), 同时Dong等[31]研究表明, 在相同粒径级别下, SIC与SOC含量同样呈负相关关系, 这主要是因为SOC矿化释放的酸可以溶解碳酸盐, 在亚表层培肥结合地膜覆盖下碳酸盐因溶解而损失的量大于由于CO2溶于水中发生沉淀而生成的量, 因此SIC含量降低[25,32]。
亚表层培肥结合地膜覆盖增加了0~60 cm土层土壤TC含量, 这与Ding等[33]研究结果一致, 本研究中OM+PM处理下, SOC与TC存在显著线性关系, 而SIC与TC却并不显著(图3), 因此土壤TC含量对SOC变化更为敏感, 这说明虽然亚表层培肥结合地膜覆盖措施会降低SIC含量, 但SOC的提升幅度更大, 因此在6年的试验中并没有导致土壤TC的损失。然而我们也发现在仅地膜覆盖条件下, SIC与TC存在显著线性关系, 而SOC与TC却并不显著(图3), 表明土壤TC含量对土壤SIC变化更为敏感, 这可能由于覆膜主要对土壤水分和温度产生影响, 而温度和水分对土壤SIC的影响更大[34]。另外, 研究发现土壤理化因子可以解释土壤碳含量变化的60.7%~91.9% (图4), 说明土壤理化因子是影响土壤碳含量变化的主要因素, 其中0~40 cm土壤碳含量(SOC、SIC和TC)主要受土壤全氮和pH影响, 而40~60 cm 主要受土壤pH和盐分影响(图4), 这与不同土层土壤因子对亚表层培肥结合地膜覆盖的响应不同有关。
3.3 亚表层培肥条件下土壤有机碳、无机碳变化的主要影响因素
长期以来, 有机培肥措施一直是增加盐碱地土壤有机碳的有效途径[31,34-36]。本研究发现, 亚表层培肥措施在有无地膜覆盖条件下均可以显著增加土壤SOC含量, 产生这种结果的原因来自多个方面: 首先, 亚表层有机培肥将更多的碳输入到土壤中, 而土壤全氮的增加可以刺激作物和根系生物量的产生, 继而增加植物根系分泌物, 有利于SOC积累[37-40]; 其次, 盐分是影响土壤碳循环和微生物代谢的主要因素, 较高的盐分含量会分散土壤胶体颗粒并降低土壤团聚体的稳定性[41], 将有机肥施用于亚表层可以降低土壤中水溶性盐离子含量, 增加阳离子交换量, 显著降低土壤盐分含量, 在一定程度上降低盐分对SOC的不利影响[42]; 再者, 盐碱土壤pH较高, 破坏土壤物理性质进而影响养分和水分供应情况, 这些过程都会对土壤碳氮循环以及有机质分解产生不利影响[43]。而亚表层培肥处理(OM和OM+PM)向盐碱土壤中释放了大量氮, 促进土壤发生硝化反应, 更多的H+因此被释放到土壤中, 进而显著降低0~60 cm pH, 降低pH对土壤碳循环的不利影响[44]。本研究得到相同结果(图4)。而在亚表层培肥条件下, 地膜覆盖降低了0~20 cm土层SOC含量, 这可能是因为地膜覆盖下表层土壤矿化造成的CO2损失量高于因土壤根系分泌增加的SOC积累量导致的, 这与前3年的研究结果一致[42]。
土壤中碳酸盐的存在对土壤物理、化学和生物过程都很重要, 包括酸度缓冲、团聚体形成和稳定、养分循环、微生物和酶活性以及植物生产力等[8]。Tian等[35]研究发现施用有机肥可以增加Ca2+、Mg2+含量进而增加SIC含量; 同时也有研究发现施用有机肥可以通过增加作物产量和生物量, 生物量的提高一方面导致土壤根和微生物呼吸增加, 土壤CO2含量的增加促进了碳酸盐的形成[14], 另一方面增强了蒸散作用, 进而增加土壤碳酸盐沉淀[45]。然而也有研究发现土壤碱基阳离子对大气CO2的吸收主要依赖于土壤pH[8], pH是影响碳酸盐形成和溶解的直接因素, 与SIC含量呈显著正相关关系[10]。Zhang等[19]研究发现OM和OM+PM处理可以影响土壤盐分运移状况, 起到促进土壤脱盐, 抑制土壤返盐的作用。而所有土壤都有缓冲系统来抵抗土壤pH的降低, 当pH>8.5时, 土壤酸化在很大程度上会被碳酸钠缓冲, 而当pH在6.5~8.5之间时, 主要由碳酸盐(以碳酸钙为主)平衡[10]。因此, 土壤pH的降低会导致SIC损失。另外, 亚表层培肥措施向土壤中输入了丰富的氮源, 土壤全氮含量的增加导致的硝化作用和作物对NH4+的吸收也会增加释放到土壤中的H+, 造成SIC的损失[19], 土壤全氮与SIC含量的显著负相关关系也支撑了这一原因(图4)。因此, 在本研究中, 在有无地膜覆盖的条件下, 亚表层培肥措施都会显著降低0~40 cm土层SIC含量, 这可能是因为pH和全氮对SIC的影响起到主导作用, 并且由于OM+PM较OM处理对pH的降低效果更强(表1), 因此OM+PM处理下SIC损失量更大; 而40~60 cm土层SIC并无显著变化, 可能是土壤呼吸增加对土壤碳酸盐形成作用与pH对碳酸盐的酸化作用持平的缘故。
4. 结论
本研究在内蒙古典型盐碱农田上开展了连续6年定位试验, 测定了0~60 cm剖面土壤碳库组分含量与理化性质, 分析了亚表层培肥结合地膜覆盖措施对土壤全碳、有机碳、无机碳的影响及其主导因素, 主要结论如下:
1)亚表层培肥措施(OM和OM+PM)显著提高了土壤TC与SOC含量, 但降低了SIC含量, 回归分析结果进一步表明, 与覆膜条件下TC变化受SIC显著影响相比, 补充亚表层培肥后, TC变化则受SOC显著影响。
2)土壤理化性质(土壤水分、盐分、pH和全氮)是土壤碳含量的主要影响因素, 其中0~40 cm土层土壤碳含量主要受土壤全氮和pH影响, 而40~60 cm土层土壤碳含量主要受土壤盐分和pH影响。SOC与全氮极显著正相关, 与盐分和pH呈极显著负相关; SIC与全氮呈极显著负相关, 与pH呈极显著正相关。
综上, 亚表层有机培肥结合地膜覆盖尽管增加了无机碳的损失, 但该措施有机碳积累对全碳提升的贡献更大, 从而实现了碳积累。
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图 1 研究区2019—2020年作物生长期月降雨(MP)和月平均气温(MAT)
Figure 1. Monthly precipitation (MP) and mean air temperature (MAT) during crop growth seasons in 2019 and 2020 in the study area
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图 2 2019—2020年不同亚表层培肥结合地膜覆盖处理下不同土层土壤全碳(a、b)、有机碳(c、d)和无机碳(e、f)含量
CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。不同小写字母表示同一土层不同处理间差异显著(P<0.05)。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. Different lowercase letters mean significant differences (P<0.05) under different treatments for the same soil layer.
Figure 2. Contents of soil total carbon (TC; a, b), organic carbon (SOC; c, d) and inorganic carbon (SIC; e, f) of different soil layers under different treatments of subsurface organic ameliorant and film mulching in 2019 and 2020
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图 3 不同亚表层培肥结合地膜覆盖处理下土壤有机碳(SOC)、无机碳(SIC)及全碳(TC)间相关性分析
CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。实线和阴影区域分别表示线性模型拟合和95%置信区间。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. The dotted lines and shadow areas indicate linear model fits and 95% confidence intervals, respectively.
Figure 3. Correlation analysis among soil organic carbon (SOC), inorganic carbon (SIC) and total carbon (TC) contents under different treatments of subsurface organic ameliorant and film mulching
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图 4 不同亚表层培肥结合地膜覆盖处理下不同土层理化性状与碳含量之间相关性的冗余分析(a, d, g)、土壤理化性状对土壤碳含量变化的解释率(b, e, h)及两者间相关性分析(c, f, i)
CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。TC: 全碳; SOC: 有机碳; SIC: 无机碳; TN: 全氮; Moisture: 含水率; Salt: 盐分。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. TC: total carbon; SOC: organic carbon; SIC: inorganic carbon; TN: total nitrogen. *: P<0.05; **: P<0.01.
Figure 4. Redundancy analyses (RDA) of the correlations between soil physicochemical properties and carbon content (a, d, g), and the explained rates of soil physicochemical properties on variance of soil carbon (b, e, h), and Pearson correlation among them (c, f, i) of different soil layers under different treatments of subsurface organic ameliorant and film mulching
表 1 2019—2020年不同亚表层培肥结合地膜覆盖处理对不同土层土壤理化性质的影响
Table 1 Soil physicochemical properties of different layers under different treatments of subsurface organic ameliorant and film mulching in 2019 and 2020
理化性质
Physicochemical property处理
Treatment2019 2020 0~20 cm 20~40 cm 40~60 cm 0~20 cm 20~40 cm 40~60 cm 全氮
Total N
(g∙kg−1)CK 0.71±0.01b 0.61±0.03c 0.69±0.03a 0.69±0.06b 0.61±0.04c 0.55±0.05a OM 0.96±0.01a 0.88±0.06b 0.72±0.05a 1.18±0.03a 0.86±0.03b 0.56±0.05a PM 0.79±0.02b 0.65±0.03c 0.72±0.03a 0.69±0.04b 0.63±0.04c 0.56±0.05a OM+PM 0.96±0.05a 1.21±0.05a 0.72±0.05a 1.27±0.01a 1.15±0.03a 0.56±0.05a 含水率
Moisture
(%)CK 9.28±0.14b 13.27±0.06b 14.97±0.25c 13.83±0.36a 14.00±0.09b 14.47±0.44c OM 5.23±0.00c 13.81±0.43b 17.97±0.34a 10.97±0.56b 14.52±0.10b 16.89±0.16a PM 10.50±0.51a 15.80±0.22a 17.33±0.42a 13.19±0.50a 16.25±0.01a 17.51±0.29a OM+PM 4.93±0.14c 10.90±0.52c 16.11±0.36b 11.74±0.07b 10.55±0.31c 15.99±0.12b 含盐量
Salt content
(g∙kg−1)CK 4.43±0.22a 2.58±0.13a 2.13±0.33a 3.59±0.06a 2.28±0.15a 2.65±0.06a OM 3.73±0.12b 2.06±0.21b 2.18±0.12a 2.37±0.08b 2.20±0.11a 2.55±0.04a PM 3.97±0.06ab 2.69±0.12a 2.44±0.12a 3.49±0.00a 2.38±0.04a 2.69±0.10a OM+PM 2.98±0.19c 1.90±0.02b 2.31±0.29a 2.11±0.17b 2.06±0.02a 2.58±0.26a pH CK 8.03±0.04a 8.25±0.00a 8.21±0.05a 7.91±0.07a 8.21±0.11a 8.26±0.03ab OM 7.74±0.11bc 7.62±0.01b 7.90±0.02b 7.67±0.11b 7.55±0.03b 8.14±0.02b PM 7.96±0.08ab 8.12±0.08a 8.10±0.07a 7.98±0.02a 8.17±0.01a 8.29±0.01a OM+PM 7.70±0.03c 7.59±0.05b 7.91±0.03b 7.76±0.05ab 7.31±0.08c 7.97±0.08c CK: 常规对照; OM: 亚表层有机培肥; PM: 地膜覆盖; OM+PM: 亚表层有机培肥+地膜覆盖。不同小写字母表示同一土层不同处理间差异显著(P<0.05)。CK: conventional control; OM: subsurface organic ameliorant; PM: film mulching; OM+PM: subsurface organic ameliorant and film mulching. Different lowercase letters mean significant differences (P<0.05) under different treatments for the same soil layer. 
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[1] LAL R, KIMBLE J M, ESWARAN H, et al. Global Climate Change and Pedogenic Carbonates[M]. Boca Raton: CRC Press, 2000
[2] WU H B, GUO Z T, PENG C H. Distribution and storage of soil organic carbon in China[J]. Global Biogeochemical Cycles, 2003, 17(2): 1048
[3] WU H B, GUO Z T, GAO Q, et al. Distribution of soil inorganic carbon storage and its changes due to agricultural land use activity in China[J]. Agriculture, Ecosystems & Environment, 2009, 129(4): 413−4212
[4] SANDERMAN J, BALDOCK J A. Accounting for soil carbon sequestration in national inventories: a soil scientist’s perspective[J]. Environmental Research Letters, 2010, 5(3): 034003 doi: 10.1088/1748-9326/5/3/034003
[5] SANDERMAN J. Can management induced changes in the carbonate system drive soil carbon sequestration: a review with particular focus on Australia[J]. Agriculture Ecosystems & Environment, 2012, 155: 70−77
[6] KIM J H, JOBBÁGY E G, RICHTER D D, et al. Agricultural acceleration of soil carbonate weathering[J]. Global Change Biology, 2020, 26(10): 5988−6002 doi: 10.1111/gcb.15207
[7] LIU S S, ZHOU L H, LI H, et al. Shrub encroachment decreases soil inorganic carbon stocks in Mongolian grasslands[J]. Journal of Ecology, 2020, 108(2): 678−686 doi: 10.1111/1365-2745.13298
[8] RAZA S, MIAO N, WANG P Z, et al. Dramatic loss of inorganic carbon by nitrogen-induced soil acidification in Chinese croplands[J]. Global Change Biology, 2020, 26(6): 3738−3751 doi: 10.1111/gcb.15101
[9] FERDUSH J, PAUL V. A review on the possible factors influencing soil inorganic carbon under elevated CO2[J]. CATENA, 2021, 204: 105434 doi: 10.1016/j.catena.2021.105434
[10] RAZA S, ZAMANIAN K, ULLAH S, et al. Inorganic carbon losses by soil acidification jeopardize global efforts on carbon sequestration and climate change mitigation[J]. Journal of Cleaner Production, 2021, 315: 128036 doi: 10.1016/j.jclepro.2021.128036
[11] KUZYAKOV Y, SHEVTZOVA E, PUSTOVOYTOV K. Carbonate re-crystallization in soil revealed by 14C labeling: Experiment, model and significance for paleo-environmental reconstructions[J]. Geoderma, 2006, 131(1/2): 45−58
[12] MI N, WANG S Q, LIU J Y, et al. Soil inorganic carbon storage pattern in China[J]. Global Change Biology, 2008, 14(10): 2380−2387 doi: 10.1111/j.1365-2486.2008.01642.x
[13] ZAMANIAN K, ZAREBANADKOUKI M, KUZYAKOV Y. Nitrogen fertilization raises CO2 efflux from inorganic carbon: a global assessment[J]. Global Change Biology, 2018, 24(7): 2810−2817 doi: 10.1111/gcb.14148
[14] BUGHIO M A, WANG P L, MENG F Q, et al. Neoformation of pedogenic carbonates by irrigation and fertilization and their contribution to carbon sequestration in soil[J]. Geoderma, 2016, 262: 12−19 doi: 10.1016/j.geoderma.2015.08.003
[15] WANG X J, XU M G, WANG J P, et al. Fertilization enhancing carbon sequestration as carbonate in arid cropland: assessments of long-term experiments in northern China[J]. Plant and Soil, 2014, 380(1/2): 89−100
[16] WANG X J, WANG J P, XU M G, et al. Carbon accumulation in arid croplands of Northwest China: pedogenic carbonate exceeding organic carbon[J]. Scientific Reports, 2015, 5: 1−12 doi: 10.9734/JSRR/2015/14076
[17] 李亮, 史海滨, 李和平. 内蒙古河套灌区秋浇荒地水盐运移规律的研究[J]. 中国农村水利水电, 2012(4): 41−44 LI L, SHI H B, LI H P. Research on the transport of moisture and salt in the saline land of the Inner Mongolia Hetao Irrigation District[J]. China Rural Water Conservancy and Hydropower, 2012(4): 41−44
[18] 朱姝, 窦森, 陈丽珍. 秸秆深还对土壤团聚体中胡敏酸结构特征的影响[J]. 土壤学报, 2015, 52(4): 747−758 ZHU S, DOU S, CHEN L Z. Effect of deep application of straw on composition of humic acid in soil aggregates[J]. Acta Pedologica Sinica, 2015, 52(4): 747−758
[19] ZHANG T A, RUAN H, CHEN H Y. Global negative effect of nitrogen deposition on soil microorganisms[J]. The ISME Journal, 2018, 12(7): 1817−1825 doi: 10.1038/s41396-018-0096-y
[20] 张宏媛, 逄焕成, 宋佳珅, 等. 亚表层有机培肥调控盐渍土孔隙结构与水盐运移机制[J]. 农业机械学报, 2022, 53(2): 355−364 ZHANG H Y, PANG H C, SONG J S, et al. Effects of pore structure and water-salt movement for saline soil under subsurface organic amendment[J]. Transactions of the Chinese Society for Agricultural Machinery, 2022, 53(2): 355−364
[21] ZHANG H Y, PANG H C, SONG J S, et al. Subsurface organic ameliorant plus polyethylene mulching strengthened soil organic carbon by altering saline soil aggregate structure and regulating the fungal community[J]. Land Degradation & Development, 2022 doi: 10.1002/ldr.4330
[22] ZHANG H Y, LU C, PANG H C, et al. Straw layer burial to alleviate salt stress in silty loam soils: impacts of straw forms[J]. Journal of Integrative Agriculture, 2020, 19(1): 265−276 doi: 10.1016/S2095-3119(19)62737-1
[23] 王巧环, 任玉芬, 孟龄, 等. 元素分析仪同时测定土壤中全氮和有机碳[J]. 分析试验室, 2020, 19(1): 265−276 WANG Q H, REN Y F, MENG L. Simultaneous determination of total nitrogen and organic carbon in soil with an elemental analyzer[J]. Chinese Journal of Analysis Laboratory, 2020, 19(1): 265−276
[24] 胡诚, 乔艳, 李双来, 等. 长期不同施肥方式下土壤有机碳的垂直分布及碳储量[J]. 中国生态农业学报, 2010, 18(4): 689−692 doi: 10.3724/SP.J.1011.2010.00689 HU C, QIAO Y, LI S L, et al. Vertical distribution and storage of soil organic carbon under long-term fertilization[J]. Chinese Journal of Eco-Agriculture, 2010, 18(4): 689−692 doi: 10.3724/SP.J.1011.2010.00689
[25] ZHAO W, ZHANG R, HUANG C Q, et al. Effect of different vegetation cover on the vertical distribution of soil organic and inorganic carbon in the Zhifanggou Watershed on the Loess Plateau[J]. CATENA, 2016, 139: 191−198 doi: 10.1016/j.catena.2016.01.003
[26] PANT P K, RAM S, BHATT P, et al. Vertical distribution of different pools of soil organic carbon under long-term fertilizer experiment on rice-wheat sequence in mollisols of North India[J]. Communications in Soil Science and Plant Analysis, 2021, 52(3): 235−255 doi: 10.1080/00103624.2020.1859527
[27] GUO Y, WANG X J, LI X L, et al. Dynamics of soil organic and inorganic carbon in the cropland of upper Yellow River Delta, China[J]. Scientific Reports, 2016 doi: 10.1038/srep36105
[28] SU Y Z, WANG X F, YANG R, et al. Effects of sandy desertified land rehabilitation on soil carbon sequestration and aggregation in an arid region in China[J]. Journal of Environmental Management, 2010, 91(11): 2109−2116 doi: 10.1016/j.jenvman.2009.12.014
[29] 黄斌, 王敬国, 金红岩, 等. 长期施肥对我国北方潮土碳储量的影响[J]. 农业环境科学学报, 2006, 25(1): 161−164 HUANG B, WANG J G, JIN H Y, et al. Effects of long-term application of fertilizer on carbon storage in calcareous meadow soil[J]. Journal of Agro-Environment Science, 2006, 25(1): 161−164
[30] 曾骏, 郭天文, 包兴国, 等. 长期施肥对土壤有机碳和无机碳的影响[J]. 中国土壤与肥料, 2008(2): 11−14 doi: 10.11838/sfsc.20080203 ZENG J, GUO T W, BAO X G, et al. Effects of soil organic carbon and soil inorganic carbon under long-term fertilization[J]. Soil and Fertilizer Sciences in China, 2008(2): 11−14 doi: 10.11838/sfsc.20080203
[31] DONG X L, HAO Q Y, LI G T, et al. Contrast effect of long-term fertilization on SOC and SIC stocks and distribution in different soil particle-size fractions[J]. Journal of Soils and Sediments, 2017, 17(4): 1054−1063 doi: 10.1007/s11368-016-1615-y
[32] SHI Y, BAUMANN F, MA Y, et al. Organic and inorganic carbon in the topsoil of the Mongolian and Tibetan grasslands: pattern, control and implications[J]. Biogeosciences, 2012, 9(6): 2287−2299 doi: 10.5194/bg-9-2287-2012
[33] DING F, LI S Y, LÜ X T, et al. Opposite effects of nitrogen fertilization and plastic film mulching on crop N and P stoichiometry in a temperate agroecosystem[J]. Journal of Plant Ecology, 2019, 12(4): 682−692 doi: 10.1093/jpe/rtz006
[34] WANG Y, HU N, GE T. Soil aggregation regulates distributions of carbon, microbial community and enzyme activities after 23-year manure amendment[J]. Applied Soil Ecology, 2017, 111: 65−72 doi: 10.1016/j.apsoil.2016.11.015
[35] TIAN Y F, WANG Q Q, GAO W, et al. Organic amendments facilitate soil carbon sequestration via organic carbon accumulation and mitigation of inorganic carbon loss[J]. Land Degradation & Development, 2022, 33(9): 1423−1433
[36] SUN Z C, QIN W L, WANG X, et al. Effects of manure on topsoil and subsoil organic carbon depend on irrigation regimes in a 9-year wheat-maize rotation[J]. Soil and Tillage Research, 2021, 205: 104790 doi: 10.1016/j.still.2020.104790
[37] GE T D, LUO Y, SINGH B P. Resource stoichiometric and fertility in soil[J]. Biology and Fertility of Soils, 2020, 56(8): 1091−1092 doi: 10.1007/s00374-020-01513-5
[38] PROMMER J, WALKER T W, WANEK W, et al. Increased microbial growth, biomass, and turnover drive soil organic carbon accumulation at higher plant diversity[J]. Global Change Biology, 2020, 26(2): 669−681 doi: 10.1111/gcb.14777
[39] YANG Y, CHEN X L, LIU L X, et al. Nitrogen fertilization weakens the linkage between soil carbon and microbial diversity: a global meta-analysis[J]. Global Change Biology, 2022, 28(21): 6446−6461 doi: 10.1111/gcb.16361
[40] WANG H, FENG D, ZHANG A Q, et al. Effects of saline water mulched drip irrigation on cotton yield and soil quality in the North China Plain[J]. Agricultural Water Management, 2022, 262: 107405 doi: 10.1016/j.agwat.2021.107405
[41] CHEN Q Y, HU Y L, HU A, et al. Shifts in the dynamic mechanisms of soil organic matter transformation with nitrogen addition: from a soil carbon/nitrogen-driven mechanism to a microbe-driven mechanism[J]. Soil Biology and Biochemistry, 2021, 160: 108355 doi: 10.1016/j.soilbio.2021.108355
[42] ZHANG H Y, PANG H C, LU C, et al. Subsurface organic amendment plus plastic mulching promotes salt leaching and yield of sunflower[J]. Agronomy Journal, 2019, 111(1): 457−466 doi: 10.2134/agronj2018.02.0097
[43] WONG V N L, GREENE R S B, DALAL R C, et al. Soil carbon dynamics in saline and sodic soils: a review[J]. Soil Use and Management, 2010, 26(1): 2−11 doi: 10.1111/j.1475-2743.2009.00251.x
[44] CHEN B Q, LIU E K, TIAN Q Z, et al. Soil nitrogen dynamics and crop residues: a review[J]. Agronomy for Sustainable Development, 2014, 34(2): 429−442 doi: 10.1007/s13593-014-0207-8
[45] RABENHORST M C, WILDING L, WEST L T. Identification of pedogenic carbonates using stable carbon isotope and microfabric analyses[J]. Soil Science Society of America Journal, 1984, 48: 125−132 doi: 10.2136/sssaj1984.03615995004800010023x
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