Effects of long-term combined application of chemical fertilizer and organic materials on stoichiometry of soil microbial biomass and enzyme activity in subtropical paddy fields
-
摘要:目的
利用肥料长期定位试验，研究化肥与不同有机物料配施下，亚热带稻田土壤的微生物生物量碳氮磷含量、土壤胞外酶活性及其化学计量比的差异，揭示不同有机肥源对土壤微生物生物量稳定性的影响特征。
方法依托位于湖南省宁乡市农技中心的稻田长期定位试验(始于1986年)，选取5个施肥处理，分别为不施肥对照(CK)、单施化肥(NPK)、30%猪粪有机肥替代化肥氮(30%OM)、60%猪粪有机肥替代化肥氮(60%OM)、秸秆还田+化肥(NPKS)，种植制度为一年三熟，早稻−晚稻−大麦轮作。于2022年9月晚稻成熟期采集表层(0—20 cm)土壤样品，测定土壤有机碳(SOC)、全氮(TN)、全磷(TP)含量，微生物生物量碳、氮、磷(MBC、MBN、MBP)含量和β-葡萄糖苷酶(βG)、β-N-乙酰氨基葡萄糖苷酶(NAG)、酸性磷酸酶(ACP)活性，并计算化学计量比。
结果长期施肥显著提高了土壤SOC、TN和TP含量，60%OM处理3个指标的增幅均最高(P<0.05)，30%OM处理的增幅也显著高于NPK处理，而NPKS处理的TN增幅与NPK处理相当。3个有机无机肥配合处理之间土壤C/N无显著差异，而NPKS处理的C/P和N/P均显著高于60%OM和30%OM处理。3个有机无机肥配合处理MBC含量无显著差异，均高于NPK处理；MBN和MBP含量均以60%OM处理最高，显著高于其他处理，其次为30%OM处理，NPKS处理MBN含量高于NPK处理，而MBP含量与NPK处理相当，因而NPKS处理的MBC/MBN和MBC/MBP均显著高于两个猪粪处理，低于NPK处理。与CK相比，NPK处理仅显著增加了βG活性，而有机无机肥配施提高了土壤βG、NAG和ACP活性，30%OM处理土壤中的βG/NAG和βG/ACP显著高于NPK处理，而60%OM处理则显著低于NPK处理。相关性分析表明，土壤微生物生物量及其化学计量，以及βG和ACP活性，均与土壤碳、氮、磷含量及其化学计量呈正相关。进一步冗余分析表明，土壤TP含量和N/P是驱动土壤微生物生物量及其化学计量变化的关键因子。
结论长期将化肥与有机肥配合施用，能显著提升稻田土壤的有机碳、全氮和全磷含量，同时增加微生物生物量和胞外酶活性。其中，以60%的猪粪替代化肥氮的效果最为突出，不仅显著提高了土壤碳、氮、磷的含量，而且显著增加了微生物生物量碳、氮、磷含量，但降低了胞外酶化学计量比，并维持较低的胞外酶化学计量平衡。因此，猪粪与氮磷钾配施通过增加土壤有机碳、氮、磷投入，维持较稳定的积累，进而提升土壤肥力，提高适应环境变化的能力。而氮磷钾与秸秆配施可能造成土壤磷素的限制，降低土壤养分的供应能力。
Abstract:ObjectivesIn order to reveal the influence of different organic fertilizer sources on the stability of soil microbial carbon, nitrogen and phosphorus content, soil extracellular enzyme activity and stoichiometric ratio of soil microbial biomass under the combination of fertilizer and different organic materials were studied by long-term positioning experiment of fertilizer.
MethodsThe study was based on a long-term field experiment located in the Agricultural Technology Center of Ningxiang City (since 1986). Five fertilization treatments were selected including no fertilizer (CK), chemical fertilizer (NPK), 30% pig manure organic fertilizer replaces fertilizer nitrogen (30%OM), 60% pig manure organic fertilizer replaces fertilizer nitrogen (60%OM) and chemical fertilizer with rice straw (NPKS), the planting system is three crops per year, early rice-late rice-barley rotation. Soil samples (0−20 cm) were collected at the mature stage of late rice in September 2022. Soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP) contents, microbial biomass carbon, nitrogen, phosphorus (MBC, MBN, MBP) contents, and β-glucosidase (βG), β-N-acetylglucosaminidase (NAG) and acid phosphatase (ACP) activities were determined, and the stoichiometric ratio was calculated.
ResultsLong-term fertilization significantly increased SOC, TN and TP contents in soil, and 60%OM treatment had the highest increases (P<0.05). The increase of 30%OM was also significantly higher than that of NPK treatment, while the increase of TN in NPKS treatment was similar to that in NPK treatment. There was no significant difference in soil C/N among the three combined treatments, while the C/P and N/P of NPKS treatment were significantly higher than those of 60%OM and 30%OM treatment. There was no significant difference in MBC content among the three organic and inorganic treatments, which was significantly higher than that of NPK treatment. The content of MBN and MBP in 60%OM treatment was the highest, significantly higher than that in other treatments, followed by 30%OM. Meanwhile, the MBN content in the NPKS treatment was higher than that in the NPK treatment, whereas the MBP content was equivalent to that in the NPK treatment. Therefore, the MBC/MBN and MBC/MBP in NPKS treatment were significantly higher than that in both pig manure treatments, and lower than that in NPK treatment. Compared with CK, NPK treatment only increased βG activity, while organic and inorganic application increased βG, NAG and ACP activities in soil. The βG/NAG and βG/ACP in soil treated with 30%OM were significantly higher than those treated with NPK, while those treated with 60%OM were significantly lower than those treated with NPK. Correlation analysis showed that soil microbial biomass and its stoichiometry as well as βG and ACP enzyme activities were positively correlated with soil carbon, nitrogen and phosphorus content and their stoichiometry. Further redundancy analysis showed that soil TP content and N/P were the key factors affecting soil microbial biomass and its stoichiometric changes.
ConclusionsLong-term combined application of chemical fertilizer and organic fertilizer effectively increased the contents of organic carbon, total nitrogen and total phosphorus in paddy soil, and increased microbial biomass and extracellular enzyme activity. In particular, 60% pig manure instead of fertilizer nitrogen had the most significant effect on increasing soil carbon, nitrogen and phosphorus contents, and further increased the contents and ratio of carbon, nitrogen and phosphorus in microbial biomass, but decreased the extracellular enzyme stoichiometric ratio. And maintain a low extracellular enzyme stoichiometric balance. Therefore, the combined application of pig manure and NPK can maintain a relatively stable accumulation by increasing the input of organic carbon, nitrogen and phosphorus in soil, thus improving soil fertility and having a high ability to adapt to environmental changes. The combined application of nitrogen, phosphorus and potassium with straw may limit soil phosphorus and reduce the supply capacity of soil nutrients.
-
土壤微生物是土壤有机质分解转化的关键驱动者，土壤微生物生物量和胞外酶活性是表征土壤养分有效性和土壤质量的重要指标[1−2]。提高土壤微生物生物量以及与土壤碳、氮、磷循环相关的胞外酶活性，可有效提升作物产量、改善土壤质量[3−6]。土壤微生物生物量碳氮磷和酶化学计量比，反映微生物群落代谢活动所需养分与土壤养分有效性之间的生物地球化学平衡[7−9]。土壤微生物生物量碳氮比一般反映土壤微生物群落结构和指示土壤固碳能力，土壤微生物生物量碳磷比可表征土壤无机磷损失的风险域值和预测无机磷转化为有机磷的速率，而土壤微生物生物量氮磷比可用于诊断土壤养分限制作用[10−12]。土壤生物分泌的胞外酶是生物化学反应的关键媒介和催化剂，其中，β-葡萄糖苷酶(βG)、β-N-乙酰氨基葡萄糖苷酶(NAG)、酸性磷酸酶(ACP)分别是催化土壤的碳、氮、磷转化的有代表性的酶，这3种胞外酶含量的比值可敏感指示土壤微生物养分需求和土壤养分周转速率[13]。因此，研究土壤微生物生物量、胞外酶活性和土壤碳、氮、磷养分的平衡关系，对于深入理解驱动土壤碳、氮、磷养分转化的生物地球化学机制，有效提升土壤肥力和生产力具有重要意义[14−15]。
化肥施用或者化肥配合不同有机物料(秸秆、粪肥等)还田所投入的养分量与比例存在差异，从而可能改变土壤和微生物之间的养分平衡，影响微生物代谢过程的养分分配以及土壤胞外酶活性，最终影响土壤碳、氮、磷元素的积累[16−18]。已有大量研究报道了化肥、有机肥以及两者不同配比施用方式对农田土壤肥力的影响，均表明有机肥的施用显著提高了土壤碳氮、磷、养分含量以及微生物生物量，改变了土壤微生物群落结构组成和胞外酶活性[19−22]。土壤中碳、氮、磷元素循环过程是耦合的。与单质化肥相比，有机物料的元素组成更为平衡，土壤微生物介导的元素周转过程也更为复杂。目前，有机物料与化肥配施下土壤养分、微生物生物量以及酶化学计量比的变化及其相互关系仍不明确，有待深入研究。
为深入理解长期化肥与有机物料施用下土壤微生物生物量与胞外酶活性的化学计量特征及其相互关系，本研究依托位于湖南省宁乡市的稻田长期施肥定位试验，分析不同施肥处理下土壤微生物生物量和胞外酶活性差异，探讨土壤微生物及胞外酶活性计量比对长期化肥配施有机物料的响应特征，揭示不同施肥措施对农田土壤碳、氮、磷转化生物地球化学特征的影响，以期为区域农田土壤养分调控和土地资源的可持续利用提供科学依据。
1. 材料与方法
1.1 试验地概况
长期定位试验位于湖南省宁乡市农技中心(28°07′N，112°18′E)，始于1986年。该地区为典型的双季稻主产区，属于中亚热带湿润季风气候，海拔36.1 m，年均气温16.8℃，年均降水量1553.7 mm，年均蒸发量1353.9 mm，常年无霜期274天。土壤类型为水稻土。种植制度在1986—1992年间为稻−稻−紫云英，1993年至今为稻−稻−大麦。试验开始前0—20 cm耕层土壤有机碳(SOC)、全氮(TN)和全磷(TP)含量分别为17.05、2.01和0.59 g/kg，土壤pH值为6.85。
1.2 试验设计
本研究选取5个施肥处理：不施任何肥料(CK)；氮、磷、钾化肥平衡施用(NPK)；以30%、60%猪粪有机肥替代化肥处理中30%和60%的氮量(30%OM、60%OM)；水稻收获后秸秆全量还田，化肥氮用量扣除秸秆带入的氮量(NPKS)。早稻秸秆N、P2O5、K2O的含量分别为0.65%、0.13%和0.89%，晚稻秸秆N、P2O5、K2O的含量分别为0.68%、0.15%和0.91%。腐熟猪粪N、P2O5、K2O含量分别为1.77%、0.83%、1.12%。不同施肥处理氮、磷、钾肥施用量如表1所示，氮肥为碳铵或尿素，磷肥为钙镁磷肥，钾肥为氯化钾。各试验小区面积66.7 m2 (10.00 m×6.67 m)，小区之间以水泥埂(埋深100 cm，高出田面35 cm)隔开，以免水肥窜排窜灌。各施肥处理的磷肥、秸秆和有机肥均作为基肥一次性施入，氮肥和钾肥作基肥和追肥分两次施入(基追比7∶3)。田间管理措施按当地习惯方式进行。
表 1 不同施肥处理年均肥料施用量(kg/hm2)Table 1. Annual fertilizer application amounts of different fertilization treatments处理 Treatment 作物 Crop N P2O5 K2O 猪粪 Pig manure 水稻秸秆 Rice straw NPK 早稻 Early rice 142.5 54.0 63.0 0 0 晚稻 Late rice 157.5 43.2 81.0 0 0 大麦 Barley 157.5 43.2 81.0 0 0 30%OM 早稻 Early rice 96.0 32.2 33.6 2625 0 晚稻 Late rice 110.2 21.0 51.1 2670 0 大麦 Barley 110.2 21.0 51.1 2670 0 60%OM 早稻 Early rice 49.6 10.4 4.2 5250 0 晚稻 Late rice 63.0 9.7 3.2 5340 0 大麦 Barley 63.0 9.7 3.2 5340 0 NPKS 早稻 Early rice 124.5 50.4 38.3 0 2775 晚稻 Late rice 133.0 37.8 48.2 0 3600 大麦 Barley 133.0 37.8 48.2 0 3600 注：NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。
Note: NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent pig manure replacing 30% and 60% chemical N fertilizer; NPKS represents rice straw return and the insufficient N amount is supplemented with chemical N fertilizer.1.3 土壤样品采集
于2022年9月晚稻成熟期在各施肥处理小区随机选取5～10个采样点，按“S”型路线用土钻采集耕层(0—20 cm)土壤样品，充分混匀置于便携式冰盒中带回实验室。采集的新鲜土样挑去可见的动植物残体、石砾等，分成两部分，一部分过2 mm筛后于4℃冰箱冷藏保存，用于土壤微生物生物量和酶活性的测定，另一部分土样自然风干后分别研磨过2、1和0.149 mm孔径的尼龙筛，用于土壤有机碳、全氮、全磷等基本理化性状的测定。
1.4 测定指标与分析方法
土壤有机碳(SOC)含量采用重铬酸钾氧化硫酸亚铁滴定法测定[23]；全氮(TN)和全磷(TP)含量分别采用浓硫酸消煮法和硝酸−氢氟酸−高氯酸消解法提取，后采用连续流动分析仪(AA3型号，布朗卢比公司，德国)测定。
土壤微生物生物量碳、氮(MBC、MBN)含量采用氯仿熏蒸—0.5 mol/L K2SO4浸提，利用总有机碳分析仪(TOC-V系列CPH/CPN型号，岛津公司，日本)测定，以熏蒸和未熏蒸土样提取液测定的碳、氮差值除以转换系数0.45，计算得出土壤MBC和MBN含量。土壤微生物生物量磷(MBP)采用氯仿熏蒸−0.5 mol/L NaHCO3浸提，连续流动分析仪测定。
土壤β-葡萄糖苷酶(βG)、β-N-乙酰氨基葡萄糖苷酶(NAG)和酸性磷酸酶(ACP)活性采用96微孔酶标板荧光分析法[24]，利用多功能酶标仪(Scientific Fluoroskan Ascent FL, Thermo)在激发波长365 nm、发射波长450 nm的条件下测定。
1.5 数据处理与统计分析
土壤微生物生物量碳、氮、磷比分别通过MBC/MBN/MBP计算；土壤碳、氮、磷相关酶计量比分别通过βG/NAG/ACP计算；土壤碳、氮、磷比分别采用SOC/TN/TP计算。
采用Microsoft Excel 2021和SPSS 26.0处理数据和统计分析，用Origin 2022绘图。数据通过齐次检验后采用单因素方差分析(One-way ANOVA)和最小显著差异法(LSD)进行处理间的差异性分析(P<0.05为差异显著)。采用Pearson相关性分析和Canoco 5.0冗余分析(RDA)，探讨SOC、TN、TP、胞外酶活性及化学计量特征对土壤微生物生物量及其化学计量的影响。
2. 结果与分析
2.1 长期不同施肥处理土壤碳、氮、磷含量及其化学计量特征
与CK相比，长期施肥处理显著增加了SOC、TN和TP的含量(图1)，以60%OM处理下增加最多，SOC、TN和TP含量分别由CK处理的18.21、1.82、0.36 g/kg增加到27.85、2.81、2.28 g/kg，增幅分别达53%、54%和534%；其次为30%OM和NPKS处理，而NPK处理的增幅最低。相较于NPK处理，化肥与有机物料(有机肥、秸秆)配施由于外源有机物质的输入，更有利于土壤有机质的形成和养分的积累。
![]()
图 1 不同施肥处理土壤有机碳、全氮、全磷含量及其化学计量特征注：CK为不施肥；NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。柱上不同小写字母表示处理间差异显著 (P<0.05)。Figure 1. The contents and stoichiometric ratios of soil organic carbon (SOC), total nitrogen (TN) and phosphorus (TP) under different fertilization treatmentsNote: CK represents no fertilizer control; NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent replacing 30% and 60% chemical fertilizer N with pig manure; NPKS represents rice straw return and the straw N is deducted from chemical fertilizer N. Different lowercase letters above the bars indicate significant difference among treatments (P<0.05).长期不同施肥土壤C/N (9.68～10.01)差异并不显著，但土壤C/P (12.65～51.34)和N/P (1.23～5.10)与CK相比均显著下降，降幅分别介于39%～75%和39%～76%。
2.2 长期不同施肥处理土壤微生物生物量碳、氮磷、含量及其化学计量特征
不同施肥处理对土壤MBC、MBN和MBP含量的影响差异显著(图2)。与CK相比，NPK处理MBC含量显著增加了58%，MBN含量则显著降低了56%；30%OM处理MBC和MBP含量分别显著增加了73%和703%；60%OM处理下MBC、MBN和MBP含量分别显著增加了123%、102%和1742%；NPKS处理仅显著增加了MBC含量，增幅为127%。
![]()
图 2 不同施肥处理土壤微生物生物量碳、氮、磷含量及其化学计量特征注：CK为不施肥；NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。柱上不同小写字母表示处理间差异显著 (P<0.05)。Figure 2. The contents and stoichiometric ratios of soil microbial biomass carbon (MBC), nitrogen (MBN) and phosphorus (MBP) under different fertilization treatmentsNote: CK represents no fertilizer control; NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent replacing 30% and 60% chemical fertilizer N with pig manure; NPKS represents rice straw return and the straw N is deducted from chemical fertilizer N. Different lowercase letters above the bars indicate significant difference among treatments (P<0.05).由于不同施肥处理对微生物生物量碳氮磷含量的影响差异，导致微生物生物量碳氮磷化学计量比在不同施肥处理间亦存在显著差异(图2)。与CK相比，NPK、30%OM和NPKS处理下MBC/MBN分别显著提高了252%、72%和142%，而60%OM处理下MBC/MBN差异不显著；NPK和NPKS处理下MBC/MBP显著提高，而有机无机肥配施处理(30%OM和60%OM)下MBC/MBP显著下降。但是，长期不同施肥处理均显著降低了MBN/MBP，以30%OM和60%OM处理的降幅最大，分别为86%和89%。
2.3 不同施肥处理土壤胞外酶活性及化学计量特征
不同施肥处理土壤βG、NAG和ACP活性差异较大，分别介于15.84～78.99、55.21～340.06和483.85～793.11 nmol/(g·h) (图3)。与CK相比，各施肥处理均显著增加了βG活性，以30%OM处理的增幅最大，达399%，其次为NPKS处理，增幅达258%；NAG活性在60%OM和NPKS处理下显著增加；而ACP活性仅在NPKS处理下明显增加。总体而言，长期单施化肥对土壤胞外酶活性影响不大，而化肥配合有机物料施用对胞外酶活性具有一定的促进作用，且以秸秆还田的效果更为明显。
![]()
图 3 不同施肥处理土壤β-葡萄糖苷酶、β-N-乙酰氨基葡萄糖苷酶、酸性磷酸活性及化学计量特征注：CK为不施肥；NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。方柱上不同小写字母表示处理间差异显著(P<0.05)。Figure 3. The activities and stoichiometric ratios of β-glucosidase (βG), β-N-acetylglucosaminidase (NAG), acid phosphatase (ACP) under different fertilization treatmentsNote: CK represents no fertilizer control; NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent replacing 30% and 60% chemical fertilizer N with pig manure; NPKS represents rice straw return and the straw N is deducted from chemical fertilizer N. Different lowercase letters above the bars indicate significant difference among treatments (P<0.05).不同施肥处理对土壤胞外酶化学计量的影响差异显著(图3)。CK处理下βG/NAG、βG/ACP和NAG/ACP分别为0.47、0.05和0.12。与CK相比，30%OM处理显著增加了βG/NAG (1.12)和βG/ACP (0.13)；而60%OM处理却显著降低βG/NAG (0.15)和βG/ACP (0.04)，仅有NAG/ACP显著升高；NPKS处理下βG/ACP和NAG/ACP均显著升高，而βG/NAG却显著降低。
2.4 土壤微生物生物量、胞外酶化学计量与土壤碳、氮、磷养分计量的关系
由图4可知，土壤MBC、MBN和MBP含量与SOC、TN和TP含量均呈显著或极显著正相关关系。MBC、MBP与C/P和N/P呈显著负相关关系。MBN/MBP与SOC、TN和TP含量呈极显著负相关关系，而与C/P和N/P则呈极显著正相关关系。此外，土壤胞外酶活性与土壤碳氮磷养分之间的相关性较弱，仅有βG和ACP活性与TN和SOC含量之间存在正相关关系。
![]()
图 4 土壤微生物生物量、胞外酶活性与土壤碳氮磷含量及化学计量比之间的相关性注：SOC—土壤有机碳；TN—全氮；TP—全磷；MBC—微生物生物量碳；MBN—微生物生物量氮；MBP—微生物生物量磷；βG—β-葡萄糖苷酶；NAG—β-N-乙酰氨基葡萄糖苷酶；ACP—酸性磷酸酶。红色、蓝色圆点分别代表正、负相关，*、**、***分别表示0.05、0.01、0.001水平显著相关。Figure 4. Correlation between soil microbial biomass, extracellular enzyme activity and soil carbon, nitrogen, phosphorous contents and stoichiometric ratiosNote: SOC—Soil organic carbon; TN—Total nitrogen; TP—Total phosphorus; MBC—Microbial biomass carbon; MBN—Microbial biomass nitrogen; MBP—Microbial biomass phosphorus; βG—β-Glucosidase; NAG—β-N-acetylglucosaminidase; ACP—Acid phosphatase. Red and blue round dot indicate positive and negative correlation, respectively. *, ** and *** indicate significant correlations at 0.05, 0.01, and 0.001 levels, respectively.基于上述相关性分析结果，进一步以不同施肥处理下土壤微生物生物量及其化学计量作为响应变量，土壤碳氮磷含量及化学计量作为解释变量进行冗余分析(RDA)，结果(图5)显示，第1主轴(RDA1)和第2主轴(RDA2)分别解释了总变异的79.97%和0.59%。TP是影响土壤微生物生物量变化的主导因子(P=0.008)，其次是N/P (P=0.008)，两者在调节农田土壤微生物生物量及化学计量比上具有关键作用。
![]()
图 5 土壤微生物生物量与土壤碳氮磷含量及化学计量比之间的冗余分析注：SOC—土壤有机碳；TN—全氮；TP—全磷；MBC—微生物生物量碳；MBN—微生物生物量氮；MBP—微生物生物量磷。蓝色、红色线段分别代表响应变量和解释变量，线段长短代表解释变量对响应变量的影响程度大小。Figure 5. Redundancy analysis of soil microbial biomass with soil carbon, nitrogen, phosphorous contents and stoichiometric ratiosNote: SOC—Soil organic carbon; TN—Total nitrogen; TP—Total phosphorus; MBC—Microbial biomass carbon; MBN—Microbial biomass nitrogen; MBP—Microbial biomass phosphorus. The blue and red line segments indicate the response and explanatory variables, respectively. The length of line segment indicates the influence of the explanatory variable on the response variable.3. 讨论
土壤微生物是土壤中十分活跃的生物组分，参与土壤有机质分解和养分循环过程。土壤微生物生物量是土壤养分的储备库，其含量高低也可表征土壤肥力状况[25]。本研究中长期定位试验结果表明，化肥配施有机物料可改善稻田土壤肥力状况，土壤SOC、TN、TP含量均显著高于不施肥CK，这与前人[26−27]研究结果类似。其原因在于：一方面，猪粪和秸秆本身含有较高的碳、氮、磷等养分，其施用可直接提高土壤有机质和养分水平[28]；另一方面，化肥、猪粪和秸秆等肥料施用促进了水稻增产，增加了水稻根系体积，因而增加了留在土壤中的有机物质量。
全球土壤微生物生物量MBC∶MBN∶MBP值介于60∶7∶1至42∶6∶1，耕地土壤微生物生物量MBC∶MBN∶MBP值介于93∶10∶1至9∶1∶1[10]。不同的MBC∶MBN∶MBP值指示土壤微生物受到不同养分元素、不同程度的限制作用。本研究中，0—20 cm表土C/N为9.68～10.01，处于本区域水稻土耕作层C/N的范围(6.0～35.1)[29]。不同施肥处理土壤的C/N差异不显著，在有机无机肥配施及秸秆还田措施下，SOC和TN含量提升的幅度类似(图1)，这可能导致不同施肥处理土壤C/N差异不明显。这一结果与对荒漠草原和森林生态系统的研究结果基本类似[30−31]。化肥与有机肥配施显著降低了土壤的C/P和N/P，主要可能与施肥处理大幅度提高土壤TP含量有关(图1)，指示土壤磷素的限制作用减弱。
本研究中，土壤MBC含量在NPK、有机肥配施及秸秆还田处理下增加显著，原因可能是化肥以及有机物料的投入改善了土壤碳氮磷的养分状况和有效性，满足了土壤微生物生长所需的碳源和养分，从而促进了生物量的增加。尽管如此，化肥与有机肥配施下MBC/MBP和MBN/MBP相比于对照处理均显著降低，这可能是因为有机肥配施提高了土壤中有效磷的水平，从而为微生物群体提供了丰富的磷源。这暗示，化肥与有机肥配施有助于降低土壤磷素的限制作用，增强土壤磷素的供给能力，提高土壤肥力的稳定性。基于生长速率理论，微生物在高速增殖阶段会加速核糖体RNA的生物合成，这一生理活动可能导致MBC/MBP和MBN/MBP的比值下降[32]；而化肥与秸秆配施则促进了MBC/MBN和MBC/MBP的增加，其原因可能跟秸秆投入促进了土壤微生物呼吸速率和土壤矿化作用，导致土壤微生物生物量增加有关[33]。相关性分析也证明了MBC、MBN和MBP含量与土壤碳氮磷养分含量之间的显著正相关关系(图4)，且冗余分析结果显示TP和N/P对土壤微生物生物量及其化学计量的变化贡献较大(图5)，这也进一步证实了不同施肥措施可能主要通过改变土壤中可利用养分的含量，进而对微生物生物量产生影响。一方面，有机物料的投入提高了土壤磷素的有效性，增加植物根系生物量并进一步促进土壤微生物的生长[34]；另一方面，有机物料的添加促进土壤有机质积累，改善土壤磷素循环，从而促使土壤微生物生物量增加[35]。猪粪中的有机物质易于分解，能快速直接地为微生物提供碳源，秸秆中有机聚合物结构更为复杂，如纤维素、半纤维素和木质素等，这些组成和结构复杂的碳源则需要更多的微生物活动和酶解过程来分解，从而对MBC含量产生更大影响[36]。NPK处理下MBP含量无显著变化，但却显著降低了MBN含量，这与徐阳春等[37]的研究结果一致，其原因可能是：一方面，长期单施化肥会破坏土壤团聚体，导致土壤板结，破坏微生物的生存环境；另一方面，化肥往往以提供氮、磷、钾等主要养分为主，长期单一施用化肥可能导致其他微量元素缺乏，影响微生物的生长和代谢，进而使MBN含量降低[17]。MBP含量在有机肥配施处理下均显著增加，是由于猪粪中含有一定量的磷，施入土壤后可以为微生物提供磷源，促进微生物的生长和繁殖，从而增加MBP含量。各施肥处理下MBN/MBP均显著低于CK，不同比例的有机肥配施处理显著低于单施化肥和化肥配施秸秆处理。相关性分析显示，MBN/MBP与N/P呈极显著正相关关系，而不同比例有机肥配施的N/P远低于单施化肥和化肥配施秸秆，可能是由于氮素的损失途径较多，而磷素在土壤中相对较为稳定[38−39]。
土壤胞外酶是土壤有机质分解和养分循环的催化剂，其活性反映了土壤中各种生物化学过程速率[40]，其活性大小主要受土壤温度、湿度及微生物群落结构等众多因素的影响[41]。酶化学计量比能够反映土壤微生物对碳和养分的需求状况，可作为土壤碳、氮、磷有效性的表征指标[42]。本研究发现，长期不同施肥处理下βG、NAG、ACP活性变化不一。不同施肥处理下βG酶活性均显著增加，这与石丽红等[27]、Zhang等[43]的研究结果一致，可能原因是肥料的输入促进了土壤微生物的代谢和繁殖，改善了土壤健康状况，促进微生物分泌更多参与碳元素循环的酶，从而提高βG酶活性[44−45]。但如果肥料用量超过其最大临界范围，这种促进作用可能不会持续增加[46]，比如60%OM处理对βG酶活性促进作用较小。但是，NPK处理对NAG和ACP活性并无显著影响，可能是因为化肥投入并未直接提供有机碳源，对微生物代谢的促进作用相对较弱，导致NAG和ACP活性对其反应不敏感。NPKS处理对βG、NAG和ACP活性均有促进作用，可能原因是：一方面，有机物料的投入使土壤碳、氮达到适宜水平，养分含量均衡，促进了与碳、氮相关的βG和NAG的分解[47]；另一方面，秸秆分泌的有机酸会将有机磷转化为无机磷，增加ACP活性[13]。本研究结果显示，CK和NPK处理的βG/NAG和βG/ACP均低于全球平均水平(分别为1.14和0.62)[48]，可能存在一定的氮、磷养分限制。相较于CK和NPK处理，30%OM处理下βG/NAG和βG/ACP均显著增加，说明低量有机肥配合化肥施用能够在一定程度缓解氮、磷养分资源限制情况。60%OM处理下βG/NAG和βG/ACP均显著降低，这表明高量有机肥施用可能会加剧氮、磷养分资源限制。NPKS处理下βG/ACP显著升高，βG/NAG却显著降低，表明长期秸秆还田下土壤微生物生长受磷限制亦能得到缓解，但是可能会导致氮养分资源限制。因此，尽管秸秆还田和有机肥的投入刺激了有机质的分解，有效促进了微生物的生长[11]，但是需要考虑适量的有机肥施用比例和秸秆还田量，才能促进土壤氮、磷养分的有效利用。
4. 结论
土壤全磷含量以及N/P决定着微生物量碳氮磷含量、胞外酶活性及其化学计量比。长期施用化肥虽然提高了土壤全磷含量，但同时提高了MBC/MBN和MBC/MBP值，增加了土壤微生物磷的限制，不利于土壤养分的平衡和土壤微生物肥力的稳定。有机无机肥配施处理下的土壤微生物生物量碳、氮、磷含量显著高于氮磷钾化肥平衡施用处理，说明有机无机肥配施有利于提升土壤微生物肥力和增强养分供应能力。化肥配施氮磷含量丰富的有机物料可有效提升土壤微生物碳、氮、磷含量，但配施猪粪的效果优于配施秸秆，而配施秸秆提升土壤胞外酶活性，增强养分供应能力的效果优于配施猪粪。然而，猪粪替代30%化肥氮量条件下，则显著提高土壤中βG/NAG和βG/ACP值，说明土壤微生物氮、磷的限制作用减弱，土壤微生物肥力稳定性升高，养分供应能力增强。配施秸秆对微生物生物量碳氮磷比的降低作用弱于配施猪粪，低比例的猪粪配施能够有效提高土壤碳氮和碳磷相关酶活性的比值。因此，适宜比例的有机肥配施和秸秆还田是改善土壤微生物系统稳定性和养分供应能力的有效策略。
-
![]()
图 1 不同施肥处理土壤有机碳、全氮、全磷含量及其化学计量特征
注：CK为不施肥；NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。柱上不同小写字母表示处理间差异显著 (P<0.05)。
Figure 1. The contents and stoichiometric ratios of soil organic carbon (SOC), total nitrogen (TN) and phosphorus (TP) under different fertilization treatments
Note: CK represents no fertilizer control; NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent replacing 30% and 60% chemical fertilizer N with pig manure; NPKS represents rice straw return and the straw N is deducted from chemical fertilizer N. Different lowercase letters above the bars indicate significant difference among treatments (P<0.05).
![]()
图 2 不同施肥处理土壤微生物生物量碳、氮、磷含量及其化学计量特征
注：CK为不施肥；NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。柱上不同小写字母表示处理间差异显著 (P<0.05)。
Figure 2. The contents and stoichiometric ratios of soil microbial biomass carbon (MBC), nitrogen (MBN) and phosphorus (MBP) under different fertilization treatments
Note: CK represents no fertilizer control; NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent replacing 30% and 60% chemical fertilizer N with pig manure; NPKS represents rice straw return and the straw N is deducted from chemical fertilizer N. Different lowercase letters above the bars indicate significant difference among treatments (P<0.05).
![]()
图 3 不同施肥处理土壤β-葡萄糖苷酶、β-N-乙酰氨基葡萄糖苷酶、酸性磷酸活性及化学计量特征
注：CK为不施肥；NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。方柱上不同小写字母表示处理间差异显著(P<0.05)。
Figure 3. The activities and stoichiometric ratios of β-glucosidase (βG), β-N-acetylglucosaminidase (NAG), acid phosphatase (ACP) under different fertilization treatments
Note: CK represents no fertilizer control; NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent replacing 30% and 60% chemical fertilizer N with pig manure; NPKS represents rice straw return and the straw N is deducted from chemical fertilizer N. Different lowercase letters above the bars indicate significant difference among treatments (P<0.05).
![]()
图 4 土壤微生物生物量、胞外酶活性与土壤碳氮磷含量及化学计量比之间的相关性
注：SOC—土壤有机碳；TN—全氮；TP—全磷；MBC—微生物生物量碳；MBN—微生物生物量氮；MBP—微生物生物量磷；βG—β-葡萄糖苷酶；NAG—β-N-乙酰氨基葡萄糖苷酶；ACP—酸性磷酸酶。红色、蓝色圆点分别代表正、负相关，*、**、***分别表示0.05、0.01、0.001水平显著相关。
Figure 4. Correlation between soil microbial biomass, extracellular enzyme activity and soil carbon, nitrogen, phosphorous contents and stoichiometric ratios
Note: SOC—Soil organic carbon; TN—Total nitrogen; TP—Total phosphorus; MBC—Microbial biomass carbon; MBN—Microbial biomass nitrogen; MBP—Microbial biomass phosphorus; βG—β-Glucosidase; NAG—β-N-acetylglucosaminidase; ACP—Acid phosphatase. Red and blue round dot indicate positive and negative correlation, respectively. *, ** and *** indicate significant correlations at 0.05, 0.01, and 0.001 levels, respectively.
![]()
图 5 土壤微生物生物量与土壤碳氮磷含量及化学计量比之间的冗余分析
注：SOC—土壤有机碳；TN—全氮；TP—全磷；MBC—微生物生物量碳；MBN—微生物生物量氮；MBP—微生物生物量磷。蓝色、红色线段分别代表响应变量和解释变量，线段长短代表解释变量对响应变量的影响程度大小。
Figure 5. Redundancy analysis of soil microbial biomass with soil carbon, nitrogen, phosphorous contents and stoichiometric ratios
Note: SOC—Soil organic carbon; TN—Total nitrogen; TP—Total phosphorus; MBC—Microbial biomass carbon; MBN—Microbial biomass nitrogen; MBP—Microbial biomass phosphorus. The blue and red line segments indicate the response and explanatory variables, respectively. The length of line segment indicates the influence of the explanatory variable on the response variable.
表 1 不同施肥处理年均肥料施用量(kg/hm2)
Table 1 Annual fertilizer application amounts of different fertilization treatments
处理 Treatment 作物 Crop N P2O5 K2O 猪粪 Pig manure 水稻秸秆 Rice straw NPK 早稻 Early rice 142.5 54.0 63.0 0 0 晚稻 Late rice 157.5 43.2 81.0 0 0 大麦 Barley 157.5 43.2 81.0 0 0 30%OM 早稻 Early rice 96.0 32.2 33.6 2625 0 晚稻 Late rice 110.2 21.0 51.1 2670 0 大麦 Barley 110.2 21.0 51.1 2670 0 60%OM 早稻 Early rice 49.6 10.4 4.2 5250 0 晚稻 Late rice 63.0 9.7 3.2 5340 0 大麦 Barley 63.0 9.7 3.2 5340 0 NPKS 早稻 Early rice 124.5 50.4 38.3 0 2775 晚稻 Late rice 133.0 37.8 48.2 0 3600 大麦 Barley 133.0 37.8 48.2 0 3600 注：NPK为氮、磷、钾平衡施肥；30%OM和60%OM分别为30%和60%猪粪有机肥替代化肥氮；NPKS为水稻秸秆全量还田且不足的氮量以化肥氮补充。
Note: NPK represents balanced application of nitrogen, phosphorus and potassium fertilizer; 30%OM and 60%OM represent pig manure replacing 30% and 60% chemical N fertilizer; NPKS represents rice straw return and the insufficient N amount is supplemented with chemical N fertilizer.
下载: 导出CSV
-
[1] 李东坡, 武志杰, 陈利军, 等. 长期培肥黑土微生物量碳动态变化及影响因素[J]. 应用生态学报, 2004, 15(8): 1334−1338. DOI: 10.3321/j.issn:1001-9332.2004.08.007 Li D P, Wu Z J, Chen L J, et al. Dynamics of microbial biomass C in a black soil under long-term fertilization and related affecting factors[J]. Chinese Journal of Applied Ecology, 2004, 15(8): 1334−1338. DOI: 10.3321/j.issn:1001-9332.2004.08.007
[2] Geisseler D, Scow K M. Long-term effects of mineral fertilizers on soil microorganisms − A review[J]. Soil Biology & Biochemistry, 2014, 75: 54−63.
[3] 夏文建, 柳开楼, 张丽芳, 等. 长期施肥对红壤稻田土壤微生物生物量和酶活性的影响[J]. 土壤学报, 2021, 58(3): 628−637. Xia W J, Liu K L, Zhang L F, et al. Effect of long-term fertilization on soil microbial biomass and enzyme activities in reddish paddy soil[J]. Acta Pedologica Sinica, 2021, 58(3): 628−637.
[4] 魏亮, 汤珍珠, 祝贞科, 等. 水稻不同生育期根际与非根际土壤胞外酶对施氮的响应[J]. 环境科学, 2017, 38(8): 3489−3496. Wei L, Tang Z Z, Zhu Z K, et al. Responses of extracellular enzymes to nitrogen application in rice of various ages with rhizosphere and bulk soil[J]. Environmental Science, 2017, 38(8): 3489−3496.
[5] 杜林森, 唐美铃, 祝贞科, 等. 长期施肥对不同深度稻田土壤碳氮水解酶活性的影响特征[J]. 环境科学, 2018, 39(8): 3901−3909. Du L S, Tang M L, Zhu Z K, et al. Effects of long-term fertilization on enzyme activities in profile of paddy soil[J]. Environmental Science, 2018, 39(8): 3901−3909.
[6] Jian S Y, Li J W, Chen J, et al. Soil extracellular enzyme activities, soil carbon and nitrogen storage under nitrogen fertilization: A meta-analysis[J]. Soil Biology & Biochemistry, 2016, 101: 32−43. DOI: 10.1016/j.soilbio.2016.07.003
[7] 陈玉军, 李婷, 朱立安, 等. 淹水梯度对红树林湿地土壤微生物生物量与酶活性的影响[J]. 水土保持通报, 2022, 42(6): 68−75. DOI: 10.3969/j.issn.1000-288X.2022.6.stbctb202206009 Chen Y J, Li T, Zhu L A, et al. Effects of flooding on soil microbial biomass and enzyme activities in a mangrove wetland[J]. Bulletin of Soil and Water Conservation, 2022, 42(6): 68−75. DOI: 10.3969/j.issn.1000-288X.2022.6.stbctb202206009
[8] 魏书蒙, 陈详腾, 赵光宇, 等. 杉木人工林近自然改造对土壤化学性质及酶活性的影响[J]. 生态学报, 2024, 44(10): 4277−4287. Wei S M, Chen X T, Zhao G Y, et al. Effects of closer-to-nature transformation of Chinese fir plantation on soil chemical properties and enzyme activities[J]. Acta Ecologica Sinica, 2024, 44(10): 4277−4287.
[9] Feyissa A, Gurmesa G A, Yang F, et al. Soil enzyme activity and stoichiometry in secondary grasslands along a climatic gradient of subtropical China[J]. Science of the Total Environment, 2022, 825: 154019. DOI: 10.1016/j.scitotenv.2022.154019
[10] Chen G L, Yuan J H, Wang S Q, et al. Soil and microbial C: N: P stoichiometries play vital roles in regulating P transformation in agricultural ecosystems: A review[J]. Pedosphere, 2024, 34(1): 44−51. DOI: 10.1016/j.pedsph.2023.06.002
[11] 崔继文, 徐新朋, 何萍, 等. 氮素有机替代对东北黑土区土壤微生物碳磷资源限制的影响[J]. 植物营养与肥料学报, 2020, 26(11): 1953−1966. DOI: 10.11674/zwyf.20317 Cui J W, Xu X P, He P, et al. Effects of organic nitrogen substitution on soil microobial resources limitation by carbon and phosphorus in black soil of Northeast China[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(11): 1953−1966. DOI: 10.11674/zwyf.20317
[12] 王传杰, 王齐齐, 徐虎, 等. 长期施肥下农田土壤−有机质−微生物的碳氮磷化学计量学特征[J]. 生态学报, 2018, 38(11): 3848−3858. Wang C J, Wang Q Q, Xu H, et al. Carbon, nitrogen and phosphorus stoichiometric characteristics of bulk soil, organic matter, and soil microbial biomass under long-term fertilization in cropland[J]. Acta Ecologica Sinica, 2018, 38(11): 3848−3858.
[13] Schimel J P, Weintraub M N. The implications of exoenzyme activity on microbial carbon and nitrogen limitation in soil: A theoretical model[J]. Soil Biology & Biochemistry, 2003, 35(4): 549−563.
[14] Yang J, Gao W, Ren S R, et al. Long-term effects of combined application of chemical nitrogen with organic materials on crop yields, soil organic carbon and total nitrogen in fluvo-aquic soil[J]. Soil and Tillage Research, 2015, 151: 67−74. DOI: 10.1016/j.still.2015.03.008
[15] 陈飞, 刘方, 白晓永, 等. 喀斯特山地不同微地貌下土壤碳氮磷空间异质性及生态化学计量特征[J]. 生态学报, 2022, 42(24): 10201−10213. Chen F, Liu F, Bai X Y, et al. Spatial heterogeneity and ecological stoichiometric characteristics of soil carbon, nitrogen and phosphorus under different microgeomorphology in Karst mountains[J]. Acta Ecologica Sinica, 2022, 42(24): 10201−10213.
[16] 王绍强, 于贵瑞. 生态系统碳氮磷元素的生态化学计量学特征[J]. 生态学报, 2008, 28(8): 3937−3947. DOI: 10.3321/j.issn:1000-0933.2008.08.054 Wang S Q, Yu G R. Ecological stoichiometric characteristics of carbon, nitrogen and phosphorus elements[J]. Acta Ecologica Sinica, 2008, 28(8): 3937−3947. DOI: 10.3321/j.issn:1000-0933.2008.08.054
[17] 李琳琳, 石宁, 王菲. 不同有机物料改善富磷菜田土壤微生物结构功能和蔬菜磷素吸收利用研究[J]. 植物营养与肥料学报, 2024, 30(1): 114−127. Li L L, Shi N, Wang F. Application of organic materials improves microbial conmunuty structure and vegetable phosphorus nutrition under optimum chemical fertilization[J]. Journal of Plant Nutrition and Fertilizers, 2024, 30(1): 114−127.
[18] 缪玉琳, 梁丰, 谢军, 等. 长期有机肥替代化肥对水稻土有机碳稳定性的影响[J]. 土壤学报, 2023, 60(2): 512−522. DOI: 10.11766/trxb202105260276 Miao Y L, Liang F, Xie J, et al. Effect of long-term organic fertilizer instead of chemical fertilizer on organic carbon stability of paddy soil[J]. Acta Pedologica Sinica, 2023, 60(2): 512−522. DOI: 10.11766/trxb202105260276
[19] Wu L, Zhang W J, Wei W J, et al. Soil organic matter priming and carbon balance after straw addition is regulated by long-term fertilization[J]. Soil Biology & Biochemistry, 2019, 135: 383−391. DOI: 10.1016/j.soilbio.2019.06.003
[20] Zhu Z K, Fang Y Y, Liang Y Q, et al. Stoichiometric regulation of priming effects and soil carbon balance by microbial life strategies[J]. Soil Biology & Biochemistry, 2022, 169: 108669.
[21] 李新悦, 李冰, 王昌全, 等. 长期秸秆还田对水稻土团聚体有机碳及胞外酶的影响[J]. 土壤学报, 2024, 61(1): 235−246. Li X Y, Li B, Wang C Q, et al. Effects of long-term straw returning on organic carbon and extracellular enzymes in paddy soil aggregates[J]. Acta Pedologica Sinica, 2024, 61(1): 235−246.
[22] 程琪, 毛霞丽, 孙涛, 等. 长期化肥与不同有机物料配施对土壤微生物生态化学计量特征和群落结构的影响[J]. 植物营养与肥料学报, 2024, 30(2): 209−220. DOI: 10.11674/zwyf.2023398 Cheng Q, Mao X L, Sun T, et al. Effects of long-term combined application of chemical fertilizers with different organic materials on soil microbial ecological stoichiometry and community structure[J]. Journal of Plant Nutrition and Fertilizers, 2024, 30(2): 209−220. DOI: 10.11674/zwyf.2023398
[23] 鲁如坤. 土壤农业化学分析方法[M]. 北京: 中国农业科技出版社, 2000. Lu R K. Soil agricultural chemistry analysis method[M]. Beijing: China Agricultural Science and Technology Publishing House, 2000.
[24] Saiya-Cork K R, Sinsabaugh R L, Zak D R. The effects of long-term nitrogen deposition on extracellular enzyme activity in an Acer saccharum forest soil[J]. Soil Biology & Biochemistry, 2002, 34(9): 1309−1315. DOI: 10.1016/S0038-0717(02)00074-3
[25] Zhang J H, Li M X, Xu L, et al. C: N: P stoichiometry in terrestrial ecosystems in China[J]. Science of the Total Environment, 2021, 795: 148849. DOI: 10.1016/j.scitotenv.2021.148849
[26] 郭振, 王小利, 徐虎, 等. 长期施用有机肥增加黄壤稻田土壤微生物量碳氮[J]. 植物营养与肥料学报, 2017, 23(5): 1168−1174. DOI: 10.11674/zwyf.17039 Guo Z, Wang X L, Xu H, et al. A large number long-term application of organic fertilizer can efffectively increase microbial biomass carbon and nitrogen in yellow paddy soil[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(5): 1168−1174. DOI: 10.11674/zwyf.17039
[27] 石丽红, 李超, 唐海明, 等. 长期不同施肥措施对双季稻田土壤活性有机碳组分和水解酶活性的影响[J]. 应用生态学报, 2021, 32(3): 921−930. Shi L H, Li C, Tang H M, et al. Effects of long-term fertilizer management on soil labile organic carbon fractions and hydrolase enzyme activity under a double-cropping rice stystem of southern China[J]. Chinese Journal of Applied Ecology, 2021, 32(3): 921−930.
[28] Zhou P, Sheng H, Li Y, et al. Lower C sequestration and N use efficiency by straw incorporation than manure amendment on paddy soils[J]. Agriculture, Ecosystems and Environment, 2016, 219: 93−100. DOI: 10.1016/j.agee.2015.12.012
[29] Sheng H, Yin Z R, Zhou P, et al. Soil C: N: P ratio in subtropical paddy fields: Variation and correlation with environmental controls[J]. Journal of Soils and Sediments, 2022, 22(1): 21−31. DOI: 10.1007/s11368-021-03046-2
[30] 刘姝萱, 安慧, 张馨文, 等. 氮磷添加对荒漠草原土壤养分含量及生态化学计量特征的影响[J]. 环境科学, 2023, 44(5): 2724−2734. Liu S X, An H, Zhang X W, et al. Effects of nitrogen and phosphorus addition on soil nutrient content and stoichiometry in desert grassland[J]. Environmental Science, 2023, 44(5): 2724−2734.
[31] Gao Y, He N P, Yu G R, et al. Long-term effects of different land use types on C, N, and P stoichiometry and storage in subtropical ecosystems: A case study in China[J]. Ecological Engineering, 2014, 67: 171−181. DOI: 10.1016/j.ecoleng.2014.03.013
[32] Liu X, Zhou F, Hu G Q, et al. Dynamic contribution of microbial residues to soil organic matter accumulation influenced by maize straw mulching[J]. Geoderma, 2019, 333: 35−42. DOI: 10.1016/j.geoderma.2018.07.017
[33] 宋大利, 侯胜鹏, 王秀斌, 等. 中国秸秆养分资源数量及替代化肥潜力[J]. 植物营养与肥料学报, 2018, 24(1): 1−21. Song D L, Hou S P, Wang X B, et al. Nutrient resource quantity of crop straw and its potential of substituting[J]. Journal of Plant Nutrition and Fertilizers, 2018, 24(1): 1−21.
[34] Chen C, Xiao W Y. The global positive effect of phosphorus addition on soil microbial biomass[J]. Soil Biology & Biochemistry, 2023, 176: 108882. DOI: 10.1016/j.soilbio.2022.108882
[35] 张燕, 强薇, 罗如熠, 等. 氮磷添加对土壤微生物生长、周转及碳利用效率的影响研究进展[J]. 应用与环境生物学报, 2022, 28(2): 526−534. Zhang Y, Qiang W, Luo R Y, et al. Effects of nitrogen and phosphorus addition on soil microbial growth, turnover, and carbon use efficiency: A review[J]. Chinese Journal of Applied and Environmental Biology, 2022, 28(2): 526−534.
[36] Liu Q Y, Xu X L, Wang H M, et al. Dominant extracellular enzymes in priming of SOM decomposition depend on temperature[J]. Geoderma, 2019, 343: 187−195. DOI: 10.1016/j.geoderma.2019.02.006
[37] 徐阳春, 沈其荣, 冉炜. 长期免耕与施用有机肥对土壤微生物生物量碳、氮、磷的影响[J]. 土壤学报, 2002, 39(1): 89−96. DOI: 10.11766/trxb200103110113 Xu Y C, Shen Q R, Ran W. Effects of zero-tillage and application of manure on soil microbial biomass C, N and P after sixteen years of cropping[J]. Acta Pedologica Sinica, 2002, 39(1): 89−96. DOI: 10.11766/trxb200103110113
[38] Sparling G P, Shepherd T G, Kettles H A. Changes in soil organic C, microbial C and aggregate stability under continuous maize and cereal cropping, and after restoration to pasture in soils from the Manawatu region, New Zealand[J]. Soil and Tillage Research, 1992, 24(3): 225−241. DOI: 10.1016/0167-1987(92)90089-T
[39] 徐一兰, 唐海明, 肖小平, 等. 长期施肥对双季稻田土壤微生物学特性的影响[J]. 生态学报, 2016, 36(18): 5847−5855. Xu Y L, Tang H M, Xiao X P, et al. Effects of different long-term fertilization regimrs on the soil microbiological properties of a paddy field[J]. Acta Ecologica Sinica, 2016, 36(18): 5847−5855.
[40] 姚云柯, 周卫, 孙建光, 等. 田间条件下不同促腐菌对水稻秸秆腐解及胞外酶活性的影响[J]. 植物营养与肥料学报, 2020, 26(11): 2070−2080. DOI: 10.11674/zwyf.20264 Yao Y K, Zhou W, Sun J G, et al. Effects of different straw decomposition inoculants on increasing the activities of extracellular enzymes and decomposition of rice straw buried into soil[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(11): 2070−2080. DOI: 10.11674/zwyf.20264
[41] Xu Z W, Yu G R, Zhang X Y, et al. Soil enzyme activity and stoichiometry in forest ecosystems along the North-South Transect in eastern China (NSTEC)[J]. Soil Biology & Biochemistry, 2017, 104: 152−163. DOI: 10.1016/j.soilbio.2016.10.020
[42] He L Y, Lu S X, Wang C G, et al. Changes in soil organic carbon fractions and enzyme activities in response to tillage practices in the Loess Plateau of China[J]. Soil & Tillage Research, 2021, 209: 104940.
[43] Zhang X Y, Dong W Y, Dai X Q, et al. Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer[J]. Science of the Total Environment, 2015, 536: 59−67. DOI: 10.1016/j.scitotenv.2015.07.043
[44] 郭天财, 宋晓, 马冬云, 等. 施氮量对冬小麦根际土壤酶活性的影响[J]. 应用生态学报, 2008, 19(1): 110−114. Guo T C, Song X, Ma D Y, et al. Effect of nitrogen application rate on soil enzyme activity in wheat rhizosphere[J]. Chinese Journal of Applied Ecology, 2008, 19(1): 110−114.
[45] Chen J, Sinsabaugh R L. Linking microbial functional gene abundance and soil extracellular enzyme activity: Implications for soil carbon dynamics[J]. Global Change Biology, 2021, 27(7): 1322−1325. DOI: 10.1111/gcb.15506
[46] Adetunji A T, Lewu F B, Mulidzi R, et al. The biological activities of β-glucosidase, phosphatase and urease as soil quality indicators: A review[J]. Journal of Soil Science & Plant Nutrition, 2017, 17(3): 794−807.
[47] Zhao S C, Li K J, Zhou W, et al. Changes in soil microbial community, enzyme activities and organic matter ractions under long-term straw return in north-central China[J]. Agriculture, Ecosystems and Environment, 2016, 216: 82−88. DOI: 10.1016/j.agee.2015.09.028
[48] Sinsabaugh R L, Hill B H, Follstad Shah J J. Ecoenzymatic stoichiometry of microbial organic nutrient acquisition in soil and sediment[J]. Nature, 2009, 462: 795−798. DOI: 10.1038/nature08632
计量
- 文章访问数: 244
- HTML全文浏览量: 26
- PDF下载量: 54
