The responses of soil labile organic carbon fractions and enzyme activities to tillage practices are important to address the issues of agricultural sustainability. However, how these critical soil characteristics change throughout the various growth stages of winter wheat under different tillage practices are less clearly understood. A long-term field experiment (11 years) of six tillage practices (no tillage, NT; subsoiling tillage, ST; plow tillage, PT; NT with ST rotation, NT/ST; ST with PT rotation, ST/PT; and PT with NT rotation, PT/NT) was started in the Loess Plateau in 2007, and the changes in soil labile organic carbon fractions and enzyme activities were measured at the sowing, jointing, filling, and harvest stages in 2018. This experiment led to several conclusions: (1) NT/ST, NT, ST, ST/PT, and PT/NT treatments significantly increased soil organic carbon (SOC) by 2.05%-43.93%, microbial biomass carbon (MBC) by 9.13%-84.61%, permanganate oxidizable organic carbon (POXC) by 3.64%-89.62%, and particulate organic carbon (POC) by 6.41%-77.59% throughout all stages of growth when compared with PT; (2) The activities of cellobiohydrolase (CBH), β-glucosidase (BG), β-xylosidase (BXYL), β-N-acetylglucosamines (NAG) and alkaline phosphatase (AP) were 17.15%-169.16%, 2.85%-65.72%, 6.69%-96.99%, 22.76%-136.65% and 0.12%-29.11% higher after the NT/ST, NT, ST, ST/PT, and PT/NT treatments, respectively, than after PT throughout all the stages of growth; (3) These conservation tillage practices improved the soil ecoenzymatic stoichiometry by increasing the ratios of Ln(CBH + BG + BXYL): Ln(AP) and Ln(NAG):Ln(AP) and by reducing the ratio of Ln(CBH + BG + BXYL): Ln(NAG) compared with PT; (4) Soil enzyme activities were positively associated with the SOC fractions. Redundancy analyses (RDA) found that the key factors driving the changes in soil enzyme activities were POXC and SOC at the sowing stage, SOC and MBC at the jointing and harvest stages, and SOC and POC at the filling stage; (5) the NT/ST treatment was associated with the highest SOC fractions, soil enzyme activities and yield, and thus was a sustainable, efficient method to improve soil quality and crop yield in the Loess Plateau.

土壤不稳定的有机碳组分和酶活性对耕作方式的响应对于解决农业可持续性问题很重要。但是，对于这些关键的土壤特性如何在不同耕作方式下的整个冬小麦各个生长阶段发生变化的了解还很少。六个耕作实践的长期野外试验（11年）（不耕作，NT；深松耕作，ST；犁耕，PT； NT带有ST旋转，NT / ST； ST带有PT旋转，ST / PT；和PT随着NT的旋转，PT / NT于2007年在黄土高原开始，并在2018年的播种，拔节，灌浆和收获阶段测量了土壤不稳定有机碳组分和酶活性的变化。结论：（1）NT / ST，NT，ST，ST / PT，和PT / NT处理显着增加了土壤有机碳（SOC）2.05％-43.93％，微生物生物量碳（MBC）9.13％-84.61％，高锰酸盐可氧化有机碳（POXC）3.64％-89.62％和颗粒有机与PT相比，在所有增长阶段的碳（POC）降低了6.41％-77.59％；（2）纤维二糖水解酶（CBH），β-葡萄糖苷酶（BG），β-木糖苷酶（BXYL），β-N-乙酰基葡萄糖胺（NAG）和碱性磷酸酶（AP）的活性分别为17.15％-169.16％，2.85％-65.72在NT / ST，NT，ST，ST / PT和PT / NT处理后的整个阶段中，分别比在PT处理后分别提高％，6.69％-96.99％，22.76％-136.65％和0.12％-29.11％。增长 （3）通过增加Ln（CBH + BG + BXYL）：Ln（AP）和Ln（NAG）的比例，这些保护性耕作方法改善了土壤生态酶化学计量：Ln（AP）并通过降低Ln（CBH + BG + BXYL）：Ln（NAG）与PT的比例来实现；（4）土壤酶活性与SOC组分呈正相关。冗余分析（RDA）发现，影响土壤酶活性变化的关键因素是播种期的POXC和SOC，拔节期和收获期的SOC和MBC以及灌浆期的SOC和POC。（5）NT / ST处理与最高的SOC含量，土壤酶活性和产量相关，因此是提高黄土高原土壤质量和作物产量的可持续，有效方法。拔节阶段的SOC和MBC，灌浆阶段的SOC和POC；（5）NT / ST处理与最高的SOC含量，土壤酶活性和产量相关，因此是提高黄土高原土壤质量和作物产量的可持续，有效方法。拔节阶段的SOC和MBC，灌浆阶段的SOC和POC；（5）NT / ST处理与最高的SOC含量，土壤酶活性和产量相关，因此是提高黄土高原土壤质量和作物产量的可持续，有效方法。