短期免耕对黑土有机碳、全氮和速效养分的影响

对中层黑土上连续监测了6年的玉米免耕和秋翻两种耕作处理下的耕层土壤有机碳、全氮和速效氮、磷、钾进行了分析。结果表明:耕作处理对土壤养分的影响主要表现在不同的土壤深度上,免耕造成了土壤有机碳和全氮的分层化,即表层0~5 cm有机碳和全氮含量明显高于亚表层,而秋翻土壤有机碳和全氮分布则比较均匀。免耕处理的速效养分均表现为表层与亚表层存在明显差异。免耕处理下有机碳、全氮和速效氮、磷、钾在土壤表层发生明显富集。     

不同土壤耕作方式对东北风沙土区玉米田土壤质量及产量的影响

[目的]研究黑龙江省西部不同土壤耕作方式对玉米产量及土壤性状的影响,为该地区农业生产提供参考。[方法]比较常规耕作、旋耕、翻耕、深翻和超深翻耕作对玉米产量和土壤物理特性的影响。[结果]翻耕和超深翻耕作增加了土壤含水量和田间持水量,降低了耕层土壤渗透速率、土壤容重和土壤紧实度,但是增加犁底层土壤渗透速率、土壤容重和土壤紧实度。翻耕、深翻和超深翻处理耕层土壤三相结构距离(STPSD)和土壤结构指数(GSSI)较好;翻耕、深翻和超深翻处理显著降低犁底层土壤的GSSI,增加STPSD;旋耕处理没有显著影响犁底层土壤GSSI和STPSD。与常规耕作处理相比,翻耕和超深翻分别增加玉米产量7.6%和6.0%。翻耕比超深翻玉米产量高10.9%。深翻处理玉米产量为5.58t/hm2,比常规耕作减产8.1%。[结论]在不完全打破犁底层情况下,在黑龙江西部地区翻耕是比较理想的耕作方式。     

耕作措施对双季稻田土壤碳及有机碳储量的影响

针对不同耕作措施对双季稻田的固碳效应和固碳潜力问题,选择湖南省宁乡县的双季稻区试验点进行了有机碳、活性有机碳以及耕层有机碳储量的研究,以期为制定适合于稻田条件下的合理耕作方式提供理论依据。结果表明,耕作措施和秸秆还田对有机碳（SOC）和活性有机碳（AOC）含量均产生不同程度的影响。免耕处理下,有机碳和活性有机碳含量皆随土壤深度的增加而减少,土壤0～5cm的SOC和AOC的含量最高,且与其他层次达到显著性差异水平（P＆lt;0.05）,具有明显的表层富集现象。与免耕相比,旋耕和翻耕则更利于5～10cm和10～20cm土层的有机碳和活性有机碳的积累。比较秸秆还田对SOC和AOC的影响表明,秸秆还田有效地提高了0～10cm有机碳含量,但对10～20cm并未产生显著影响,秸秆的输入并未增加土壤活性有机碳的含量。采用等质量方法计算了耕层土壤有机碳储量,结果显示旋耕秸秆还田使有机碳储量明显增加,而免耕只增加了土壤0～5cm和5～10cm土层有机碳储量,10～20cm有机碳储量有所降低,但耕作措施对有机碳储量的长效作用还有待于进一步研究。     

Short-term effects of tillage practices on soil aggregate fractions in a Chinese Mollisol

Abstract

Soil aggregate-size distribution and soil aggregate stability are used to characterize soil structure. Quantifying the changes of structural stability of soil is an important element in assessing soil and crop management practices. A 5-year tillage experiment consisting of no till (NT), moldboard plow (MP) and ridge tillage (RT), was used to study soil water-stable aggregate size distribution, aggregate stability and aggregate-associated soil organic carbon (SOC) at four soil depths (0–5, 5–10, 10–20 and 20–30 cm) of a clay loam soil in northeast China. Nonlinear fractal dimension (D_m) was used to characterize soil aggregate stability. No tillage led to a significantly greater aggregation for >1 mm aggregate and significant SOC changes in this fraction at 0–5 cm depth. There were significant positive relationships between SOC and >1 mm aggregate, SOC in each aggregate fraction, but there was no relationship between soil aggregate parameters (the proportion of soil aggregates, aggregate-associated SOC and soil stability) and soil bulk density. After 5 years, there was no difference in D_m of soil aggregate size distribution among tillage treatments, which suggested that D_m could not be used as an indicator to assess short-term effects of tillage practices on soil aggregation. In the short term, > 1 mm soil aggregate was a better indicator to characterize the impacts of tillage practices on quality of a Chinese Mollisol, particularly in the near-surface layer of the soil.     

不同耕作方式对中国东北黑土有机碳的短期影响

A tillage experiment, consisting of moldboard plow （MP）, ridge tillage （RT）, and no-tillage （NT）, was performed in a randomized complete block design with four replicates to study the effect of 3-year tillage management on SOC content and its distribution in surface layer （30 cm） of a clay loam soil in northeast China. NT did not lead to significant increase of SOC in topsoil （0-5 cm） compared with MP and RT; however, the SOC content in NT soil was remarkably reduced at a depth of 5-20 cm. Accordingly, short-term （3-year） NT management tended to stratify SOC concentration, but not necessarily increase its storage in the plow layer for the soil.     

Soil carbon and nitrogen accumulation with long-term no-till versus moldboard plowing overestimated with tilled-zone sampling depths

Numerous investigators of tillage system impacts on soil organic carbon (OC) or total nitrogen (N) have limited their soil sampling to depths either at or just below the deepest tillage treatment in their experiments. This has resulted in an over-emphasis on OC and N changes in the near-surface zones and limited knowledge of crop and tillage system impacts below the maximum depth of soil disturbance by tillage implements. The objective of this study was to assess impacts of long-term (28 years) tillage and crop rotation on OC and N content and depth distribution together with bulk density and pH on a dark-colored Chalmers silty clay loam in Indiana. Soil samples were taken to 1 m depth in six depth increments from moldboard plow and no-till treatments in continuous corn and soybean–corn rotation. Rotation systems had little impact on the measured soil properties; OC content under continuous corn was not superior to the soybean–corn rotation in either no-till or moldboard plow systems. The increase in OC (on a mass per unit area basis) with no-till relative to moldboard plow averaged 23 t ha⁻¹ to a constant 30 cm sampling depth, but only 10 t ha⁻¹ to a constant 1.0 m sampling depth. Similarly, the increase in N with no-till was 1.9 t ha⁻¹ to a constant 30 cm sampling depth, but only 1.4 t ha⁻¹ to a constant 1.0 m sampling depth. Tillage treatments also had significant effects on soil bulk density and pH. Distribution of OC and N with soil depth differed dramatically under the different tillage systems. While no-till clearly resulted in more OC and N accumulation in the surface 15 cm than moldboard plow, the relative no-till advantage declined sharply with depth. Indeed, moldboard plowing resulted in substantially more OC and N, relative to no-till, in the 30–50 cm depth interval despite moldboard plowing consistently to less than a 25 cm depth. Our results suggest that conclusions about OC or N gains under long-term no-till are highly dependent on sampling depth and, therefore, tillage comparisons should be based on samples taken well beyond the deepest tillage depth.     

免耕秸秆还田和传统耕作方式下东北黑土氨基糖态碳的积累特征

以吉林德惠市中层黑土进行7年田间定位试验的小区土壤为研究对象,对免耕(NT)和传统耕作下(CT)耕层(0～20 cm)氨基糖态碳含量的变化特征进行了分析。结果表明,与传统耕作相比,实施免耕7年后整个耕层土壤中氨基糖态碳含量显著增加(p<0.05),以表层(0～5 cm)增加幅度最大,高达94.7%。说明在研究地区,免耕措施有利于微生物代谢物如细胞壁物质等作为潜在的碳源逐渐积累在土壤中。免耕土壤中不同微生物来源氨基糖态碳的含量均较传统耕作有显著增加,但是变化特征有所不同,其中免耕条件下真菌来源的氨基葡萄糖的积累量较传统耕作高出1倍多,而且氨基葡萄糖与细菌来源的胞壁酸的比值(6.9～7.3)显著高于传统耕作(4.7～5.4),暗示实施免耕秸秆还田7年后土壤中真菌已逐渐转为优势群体,而真菌占优势的农田生态系统具有更大的固碳潜力。     

Tillage and residue management effects on β-glucosaminidase activity in soils

There is an increasing interest in assessing the effects of tillage systems and residue management on biochemical processes, especially enzyme activities, of soils. This study was carried out to investigate the effects of three tillage systems (no-till, chisel plow and moldboard plow) and four residue placements (bare, normal, mulch and double mulch) on the activity of N-acetyl-β-glucosaminidase (NAGase, EC 3.2.1.30) involved in C and N cycling in soils. The activity values were significantly affected by tillage and residue management practices, being greatest in soils with no-till/double mulch and least with no-till/bare and moldboard/normal. Also, they were the highest under no-till/ double mulch-treated soils. Linear regression analyses showed that the activity of NAGase was significantly correlated with organic C in the surface soils (r=0.89***) and with organic C content at different depths (r=0.97***). The NAGase activity values were significantly correlated with the arylamidase activity values of the soils (r=0.63**), suggesting that tillage and residue management practices have similar impacts on the activities of these enzymes. The activity of this enzyme decreased markedly with increasing depth of the surface soil (0-15 cm) of the no-till/ double mulch-treated plots.     

Soil organic matter quality as influenced by tillage,lime, and phosphorus

In Eastern Canada, cereal yields are often restricted by soil acidity and low fertility. Continuous cereal production can also lead to soil structural degradation. The addition of lime and fertilizers and the adoption of conversation tillage practices are proposed solutions which may have a positive impact on soil quality. The objective of the present work was to assess the impact of 3 years of different tillage practices and P additions, and of a single lime addition on organic C and total N, microbial biomass C, and on N mineralization at the surface layer (0–7.5 cm) of a Courval sandy clay loam (Humic Gleysol). The easily mineralizable N, total amount of N mineralized in 22.1 weeks, the rate of N mineralization, and microbial biomass C were significantly greater in the minimum tillage than in the moldboard plow treatment. Chisel plow treatment showed intermediate values. The ratios of potentially mineralizable N and of easily mineralizable to total soil N were also significantly larger under minimum tillage and chisel plowing than under moldboard plowing. The lime and P treatments had no significant effect on the measured soil quality parameters. The total amount of N mineralized per unit of biomass C decreased as the tillage intensity increased, suggesting a decrease in the efficiency of the biomass in transforming organic N into potentially plant-available forms and thus a loss in soil organic matter quality. The results of this study indicate that conservation tillage practices such as rototilling and chisel plowing are efficient ways of maintaining soil organic matter quality when old pastures are brought back into cultivation.     

北方农牧交错带免耕对农田耕层土壤温度的影响

针对北方农牧交错带部分地区免耕措施生态效益好但作物产量有所下降的现状，为了找出影响作物生长的因素，对比分析了免耕和翻耕两种耕作方式下耕层土壤温度的变化。结果表明：免耕地升温和降温都比较缓慢且幅度小，翻耕地土壤温度在日间总体高于免耕地。在垂直方向上，土壤温度随土层深度降低，但一天中不同时刻的表现差异显著。土壤温度变化与当时气温呈正相关关系, 相关系数大于0.5。与免耕地相比，翻耕地气温与土壤温度的直线回归关系更显著。受土壤温度等物理性状的影响，免耕地作物生物量及产量明显不如翻耕地。因此，北方农牧交错带要通过农艺措施改善土壤物理结构，提高免耕农田作物产量。     

耕作与轮作方式对黑土有机碳和全氮储量的影响

土壤有机碳(SOC)及全氮(TN)对土壤肥力、作物产量、农业可持续发展以及全球碳、氮循环等都具有重要影响。为探索不同耕作和轮作方式对耕层黑土SOC和TN储量的影响,本文以吉林省德惠市进行了8 a的田间定位试验中层黑土为研究对象,对免耕、垄作和秋翻三种耕作方式及玉米-大豆轮作和玉米连作两种轮作方式下SOC和TN在各土层的含量变化进行了分析,并采用等质量土壤有机质储量计算方法,对比分析了不同处理对0～30 cm SOC和TN储量的影响。结果表明,与试验开始前相比,玉米-大豆轮作系统中,秋翻下SOC和TN储量均有所降低;免耕显著增加了0～5 cm SOC及TN含量,但SOC在亚表层亏损,导致其储量并未增加;而垄作处理下SOC及TN含量在0～5、5～10 cm的均显著增加,0～30 cm储量亦分别增加了4.9%和10.7%。玉米连作系统的两种耕作处理(免耕和秋翻)下SOC和TN储量均有所增加,且TN储量增幅均高于玉米-大豆轮作系统,其中免耕下TN储量增幅是玉米-大豆轮作的3.2倍。所有处理下C/N均呈降低趋势,其中垄作0～5 cm C/N由12.05降至11.04,降低幅度分别是免耕和秋翻的3.2和2.8倍。综上可知,对质地黏重排水不良的中层黑土,玉米-大豆轮作系统下免耕并不是促进SOC固定的有效形式,而垄作则促进了黑土SOC和TN的积累,这不仅有利于土壤肥力的改善,而且是使农田黑土由CO2"源"变为"汇"的有效形式之一。与玉米-大豆轮作相比,玉米连作下三种耕作方式都有利于SOC和TN积累。     

秸秆还田方式与施氮量对春玉米产量及干物质和氮素积累、转运的影响

【目的】 探讨秸秆还田方式与施氮量对东北春玉米产量、干物质和氮素积累、转运的影响,明确适宜的秸秆还田方式及施氮量。 【方法】 连续两年在辽宁铁岭市进行了田间试验。设置秸秆还田方式 (旋耕、翻耕) 与施氮量两因素田间定位试验,研究了春玉米产量及干物质和氮素积累、转运特性。 【结果】 秸秆旋耕和翻耕还田产量和籽粒氮素积累量差异并不显著,但前者显著增加了地上部干物质和氮素积累量,及花后氮素积累量、花后干物质积累对籽粒干物质积累贡献率、花后氮素积累对籽粒氮素积累贡献率,而后者则显著提高了花前营养器官干物质、氮素转运量和转运率,花前营养器官干物质和氮素转运对籽粒干物质和氮素积累贡献率分别达到了12.4%、44.1%。随着施氮量的增加,产量和籽粒氮素积累量,地上部干物质和氮素积累量呈逐渐增大的趋势。但施氮量超过262.5 kg/hm2后,产量和籽粒氮素积累量差异则不显著。施氮量262.5 kg/hm2时,花前营养器官干物质和氮素转运量和转运率最高,花前营养器官干物质和氮素转运对籽粒干物质和氮素积累贡献率分别达到了16.7%、45.2%。 【结论】 短期秸秆旋耕和翻耕还田,春玉米产量和籽粒氮素积累量差异不显著,然而秸秆旋耕还田作业成本较低,且配施262.5 kg/hm2氮产量较高,可作为秸秆还田初期推荐施氮量。      

免耕对黑土春夏季节温度和水分的影响

通过田间定位试验,研究免耕与常规耕作对东北黑土区玉米和大豆生长早期土壤温度和水分的影响。研究结果表明:播种前,由于免耕与常规耕作(秋翻)覆盖率和含水量不同,免耕处理的玉米和大豆小区土壤的白天5cm地温均低于常规耕作处理,夜间差异不大;相同深度的玉米和大豆秋翻处理土壤日平均温度分别比免耕高0. 7℃和0. 5℃;随土壤深度的增加,土壤温度的差异逐渐减小。播种后,除了下午免耕5cm地温略低于秋翻外,下午至夜间免耕的10cm和15cm地温,均略高于秋翻的土壤温度。这是由于免耕下土壤水分增高引起的土壤热容量加大,从而缓解夜间降温和寒流影响,减缓土壤温度下降的结果。播种前,免耕处理的玉米和大豆地土壤水分分别比秋翻处理高2. 4%和1. 8%。播种后的一个月期间,免耕大豆土壤含水量比秋翻高2. 3%。初步的研究结果表明,免耕可以在一定程度上缓解春季黑土墒情不好的问题,这对保证出苗和幼苗的健康生长非常重要。     

Tillage and residue management effects on arylamidase activity in soils

Recent interest in soil tillage and residue management has focused on low-input sustainable agriculture. This study was conducted to investigate the effect of three tillage systems (no-till, chisel plow, and moldboard plow) and four residue placements (bare, normal, mulch, and double mulch) on a most recently detected enzyme in soils, arylamidase activity. This enzyme catalyzes the hydrolysis of an N-terminal amino acid from peptides, amides, or arylamides. Results showed that arylamidase activity is greatly affected by tillage and crop residue placement. The greatest activity was found with chisel/mulch, moldboard plow/mulch, and no-till/double mulch, and the lowest with moldboard plow/normal and no-till/bare. Arylamidase activity was significantly correlated with organic C (r=0.59**) and soil pH _CaCl2 (r=0.55**)_, and decreased with soil depth. Results of this work suggest that the activity of this enzyme is affected by soil management, and indicate its potential ecological significance because of its role in the N cycle.     

Effect of conservation tillage on crop yield and soil organic carbon in Northeast China: A meta-analysis

Northeast China, the important grain-producing region in China, is under threat from soil degradation because of long-term conventional tillage (CT). The adoption of conservation tillage is anticipated to restore soil fertility, maintain crop yields and enhance sustainability. However, the integrated effects of conservation tillage practice on crop yields and soil organic carbon (SOC) remain unclear. In this meta-analysis of peer-reviewed studies conducted in the Northeast China region, we assess crop yields and SOC values under no-till, ridge tillage and subsoiling tillage practices. The results indicate that in areas with mean annual temperatures (MAT) below 3°C, crop yields were significantly (p < .05) higher under ridge tillage (0.8%) and subsoiling tillage (13.1%) compared with CT, whereas yields reduced under no-till (−3.7%). Ridge tillage generally had a similar effect on crop yield as no-till, without the negative impact in colder regions. We also report that no-till practice increased SOC concentrations by 24.1%, 43.9% and 17.4% in areas of higher temperature (MAT > 6°C), low mean annual precipitation (MAP) (<500 mm) and continuous cropping conditions, respectively. Ridge tillage and subsoiling tillage also had positive effects on SOC concentrations (to a lesser degree than no-till), indicating that conservation tillage can enhance SOC in Northeast China. Overall, the implementation of different conservation tillage measures in Northeast China was found to enhance crop yields and sequester carbon. We recommend that ridge tillage is used in colder areas and that subsoiling tillage is used in rotation with other tillage measures to maintain crop yields.     

An approach for draft prediction of combination tillage implements in sandy clay loam soil

A methodology to predict the draft requirements of combination tillage implements in any soil and operating conditions was developed. This methodology required the draft requirements of individual tillage implements in undisturbed soil condition and draft utilization ratio of the rear passive set of combination tillage implement, which is defined as the ratio of the drafts of the rear passive set operating in combination and individually. Laboratory experiments were conducted to measure the draft requirements of a reference tillage tool (single disk), three scale-model individual (moldboard plow, cultivator and disk gang) and two combination (moldboard plow with disk gang and cultivator with disk gang) tillage implements at different depths (5, 7.5 and 10 cm), speeds (1.2, 2.2, 3.2 and 4.2 km/h), wet bulk densities (in the range of 1.27–1.85 g/cm³) and cone index penetration resistance values (in the range of 445–1450 kPa) in soil bin filled with sandy clay loam soil. The average draft utilization ratio of the reference tillage tool obtained were analyzed by both orthogonal and multiple regression techniques to develop the regression equation considering soil properties, operating and tool parameters. The developed draft equation based on the above mentioned methodology was verified with the data obtained for the draft of scale-model and prototype combination tillage implements in the laboratory and field conditions, respectively. It was found that the developed equation predicted the draft of both combination tillage implements within an average absolute variation of 18.0 and 13.5%, respectively.     

Soil Hydraulic Properties: Influence of Tillage and Cover Crops

Understanding the effects of cover crops and tillage on soil physical properties is important for determining soil productivity. This study was conducted at Lincoln University's Freeman Center, USA to evaluate the effects of tillage and cover crop management on soil hydraulic properties. The field site included three replicate blocks in a randomized complete block design with each plot measuring 21.3 m in length and 12.2 m in width. Treatment factors were tillage at two levels(moldboard plow tillage vs. no tillage) and cover crop at two levels(cereal rye(Secale cereal) cover crop vs. no cover crop). Soil samples were collected in late spring/early summer from each treatment at 10-cm depth increments from the soil surface to a depth of 40 cm using cores(76.2-mm diameter and 76.2-mm length). Soil bulk density was 13% lower with tillage compared with no-tillage. Volumetric water content was significantly higher at 0.0 and -0.4 k Pa pressures with tillage compared with no tillage. Tillage increased the proportion of coarse mesopores by 32% compared with no tillage, resulting in 87% higher saturated hydraulic conductivity(K_(sat)). Cover crop increased the proportion of macropores by 24% compared with no cover crop; this can potentially increase water infiltration and reduce runoff. As a result of higher macroporosity, Ksat was higher under cover crop compared with no cover crop. This study demonstrated that tillage can benefit soil hydraulic properties in the short term, but these effects may not persist over time. Cover crops may slightly improve soil hydraulic properties, but longer term studies are needed to evaluate the long-term effects.     

Earthworm populations and growth rates related to long-term crop residue and tillage management

Conventional tillage creates soil physical conditions that may restrict earthworm movement and accelerate crop residue decomposition, thus reducing the food supply for earthworms. These negative impacts may be alleviated by retaining crop residues in agroecosystems. The objective of this study was to determine the effects of various tillage and crop residue management practices on earthworm populations in the field and earthworm growth under controlled conditions. Population assessments were conducted at two long-term (15+ years) experimental sites in Québec, Canada with three tillage systems: moldboard plow/disk harrow (CT), chisel plow or disk harrow (RT) and no tillage (NT), as well as two levels of crop residue inputs (high and low). Earthworm growth was assessed in intact soil cores from both sites. In the field, earthworm populations and biomass were greater with long-term NT than CT and RT practices, but not affected by crop residue management. Laboratory growth rates of Aporrectodea turgida (Eisen) in intact soil cores were affected by tillage and residue inputs, and were positively correlated with the soil organic C pool, suggesting that tillage and residue management practices that increase the soil organic C pool provide more organic substrates for earthworm growth. The highest earthworm growth rates were in soils from RT plots with high residue input, which differed from the response of earthworm populations to tillage and residue management treatments in the field. Our results suggest that tillage-induced disturbance probably has a greater impact than food availability on earthworm populations in cool, humid agroecosystems.     

不同耕法及秸秆还田对土壤水分运移变化的影响

[目的]探讨不同耕法与秸秆还田方式下,旱地草甸土土壤水分随深度运移的变化,为今后生产中因地制宜制定科学合理的耕作与培肥技术提供理论依据。[方法]采用田间定位试验,研究3种耕法免耕、浅翻、深翻与3种秸秆还田方式覆盖还田、浅翻还田、深翻还田条件下,作物生长不同时期、不同深度土层土壤含水量、田间持水量和容重的变化。[结果]土壤水分的年际间变化与降水量和降水变率有一定的关系。秸秆不还田条件下,连续2 a免耕,年际间土壤含水量随深度变化的特征曲线基本一致,0—20 cm耕层田间持水量降低13.62%,而浅翻与深翻分别增加11.32%和27.98%;耕翻深度对20—30 cm土层水分的影响较大,随作物生长和地表覆盖度增加,40 cm以下土层含水量的变化减弱。秸秆还田条件下,0—20 cm耕层浅翻还田与深翻还田田间持水量分别增加16.24%,5.08%,而土壤容重降低0.12,0.09 g/cm~3。[结论]同一耕法有秸秆还田处理土壤水分含量高于无秸秆还田,降水量越少,差异越明显。与免耕和免耕覆盖比较,翻耕与翻耕还田均增加了作物生长期间土壤含水量,提高了作物抗旱能力,产量有增加趋势。     

Seasonal variation of microbial biomass, activity, and community structure in soil under different tillage and phosphorus management practices

No-tillage systems contribute to physical, chemical and biological changes in the soil. The effects of different tillage practices and phosphorus (P) fertilization on soil microbial biomass, activity, and community structure were studied during the maize growing season in a maize–soybean rotation established for 18 years in eastern Canada. Soil samples were collected at two depths (0–10 and 10–20 cm) under mouldboard plow (MP) and no-till (NT) management and fertilized with 0, 17.5, and 35 kg P ha^?1. Results show that the duration of the growing season had a greater effect on soil microbiota properties than soil tillage or P fertilization at both soil depths. Seasonal fluctuations in soil microbial biomass carbon (SMB-C) and nitrogen (SMB-N), in dehydrogenase and alkaline phosphomonoesterase activities, and in total phospholipids fatty acid (PLFA) level, were greater under NT than MP management. The PLFA biomarkers separated treatments primarily by sampling date and secondly by tillage management, but were not significantly affected by P fertilization. The abundance of arbuscular mycorrhizal fungi (AMF; C16:1ω5) and fungi (C18:2ω6,9) was lower under NT than MP at the 10–20-cm soil depth in July. Phosphorus fertilization increased soil microbial biomass phosphorus (SMB-P) and Mehlich-3 extractable P, but had a limited impact on the other soil properties. In conclusion, soil environmental factors and tillage had a greater effect on microorganisms (biomass and activity) and community structure than P fertilization.