兰州大学机构库
地膜减量背景下接种丛枝菌根真菌对旱地玉米生产力及土壤有机碳的影响及机理
Alternative TitleEffects of arbuscular mycorrhizal fungal inoculation on dryland maize (Zea mays L.) productivity and soil organic carbon and the relevant mechanisms under the scenario of reduced plastic film mul中文ng
任爱天
Subtype博士
Thesis Advisor熊友才
2020-11-01
Degree Grantor兰州大学
Place of Conferral兰州
Degree Discipline生态学
Keyword地膜覆盖 膜减量 旱地玉米 土壤有机碳 AM真菌 秸秆覆盖 黄土高原
Abstract~如何在地膜减量条件下维持旱地玉米生产力,并有助于土壤培肥是目前旱地农业生态系统管理中的关键问题。土壤微生物在农业生态系统中提供了一系列重要的生态服务,尤其是土壤有益微生物-丛枝菌根(AM)真菌。目前在半干旱区地膜覆盖条件下接种外来AM真菌菌种是否能够很好的定殖生长并对作物和土壤产生积极效应仍不清楚。在地膜减量条件下,开展AM真菌的接种对作物产量,土壤有机碳和水分的影响以及AM真菌的多样性的研究很有必要。 本文首先采用meta分析方法,综合评估了黄土高原雨养农业区地膜覆盖条件下玉米生产力及土壤水分和有机碳库的变化。其次通过膜草二元覆盖和一膜两年用耕作实践降低地膜覆盖量的同时接种AM真菌,研究不同农业管理措施对土壤水分、易变有机碳组分、玉米产量和本地自然发生的AM真菌群落的影响。主要结果如下: (一)地膜覆盖条件下玉米生产力及土壤水分平衡和有机碳库的meta分析 1.在年平均降水量250-400 mm、400-500 mm、500-600 mm和>600 mm区域中,地膜覆盖下产量和水分利用效率(WUE)分别提高了142和190%、38.6和35.5%、33.9和32.2%、22.4和30.8%。在年平均降水量240-400 mm时,地膜覆盖促进作用最显著。此外,与半膜覆盖相比,全膜覆盖显著的提高了玉米产量和WUE。施氮水平低于125、125-215和大于215 kg ha-1时,产量和WUE分别增加了47.8%和45.9%、50.2%和46.8%、47.1%和58.2%。地膜覆盖影响着玉米生长季和休耕季土壤的水分动态,但它没有破坏土壤水分的年际平衡。 2.全膜覆盖增加了对玉米地土壤轻组有机碳(LFOC)、颗粒碳(POC)和总有机碳(TOC)消耗。LFOC、POC和TOC的效应值分别为0.92(0.90-0.94),0.96(0.96-0.97)和0.98(0.98-0.99)。说明地膜覆盖对易变有机碳有显著的负作用,而对易氧化有机碳(EOC)和微生物生物量碳(MBC)没有显著的影响。 (二)玉米产量、土壤水分、土壤有机碳组分和AM真菌群落对不同农业管理措施的响应 3.在第二个生长季,膜草二元覆盖试验(地膜用量是全膜覆盖的2/3)和一膜两年用试验(免耕不更换地膜,地膜用量是全膜覆盖的1/2)的地膜覆盖处理较不覆膜处理均显著的增加了玉米播前0-60 cm土层的储水量(SWS)。其中接种AM真菌后促进效应更显著。收获时,其0-20 cm土层的SWS也显著的增加。其中在一膜两年用试验中接种AM真菌对土壤水分影响效果较为明显。在60-120 cm的土层,平地AM真菌接种处理土壤SWS最高,较其他处理平均SWS增加了13.1-20.1%。 4. 第二个生长季,膜草二元覆盖试验和一膜两年用试验中地膜覆盖处理均显著增加了玉米的叶面积比。此外,膜草二元覆盖和一膜两年用试验的地膜覆盖处理较平地不覆膜种植均显著的增加了玉米穗长,穗直径,千粒重和降低了秃顶长度,进而增加了玉米的产量和水分利用效率。在第二个生长季,一膜两年用试验中地膜覆盖接种AM真菌增加了玉米穗长,同时显著的增加了玉米产量,水分利用效率和生物量。 5.膜草二元覆盖试验中,各处理间的TOC含量没有显著的差异,但是不稳定有机碳的变化与生长年限和处理方式有关。秸秆覆盖和AM真菌接种在第一个生长季LFOC含量较对照提高了5.57-15.1%,第二个生长季提高了8.46-15.6%。此外,在2016年,秸秆覆盖处理土壤POC的含量较对照和不覆盖秸秆处理增加了3.80-5.82%;秸秆覆盖结合AM真菌接种处理POC的含量较其他处理增加了10.5-12.4%。2017年秸秆覆盖处理土壤POC的含量较对照和不覆盖秸秆处理增加了9.19-20.4%;秸秆覆盖结合AM真菌接种处理POC的含量较其他处理增加了13.0-23.7%。土壤表层硝态氮(NO3--N)和氨氮(NH4+-N)含量不受秸秆覆盖和接种AM真菌的影响。但是AM真菌接种显著的降低了第二个生长季土壤总氮(TN)和速效磷(AP)含量。接种AM真菌显著的增加了根外菌丝长度(EMH,18.4-29.8%)和球囊霉素相关的土壤蛋白(GRSP)的含量。LFOC和POC均随GRSP和EMH的增加而显著增加。此外,EMH和菌根侵染率显著的增加了玉米对N和P的吸收。 6.全膜覆盖下的田间试验土壤有机碳含量的变化与meta分析的结果一致。全膜覆盖较不覆盖处理显著降低了POC和LFOC的水平。但是在一膜两年用条件下,土壤不稳定有机碳含量有所增加,接种AM真菌后增加效果更显著。接种AM真菌后LFOC含量较不接种处理增加了12.9-35.5%;POC含量增加了6.44-22.3%。同时,接种AM真菌后,地上部N浓度较不接种处理提高了9.21%。与常规翻耕相比,免耕条件下AM真菌接种后EMH提高了16.9-19.8%。接种F. mosseae后,根际土壤中检测到的F. mosseae相对丰度明显增加。在2017年免耕措施中,平地AM真菌接种处理中F. mosseae的相对丰度高达55.0%,地膜覆盖条件下AM真菌接种处理中为20.8%,而对照中只有1.63%。接种后AM真菌的侵染率也显著增加,表明接种剂在与自然发生的AM真菌竞争中成功定殖玉米根系。菌根侵染率、GRSP和EMH在免耕条件下与EOC、LFOC、POC和地上N浓度显著相关。 7.菌根抑制剂可能通过降低EMH、GRSP含量和土壤AM真菌多样性,进而降低不稳定的土壤有机碳含量。较对照处理,苯菌灵的应用显著降低了POC(21.1%)、MBC(8.92%)和LFOC(28.6%)的含量;菌根侵染率、EMH、已提取GRSP(EE-GRSP)和总GRSP(T-GRSP)分别降低了26.0%、49.0%、30.2%和18.3%。菌根的抑制也显著的降低了地上N浓度(38.6%),但显著增加了0-100 cm土层中NO3--N和NH4+-N的积累。此外,Glomeraceae在所有处理中(免耕条件下AM真菌的接种试验和苯菌灵抑制试验)占主导地位。 8.AM真菌richness和shannon 指数不受地膜覆盖和AM真菌接种及其交互作用的影响。但施用苯菌灵显著的降低了AM真菌alpha多样性。地膜覆盖和苯菌灵的施加显著影响AM真菌群落组成,其变化与土壤有机碳组分(LFOC和POC)和土壤N含量密切相关。相关分析表明,接种AM真菌条件下,AM真菌多样性与土壤SOC组分之间没有显著的关系。但在苯菌灵处理下土壤AM真菌的多样性(alpha多样性)与土壤SOC组分呈显著正相关。 这些结果表明,在半干旱地区,地膜覆盖增加作物产量的同时,保持了土壤水分的年际平衡,但是降低了土壤易变有机碳组分的含量。地膜减量接种AM真菌可以降低地膜用量的同时提高水分利用效率,维持了SOC的稳定,进而促进了旱地农业生态系统的可持续性。AM真菌的丰度、多样性与不稳定的SOC之间密切的相关性,进一步说明AM真菌在旱地农业生态系统中对作物生产力的提高和SOC的稳定所起的重要作用。同时,AM 真菌的接种没有显著的改变本土自然发生的AM真菌群落组成和多样性。因此,AM真菌接种可以作为一种有效的耕作措施来减少旱地农业土壤地膜的残留量的同时增加土壤SOC组分含量,进而提高作物产量和维持农业生态系统的可持续性。
Other Abstract~In the semiarid Loess Plateau region of Northwestern 中文na, where insufficient precipitation and poor soil fertility are major constraints to increasing crop productivity. Plastic film mul中文ng, which as an efficient farming technology has been extensively used in drought-prone, high altitude and/or high latitude regions. However, the negative effects of plastic mul中文ng have recently received more attention. Due to the increase in plant growth, plants under plastic mul中文ng require more water input. If the evapotranspiration (ET) of plants and soils exceeds the precipitation, the decreasing soil moisture levels can aggravate soil water scarcity in subsoil soil layers. In addition, plastic mul中文ng increases the soil temperature and water and then increase soil organic carbon (SOC) mineralization and thus negatively affect the SOC balance if the increased carbon consumption is not balanced by increased input. Importantly, current plastic mul中文ng practices are usually to cover with new plastic film every year, and a large amount of residual plastic film is directly incorporated into the soil during the cultivation process. To reduce the amount of plastic film usage but still maintain high field productivity and sustainability is a huge practical chall英语e for dryland agriculture. Soil microbial community plays a crucial role in the agricultural ecosystem. Among these microbes are arbuscular mycorrhizal (AM) fungi, which have come to be viewed not only as plant symbionts, but as essential to both plant and soil, serving as the critical link in the plant-soil continuum. AM fungi may also potentially improve soil health through their external hyphae (EMH) that improve crop water use, sustain soil structure and increase SOC storage. However, in the plastic film mul中文ng system, it is not known whether allochthonous AM fungal inoculation can affect soil AM fungal diversity and thus affect the crop yield and soil labile SOC fractions. We first conducted a meta-analysis based on all available data to evaluate the effect of plastic mul中文ng on maize productivity, soil moisture and soil labile organic C fractions in rain-fed regions; and then field experiment adds the dimension of inoculation with AM fungi to access the effect of reduced plastic film mul中文ng and AM fungal inoculation on soil labile organic C fractions, crop productively and resident AM fungal community composition. The major results were presented as follows: 1. Impacts of plastic film mul中文ng on maize productivity, soil water sustainability and soil organic carbon: insights from a meta-analysis in rain-fed regions. 1) Plastic mul中文ng significantly and positively impacted both crop yield and WUE. Increased yields and WUE were highest when annual mean precipitation was 250-400 mm (142% and 190%), followed by 400-500 mm (39% and 35%), 500-600 mm (34% and 32%) and over 600 mm (22% and 31%). In the meanwhile, full plastic mul中文ng significantly increased the crop yield and WUE, in comparison with half plastic mul中文ng. The increases in yield and WUE were 48% and 46%, 50% and 47%, and 47% and 58% under high, moderate, and low nitrogen applications, respectively. Additionally, increased vegetation growth due to plastic mul中文ng can turn to impact soil water dynamics across growing and fallow seasons, but it did not disrupt the annual equilibrium of SWS. Particularly, more precipitation harvesting and storage at deep soil layer during the non-growing season appeared to fully offset the extra water loss by enhanced evapotranspiration. 2) Plastic mul中文ng significantly enhanced the light fraction organic C (LFOC) and particulate organic C (POC) decomposition. The effect size of LFOC and POC were 0.92 (0.90-0.94) and 0.96 (0.96-0.97), respectively. However, those of easily oxidizable C (EOC) 1.01 (0.96-1.07) were not significant. The plastic film mul中文ng increased microbial biomass C (MBC), and the effect size was 1.12 (0.90-1.41). 2. Response of maize yield, soil water storage, SOC fractions and AM fungal communities to different agricultural practices. 3) In the second growing season, plastic film mul中文ng treatments (the experiment of plastic mul中文ng combination with straw mul中文ng: the amount of plastic film was 2/3 of the total plastic film mul中文ng; use of plastic film once every 2 years coupled with no-tillage practice: the amount of plastic film was 1/2 of the total plastic film mul中文ng) significantly increased soil water storage (SWS) for maize in 0 to 60 cm soil profile before sowing, the effects of the combination of plastic mul中文ng and AM fungal inoculation is more significant. In the harvesting stage, plastic mul中文ng significantly increased SWC at 0 to 20 cm soil profile. The soil water content in CK, plastic film mul中文ng, and plastic film mul中文ng combined with AM fungal inoculation was 13.1%, 15.4% and 20.1% lower than that of AMF treatment in 60 to 200 cm soil layer under non-tillage. 4) Plastic mul中文ng significantly increased the leaf area ratio of maize in the second growing season. Inoculation with AM fungi increased the specific leaf area and leaf area ratio under no-tillage. Compared with non-mul中文ng treatment, plastic mul中文ng improved ear l英语th, ear diameter, 1000-grain weight, and reduced the bare tip l英语th. Furthermore, plastic mul中文ng significantly increased the maize yield and WUE, which are consistent with the meta-analysis results. In the second growing season, inoculation with AM fungi significantly increased the ear l英语th. Although inoculation with AM fungi did not significantly increase corn yield, water use efficiency and biomass in the first growing season, while AM fungi had a significant growth-promoting effect in the second growing season. 5) In this study, across each growing season, the TOC contents remained insignificant differences among various treatments. While the labile organic C differed with different years and treatments. We found that based on alternative double-ridge film mul中文ng (ADM), AM fungal inoculation (ADM+A), additional straw mul中文ng (ADMS) and combination with AM fungal inoculation and straw mul中文ng (AMDS+A) significantly increased the content of LFOC in 2016 (5.57-15.1%) and 2017 (8.46-15.6%). In addition, compared with ADM and ADM+A, ADMS increased the POC content by 5.82% and 3.80%; and ADMS+A increased POC by 12.4% and 10.5% in 2016, respectively. In 2017, ADMS increased the POC content by 20.4% and 9.19%; and ADMS+A increased POC by 23.7% and 13.0 % when compared with ADM and ADM+A treatments, respectively. Moreover, the amount of nitrate-nitrogen (NO3--N) and ammonia nitrogen (NH4+-N) in topsoil (0-20 cm) was not significantly influenced by straw mul中文ng and AM fungal inoculation. While AM inoculation significantly reduced the content of total nitrogen (TN) and available phosphorus (AP) and significantly increased the content of shoot N and P in 2017. Field inoculation with AM fungi appeared to have stimulated EMH production and significantly increased the glomalin-related soil protein (GRSP) content. Shoot and root biomass was also generally affected by AM fungal inoculation and straw mul中文ng. Critically, EMH and GRSP have highly correlated with the soil labile organic C. A significant negative linear relationship between TN and EMH. Shoot N and P were also significantly correlated with EMH and mycorrhizal colonization. 6) Our meta-analysis was consistent with our field experiment where full plastic mul中文ng significantly decreased levels of soil POC and LFOC. While positive effects on soil labile organic C were observed when inoculation increased root colonization, EMH and glomalin content, particularly under the non-tillage. AM fungal inoculation significantly increased LFOC content by 12.9%-35.5% and POC content by 6.44%-22.3% compared with non-AM fungal treatments, particularly under the no-tillage. AM inoculation treatment significantly increased the shoot N concentration by 10.2% and 9.21% under tillage and no-tillage when compared with the CK, respectively. Notably, AM inoculation significantly increased EMH by16.9-19.8% under non-tillage conditions, in comparison with tillage. Inoculation with F. mosseae strongly increased the relative abundance of F. mosseae detected in rhizosphere soil. Meanwhile, AM fungal root colonization significantly increased with inoculation, indicating successful competition by the inoculant for root niche space against naturally occurring AM fungi at this site. Root mycorrhizal colonization, T-GRSP and EMH were positively correlated with EOC, LFOC, POC and shoot N concentration under no-tillage practices. EMH was positively correlated with LFOC content under tillage conditions. 7) Fungicide applications reduced labile organic C, possibly through decreasing EMH, glomalin content and soil AM fungal diversity. Benomyl application significantly decreased the POC, MBC, LFOC content, root mycorrhizal colonization, EMH, EE-GRSP and T-GRSP by 21.1%, 8.92%, 28.6%, 26.0%, 49.0%, 30.2% and 18.3% respectively. Shoot N concentration was reduced by 38.6% following benomyl applications. However, benomyl application significantly increased the NO3--N and NH4+-N accumulation in the 0-100 cm soil layers. 8) No significant difference in AM fungal richness and Shannon diversity were found between plastic mul中文ng and inoculation with AM fungal and their interactive effect. AM fungal diversity was significantly higher on control plots than fungicide application plots. The community composition of AM fungi was significantly influenced by plastic mul中文ng and fungicide applications, which was strongly correlated to soil organic C fractions (LFOC, POC), NO3--N, TN, and GRSP. Pearson’s correlation analysis indicated that MBC, EOC and LFOC were significantly correlated with GRSP content (AM fungal inoculation studies). EMH significantly positively correlated with POC, and negatively correlated with TN. However, there was no significant relationship between diversity and C fractions. Furthermore, the relationship between AM fungal diversity (alpha diversity, Shannon) and these C fractions were positively correlated under fungicide applications. The adoption of plastic mul中文ng increased crop productivity, while the plastic mul中文ng decreasing the SOC content. We observed a significant positive effect of AM fungal inoculation on soil water storage, maize productivity, and SOC under the scenario of reduced plastic film mul中文ng. Furthermore, a close positive correlation between AM fungal abundance, diversity and labile organic C was also observed. These results may further support the important role of AM fungi in the maintenance of SOC and benefits to plant productivity in agricultural ecosystems. Importantly, AM fungal inoculation can promote plant growth under the plastic mul中文ng, but it did not influence the composition and diversity of indigenous AM fungal communities. AM fungal inoculation may act as an effective farming solution to improve soil organic C fractions under the scenario of reduced plastic film mul中文ng, which correlated to maize productivity.
Pages157
URL查看原文
Language中文
Document Type学位论文
Identifierhttp://ir.lzu.edu.cn/handle/262010/448491
Collection兰州大学
Affiliation生命科学学院
First Author AffilicationSchool of Life Sciences
Recommended Citation
GB/T 7714
任爱天. 地膜减量背景下接种丛枝菌根真菌对旱地玉米生产力及土壤有机碳的影响及机理[D]. 兰州. 兰州大学,2020.
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