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1.
Zinc deficiency is an important limiting factor in sustainable crop production and is a factor often overlooked in determining the benefits and overall success of alfalfa pastures in rotations. A field experiment was conducted to investigate the effects of zinc and alfalfa cultivars on nodulation, herbage yield, leaf drop and disease severity (Phytophthora root rot disease and common leaf spot disease) in alfalfa (Medicago sativa L.). Ten cultivars of alfalfa (Hunter River, Hunterfield, Sceptre Aurora, Genesis, Aquarius, Venus (Y8622), PL69, P5929 and PL34HQ) were tested at two levels of zinc (+Zn: 4 kg ha–1, -Zn: no zinc added) on a Zn-deficient soil (DTPA zinc of top 0–15 cm soil was 0.4 mg kg–1 soil, while 15–30 cm subsoil Zn was 0.1 mg kg–1 soil) under field conditions. Zinc application significantly increased number and dry weight of nodules, herbage yield and leaf to stem ratio of alfalfa plants. There was a significant reduction in leaf drop, and occurrence of Phytophthora root rot (caused by fungus Phytophthora megasperma f. sp. medicaginis) and common leaf spot (caused by fungus Pseudopeziza medicaginis) diseases with Zn application. Alfalfa cultivars had a differential response to low Zn. Hunter River and Hunterfield were the most affected by omitting zinc application, while Sceptre, PL34HQ and Aquarius were comparatively less affected. The present study suggest that Zn nutrition effects nodulation, leaf drop, disease occurrence and production potential of alfalfa. The alfalfa cultivars have differential ability to low Zn supply. Growing of Zn-efficient cultivars and adequate Zn nutrition may also improve the N2-fixation by alfalfa on low-Zn soils.  相似文献   

2.
Two new species of oribatid mites of the genus Galumna (Oribatida, Galumnidae) are described from litter and soil in the Korup National Park, Cameroon. Galumna korupensis sp. n. differs from Galumna tricuspidata Engelbrecht, 1969 by the smaller body size, the presence of two oval postanal porose areas, one tooth on each lamellar lines and striate genital plates, and the absence of median pore and lateral teeth on the rostrum. Galumna cameroonica sp. n. differs from Galumna incisa Mahunka, 1982 by the presence of long cilia on bothridial heads, band-like postanal porose area, striate genital plates, three pairs of notogastral porose areas, and the position of notogastral lyrifissures im.  相似文献   

3.
Seasonal changes in abundance and distribution pattern of soil micro-arthropods were studied in connection with a few environmental factors in a Japanese cedar (Cryptomeria japonica D. Don) plantation. The soil arthropods were sampled from three different depths at intervals of two months for two years. Of the collected animals (total 51000–155000 m−2), Collembola (20000–76000 m−2), oribatid mites (19000–55000 m−2) and carnivorous mites (6200–21000 m−2) were the numerically dominant animal groups. Low seasonal variations in abundance indicated their seasonal stability in population levels. The trends in seasonal fluctuation were similar among these groups and between the two years, showing bimodal pattern with little peaks in early summer and winter. The pattern of seasonal fluctuation in abundance of carnivorous mites (P d) was significantly synchronized with that in the total abundance of Collembola and oribatid mites (P τ). Thus, the number-ratios (P d/P τ) were fairly constant, ranging from 0.10 to 0.25. Seasonal changes in vertical distribution of the three animal groups showed a similar pattern for both years. The downward migrations were shown to be more affected by low temperatures in winter accompanied by snow coverage rather than by the desiccation of the surface soil in summer. All the three groups demonstrated as a whole slightly aggregated patterns of horizontal distribution throughout the two years. Temporal increases in the patchiness indices were observed from summer to autumn when the moisture content of the surface soil was low.  相似文献   

4.
以大兴安岭多年冻土区泥炭地为研究对象,通过室内模拟增温实验,研究温度升高对不同深度(0-150 cm)土壤氮循环功能基因丰度的影响。同时针对0-20 cm和20-40 cm土壤设置两个水分处理,分别为土壤原始含水量和淹水状态,研究水分变化对表层土壤氮循环功能基因丰度的影响。结果表明温度升高显著提高了活动层(0-60 cm)、过渡层(60-80 cm)、永冻层(80-100 cm)中nifH、nirK基因丰度,温度升高显著提高了活动层(0-40 cm)和过渡层(60-80 cm)中nirS基因丰度。温度升高显著提高了过渡层(60-80 cm)NH4+-N和较深永冻层(140-150 cm)NO3--N的含量,但降低了过渡层(60-80 cm)NO3--N和较深永冻层(120-150 cm)NH4+-N的含量,相关性分析表明,NH4+-N含量与nifH和nirS基因丰度呈显著正相关,NO3--N含量与nirK基因丰度呈显著正相关,说明温度升高能够通过改变微生物丰度促进过渡层固氮作用和反硝化作用。在增温条件下,淹水处理使表层土壤nirS和nirK基因丰度及NH4+-N含量降低,但提高了NO3--N含量,说明淹水造成了过度还原的条件使反硝化底物浓度降低,降低反硝化微生物活性进而抑制了土壤反硝化作用。该结果对于明确未来气候变化影响下冻土区泥炭地土壤氮循环过程具有重要意义。  相似文献   

5.
In an experiment on the effect of zooplankton density on feeding behaviour and prey size selection in Atlantic salmon (Salmo salar) alevins, total behavioural activity (feeding, social, ambiguous) was positively related to prey abundance up to a density of 350 items 1?1, after which activity peaked. Feeding error (missed attacks and/or rejected ingestions) increased with prey density. The likelihood that an alevin would attack an item upon which it had binocularly fixed (no. bites/no. visual fixes) peaked at densities of 270 items 1?1 and then declined. Feeding success (no. ingestions per bite or per fixation) also peaked and then declined. Changes in success were reflected in total number of items found in the gut. At high prey abundance (608 items 1?1) only 0.5 – 0.9 mm copepods were preferred components of alevin diets. Over all prey densities, preferred sizes of cladocerans and copepods did not overlap. These results may reflect a perceptual constraint (at high zooplankton densities) on alevin feeding behaviour.  相似文献   

6.
王子婷  杨磊  李广  柴春山  张洋东  陈荣  张继强 《生态学报》2019,39(10):3720-3729
半干旱黄土丘陵区土壤水分亏缺引起人工苜蓿草地退化会显著影响其他草本植物的分布及多样性,然而地形驱动下的苜蓿草地退化及植被群落多样性响应还尚不清楚。以典型半干旱黄土丘陵区龙滩小流域为研究区,对不同地形条件下退化苜蓿草地地上生物量、草本多样性及生长季内0—200 cm土壤水分进行了定位监测,利用方差分析、相关分析和典范对应分析(CCA)明确坡面地形、苜蓿生长状况和土壤水分与其他草本植物分布及多样性之间的关系。结果表明:(1)地形显著影响植被群落特征,西坡、东坡和北坡样带苜蓿地上生物量明显不同,西坡和东坡样带中、下坡位苜蓿地上生物量明显高于上坡位,而其他草本的生物量、物种丰富度和多样性指数的变化趋势则与苜蓿相反;(2)苜蓿地上生物量与80—200 cm土壤水分显著正相关,而与0—20 cm和20—80 cm土壤水分的相关性较小;(3)地形特征、不同深度土壤水分和苜蓿地上生物量解释了退化苜蓿草地其他草本群落变异的87.8%,其中坡向、苜蓿地上生物量、0—20 cm和20—80 cm土壤水分4个因子解释了79.3%的群落变异。研究认为,半干旱黄土丘陵区不同地形条件引起坡面土壤水分变化,进而影响退化苜蓿草地地上生物量,使得苜蓿退化程度不同,而苜蓿退化程度和0—80 cm土壤水分决定了不同部位草本分布及多样性。  相似文献   

7.
Aim This study investigates the species–area relationship (SAR) for oribatid mite communities of isolated suspended soil habitats, and compares the shape and slope of the SAR with a nested data set collected over three spatial scales (core, patch and tree level). We investigate whether scale dependence is exhibited in the nested sampling design, use multivariate regression models to elucidate factors affecting richness and abundance patterns, and ask whether the community composition of oribatid mites changes in suspended soil patches of different sizes. Location Walbran Valley, Vancouver Island, Canada. Methods A total of 216 core samples were collected from 72 small, medium and large isolated suspended soil habitats in six western redcedar trees in June 2005. The relationship between oribatid species richness and habitat volume was modelled for suspended soil habitat isolates (type 3) and a nested sampling design (type 1) over multiple spatial scales. Nonlinear estimation parameterized linear, power and Weibull function regression models for both SAR designs, and these were assessed for best fit using R2 and Akaike's information criteria (ΔAIC) values. Factors affecting oribatid mite species richness and standardized abundance (number per g dry weight) were analysed by anova and linear regression models. Results Sixty‐seven species of oribatid mites were identified from 9064 adult specimens. Surface area and moisture content of suspended soils contributed to the variation in species richness, while overall oribatid mite abundance was explained by moisture and depth. A power‐law function best described the isolate SAR (S = 3.97 × A0.12, R2 = 0.247, F1,70 = 22.450, P < 0.001), although linear and Weibull functions were also valid models. Oribatid mite species richness in nested samples closely fitted a power‐law model (S = 1.96 × A0.39, R2 = 0.854, F1,18 = 2693.6, P < 0.001). The nested SAR constructed over spatial scales of core, patch and tree levels proved to be scale‐independent. Main conclusions Unique microhabitats provided by well developed suspended soil accumulations are a habitat template responsible for the diversity of canopy oribatid mites. Species–area relationships of isolate vs. nested species richness data differed in the rate of accumulation of species with increased area. We suggest that colonization history, stability of suspended soil environments, and structural habitat complexity at local and regional scales are major determinants of arboreal oribatid mite species richness.  相似文献   

8.
【目的】通过研究林地转型耕地对土壤编码碱性磷酸酶基因的细菌群落丰度、多样性和结构的影响,为丘陵区耕地长期施肥下农田土壤微生物多样性丧失的影响机制以及未来的退耕还林过程中土壤微生物多样性的提升和土地可持续利用研究提供一些基础数据和技术支撑。【方法】采用实时荧光定量PCR (real-time quantitative PCR,qPCR)和高通量测序技术解析土壤编码碱性磷酸酶基因的细菌群落的丰度、多样性和结构变化,并耦合土壤化学性质分析,明确土壤编码碱性磷酸酶基因的细菌群落丰度和多样性与土壤化学性质的关系以及关键的驱动因子。【结果】林地垦殖为农田后,长期施肥导致土壤酸化,pH从5.58降至4.72,而土壤速效磷则从2.49 mg/kg增至49.3 mg/kg。相应地,耕地土壤编码碱性磷酸酶基因的细菌群落的丰度和Shannon指数均显著低于林地。基于编码碱性磷酸酶的phoD基因(alkaline phosphatase-encoding gene)序列的物种分类表明,丘陵区土壤编码碱性磷酸酶基因的细菌群落的优势门为变形菌门(Proteobacteria)、蓝藻门(Cyanobacteria)、浮霉菌门(Planctomycetes)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)和疣微菌门(Verrucomicrobia),其中林地土壤的蓝藻门的相对丰度显著高于耕地。耕地土壤的慢生根瘤菌属(Bradyrhizobium)和芽孢杆菌属(Bacillus)的相对丰度显著高于林地,而中慢生根瘤菌属(Mesorhizobium)、假单胞菌属(Pseudomonas)、Chlorogloea属、Gemmata属、Phormidesmis属和Pseudolabrys属的相对丰度显著低于林地。土壤编码碱性磷酸酶基因的细菌群落结构因林地转型耕地而发生显著改变。phoD基因丰度和Shannon指数与pH显著正相关,而与总磷、速效磷、硝态氮和铵态氮均显著负相关,其中土壤速效磷是这些影响因素中影响最强烈的,长期施用无机磷肥导致含碱性磷酸酶的土壤细菌群落对有机磷分解的能力退化。【结论】林地转型耕地加之长期施肥改变了土壤pH和速效磷,并在其他理化因子的协同驱动下,导致土壤编码碱性磷酸酶基因的细菌群落丰度、多样性和结构的显著变化。  相似文献   

9.
Abstract Despite decades of research, the primary factors determining savanna structure remain elusive – a conundrum termed ‘the savanna problem’. After 47 years of annual burning in Terminalia woodland and Acacia/Combretum savanna on sandy, granite‐derived soils in the southern Kruger National Park, South Africa, a dense cover of trees and shrubs persists on some burnt plots and is largely absent from others. We postulated that intense browsing pressure by antelope and other herbivores prevents recruitment of trees in burnt plots and that herbivores concentrate on plots that are richest in nutrients. Herbivore abundance did not show a relationship with soil macronutrients and we consequently investigated micronutrient status. The reduction in tree cover as a result of annual burning was positively correlated with mass of herbivores (15–1500 kg) (r 2 = 0.61, n = 8). This index of herbivore abundance was in turn positively correlated with total Zn (r 2 = 0.64, n = 8). Other indices of herbivore abundance showed significant relationships with total clay content and total Mn. We suggest that herbivores concentrate on sites with greater clay content (possibly due to a greater availability of micronutrients), and that tree cover can remain relatively dense under a regime of annual burning if browsing pressure is not intense. The long‐term burn experiments in the Kruger National Park savanna provide a platform for unravelling the savanna problem. Determining possible interactions between soil properties, herbivory and fire is a step in this direction.  相似文献   

10.
Abstract. Spatial and temporal soil partitioning between roots of the two savanna plant components, i.e. trees and grasses, were investigated in a West African humid savanna. Vertical root phytomass distribution was described for grass roots, large (> 2 mm) and fine (< 2 mm) tree roots, in open sites and beneath tree canopies. These profiles were established monthly over one year of vegetation growth. Natural 13C abundance measurement was used to determine the woody/herbaceous phytomass ratio in root samples. Tree and grass root distributions widely overlapped and both were mostly located in the top 20 cm of the soil. Grass root phytomass decreased with depth whereas woody root phytomass peaked at about 10 cm depth. No time partitioning was detected. These structural results do not support the hypothesis of soil resource partitioning between trees and grasses and are thus consistent with functional results previously reported.  相似文献   

11.
【目的】探讨沿黄流域土壤中铁还原菌(ferric reducing bacteria, Fe RB)、不产氧光合细菌(anoxygenic phototrophic bacteria, An PB)的分布机制。【方法】以沿黄流域(原阳段)为研究对象,采集黄河滩地和稻田土样,利用16Sr RNA基因高通量测序和实时荧光定量分析技术,结合统计学分析,揭示Fe RB、An PB菌群结构、丰度和主要环境影响因子。【结果】二者中的优势Fe RB在科(属)水平为Hydrogenophilaceae(Thiobacillus)、 Bacillaceae(Bacillus)、 Clostridiaceae、Rhodobactereace(Rhodobacter)、 Geobacteraceae(Geobacter),优势An PB为Rhodobactereace(Rhodobacter)、 Chloroflexaceae(Chloronema)、 Acetobacteraceae(Roseomonas)。An PB中Rhodobacteraceae与Fe RB中Bacillaceae、 Clostri...  相似文献   

12.
半干旱黄土丘陵区撂荒坡地土壤水分循环特征   总被引:11,自引:3,他引:8  
宁婷  郭忠升 《生态学报》2015,35(15):5168-5174
为深入了解半干旱黄土丘陵区土壤水分循环特征和为开展荒地造林工作提供背景数据,在宁南上黄生态试验站,选取典型多年撂荒坡地,进行土壤水分的长期定位观测,分析其土壤水分补给、消耗特征与时空变异性。结果表明:研究区降雨入渗量和入渗深度随降雨量增加而增加,入渗补给系数约为0.44,雨水资源化率有待提高。定义全年一半以上的次降水事件中能被有效补给的土层深度为降水普遍入渗深度,则研究区降水普遍入渗深度为0—40 cm,观测期内最大入渗深度不超过300 cm。同时,土壤水分的蒸散发量在丰水年平水年干旱年,主要蒸散发作用层位于0—200 cm土层范围内,最大蒸散发深度达到300 cm以下。该区土壤储水量的季节变化为"V"型,剖面土壤平均含水量的垂直变异则呈现反"S"型。土壤水分的变异系数随土层深度的增加表现出幂函数递减趋势,结合有序聚类法的分层结果,可采用0.20和0.05两个CV值将撂荒地土壤剖面划分为水分活跃层(0—40 cm)、次活跃层(40—200 cm)和相对稳定层(200 cm以下)3个层次。  相似文献   

13.
Spatial and temporal patterns of morel fruiting   总被引:2,自引:0,他引:2  
The biotic and abiotic factors conditioning morel fruit body production are incompletely known. We examined spatial and temporal patterns of Morchella esculenta fruiting over five years in a wooded site in Missouri, USA. Fruiting onset was inversely correlated with spring air and soil temperatures, whereas abundance was positively correlated with rain events (>10 mm) during the 30 d preceding fruiting. The two years with the greatest fruiting had the shortest fruiting seasons (6–7 d). Fruiting season length was positively correlated with soil warming, suggesting that a narrow range of optimum soil temperatures favour the explosive production of fruit bodies. All woody stems of at least 1 cm diam were mapped and stem diameter and crown condition were noted. Morel fruit bodies were significantly closer to stems of Carya spp., Tilia americana and Ulmus americana than predicted by the frequencies of these woody species or their contribution to the total basal area on the site. Although intra-annual clustering of fruit bodies was often observed, inter-annual clustering was not. The spatial pattern of M. esculenta fruiting appears to be associated with vegetation pattern, whereas the onset and abundance of fruiting are determined by the interaction of spring temperatures with availability of supporting precipitation.  相似文献   

14.
以陕西延安黄土丘陵区5种不同植被类型(人工刺槐林、天然侧柏林、天然辽东栎林、灌丛和裸地)为研究对象,分析了土壤微生物生物量碳、氮含量、细菌和真菌的丰度变化规律及其与土壤基本化学性质的关系。结果表明:(1)4种植被类型的土壤质量较之裸地都有不同程度的改善,总体趋势:天然林地人工林地裸地;(2)土壤微生物生物量碳、氮的总体趋势:天然林地最高,人工林次之,裸地最低,且与土壤有机碳(SOC)、全氮(TN)和速效磷(AP)极显著正相关(P0.01);(3)裸地土壤的细菌丰度最低,人工刺槐林真菌含量显著低于天然辽东栎林。细菌丰度与土壤营养状况呈显著正相关(P0.05),而真菌与土壤营养无明显相关性,只与土壤pH负相关。说明在该研究区域,植被类型与土壤质量对微生物资源都具有不同程度的作用。  相似文献   

15.
Peatland soils contain large amounts of nitrogen (N) in the soil and mineralization can contribute substantially to the annual mineral N supply of grasslands. We investigated the contribution of N mineralization from peat with respect to the total annual N uptake on grasslands with anthropogenic A horizons and submerged tile drains. The study included i) a pot experiment to determine potential N mineralization from the topsoil and the subsoil, ii) a 1-year field experiment to study herbage yields and N uptake under fertilized and non-fertilized conditions and iii) a 3-year field study where herbage yield and N uptake from the top 30 cm and the entire soil profile were monitored. The 3-year field study yielded an average N uptake of 342 kg?ha?1 under non-fertilized conditions but the contribution of subsoil peat N mineralization to the total N uptake was found to be negligible. Our calculations demonstrate that peat N mineralization contributed only 10% to 30% to the total N-uptake, mainly coming from the top 30 cm. Most of the N uptake under unfertilized conditions appears to be largely the result of mineralization from long-term inputs of dung, ditch sludge, farmyard manure, cow slurry and non-harvested herbage.  相似文献   

16.
The distribution and abundance of subtidal meiofauna in Mandovi estuary of Goa were studied from June 1983 to June 1984. Monthly faunal abundance ranged from 491 to 2791/10 cm2 and dry weight biomass from 0.16 to 2.80 mg 10 cm2. Free living nematodes were the dominant group contributing over 75% of the total density and 30 to 42% of the total biomass. Among nematodes the deposit feeders were more abundant in fine muddy substratum while epigrowth feeders dominated in sandy substratum.Harpacticoids were next, comprising 6.9 to 8.7% of the total meiofauna number, followed by turbellaria (3.8–4.5%), polychaeta (2.8–3.2%) and ostracods (1.6–4.5%) The contribution of other groups to faunal density was 4.5–6.2%. In the biomass the ostracods contributed most (29.8–54.7%), followed by nematodes (23.8–34.6%). Over 60% of the fauna occurred in the top 2 cm of the sediment and the faunal density reduced significantly with increasing depth in the sediment. The vertical distribution of meiofauna was positively correlated to the vertical distribution of Eh, chlorophyll a and interstitial water. Seasonality was greatly influenced by the south-west monsoon and the fauna quickly repopulated after the monsoon. Salinity, temperature and food influenced the faunal abundance.  相似文献   

17.
In this paper we report on the seasonal abundance of velvet mite larvae of Allothrombium pulvinum Ewing and Allothrombium monochaetum Goldarazena and Zhang in a meadow located in the mediterranean Navarra-Nafarroa region (northern Spain). Larvae of A. monochaetum peaked in numbers on Aphis fabae in mid-June while larvae of A. pulvinum peaked in the third week of July. Both species preferred the aphid thorax as attachment site. We also provide a list of aphid hosts of both mites and observed density of parasites on the hosts.  相似文献   

18.
以藏嵩草沼泽化草甸为研究对象,利用磷脂脂肪酸(PLFA)技术,研究连续6年N素添加对地上植被群落数量特征、土壤微生物群落结构的影响。结果表明:①藏嵩草沼泽化草甸群落生物量、枯枝落叶对施肥处理无明显响应,且莎草科植物对土壤氮素的吸收和利用率较低。②施肥增加了0-10 cm土壤微生物类群PLFAs丰富度尤其细菌和革兰氏阳性菌PLFAs,降低了10-20 cm PLFAs丰富度;③磷脂脂肪酸饱和脂肪酸/单烯不饱和脂肪酸、细菌PLFAs/真菌PLFAs的比值随土壤层次增加而增加;④0-10 cm土层革兰氏阳性菌、真菌PLFAs含量与pH、土壤速效磷、速效氮、土壤有机质显著正相关(P0.05或P0.01);10-20 cm土层,细菌、革兰氏阳性菌、真菌和总PLFAs含量与土壤有机质含量显著正相关(P0.05或P0.01)。表明藏嵩草沼泽化草甸微生物PLFAs含量和丰富度对施肥的响应存在明显的土层梯度效应,土壤微生物PLFAs含量和丰富度主要受表层土壤初始养分含量的影响。  相似文献   

19.
Fate of sheep urine-N applied to an upland grass sward   总被引:1,自引:0,他引:1  
Summary Sheep urine was applied once in August to 1 m2 plots of a N-deficientLolium perenne-dominated sward at a rate equivalent to a single urination (48 g N m–2) at an upland site. After 17 days herbage dry matter (DM) and total N were increased 19- and 63-fold respectively compared with a control receiving water only. Soil mineral N (NH 4 + and NO 3 ) levels in the top 20 cm were greater in urine plots until 30 days after urine application when cumulative yields of herbage DM and N were 10 and 21 times greater than those of the control. Maximum recovery of urine N by herbage was only 16% of that applied, and, although swards responded rapidly to urination there were substantial losses of N, perhaps via leaching and/or volatilisation, from the soil-plant system.  相似文献   

20.
黄土高原半干旱区轮作休耕模式对土壤真菌的影响   总被引:5,自引:0,他引:5  
南丽丽  谭杰辉  郭全恩 《生态学报》2020,40(23):8582-8592
通过田间试验,研究休耕(CK)、残膜覆盖、伏天深耕、施有机肥、秸秆还田和绿肥还田对土壤微生物量碳氮、酶活性及真菌群落的影响。结果表明,除过氧化氢酶外,不同处理对土壤微生物量碳氮、脲酶、碱性磷酸酶、脱氢酶、pH及有机质均有显著影响。从门水平上看,土壤真菌群落主要由子囊菌门、担子菌门和被孢霉门构成。其中伏天深耕、玉米秸秆粉碎还田+施牛羊粪+深翻耕后连续休耕3年处理的子囊菌相对丰度分别为43.23%和69.38%,显著高于CK (33.71%);从纲水平上看,座囊菌纲、粪壳菌纲、伞菌纲和被孢霉纲为优势菌纲,其中玉米秸秆粉碎还田+施牛羊粪+深翻耕后连续休耕3年处理以座囊菌纲为主(60.69%),其余处理以粪壳菌纲为主(4.11%-24.79%);真菌多样性指数施牛羊粪+深翻耕+连续3年种植豌豆(拌根瘤菌粉8.5 g/kg种子)并在盛花期翻压还田、玉米秸秆粉碎还田+施牛羊粪+深翻耕后连续休耕3年、玉米秸秆粉碎还田+施牛羊粪+深翻耕+连续3年种植箭筈豌豆并在盛花期翻压还田处理显著低于CK和其他处理,丰富度指数玉米秸秆粉碎还田+施牛羊粪+深翻耕+连续3年种植毛苕子并在盛花期翻压还田处理显著高于CK和其他处理;真菌营养类型玉米秸秆粉碎还田+施牛羊粪+深翻耕后连续休耕3年处理以腐生营养型为主(62.9%),其他处理以病理营养型和腐生营养型为主。冗余分析和Monte Carlo置换检验结果显示,土壤微生物量碳、微生物量氮、pH和有机质含量对土壤真菌群落结构影响显著(P<0.05)。与休耕(CK)、残膜覆盖、伏天深耕相比,施有机肥、秸秆还田、绿肥还田结合深耕均降低了土壤中病理营养型真菌的相对丰度,利于保持农田土壤生态系统健康。  相似文献   

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