新疆农田不同施肥区土壤昆虫群落丰富性与多样性

 【目的】在新疆国家灰漠土土壤肥力与肥料效益长期监测基地，对10种施肥处理，即（1）撂荒（不施肥、不耕作、不种植，Aband.）、（2）对照（种植、不施肥，CK）、（3）施氮肥（N）、（4）施氮磷肥（NP）、（5）施氮钾肥（NK）、（6）施磷钾肥（PK）、（7）施氮磷钾化肥（NPK）、（8）施氮磷钾化肥+有机肥（有机氮和化肥氮的比例为7﹕3）（MNPK）、（9）化肥用量增加50%配施有机肥（1.5 MNPK）、（10）化肥配施秸秆(SNPK)与新疆灰漠土区农田土壤昆虫群落之间的关系进行研究。【方法】采用改良干漏斗（Modified Tullgren）分离土壤（0～20 cm）中的土壤昆虫，同时利用陷阱法收集活动在地表的各类土壤昆虫。【结果】两种方法共获得土壤昆虫4 915只（未知标本128只），隶属9目33科。大型土壤昆虫个体数和类群数在Aband.处理中分布最多，中小型土壤昆虫则分别在N和PK处理中分布最多；MNPK处理土壤动物组成最丰富，N处理土壤动物分布最均匀。农田土壤昆虫类群分布受施肥影响极其显著（X0.05（9）=23.38，P＜0.005），Aband.区土壤昆虫群落与其它施肥处理土壤昆虫群落差异极显著（P＜0.01）。利用非度量多维标度分析法对土壤昆虫群落分类排序，则灰漠土土壤昆虫群落划分为5组，即NPK、MNPK、1.5MNPK和CK为一组，NP和PK为一组，NK和N为一组，SNPK和Aband.各为一组，表明土壤昆虫分布与肥料性质有关。主成分中前两个主成分解释总变量的98.51%，其中第一主成分反映了单施N肥和SNPK还田对土壤昆虫群落具有促进作用；第二主成分反映了1.5MNPK对土壤昆虫群落促进作用，表明施肥处理对土壤昆虫类群影响不平衡。【结论】新疆灰漠土区，肥料的种类与性质影响着土壤昆虫类群多样性与丰富性，且其影响具有不均衡性。     

Impact of Long-Term Fertilization on Cropland Soil Fauna Community at Loess Soil, Shannxi, China

The relationship between long-term fertilization and cropland network for soil fertility and fertilizers in Loess soil of Shannxi soil fauna was studied at the station＇s experiment research Provincefrom Jul. 2001 to Oct. 2002. Six types of long-term fertilizer were carried out for this study including non-fertilizer （CK）, abandonment （ABAND）, nitrogenous and phosphors and potassium fertilizers combined （NPK）, straw and NPK （SNPK）, organic material and NPK （MNPK） and 1.5 times MNPK （1.5MNPK）. 72 soil samples were collected and 5 495 species of cropland soil fauna obtained by handsorting and Cobb methods at 4 times, belonging to 6 Phyla, 11 Classes, 22 Orders, 2 Superfamilies, 61 Families and 35 Genera. The result showed that different fertilizer had significantly impacted on the cropland soil fauna （F = 2.24, P〈0.007）. The number of the cropland soil fauna was related to the soil physicochemical properties caused by long-term fertilization. The result by principal component analysis, focusing on the number of 15 key soil fauna species group＇s diversity, evenness of community and the total soil fauna individuals indicated that the effects of SNPK, NPK, MNPK and 1.5MNPK were significantly different from that of the cropland soil fauna, in which, SNPK and NPK had the positive effect on cropland soil fauna, and MNPK and 1.5 MNPK had the negative affect, others could not be explained. By principal component I, the synthetic effect of different fertilization on the total soil fauna individuals and the group was most significant, and the effect was little on evenness and diversity. By value of eigenvectors, the maximum one was 9.6248, and the minimum one was - 1.0904, that means the 6 types of fertilization did not affect evenly the cropland soil fauna.     

长期施肥对黄土区农田土壤动物群落的影响

 2001年7月至2002年10月，采用手捡法和Cobb过筛法,对陕西黄土区6种长期施肥，即对照组（不施肥，CK）、撂荒（不施肥、不耕种，用ABAND.表示）、施氮磷钾（NPK）、施氮磷钾+秸秆（SNPK）、施氮磷钾+有机肥（MNPK）和施1.5倍（氮磷钾+有机肥）（1.5MNPK）与农田土壤动物群落间相互关系进行研究。两年4次共采集72个定点土壤样品，获农田土壤动物标本5 495只，隶属6门11纲22目61科2亚科35属。调查结果表明，不同施肥处理对土壤动物的影响差异性显著（F = 2.24，P＜0.007)。土壤动物数量变化与长期施肥导致土壤性质的变化有关。主成分分析表明，SNPK、NPK、MNPK和1.5MNPK对土壤动物类群的影响能力显著不同，SNPK和NPK对土壤动物优势类群有正向作用，而MNPK和1.5MNPK则相反，对其它的解释不明显。从第一主分量看，各种施肥处理对土壤动物个体总数的综合影响最明显，对土壤动物群落均匀性、多样性影响最小；从评价值大小看，第一主成分特征向量最大值和最小值之间相差较大，表明6种施肥对农田土壤动物的影响不平衡。     

Trends of Yield and Soil Fertility in a Long-Term Wheat-Maize System

The sustainability of the wheat-maize rotation is important to China＇s food security. Intensive cropping without recycling crop residues or other organic inputs results in the loss of soil organic matter （SOM） and nutrients, and is assumed to be non- sustainable. We evaluated the effects of nine different treatments on yields, nitrogen use efficiency, P and K balances, and soil fertility in a wheat-maize rotation system （1991-2010） on silt clay loam in Shaanxi, China. The treatments involved the application of recommended dose of nitrogen （N）, nitrogen and phosphorus （NP）, nitrogen and potassium （NK）, phosphorus and potassium （PK）, combined NPK, wheat or maize straw （S） with NPK （SNPK）, or dairy manure （M） with NPK （M1NPK and M2NPK）, along with an un-treated control treatment （CK）. The mean yields of wheat and maize ranged from 992 and 2 235 kg ha-1 under CK to 5 962 and 6 894 kg ha-1 under M2NPK treatment, respectively. Treatments in which either N or P was omitted （N, NK and PK） gave significantly lower crop yields than those in which both were applied. The crop yields obtained under NP, NPK and SNPK treatments were statistically identical, as were those obtained under SNPK and MNPK. However, M2NPK gave a significant higher wheat yield than NP, and MNPK gave significant higher maize yield than both NP and NPK. Wheat yields increased significantly （by 86 to 155 kg ha-1 yr-1） in treatments where NP was applied, but maize yields did not. In general, the nitrogen use efficiency of wheat was the highest under the NP and NPK treatments; for maize, it was the highest under MNPK treatment. The P balance was highly positive under MNPK treatment, increasing by 136 to 213 kg ha-1 annually. While the K balance was negative in most treatments, ranging from 31 to 217 kg ha^-1 yr^-1, levels of soil available K remained unchanged or increased over the 20 yr. SOM levels increased significantly in all treatments. Overall, the results indicated that combinations of organic manure and inorganic nitrogen, or retuming straw with NP is likely to improve soil fertility, increasing the yields achievable with wheat-maize system in a way which is environmentally and agronomically beneficial on the tested soil.     

长期不同施肥对东北黑土区玉米产量稳定性的影响

【目的】通过阐明长期不同施肥下东北黑土区玉米产量的变化规律及其稳定性差异,为建立合理施肥模式、促进东北黑土区玉米持续稳产和高产提供科学依据。【方法】以（公主岭）国家黑土肥力与肥料效益长期试验为研究平台,利用8种不同施肥模式（CK、NP、NK、PK、NPK、M₁NPK、SNPK和M₂NPK）的25年数据分析玉米产量变化及土壤养分状况对施肥模式的响应。【结果】长期有机肥与化肥配施玉米产量总体上表现为上升趋势,有机肥氮替代部分化肥氮的有机无机配施处理增产效果也较为明显;M₁NPK、SNPK和NPK 3个等氮量施肥处理玉米平均产量差异不显著,其前11年NPK处理玉米产量高于SNPK和M₁NPK处理,后14年NPK处理玉米产量低于SNPK和M₁NPK处理;施化肥处理玉米平均产量（1990-2014年）排序为NPK＞NP＞NK＞PK、CK。氮、磷和钾肥对玉米产量的增产效应差异较大,每千克氮肥、磷肥和钾肥的产量效应分别为33.0、16.2和15.3 kg。有机无机配施处理玉米产量可持续指数（SYI）值高,分布在0.712-0.798,玉米产量可持续性好,而不平衡施肥和不施肥处理的SYI值最低;CK、PK和NK处理玉米产量变异系数较大,分布在18.5%-34.7%,产量稳定性差,而有机无机配施处理相对较小都在10.8%-13.0%。在施肥处理中,PK处理平均生产力贡献率最低,仅为37.8%,但与氮配施平均生产力贡献率达到91.2%;NPK、M₁NPK与SNPK 3个等氮量施肥处理平均生产力贡献率差异不显著。长期施用有机肥可明显提高土壤有机质、全氮、有效磷和速效钾含量,施用化肥磷对土壤有效磷含量提高较显著,但施用化肥氮和钾分别对土壤全氮和速效钾含量提高效果不显著;通过相关性分析可知玉米产量与土壤有机质、全氮和速效磷均呈极显著正相关（P＜0.01）,而与土壤速效钾含量呈显著正相关（P＜0.05）。【结论】长期不施肥或偏施化肥玉米产量的稳定性减弱、土壤生产力贡献率下降;平衡施用化肥可有效提高黑土区玉米产量稳定性和可持续性;有机肥与化肥配施具有明显的增产和稳产效果。因此,施用有机肥氮替代部分化肥氮的有机无机配施模式是东北黑土区最有效的施肥措施。     

长期施肥对红壤旱地磷组分及磷有效性的影响

为提高红土红壤磷的有效性和肥料磷的利用率，设立长期定位试验，研究了红壤旱地不同施肥条件下土壤磷素的变化规律。结果表明：长期施磷，特别是磷肥和有机肥配合施用能明显提高土壤全磷（PT）、无机磷、有机磷、Olsen-P和Bray-P含量。在施磷的条件下，土壤磷的积累主要表现为Ca2-P,Ca8-P和Al-P增加。土壤中Olsen-P和Bray-P含量与土壤中各磷组分的相关性以Ca2-P最好，Al-P和Ca8-P次之，O－P最差，土壤Olsen-P和Bray-P含量与作物产量显著正相关。     

Interaction of soil microbial communities and phosphorus fractions under long-term fertilization in paddy soil

Understanding the impact of biological activities on the soil phosphorus (P) distribution under long-term fertilizer application can facilitate better soil P fertility management. Therefore, the primary objectives of this study were to investigate the effect of long-term (since 1981) fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution. The following treatments were implemented in a long-term field trial: no fertilization (CK), inorganic N and K (NK), inorganic P and K (PK), inorganic N, P and K (NPK) and manure+NPK (MNPK) fertilization. The study showed that the soil pH, soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment. The soil microbial biomass C, N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment. Among fertilization treatments, the β-1,4-glucosidase, α-1,4-glucosidase, urease, acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment. Compared to inorganic fertilization, the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration. Continuous fertilization significantly affected the soil microbial composition. The total phospholipid fatty acid (PLFA) concentrations in the NK, PK, NPK and MNPK treatments were 23.3, 43.1, 48.7 and 87.7% higher, respectively, than in the CK treatment. A significant correlation was observed between the microbial community and soil P fractions. Moreover, the aggregated boosted tree (ABT) model showed that among the various soil biochemical properties, the total PLFA concentration was the factor that most influenced the active P pool, accounting for 35.4% of the relative influence of all soil biochemical properties examined. These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity.     

不同施肥条件下农田土壤动物群落组成及多样性变化

[目的]研究不同施肥条件下农田土壤动物群落组成及多样性变化。[方法]设对照(CK)、施氮(N)、施氮磷钾(NPK)、施氮磷钾+秸秆(SNPK)和施氮磷钾+有机肥(MNPK)5种处理,探讨不同施肥条件下农田土壤动物群落组成及多样性变化。[结果]调查发现各类土壤动物4 027头。从土壤动物类群来看,5种施肥处理中,MNPK>SNPK>CK>NPK>N;从土壤动物的数量分布来看,MNPK>SNPK>CK>NPK>N;从多样性指数来看,MNPK>SNPK>NPK>CK>N。各施肥条件下的土壤动物群落表现为中等相似。[结论]农田增加有机肥及秸秆还田有利于土壤动物生存和发展,改善土壤结构,增加农作物产量。     

长期不同施肥方式对稻麦轮作田杂草群落的影响

【目的】明确在稻麦轮作条件下,肥料管理对太湖地区稻麦轮作田杂草群落的影响特征和方式。【方法】在水稻收获后,对长期不同肥料处理小区,具体包括不施肥（CK）,仅施氮肥（N）,施氮钾肥（NK）,施磷钾肥（PK）,施氮磷肥（NP）和均衡施肥（NPK）,进行杂草群落调查。分析杂草密度、多样性指数Shannon-H’,均匀度指数Pielou-EJ和丰富度指数Margalef-DMG,并进行主成分和回归分析。【结果】杂草总密度的排列次序为NP＞CK＞N＞NK＞NPK,稻槎菜,牛繁缕,菵草和大巢菜是主要农田杂草。氮磷养分亏缺提高了杂草多样性,Shannon-H’指数排序为CK＞NK＞PK＞N＞NP＞NPK。主成分1、2的特征值分别为0.498和0.235,稻槎菜,野老鹳草,异型莎草和菵草与主成分1夹角较小,能更多地解释主成分1。对提取的主成分1、2值与土壤有效态氮磷钾回归分析,其中有效氮、磷与主成分1值回归决定系数分别为0.85、0.86（P＜0.05）,主成分2值与土壤养分因子无显著相关性。【结论】太湖地区稻麦轮作条件下,土壤养分的盈亏决定了田面杂草密度和优势种群,氮磷亏缺导致杂草群落多样性高于氮磷钾均衡施肥,且土壤氮含量对杂草群落的影响最显著。     

长期施肥管理对土娄土全碳和易氧化有机碳的影响

采用不施肥(CK),秸秆和化肥配施(SNPK),低量有机肥和化肥配施(M1NPK),高量有机肥和化肥配施(M2NPK)以及单施化肥N、NP、NPK、NK、PK 9个施肥处理,休闲(Fallow)和撂荒(Setaside)2种土壤管理方式,研究冬小麦-夏玉米轮作系统长期施肥以及土壤管理方式对土壤全碳(TOC)和易氧化有机碳(ROOC)含量动态变化的影响。结果表明,与对照相比,各施肥处理的TOC和ROOC含量均有不同程度提高。土壤TOC含量均值变化为处理M2NPK>M1NPK>SNPK>Setaside>NPK>NP>N>PK>NK>CK>Fallow,土壤ROOC含量均值变化为处理M2NPK>M1NPK>SNPK>Setaside>NPK>N>NP>PK>NK>CK>Fallow。土壤TOC和ROOC含量的变化均为处理MNPK>SNPK>Setaside>NPK>偏施化肥>CK>Fallow。土壤剖面TOC和ROOC含量均随土层深度的增加而减少。NPK处理较CK显著增加0~10 cm土层TOC含量,却明显降低30~60 cm土层TOC含量;SNPK处理显著增加0~20cm土层TOC含量;M2NPK处理显著提高0...     

长期施用不同肥料塿土PLFA指纹特征

【目的】土壤微生物群落结构的组成与活性的变化是衡量土壤肥力的重要指标,研究长期不同施肥和土壤管理方式对塿土微生物群落结构的影响,对于指导塿土施肥和土壤管理,实现农田可持续利用具有重要意义。【方法】以陕西杨凌“国家黄土肥力与肥料效益监测基地”长期肥料定位试验为基础,运用磷脂脂肪酸标记法（PLFA）,研究了塿土长期不同施肥及土地利用方式下土壤微生物群落结构及其与土壤理化性质的关系。处理包括：长期不施肥（CK）、单施氮肥（N）、长期配合施用氮钾（NK）、磷钾（PK）、氮磷（NP）、有机肥和氮磷钾（MNPK）以及长期休闲（FL）和撂荒（AB）。【结果】与对照相比,MNPK、NP和撂荒处理土壤总PLFA分别增加218.8%、73.9%和74.3%,细菌分别增加188.3%、80.8%和82.6%,真菌分别增加了315.8%、111.5%和167.0%,放线菌分别增加了23.7%、21.3%和16.3%,同时也显著增加了真菌/细菌比;N、NK和PK土壤总PLFA、细菌、真菌差异不显著,但PK显著降低放线菌的含量;与农田施肥相比,休闲和撂荒显著降低G+和G-含量。多样性指数结果表明,长期有机无机配施明显提高土壤微生物群落的Shannon-Winner多样性指数、Simpson优势度和Pielou均匀度指数,撂荒和NP也能显著增加Shannon-Winner多样性指数和Pielou均匀度指数,而长期休闲处理均明显降低了这些指数。主成分分析表明,MNPK、NP、撂荒和休闲土壤微生物群落结构发生较大变化;MNPK显著提高G-（18:1ω5c,cy19:0ω7c）、细菌（16:0,10Me22:0饱和脂肪酸）及真核生物（18:3ω6c,16:3ω6c,22:2ω6c）的多度值,撂荒（AB）和NP显著提高细菌（15﹕0,18﹕0,22﹕0,17﹕0饱和脂肪酸）的多度值。RDA分析表明,土壤理化性质对微生物菌群影响的重要性依次为有机质＞全氮＞含水量＞速效磷＞pH＞容重＞速效钾,这些理化因子均是微生物生长的关键因子。【结论】长期有机无机肥配施、氮磷配施和撂荒提高了土壤微生物群落结构多样性,从而改善了土壤生态环境,而长期休闲不利于土壤生态系统的稳定和健康。     

贝加尔针茅草原土壤微生物功能多样性对养分添加的响应

为揭示养分添加对草原土壤微生物群落功能多样性的影响,采用Biolog-Eco技术,研究了在无养分添加对照(CK)和7种不同氮磷钾养分添加方式(单养分添加:N、P、K,不同组合添加:PK、NK、NP、NPK)下贝加尔针茅草原土壤微生物群落功能多样性变化。结果表明:(1)不同养分添加条件下土壤微生物群落单孔平均颜色变化率(Average Well Color Development)AWCD值从高到低依次为NPPNPKNKNCKKPK。(2)含磷添加处理(PK除外,NP、P、NPK)和含氮添加处理(N、NK)的丰富度指数H均显著高于CK、K、PK,而均匀度指数E和优势度指数D在各处理间差异不显著。(3)主成分分析结果表明,CK、K、PK、NK处理土壤微生物群落碳源利用方式相似,而NP、P和N、NPK分别具有不同的碳源利用方式。据此可知,NP、P、NPK、N养分添加方式可以提高土壤微生物代谢活性、物种丰富度指数和微生物群落碳源利用能力,有利于土壤微生物群落功能多样性的提高。     

双季稻种植制度下长期施肥对红壤性水稻土氮素肥力的影响

设CK（不施任何肥）、NK（施氮、钾肥）、NP（施氮、磷肥）、NPK（施氮、磷、钾肥）、NK＋PM（施氮、钾肥＋猪粪）、NP＋RS（施氮、磷肥＋稻草）、NPK＋RS（施氮磷钾肥＋稻草）7个处理,通过25年长期肥料定位试验,研究了双季稻种植制度下长期施肥对红壤性水稻土氮素肥力的影响．结果表明,长期不平衡施肥处理（NK、NP）土壤各氮素含量增加不明显或出现一定幅度的减少;长期平衡施用化肥的NPK处理,土壤各氮素含量均有增长,与CK处理的差异达到显著或极显著水平;无机、有机肥长期配施处理NK＋PM、NP＋RS、NPK＋RS在单施化肥的基础上进一步提高了土壤中氮素养分的含量．双季稻种植制度下,长期平衡施肥,尤其是无机、有机肥配施能极大地增加红壤性水稻土各氮素养分含量,提高土壤氮素肥力,为水稻的高产、稳产和农业可持续发展提供良好的基础和保障．     

长期施肥对小麦、玉米根际和非根际土壤微生物量碳及水溶性有机碳含量的影响

通过20 a的长期定位试验，研究不同施肥措施下，小麦、玉米生育期根际和非根际土壤的微生物量碳（MBC）和水溶性有机碳(WSOC)动态变化。试验包括7种不同的施肥措施：不施肥对照（CK）、单施氮肥（N）、磷钾配合（PK）、氮磷配合（NP）、氮磷钾配合（NPK）、秸秆还田+氮磷钾（SNPK）和有机肥+氮磷钾（MNPK）。结果表明，SNPK和MNPK显著增加根际和非根际土壤微生物量碳和水溶性有机碳的含量。小麦生育期中MBC含量在开花期最高，而WSOC在开花期最低，与MBC趋势相反；各处理根际土壤MBC和WSOC含量均明显高于非根际土壤。玉米生育期各处理MBC变化不明显，根际土MBC含量高于非根际，而WSOC则非根际土稍高。MBC和总有机碳（TOC）比率为17.18~33.54 g·kg^-1,以玉米乳熟期CK最高。WSOC/TOC变幅为2.43~6.67 g·kg^-1，玉米乳熟期均较小麦成熟期有大幅度下降。     

Long-term fertilization leads to specific PLFA finger-prints in Chinese Hapludults soil

Soil microbes play essential roles in the biogeochemical processes of organic carbon and nutrient cycling. Many studies have reported various short-term effects of fertilization on soil microbes. However, less is known about the effects of longterm fertilization regimes on the rhizosphere. Therefore, the objective of this study was to explore how the soil microbial communities in the rhizosphere respond to different long-term fertilization strategies. Based on a 21-year field treatment experiment in Guizhou, China, we extracted phospholipid fatty acids(PLFAs) to determine the microbial community structure in both the non-rhizosphere(NR) and rhizosphere(R). Six treatments were included: no fertilizer(CK), mineral nitrogen fertilizer(N), N with potassium(NK), phosphorus with K(PK), NPK, and NPK combined with manure(MNPK). The results showed that total PLFAs under unbalanced mineral fertilization(N, NK and PK) were decreased by 45% on average in the NR compared with CK, whereas MNPK increased fungi and G~– bacteria abundance significantly in both the NR(by 33 and 23%) and R(by 15 and 20%), respectively. In addition, all microbial groups in the R under these treatments(N, NK and PK) were significantly increased relative to those in the NR, except for the ratio of F/B and G~+/G~–, which might be due to the high nutrient availability in the R. Soil pH and SOC significantly regulated the soil microbial community and structure, explaining 51 and 20% of the variation in the NR, respectively. However, the rhizosphere microbial community structure was only significantly affected by soil pH(31%). We concluded that the soil microbial community in the NR was more strongly affected by long-term fertilization than that in the R due to the rhizosphere effect in the agricultural ecosystem. Rhizosphere nutrient conditions and buffering capacity could help microbial communities resist the change from the long-term fertilization.     

不同施肥制度对土壤微生物的影响及其与土壤肥力的关系

 以国家褐潮土肥力与肥料效益监测基地的长期肥料试验为平台，系统研究了长期不同施肥制度对土壤微生物种群和生理群落的影响及其与土壤肥力的关系。结果表明：（1）长期单施化肥，农田土壤细菌、真菌数量低于长期撂荒土壤，但放线菌数量多于撂荒土壤或与之相当。（2）长期单施化肥与不施肥（CK）比较，土壤放线菌数量增加，细菌和真菌数量略有增加或与之相当。（3）总体看，NPK均衡施肥，土壤细菌、真菌和放线菌数量比非均衡施肥的N、NP、NK、PK处理略有增加或与之相近。（4）NPK配施有机肥或秸秆，可明显增加土壤中细菌、真菌、放线菌的数量，不仅明显高于单施化肥和不施肥农田，而且细菌、放线菌数量也高于撂荒土壤，真菌数量略低于撂荒土壤或与之相当。（5）长期单施化肥农田，土壤固氮菌、氨化细菌、纤维分解菌、反硝化细菌数量低于长期撂荒土壤，但硝化细菌数量比撂荒土壤多。单施化肥，土壤固氮菌、硝化细菌、纤维分解菌数量高于不施肥的CK，而氨化细菌、反硝化细菌数量却低于CK。NPK均衡施肥土壤氨化细菌、硝化细菌、纤维分解菌数量比非均衡施肥的N、NP、NK、PK处理增加，固氮菌数量二者相当，反硝化细菌数量减少。NPK配施有机肥或秸秆，土壤中固氮菌、氨化细菌、反硝化细菌、硝化细菌、纤维分解菌数量大都高于单施化肥处理，尤其明显高于非均衡施用化肥的处理。与撂荒土壤比较，NPK配施有机肥或秸秆，土壤固氮菌、氨化细菌、反硝化细菌、硝化细菌数量增多，但纤维分解菌数量降低。（6）土壤中大多数微生物种类的数量与养分含量、作物产量具有正相关关系。     

Effect of Different Fertilizer Treatments on Quantity of Soil Microbes and Structure of Ammonium Oxidizing Bacterial Community in a Calcareous Purple Paddy Soil

The quantity of soil microbes and the structure of ammonium oxidizing bacterial （AOB） community were analyzed using the dilution plate counting and most probable number method （MPN）, and denaturing gradient gel electrophoresis （DGGE）, respectively. Fertilizer application tended to increase the number of soil microbes and alter the AOB community compared to the control with no fertilizer application （CK）. Among the eight fertilizer treatments, soil samples from the treatments of mineral fertilizers （e.g., N, P, K） in combination with farmyard manure （M） had greater number.s of soil microbes and more complex structure of AOB community than those receiving mineral fertilizers alone. The principal component analyses （PCA） for ammonium oxidizing bacterial community structure showed that the eight fertilizer treatments could be divided into two PCA groups （PCA1 and PCA2）. For the soil sampled after rice harvest, PCA1 included NP, NM, NPM and NPKM fertilizer treatments, while PCA2 was consisted of CK, N, M and NPK fertilizer treatments. For soil samples collected after wheat harvest, PCA1 was consisted of M, NM, NPM and NPKM fertilizer treatments, while PCA2 was composed of CK, N, NP and NPK fertilizer treatments. For a given rotation, the richness of AOB community in PCA1 was greater than that in PCA2. In addition, AOB community structure was more complex in the soil after rice harvest than that after wheat harvest. The results indicated that different fertilizer treatments resulted in substantial changes of soil microbe number and AOB community. Furthermore, mineral fertilizers （N, NP, NPK） combined with farmyard manure were effective for increasing the quantity of soil microbes, enriching AOB community, and improving the soil biofertility.     

长期施肥条件下潮土土壤磷素对磷盈亏的响应

【目的】土壤磷素状况是评价土壤养分的重要指标之一。探讨长期施肥条件下土壤有效磷、全磷对土壤磷素盈亏（平衡）的响应,为潮土区施肥管理和土壤培肥提供科学依据。【方法】分析了天津潮土33年（1979-2012）肥料长期定位试验中,不同施肥处理下土壤磷素盈亏与Olsen磷、全磷的变化特征。【结果】长期不施肥（CK）、单施氮肥（N）、氮钾配施（NK）及秸秆与氮肥配施（NS）处理,土壤中磷素常年处于亏缺状态。施磷处理（PK,NP,NPK）和有机肥与氮肥配施（NM）,土壤中磷素均有盈余,PK处理盈余最多,但随试验年限延长（约20年后）,NP,NPK和NM处理土壤中磷素盈余量呈下降趋势。土壤有效磷增加量随磷盈亏而变化,二者呈显著正相关（P＜0.05）。施用无机磷肥或有机肥,均可使土壤中的磷素盈余,土壤中每盈余100 kg·hm^-2磷,PK、NP、NPK、NM处理土壤中的Olsen磷分别增加3.59、1.19、1.75和2.40 mg·kg^-1。长期不同施肥,土壤磷平衡与土壤全磷增量间呈正相关,但不同处理下差异较大。单施氮肥（N）和秸秆还田（NS）处理,可认为累积磷平衡对土壤全磷增量无影响。施用无机磷肥或有机肥,土壤中每盈余100 kg P·hm^-2,PK、NP、NPK、NM处理土壤中全磷分别增加0.06、0.07、0.07和0.10 g·kg^-1。【结论】土壤磷素盈亏状况与肥料配施类型密切相关,长期施用化学磷肥或有机肥,土壤有效磷、全磷增加量与土壤磷素盈亏呈显著直线正相关。有机肥与氮肥配施提升土壤全磷的速率大于施用化肥。     

长期施肥下黑土碳氮和土壤pH的空间变化

试验研究了长期不同施肥下剖面(0~100 cm)土壤有机碳、全氮、硝态氮、微生物碳氮以及土壤pH的空间变化。结果表明:与单施化肥相比,长期有机肥和化肥配施显著提高了0~20 cm表层土壤有机碳、全氮、硝态氮和微生物碳氮含量,并且土壤有机碳和微生物碳氮的增加主要集中在0~40 cm土层。在0~20 cm和20~40 cm土层,等氮量有机无机肥配施(M1NPK和SNPK)处理土壤有机碳含量显著高于化肥NPK处理(P0.05),同时二处理土壤全氮含量没有由于化肥氮施用量减少而下降。与不施肥ck相比,单施化肥显著降低了土壤微生物量碳氮含量。在40 cm土层以下,与NPK处理相比,M2NPK、NP和N处理硝态氮累积量明显增加,而M1NPK和SNPK处理硝态氮累积量明显减少。长期不同施肥对土壤酸化的影响主要集中在0~40 cm土层,单施化肥处理土壤pH显著低于不施肥(ck)和有机无机肥配施处理(P0.05),其中2012年秸秆还田(SNPK)处理0~20 cm土壤pH比NPK处理高2.17。表明有机无机肥配施不仅能提高和维持土壤碳氮水平,还能防止土壤酸化的发生,尤其施用有机肥氮替代部分化肥氮的有机无机肥配施模式是东北黑土区最有效的施肥措施之一。     

长期不同培肥处理对土壤有机氮组分及氮素矿化特性的影响

【目的】揭示长期不同培肥处理对黄土高原南部土垫旱耕人为土(土)土壤有机氮组分、氮素矿化的影响以及有机氮组分对氮素矿化潜力的贡献。【方法】采用Stanford和Smith间歇淋洗好气培养法测定了土19年长期不同施肥处理土壤矿化氮的数量,并采用Bremner法测定了培养前、后土壤有机氮各组分含量的变化。【结果】各处理土壤有机氮各组分含量高低顺序为:氨基酸氮非酸解氮酸解未知氮氨态氮氨基糖态氮。与不施肥对照相比,长期单施化肥处理土壤有机氮各组分含量有不同程度的增加,但幅度有限;化肥配施秸秆或有机肥处理显著提高了各有机氮组分含量,其中以氨基酸氮含量增加幅度最大;化肥配施秸秆或有机肥处理降低了酸解有机氮占全氮的比例。化肥长期配施有机肥或秸秆,显著提高了土壤氮素矿化势(N0)以及矿化率,其中化肥配施有机肥土壤N0大于化肥配施秸秆处理。相关分析表明,土壤氮素矿化势N0与培养前后土壤氨基酸氮变化量间呈显著负相关关系(P0.05),与土壤酸解未知态氮和非酸解氮的变化量间的负相关关系未达显著水平(P0.05)。【结论】化肥配施有机肥或秸秆,是提高土壤供氮潜力的有效手段;氨基酸氮是土壤可矿化态氮的主要贡献者。