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1.
Manure application generally increases soil organic matter (SOM) and particulate organic matter (POM) content in soil. Free and occluded POM (fPOM and oPOM) can be quantified by combining density and ultrasonic dispersion approaches, but it remains unclear which fraction of POM is more responsive to manure application, and whether manure treated soils have a more pronounced effect on POM content than unmanured soils (no or chemical fertilizer treated soils). Because neutral sugars in POM can be attributed to either plant- or microbial-derived compounds, we analyzed the pattern and ratio of different neutral sugars to clarify effects of different fertilizations on quality of POM in a study over two decades. Soil samples (0–20 cm) were collected from six fertilization treatments in a 25-year long fertilization experiment including no fertilizer (CK), low manure (M1), high manure (M2), chemical nitrogen, phosphorus and potassium fertilizers (NPK), and combined manure and chemical fertilizers (M1NPK, M2NPK). Our results showed that manure application generally led to higher organic carbon concentrations in bulk soil (M2NPK > M2 > M1NPK > M1 > CK > NPK), fPOM (M2NPK > M2 > M1 > M1NPK > NPK > CK) and oPOM (M1 > M2 > M1NPK > M2NPK > NPK > CK), respectively. As compared with unmanured treatments, manure amendments induced 48, 21 and 107% greater increases on average in neutral sugar concentrations in bulk soil, fPOM and oPOM, respectively. More plant-derived organic compounds were enriched in fPOM than oPOM and bulk soil, and the enrichment was more pronounced in manure treated soils than the unmanured soils. This study suggests that long-term use of manure enhanced microbial routing of specific monosaccharides into different POM fractions. Clearly, manure amendments improved labile SOM content and SOM quality in the Mollisol thus maintaining soil productivity over decades.  相似文献   

2.
水稻秸杆腐解过程溶解性有机质红外光谱研究   总被引:5,自引:1,他引:4  
采用傅里叶红外光谱(FTIR)分析方法研究了水稻秸杆不同腐解阶段产生溶解性有机质(dissolvedorganic matter,DOM)及其分组组分的结构特征.结果表明,水稻秸杆腐解过程中DOM组成成分的变化呈现出明显的阶段性.在第0~3天,秸杆本身含有的糖类、氨基酸等小分子物质因微生物繁殖迅速消失;第3~ 63天,主要是秸杆中的半纤维素、纤维素的分解阶段,DOM组成中多糖类、烷烃类物质呈现起伏性变化;第63天后,主要是腐殖化阶段,DOM分子结构复杂化.各分组组分的结构特征有明显差异,且各组分均随腐解延长而发生变化,即多糖类物质减少,芳香族物质增多,分子结构复杂化.  相似文献   

3.
Reuse of treated wastewater (TWW) for irrigation in agriculture is a common alternative water source in arid regions suffering from fresh water (FW) shortage. Soil aquifer treatment (SAT) is frequently used for advanced TWW purification. Infiltration rates of water through the soil can decrease as a consequence of organic matter (OM) accumulation and the consequent induction of water repellency. In this research, soil heating to high temperatures was examined for its efficiency in OM content reduction and increased infiltration. In a laboratory experiment conducted using a hand burner and a combustion oven, water repellency was found to be reduced following increased heating temperature or heating duration, directly resulting in reduction of OM level. Chemical analysis of OM extracted from the heat treated soils revealed reduction in hydrophobic substances as a consequence of increased temperatures by soil heating and heating duration. In model ponds built to simulate large infiltration basins, OM content was reduced as a result of intensive and moderate soil heating in comparison to the untreated pond. However, no reduction in water repellency and only slight changes in infiltration rate were found as a consequence of soil heating. The differences in results obtained in the laboratory and the field experiments were probably related to the fact that the soil in the field experiment has been continuously reloaded with TWW containing OM.  相似文献   

4.
在赤红土中施用溶解性有机质(DOM)——稻秆DOM(稻秆发酵液中的有机质)后,生长在该土壤上的蔬菜体内镉含量,较不施稻秆DOM的显著增加,加重了对蔬菜的危害程度  相似文献   

5.
The oxidative ratio (the ratio of moles of O2 produced per mole CO2 sequestered – OR) of the organic matter in the terrestrial biosphere governs the ability of the terrestrial biosphere to uptake CO2. The value of OR is known to vary between environments, but it would also be expected to vary with management. This study measured the OR of plant and soil samples from the long‐term grassland plots on the Park Grass experiment at Rothamsted (SE England). The selected plots included those with different fertilizer inputs, including farmyard manure or inorganic fertilizers and an unfertilized control, each with and without lime. The measurements show that: (i) Use of inorganic fertilizer caused the OR of soil organic matter to increase. (ii) Farmyard manure (FYM) caused OR of the soil to increase but that of the vegetation decreased. (iii) Liming had the effect of decreasing OR and counteracting effects of fertilizer. (iv) The OR of the ecosystem increased with FYM application but decreased with inorganic fertilizer application. The global pattern in the use of organic amendments and inorganic fertilizers suggests that the likely impact of the predicted increase in global inorganic fertilizer use will result in a net decrease in the OR of the organic matter of the terrestrial biosphere, and an increase in its ability to act as a carbon sink. Corresponding increases in global FYM use and its impact upon global OR are unlikely to be large enough to counteract this effect.  相似文献   

6.
黄土丘陵区不同植被下土壤可溶性有机物的荧光特征研究   总被引:4,自引:0,他引:4  
【目的】土壤水溶性有机质的组成和结构是土壤质量的重要判别指标,具有重要的生态意义。研究黄土丘陵地区不同植被下土壤水溶性有机物的数量和荧光结构特征,可以为该地的植被修复及土壤质量评价提供科学依据。【方法】利用传统荧光和三维荧光技术,选取激发发射荧光光谱、 同步荧光光谱得到的腐殖化指标对土壤水溶性有机物的来源和结构进行评估,通过三维荧光技术探究不同植被下土壤水溶性有机物之间组分的差异。【结果】辽东栎(Quercus liaotungensis)和油松林(Pinus tabulaeformia)地具有较高的水溶性有机物含量,含量均为0.16 mg/g; 而荒坡地和农地的水溶性有机物较低,分别为0.04和0.05 mg/g,灌木荆条(Vitex negundo var. heterophylla )和狼牙刺(Sophora viciifolia)林地的含量介于两者之间。发射激发荧光光谱、 同步荧光光谱以及三维荧光光谱表明土壤水溶性有机物大多来源于植物和微生物的混合作用; 油松林地的水溶性有机物结构较简单、 腐殖化程度较低; 而灌木林地的水溶性有机物结构较为复杂、 腐殖化程度较高。从不同植被下土壤水溶性有机物的组成来看,蛋白类的物质差异不明显; 油松和辽东栎林地土壤水溶性有机物的类酪氨酸蛋白质、 类色氨酸蛋白质、 类溶解性微生物代谢产物含量较高,灌木林地较低。最主要的差异是富里酸类和胡敏酸类物质,油松林地的水溶性小分子量的富里酸类物质占主导地位,而灌木林地的水溶性有机物芳香化程度较高,农地和抛荒地类富里酸物质和类胡敏酸类物质含量的比值最低,其水溶性腐殖质的缩聚度高。油松、 辽东栎林地水溶性有机物由于植物残体分解形成的富里酸较易被氧化,同时阴坡林地较高的含水量使得这些产物较难缩合; 而灌木林地和农田及荒地较为干旱,枯枝落叶少,腐殖酸有充分时间进行缩合,导致了水溶性有机物的高芳香化和腐殖化。【结论】不同植被下的土壤水溶性有机物的组成和结构是存在差异的,同时说明荧光技术可用于揭示水溶性有机物的组成和缩合特性研究。  相似文献   

7.
土壤异养呼吸是影响土壤有机碳积累的关键因素。以南方红壤水土流失区不同恢复年限的马尾松林(未治理地(Y0)、恢复14 a(Y14)、恢复31 a(Y31))为对象,对不同呼吸组分进行测定并结合温度、水分以及微生物等因子,研究马尾松林恢复对土壤异养呼吸的影响。结果表明:不同恢复年限马尾松林土壤异养呼吸差异显著,恢复31 a显著大于恢复14 a以及未治理地,未治理地异养呼吸速率仅为0.99 μmol?m-2?s-1,而治理14 a、31 a分别为2.20、2.80 μmol?m-2?s-1;温度是异养呼吸季节变化的主要影响因子,分别解释季节变化的40.6%(Y0)、62.2%(Y14)、66.6%(Y31);马尾松林恢复后土壤异养呼吸温度敏感性(Q10)显著增加,Y0、Y14、Y31的 Q10分别为1.58、1.93和1.82;不同恢复年限土壤异养呼吸占土壤总呼吸比例为77.94%(Y0)、70.84%(Y14)、77.35%(Y31)。结构方程表明,在马尾松林恢复过程中,土壤有机碳(SOC)、温度以及土壤微生物多样性变化是影响土壤异养呼吸变化的主要因子,其中SOC、土壤微生物与异养呼吸显著正相关,而植被恢复过程中土壤温度变化与异养呼吸显著负相关。本研究结果表明,马尾松林植被恢复过程中SOC的积累以及缺乏有效的物理保护增加了微生物对SOC的分解,另一方面土壤环境温度的降低和细菌、真菌丰度的增加以及群落中变形菌、子囊菌、酸杆菌的增加,更进一步加剧微生物对原有土壤有机质的分解强度,导致异养呼吸碳排放的持续增加,最终限制了马尾松林土壤碳吸存效率。因此,较高的土壤异养呼吸可能是影响红壤侵蚀退化区土壤有机质进一步提升的关键。  相似文献   

8.
不同有机肥输入量对黑土密度分组中碳、氮分配的影响   总被引:3,自引:1,他引:2  
为阐明不同有机肥施用量对黑土密度组分中碳、氮分配特征的影响,探讨合理调控土壤质量的施肥模式。以黑龙江省海伦国家野外科学观测研究站上进行了10年的田间定位试验土壤为研究对象,采用密度分组和腐殖质化学分组相结合的方法,探讨和分析不同有机肥施用量下土壤各密度组分中有机碳、氮的消长变化以及重组中腐殖物质的组成特征。结果表明:与试验初期相比,经过10年单施化肥处理,土壤总有机碳和全氮、各密度组分中有机碳氮以及腐殖物质各组分的含量均显著下降,而有机无机配施能够提升土壤总有机碳和全氮的含量水平,改善密度组分中有机碳氮的分配特征,土壤总有机碳、全氮和各密度组分中有机碳氮对不同有机肥施用量的响应有所差异。随着有机肥施用量的增加,土壤总有机碳和全氮的含量呈逐渐升高的趋势,二者与有机肥施用量之间达到极显著的线性相关(P<0.01);低量有机肥(7.5,15t/(hm2.a))配施化肥仅增加了土壤游离态轻组有机碳、氮的含量,并未造成闭蓄态轻组和重组中有机碳、氮的积累,而高量有机肥(22.5t/(hm2.a))配施化肥后,促进了土壤各密度组分中有机碳、氮的形成和积累;此外,低量有机肥有利于土壤富里酸的积累,高量有机肥有助于胡敏酸和胡敏素的积累,从而提高了土壤有机质的腐殖化程度,增强了土壤有机质的稳定性。在东北黑土区,加大有机肥的施用量是提高土壤肥力和土壤固碳能力的有效途径。  相似文献   

9.
Crop and land management practices affect both the quality and quantity of soil organic matter (SOM) and hence are driving forces for soil organic carbon (SOC) sequestration. The objective of this study was to assess the long‐term effects of tillage, fertilizer application and crop rotation on SOC in an agricultural area of southern Norway, where a soil fertility and crop rotation experiment was initiated in 1953 and a second experiment on tillage practices was initiated in 1983. The first experiment comprised 6‐yr crop rotations with cereals only and 2‐yr cereal and 4‐yr grass rotations with recommended (base) and more than the recommended (above base) fertilizer application rates; the second experiment dealt with autumn‐ploughed (conventional‐till) plots and direct‐drilled plots (no‐till). Soil samples at 0–10 and 10–30 cm depths were collected in autumn 2009 and analysed for their C and N contents. The quality of SOM in the top layer was determined by 13C solid‐state NMR spectroscopy. The SOC stock did not differ significantly because of rotation or fertilizer application types, even after 56 yr. However, the no‐till system showed a significantly higher SOC stock than the conventional‐till system at the 0–10 cm depth after the 26 yr of experiment, but it was not significantly different at the 10–30 cm depth. In terms of quality, SOM was found to differ by tillage type, rate of fertilizer application and crop rotation. The no‐till system showed an abundance of O‐alkyl C, while conventional‐till system indicated an apparently indirect enrichment in alkyl C, suggesting a more advanced stage of SOM decomposition. The long‐term quantitative and qualitative effects on SOM suggest that adopting a no‐tillage system and including grass in crop rotation and farmyard manure in fertilizer application may contribute to preserve soil fertility and mitigate climate change.  相似文献   

10.
周江敏  代静玉  潘根兴 《土壤》2004,36(1):46-50
采用元素分析、1HNMR和FTIR研究了黄泥土中水溶性有机质组成及结构特征,并与富里酸、胡敏酸进行比较。结果表明:胡敏酸含有大量的芳香族不饱和物质,烷基链烃多,支链长;富里酸以含有大量的羧基为主要结构特征;水溶性有机质主要由碳水化合物组成,含有大量的羟基,芳香族不饱和物质少。  相似文献   

11.
水蚀风蚀交错区不同类型植被对土壤碳氮影响的研究   总被引:1,自引:0,他引:1  
植被类型对土壤养分及其物质循环具有重要作用。通过典型采样与室内分析相结合,系统研究了水蚀风蚀交错区不同典型植被对200 cm土层内土壤全氮、有机质和C/N比值的影响,结果表明:(1)0-40 cm内土壤全氮和有机质含量随深度增加而逐渐下降,40 cm以下基本不随深度变化而变化。不同植被类型的土壤C/N比值基本不随深度变化而变化,其中裸地农田的200 cm剖面土壤C/N均值最高,剖面平均为9.5,其他植被类型基本相似为6.7~7.7。0-20 cm油松土壤C/N比值最高,为10.3,榆树最低,为5.99;(2)0-20 cm土层内沙蒿全氮含量最高,约为油松、榆树、黑豆农田的1.5倍。20-40 cm土层内,沙打旺最高,黑豆农田与农田裸地基本相似。总体而言,沙打旺和沙蒿200 cm剖面全氮含量均高于其他植被类型,油松和榆树土壤全氮含量最低;(3)0-20 cm内有机质含量沙蒿最高,榆树最低,20-40 cm层次内,沙蒿的有机质含量显著降低,最高者为农田裸地,沙打旺和黑豆农田次高,油松略高于沙蒿,榆树仍为最低。从整个0-200 cm土壤剖面看,裸地农田有机质含量最高,沙打旺次之。榆树在各层次有机质含量均低于其他植被...  相似文献   

12.
No-tillage and manure application effect on soil organic carbon (SOC) and total nitrogen (N) concentrations were studied under a 27-year-old 4-year rotation consisting corn (Zea mays L.)-soybean (Glycine max L.)-wheat (Triticum aestivum L.)-field pea (Pisum sativum L.). Under each crop, four applied N treatments were control, annual urea-N applications at the rate of 45 and 89 kg N ha?1, and composted beef cattle feedlot manure-N at the rate 179 kg N ha?1 applied once every four year. For each fertilizer treatment, no-till (NT) and conventional till (CT) were compared for basic soil properties, SOC, and total N within 0–15 cm soil. Manure application significantly reduced soil bulk density and increased SOC and total N over urea-N. Particulate organic matter, mineralizable N, and permanganate-oxidizable C fractions significantly related with SOC. Long-term manure additions and no-tillage had potential to improve soil compaction and maintain SOC over chemical fertilizer N and CT.  相似文献   

13.
Fuqiang Dai  Zhengan Su  Shuzhen Liu  Gangcai Liu   《CATENA》2011,85(3):288-294
Understanding temporal variations in soil organic matter (SOM) is important because SOM improves soil, sustains soil productivity, and sequesters carbon. The Tibetan Plateau plays a critical role in climate change at both regional and global scales. Thus, the main objective of this study was to investigate temporal variations in SOM content in Tibetan soils as an important indicator of climate change. SOM content data were obtained from soil surveys conducted in the 1980s and resampled in the 2000s. In this study, SOM content data from the A horizon of the soil profile were compared over time, and a paired t-test was conducted to verify differences between the two datasets. The results reveal that SOM content in the A horizon decreased significantly. To determine the causes of SOM content decreases in the A horizon, soil samples were grouped into ten soil types, four land-use types, and seven physiogeographical units. SOM content in four soil types (felty soils, cambisols in the World Reference Base (WRB) for soil resources; cold calcic soils, cambisols in the WRB; bog soils, gleysols in the WRB; and meadow soils, umbric gleysols/haplic phaeozem in the WRB), pasture, and broad valleys and basins of the south Tibetan zone of montane shrubby steppe decreased significantly in the A horizon. Based on the analysis of some known realities, this change should be attributed to pasture degradation resulting from overgrazing and climate warming.  相似文献   

14.
The purpose of this research was to test the hypothesis that variability in 11 soil properties, related to soil texture and soil C and N, would increase from small (1 m) to large (1 km) spatial scales in a temperate, mixed-hardwood forest ecosystem in east Tennessee, USA. The results were somewhat surprising and indicated that a fundamental assumption in geospatial analysis, namely that variability increases with increasing spatial scale, did not apply for at least five of the 11 soil properties measured over a 0.5-km2 area. Composite mineral soil samples (15 cm deep) were collected at 1, 5, 10, 50, 250, and 500 m distances from a center point along transects in a north, south, east, and westerly direction. A null hypothesis of equal variance at different spatial scales was rejected (P?0.05) for mineral soil C concentration, silt content, and the C-to-N ratios in particulate organic matter (POM), mineral-associated organic matter (MOM), and whole surface soil. Results from different tests of spatial variation, based on coefficients of variation or a Mantel test, led to similar conclusions about measurement variability and geographic distance for eight of the 11 variables examined. Measurements of mineral soil C and N concentrations, C concentrations in MOM, extractable soil NH4-N, and clay contents were just as variable at smaller scales (1-10 m) as they were at larger scales (50-500 m). On the other hand, measurement variation in mineral soil C-to-N ratios, MOM C-to-N ratios, and the fraction of soil C in POM clearly increased from smaller to larger spatial scales. With the exception of extractable soil NH4-N, measured soil properties in the forest ecosystem could be estimated (with 95% confidence) to within 15% of their true mean with a relatively modest number of sampling points (n?25). For some variables, scaling up variation from smaller to larger spatial domains within the ecosystem could be relatively easy because small-scale variation may be indicative of variation at larger scales.  相似文献   

15.
东北黑土活性有机碳、氮分布研究   总被引:1,自引:0,他引:1  
通过对东北黑土区不同地点、不同层次的土壤样品的分析,探索活性有机碳(轻组有机C,N、颗粒有机C,N和易氧化有机C,N)在东北地区的分布情况。结果表明,随着纬度的增加,土壤活性有机C、N含量增加;随着深度的增加,土壤活性有机C、N含量减少。说明纬度低的地区,活性有机碳库转化较快,库容较小,而耕作措施相近的情况下,植物残体和根残体在有机C积累方面应予以重视。  相似文献   

16.
盆栽试验分析了胡敏酸输入土壤6个月后茶树根际和非根际土壤有机质SOM及其组分,包括水溶性物质WSS、富啡酸FA、胡敏酸HA以及土壤微生物生物量SMB的变化,并对不同土壤有机质组分碳含量和茶树不同组织铅含量作了相关性分析。外源胡敏酸设置3个浓度水平(0、300、600 mg kg-1),铅设置2个浓度水平(0、300 mg kg-1),试验共有6个处理。茶苗置于温室培养,6个月后分新叶、老叶、新茎、老茎、根收获。结果表明:根际并非总是富含有机质,未加铅处理根际SOM含量低于非根际;而加铅处理根际SOM含量高于非根际。HA加入土壤能够显著增加根际和非根际SOM和SMB的含量,但是加铅处理和不加铅处理增加幅度不同。高浓度HA显著增加了根际FA的含量,可能是HA部分裂解所致。非根际有机质各组分与茶树铅含量无显著相关关系;根际SOM、HA和茶树不同组织铅含量没有显著相关关系。根际WSS、FA与茶树嫩叶、老叶、嫩茎、老茎以及根部铅含量均存在显著或极显著正相关关系;而根际SMB与茶树各个组织铅含量存在显著负相关关系。总之,胡敏酸施入土壤改变了土壤有机质及其各个组分的含量,而根际某些土壤有机质组分的改变又显著影响了茶树不同组织铅的吸收和分布。  相似文献   

17.
ABSTRACT

The aim of this study was to examine the usefulness of physical and chemical fractionation in quantifying soil organic matter (SOM) in different stabilized fraction pools. Soil samples from three land use types in Lorestan province, Southwest Iran were examined to account for the amount of organic carbon and nitrogen in different SOM fractions. Size/density separation and chemical oxidation methods were applied to separate the SOM fractions including particulate organic matter (POM), Si + C (silt and clay), DOC (dissolved organic C), rSOM (oxidation-resistant organic carbon and nitrogen) and S + SA (sand and stable aggregates). The values obtained for TOC, TN, and HWC were highest in forest lands followed by the range and agricultural lands. Among the SOM fractions, S + SA showed the highest values (5.75, 5.77 and 20.6 g kg?1 for agriculture, range and forest lands respectively) followed by POM, Si + C, rSOM, and DOC. The concentrations of C and N in the labile fractions obtained the higher values than in the stabilized fractions. Forest lands had the highest amounts of organic C and N among all fractions whereas agricultural lands showed highest values for inorganic C content of soils in different fractions.  相似文献   

18.
黑土有机质含量高光谱模型研究   总被引:54,自引:0,他引:54  
通过对黑龙江省典型黑土区土壤样品高光谱反射率的室内测定,研究了典型黑土可见光/近红外波段光谱反射特性;利用多元统计分析方法,以土壤光谱反射数据及其数学变换数据作为自变量,以黑土有机质含量对数变换数据作为因变量,建立黑土有机质含量高光谱预测模型,并对模型的稳定性和预测能力进行检验。结果表明:(1)620~810nm波段范围是黑土有机质的主要光谱响应区域,最大响应值在710nm附近;(2)对光谱数据进行归一化处理可以部分消除不同土样测试过程中存在的噪声;(3)模型及其检验的决定系数R2都在0.9以上,模型的总均方根差RMSE均小于2.1,模型具有很好的稳定性和预测能力,可以用于黑土有机质含量的快速测定;(4)归一化一阶微分模型为最优预测模型。  相似文献   

19.
Determining the proper rate of wheat residues incorporation into the soil under a wheat–maize double cropping system is an important issue in southern parts of Iran, where these two irrigated crops are consecutively grown. A 2-year experiment (2010–2011) was conducted to evaluate the effect of wheat residue incorporation rates (25%, 50% and 75%) and irrigation intervals (12, 16 and 20 days) on yield and growth of maize under no-tillage system compared to control without residue and under conventional tillage (CT) at the College of Agriculture, Shiraz University, Shiraz, Iran. The experiment was conducted as a split plot arranged in randomized complete block design with three replications. The results showed that increased irrigation intervals reduced the plant height (14.6%), leaf-area index (12.9%), rows (10.1%) and grains per ear (29.8%), thousand grain weight (6.9%), grain (33.8%) and biological yield (24.2) and harvest index (23.2%). Water deficit had no significant effect on soil organic matter and carbon-to-nitrogen ratio. Under 12 and 20 days irrigation intervals, the highest grain yields were obtained with 12.7 and 8.6 t ha?1 in CT and 25% residue incorporation into soil, respectively. Therefore, according to the results of this 2-year study, realized incorporation of 25% wheat residue soil covering percentage is recommended for this area with limited water resources.  相似文献   

20.
【目的】土壤酸化是自然过程。随着农业集约化发展,土壤酸化在部分农田呈加速趋势,而施肥是目前农田土壤酸化加速的重要诱因,研究有机肥和化肥对土壤酸化的作用差异及机理,对合理指导施肥及耕地保育有重要的意义。【方法】通过测定不同施肥处理的不同组分有机质含量及酸碱缓冲容量,探明不同施肥处理的酸化影响,从土壤有机质和盐基累积角度对有机-无机肥料不同比例配施条件下土壤酸化特征进行了研究。【结果】① 连续5年在等氮量(N 270 kg/hm2)且有机-无机肥料不同配施比例的处理中,水稻产量以有机肥比例为25%~50%的处理最高,其平均产量比单施化肥处理提高了5.1%,比对照提高44.9%。但处理间无显著性差异;② 土壤各活性有机质及总有机质等指标中仅总有机质含量随鸡粪施用比例的增加而持续增加,不同比例有机无机肥配合施用后,土壤的高活性有机质及低活性有机质均高于CK和纯化肥氮处理,但随着有机肥投入比例的升高,除中活性有机质和水稻产量之间呈显著的正相关外(P=0.0067**),高活性有机质、活性有机质及总有机质含量与水稻产量之间的相关性不显著(对应的概率值分别为P=0.192,P=0.208,P=0.160);③ 施肥提高了土壤的碳库管理指数(CPMI),且其随有机肥施用比例的上升呈增加趋势。增施鸡粪提高土壤的交换性盐基离子(Ca2+、 Mg2+、 K+、 Na+)含量,导致阳离子代换量(CEC)和pH随鸡粪施用比例的提高而升高。供试土壤酸碱缓冲容量为2.07~2.36 cmol/kg,随鸡粪施用比例的上升而增加,其与土壤阳离子代换量及有机质含量呈显著正相关。表明增施鸡粪可使土壤pH及酸碱缓冲容量上升,与鸡粪使土壤盐基累积量及有机质含量的提高有关。【结论】连续有机-无机肥施用下,土壤pH上升和酸碱缓冲容量的提高可能与该试验点下盐基离子和有机质含量随鸡粪施用比例上升有关,但其最终上升幅度及平衡点尚需进一步研究。鸡粪氮替代化肥氮比例为25%~50%时,土壤性质最优,水稻产量最高。  相似文献   

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