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有机物料高效还田是培肥黑土的重要途径,有机物料自身性质和腐解过程中的温度是影响有机物料腐解的关键要素。寒地黑土区不同种类有机物料的动态腐解过程及腐解影响因素的研究还较少。该研究通过在东北黑土区不同积温地点布设不同种类有机物料腐解田间联网试验,研究有机物料的动态腐解特征及主要影响因素。结果表明:1)有机物料自身性质存在明显差异,其中秸秆的碳氮比最高,有机肥最低,腐解指数变化趋势与碳氮比相反。2)经过720 d的腐解,6种有机物料的累积腐解率和累积释碳率具有明显的季节性和地带性变化规律。在积温较高的夏、秋季节累积腐解率和累积释碳率高于积温较低的春、冬季节;试验地点积温越高,累积腐解率和累积释碳率越大,从积温最低的黑河到积温最高的昌图,累积腐解率和累积释碳率分别增加了15.8%~41.0%和47.8%~114.0%。不同有机物料的累积腐解率表现为作物秸秆>菌糠>畜禽粪便,累积释碳率与之相反。3)有机物料腐解的同时发生碳释放和氮富集过程,除海伦和黑河地区玉米和水稻秸秆经过720 d的腐解后碳氮比未降至25以下外,其余处理碳氮比均低于25,腐解效果较好。腐解残留率衰减方程可较好的拟合了有机物料的腐解过程,作物秸秆的腐解速率常数k(0.23~0.25)显著高于木耳菌糠(0.15)和畜禽粪便(0.08~0.13)(P<0.05)。结构方程模型表明,有机物料自身性质对腐解特征的贡献率高于试验地点的积温、腐解时间和土壤性质,是影响有机物料腐解最主要的驱动因素。 相似文献
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砂滤管长期培养试验结果表明,有机物料和农肥施入土壤后,腐解残留率(Yt)与有机物料施入后的时间(t)遵循Yt=Yλ.toe方程式,式中Yo为有机物料缓分解成分的碳理占加入总碳量的百分数,λ为缓解成分的分解速率。覆膜使Yt和Yo值明显降低。田间试验结果表明,覆膜降低了有机质的活性,使PQ值(胡敏酸占可提取腐殖酸的百分数)和A2/A3比值(胡敏酸在波长200nm和300nm处吸光度之比)增高,胡敏酸对光吸收增强。 相似文献
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中国农田土壤中有机物料腐解特征的整合分析 总被引:10,自引:0,他引:10
整合1980年—2013年中国农田土壤有机物料腐解试验的相关文献,分析了华南、华北、西北和东北等典型农业区不同类型有机物料腐解一年后的残留率(h1)及其驱动因子。结果表明,中国不同有机物料h1平均为0.335 g g-1,受到物料类型、区域以及二者交互作用等因素的显著影响。总体上,h1在物料类型上呈绿肥秸秆根茬≈有机肥,在区域上呈华南≈华北西北≈东北。但h1的区域差异因物料类型而异。其中,绿肥、秸秆和根茬的h1均呈华北华南和东北,而有机肥的h1在各区域间差异不显著。同时,h1的物料类型差异也因区域而异。在湿润半湿润的华南、华北和东北地区,h1均呈根茬秸秆和绿肥;而在干旱半干旱的西北地区,受水分条件的限制,各物料类型间h1差异不显著。逐步回归结果显示,木质素与氮素含量之比(lignin∶N)是绿肥、秸秆和根茬腐解的首要影响因子,而年均温和干燥指数居于其次,表明农田土壤中植物性有机物料的腐解,物料性质较气候因子占主导。但对于腐解或半腐解状态的有机肥,其腐解已不受气候和物料性质的显著影响。此外,单一气候因子或物料性质对h1变异性的解释率往往不超过15%,气候和物料性质的综合解释率尚低于40%,表明要准确预测农田土壤有机物料的腐解过程,需要更多地重视区域或点位特征(例如,土壤理化和生物学性质等)的影响。 相似文献
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有机物料对强酸性茶园土壤的酸度调控研究 总被引:2,自引:1,他引:2
通过室内培养的方式,研究了不同添加剂量下,不同C/N与灰化碱含量的有机物料对酸性茶园土壤的改良能力.试验结果表明:有机物料的添加可以有效地减少土壤交换性酸、铝饱和度,增加土壤交换性碱基,但是在调节土壤pH能力上并非一定有效.初始阶段,“灰化碱”的释放与有机氮的矿化提高了土壤的pH,随后pH由于硝化作用出现不同程度的下降.C/N高的作物秸秆(小麦和水稻秸秆)能够有效地抑制硝化,使pH下降幅度较小;而C/N低的作物秸秆(花生秸秆和菜籽饼)促进硝化,使pH大幅度下降.最终土壤pH与其C/N呈正相关性(y=0.00343x+4.14,r=0.977),而与其灰化碱含量无关.并且随着秸秆添加剂量的加大,C/N高的作物秸秆最终调剂pH的能力是显著提高的(P<0.05),而C/N低的作物秸秆最终调剂pH的能力没有显著提高(P<0.05).因此,C/N高的作物秸秆可能更适合土壤酸度的长期调节,与其相关的田间试验需要进一步进行证实. 相似文献
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采用尼龙网袋法研究栗钙土有机质分解及土壤速效养分的变化结果表明,不同有机物(肥)料在前3个月分解较快,最初30d坡梁栗钙土和旱滩草甸栗钙土分解率分别为32.68%和30.32%。新施入有机物(肥)料可明显提高土壤有机质活性系数,平均提高16%左右,腐殖质活性顺序依次为牛粪>莜麦秸>豌豆秸。有机物(肥)料腐解周年后土壤有机碳及速效氮、速效磷、速效钾明显增加。2类土壤有机碳分别为106.67%~135.00%和53.33%~58.18%,速效氮、速效磷、速效钾分别提高34.62%~52.31%和21.10%~50.37%、18.20%~207.60%和34.20%~210.05%、64.92%~143.12%和28.75%~102.49%。 相似文献
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三江平原地区不同有机物料腐解规律的研究 总被引:5,自引:2,他引:5
利用网袋法模拟田间还田方式, 研究不同还田方式下玉米、大豆秸秆的腐解特征。结果表明: 经过150 d的分解, 玉米和大豆秸秆残留率在33.7%~61.1%之间, 秸秆还田分解趋势为: 土埋处理>露天处理, 土埋玉米秸秆>土埋大豆秸秆, 露天条件下大豆和玉米秸秆分解速率一致。从细胞结构上看, 玉米秸秆随着还田时间的延长, 基本组织和维管束遭到破坏, 细胞壁变薄, 细胞内物质消失, 细胞排列疏松; 大豆秸秆组织结构变化不明显。露天和土埋处理各有机物料有机碳分解率分别为39.9%~48.9%、49.6%~65.8%, 土埋玉米和大豆秸秆腐解速度明显高于露天处理。两个处理氮、钾分解率无太大差异, 分别为51.1%~67.7%、74.6%~91.7%, 而磷素变化比较明显, 露天和土埋处理玉米秸秆的磷释放率平均比大豆秸秆高49.4%、56.7%。作为还田物料玉米秸秆要好于大豆秸秆。 相似文献
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水分和有机物料对镉污染土壤的改良效应 总被引:1,自引:0,他引:1
通过室内培养和盆栽试验相结合的方式,系统研究了3种土壤水分含量条件下,添加不同有机物料对镉(Cd)污染土壤的改良效应。研究结果表明:淹水、田间持水量和65%相对含水量条件下添加有机物料均有利于污染土壤中可交换态Cd含量的降低,铁锰氧化物及有机结合态Cd含量的增加。随土壤中水分含量的增加,影响程度增加,即淹水>田间持水量>65%相对含水量。3种水分条件下,添加蚯蚓粪处理Cd活性降低明显,其次为猪粪处理,草炭处理相对较差。淹水条件下,油菜体内Cd的含量最低,田间持水量和65%相对含水量条件下油菜部分发育指标差异不显著。添加不同有机物料各处理促进油菜生长的顺序大致为:蚯蚓粪>草炭>CK>猪粪。 相似文献
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Decomposition of different organic materials in soils 总被引:10,自引:0,他引:10
Laboratory experiments were conducted to evaluate organic C mineralization of various organic materials added to soils. A soil sample was mixed with organic material to approximate a field application of 9 g organic C kg-1 soil (0.9% or 50 Mg ha-1). The organic materials used were four crop residues [corn (Zea mays L.), soybean (Glycine max L. Merr.), sorghum (Sorghum vulgare Pers.), and alfalfa (Medicago sativa L.)], four animal manures [chicken (Gallus domesticus), pig (Sus scrofa), horse (Equus caballus), and cow (Bos taurus)] and four sewage sludges [Correctionville (Imhoff tank), Charles City (holding tank), Davenport (secondary digester), and Keokuk (primary digester)]. The soil-organic material mixture was incubated under aerobic conditions at room temperature (20±2°C) for 30 days. The CO2 evolved was collected in standard KOH solution by continuously passing CO2-free air over the soil. Results showed that, in general, the amounts of CO2-C released mereased rapidly initially, but the pattern differed among the organic materials used. More than 50% of the total CO2 produced in 30 days of incubation was evolved in the first 6 days. Expressed as percentages of organic C added, the amounts of CO2 evolved ranged from 27% with corn to 58% with alfalfa. The corresponding percentages for animal manures ranged from 21 to 62% with horse and pig manures, respectively, and for sewage sludges they ranged from 10 to 39% for Charles City and Keokuk sludges. All CO2 evolution data conformed well to a first-order kinetic model. Potentially, readily mineralizable organic C values and first-order rate constants (k) of the organic matter-treated soils ranged from 1.422 g C kg-1 soil with ak value of 0.0784 day-1 to 6.253 g C kg-1 soil with ak value of 0.0300 day-1. The half-lives of the C remaining in soils ranged from 39 to 54 days for plant materials. The corresponding half-lives for the C remaining from animal manures and sewage sludges ranged from 37 to 169 days and from 39 to 330 days, respectively. 相似文献
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Subsoil acidity is a serious constraint to crop production, and is difficult to correct by conventional liming practices. Thus, a different approach to ameliorating acid subsoils was evaluated. Subsoil material of an acid Ultisol (pH 4.4) was packed into 50-cm long columns, then leached with solutions of CaCl2, CaCO3 (suspension) or Ca fulvates prepared from chicken manure, cowpea green manure, or sewage sludge. The total water applied was 30.26 cm (or 800 ml) in 2 days. Thereafter, the columns were dismantled and cut into 5-cm segments for chemical analysis. The results indicated that only 2% of the added Ca from CaCO3 moved past the 15-cm depth, compared to 68% from CaCl2 and 35–75% from Ca fulvates. Correspondingly, CaCO3 precipitated all KCl-extractable Al in the top 5 cm, but had no effect beyond the 10-cm depth. The CaCl2 displaced a small but significant portion of extractable Al from the top 15 cm and redeposited some of that Al in lower depths. Similar to CaCO3, Ca fulvates from chicken manure and green mamure only decreased extractable Al significantly in the top 10-cm layers, but had little effect beyond that depth. By contrast, the Ca fulvate from sewage sludge decreased Al down to the 45-cm depth. In terms of reducing Al saturation as a percentage of total extractable cations (effective cation exchange capacity), the Ca fulvates were as effective as CaCO3 in the 0-to 5-cm layer, and more effective than CaCl2 in any soil layer because of the increased exchangeable Ca and/or decreased Al. In general, surface application of common organic material-derived Ca fulvates can increase subsoil Ca and decrease the Al saturation percentage. However, Mg depletion and enrichment of unwanted metals (e.g., Na or heavy metals) may be a problem when leaching with these organic sources. 相似文献
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Alain F. Plante Richard T. Conant Rebecca Greenwood Michelle L. Haddix 《Soil biology & biochemistry》2010,42(11):1991-1996
The general consensus is that a warming climate will result in the acceleration of soil organic matter (SOM) decomposition, thus acting as a potential positive feedback mechanism. However, the debate over the relative temperature sensitivity of labile versus recalcitrant SOM has not been fully resolved. We isolated acid hydrolysis residues to represent a recalcitrant pool of SOM and particulate organic matter (POM) to represent a labile pool of SOM, and incubated each at different temperatures to determine temperature sensitivity of decomposition. Short-term incubations of POM generated results consistent with published experiments (i.e., greater proportion of C respired and lower Q10 than whole soil), while incubations of acid hydrolysis residues did not. The contrasting results illustrate the difficulty in assessing temperature sensitivity of labile versus stable SOM decomposition, partly because of the inability to quantitatively isolate labile versus stable SOM pools and to be sufficiently certain that respiration responses to temperature are not masked by processes such as enhanced stabilization or microbial inhibition/adaptation. Further study on the temperature sensitivity of decomposition of isolated SOM fractions is necessary to better explain and predict temperature responses of bulk SOM decomposition. 相似文献
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Evolution of organic matter and nitrogen during co-composting of olive mill wastewater with solid organic wastes 总被引:7,自引:0,他引:7
C. Paredes A. Roig M. P. Bernal M. A. Sánchez-Monedero J. Cegarra 《Biology and Fertility of Soils》2000,32(3):222-227
Four olive mill wastewater (OMW) composts, prepared with three N-rich organic wastes and two different bulking agents, were
studied in a pilot plant using the Rutgers system. Organic matter (OM) losses during composting followed a first-order kinetic
equation in all the piles, the slowest being the OM mineralisation rate in the pile using maize straw (MS). The highest N
losses through NH3 volatilisation occurred in the mixtures which had a low initial C/N ratio and high pH values during the process. Such losses
were reduced considerably when MS was used as the bulking agent instead of cotton waste (CW). N fixation activity increased
during the bio-oxidative phase before falling during maturation. This N fixation capacity was higher in piles with a lower
NH4
+-N concentration. Only the composts prepared with OMW, CW and poultry manure or sewage sludge reached water-soluble organic
C (CW) and NH4
+-N concentrations and CW/Norg and NH4
+/NO3
– ratios within the established limits which indicate a good degree of compost maturity. Increases in the cation-exchange capacity,
the percentage of humic acid-like C and the polymerisation ratio revealed that the OM had been humified during composting.
The germination index indicated the reduction of phytotoxicity during composting.
Received: 14 June 1999 相似文献
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