两种水分含量下生物质炭对黑土N2O排放及硝化反硝化基因丰度的影响

生物质炭对土壤结构改良、土壤肥力提升和农田温室气体排放具有重要意义。本研究以吉林省梨树县典型黑土为研究对象，通过培育实验，研究不同土壤水分含量（40%WHC和100%WHC）下，生物质炭种类（玉米秸秆生物质炭和稻壳生物质炭）和施加量（0%、1%和4%（w/w））对黑土N2O排放及硝化反硝化功能基因丰度的影响。结果表明，随着秸秆生物质炭施加量的增加，土壤N2O排放呈下降趋势，4%高量秸秆生物质炭添加下，土壤N2O排放量仅为1%低量秸秆生物质炭添加下的33.9%。同时土壤NO- 3-N也表现出一致性规律，4%高量生物质炭添加下土壤NO- 3-N含量显著低于1%低量生物质炭。在100%WHC土壤水分状况下，玉米秸秆生物质炭显著增加了土壤N2O排放，而稻壳生物质炭则显著降低了土壤N2O排放。高土壤水分显著促进了土壤N2O排放，进一步为实时荧光定量PCR结果所证实，高土壤水分通过增加nirS基因丰度进而促进了土壤反硝化作用过程，而4%高量稻壳生物质炭添加下nosZ基因丰度显著高于玉米秸秆生物质炭添加，表现出更强的N2O还原潜力。尽管amoA-AOA基因丰度在不同生物质炭添加量下并未发生显著变化，但amoA-AOB基因丰度在高量玉米秸秆生物质炭添加下显著下降。结果说明，土壤水分和生物质炭通过影响土壤硝化反硝化微生物的营养底物和代谢过程，进而影响土壤N2O排放特征。     

多种有机物料混施对苹果幼苗生长、氮素利用及土壤特性的影响

以"M9T337"苹果幼苗为试材,利用~(15)N同位素示踪技术,研究了等氮量投入下,不同有机物料单施及混施对苹果幼苗生长、~(15)N吸收利用及土壤特性的影响。试验设置CK(只施用化学肥料,不施有机物料)、S(秸秆)、B(生物炭)、F(牛粪)、SB(1/2秸秆+1/2生物炭)、SF(1/2秸秆+1/2牛粪)、FB(1/2牛粪+1/2生物炭)、SFB(1/3秸秆+1/3牛粪+1/3生物炭)8个处理。结果表明:施用有机物料可以促进苹果幼苗的生长,其中SFB处理植株鲜重、株高、茎粗、叶面积、根系活力达到最优,显著高于CK和单施有机物料的处理。添加有机物料能降低土壤容重、增加孔隙度、提高土壤含水量,其中施用生物炭的处理土壤容重降幅较大、孔隙度较高。处理期间,有机物料混合施用的处理土壤矿化氮含量、土壤酶活性及微生物数量均优于有机物料单独施用的处理。与CK和单施有机物料的处理相比,有机物料混合施用显著提高了苹果幼苗~(15)N利用率和土壤~(15)N残留率,降低了~(15)N损失率,其中3种有机物料混施效果最好。综合分析可知,有机物料能促进苹果幼苗生长,改良土壤性质,促进植株对~(15)N的吸收利用,其中牛粪、秸秆和生物炭混合施用的处理(SFB处理)效果最佳。研究结果以期为有机物料在苹果园土壤质量提升和化肥减施增效中的应用提供依据。     

生物炭的10年土壤培肥效应

大量短期的室内试验和田间试验研究表明,施用生物炭可以增加土壤碳固定,提升土壤肥力和作物产量,然而关于生物炭的长期土壤肥力效应尚不明确。为此,依托持续10年的生物炭的田间定位试验[4个处理:对照(CK)、生物炭4. 5 t·hm-2·年-1(B4. 5)、生物炭9 t·hm-2·年-1(B9. 0)、秸秆还田(SR)],研究了长期施用生物炭对土壤肥力状况的影响。结果显示,与对照相比,长期施用生物炭和秸秆还田对土壤p H值没有显著影响,但容重降低了2. 2%～8. 2%,施用生物炭的土壤电导率降低了1. 5%～7. 8%,而秸秆还田处理土壤电导率提高了4. 7%～13. 4%。施炭和秸秆还田使土壤有机质(SOM)含量增加57. 7%～123. 1%,总氮含量提高11. 3%～21. 9%,总磷没有显著性变化。不同处理土壤NH+4-N含量的差异不显著,而施用生物炭和秸秆还田土壤NO-3-N含量增加3. 8%～67. 1%,且高炭处理的效果显著。土壤有效磷含量显著降低了23. 1%～42. 0%,速效钾含量上升了2. 0%～23. 1%。总体而言,长期施用生物炭提升了土壤肥力,尤其是对土壤有机质的提升有显著的效果。     

Evaluating the Impact of Combined Application of Biochar and Compost on Hydro-physical Properties of Loamy Sand Soil

ABSTRACT

Biochar, compost and their combination are important organic amendment materials for improving the hydro-physical properties of sandy soils. Series of soil columns experiments were conducted for investigating the application effects of date palm biochar and compost on evaporation, moisture distribution, infiltration, sorptivity (Sp), saturated hydraulic conductivity (K_sat) and water holding capacity (WHC) at application rates of 1%, 2%, 3% and 4% (10, 20, 30 and 40 g kg^?1). The columns were filled manually with air-dried soil with 35 cm depth and the thickness of surface amended layer was 10 cm (T10) and 20 cm (T20) from soil surface at bulk density of 1400 kg m^?3. The results showed that the behavior of soil moisture distribution was influenced by application of biochar, compost and biochar-compost mixture. Moreover, in the amended layer T10, applying biochar at rate of 1%, 2%, 3% and 4% reduced significantly cumulative evaporation by 5.8%, 10.8%, 12.8% and 16.1%, respectively. Meanwhile, the reduction for the biochar-compost mixture at application rates of 1%, 2%, 3% and 4% was 10%, 12.2%, 14.5% and 20%, respectively. In layer T20, applying biochar at rate of 1%, 2%, 3% and 4% reduced cumulative evaporation by 10.24%, 13.0%, 18.3% and 21.5% but this reduction amounted to 18.2%, 21%, 23% and 24% for the biochar-compost mixture, respectively. It was generally observed that the highest application rate (4%) for applied amendments was the most effective impact on Sp, K_sat and WHC compared with other rates.     

Ash and biochar amendment of coarse sandy soil for growing crops under drought conditions

Appropriate soil amendments may increase plant available water and crop yields on coarse sandy soils under drought conditions. In this study, we applied straw ash or straw biochar from gasification to a Danish coarse sandy subsoil to assess the effects on soil water retention, evapotranspiration and crop yields. Spring barley (2016, 2017) and winter wheat (2018) were grown over three years in columns containing 25cm of organic matter-rich topsoil, 80 cm of amended coarse sandy soil (1.5%, 3%, 6% wt. ash or 1% wt. biochar or control soil) and 45 cm of un-amended subsoil. Precipitation, evaporative demands and soil moisture were recorded across the growth seasons, with 2018 having severe drought conditions. This year evapotranspiration levels increased with increasing ash and biochar content (by 54% and 33% for the 6% ash- and 1% biochar-amended soils, respectively), and plant dry matter increased by 18% in both the 1% biochar- and 6% ash-treated soils compared to the untreated control. A linear relationship was established between in situ field capacity and ash dosage (R² = .96), showing an increase of 2.2% per percentage (wt.) of ash added, while the 1% biochar treatment increased the capacity by 3.5%, indicating a higher efficiency than for ash. However, we did not find significant positive effects on grain yields. The results show that ash and biochar have the potential to significantly increase soil water retention, evapotranspiration and total dry matter yield in drought conditions, but that this may not correspond to an increase in grain yield.     

施用小麦秸秆或其生物炭对烟田土壤理化特性及有机碳组分的影响

  【目的】  以2年田间定位试验为依托,研究小麦秸秆及其生物炭连续施用对植烟土壤理化性状和有机碳组分的影响,为烟区土壤质量提升提供依据。  【方法】  田间试验在山东省诸城市潮褐土烟田上进行。试验设4个处理,分别为:常规施肥且秸秆不还田(CK),常规施肥+小麦秸秆还田(FS),常规施肥+小麦秸秆生物炭2.25 t/hm2 (FB1)和4.50 t/hm2 (FB2)。在烟叶收获后,采集0—20 cm耕层土样,测定了土壤基础理化指标和总有机碳(TOC)、微生物生物量碳(MBC)、热水溶性有机碳(HWC)、活性有机碳(LOC)及轻组有机碳(LFOC)含量,并计算土壤碳库管理指数(CPMI)。  【结果】  连续施用小麦秸秆或其生物炭2年后,FB1和FB2处理TOC含量显著高于CK,增幅分别为74.9%和116.0%,而FS与CK处理间差异不显著。LFOC含量的变化趋势与TOC类似,FB1和FB2处理LFOC含量分别较CK处理显著增加154%和326%。FS处理HWC含量显著高于CK和FB1处理,而与FB2处理差异不显著。与CK相比,FS处理HWC含量增加了107%。FS和FB2处理MBC含量较CK分别增加了252%和144%,而FB1处理与CK相比差异不显著。FS处理LOC含量较CK显著增加了68.9%,而FB1、FB2处理LOC含量与CK相比差异不显著。FS处理还能显著降低土壤容重、增加土壤含水量及有效磷含量,其对部分土壤理化特性的改良效果优于生物炭处理(FB1和FB2)。此外,CPMI也以FS处理最高,较CK显著增加了73.5%,而FB1、FB2处理与CK处理差异不显著。  【结论】  连续秸秆还田有利于提升烟田土壤活性有机碳(MBC、HWC和LOC)含量,降低土壤容重,提高有效磷含量,提高土壤CPMI。而同量秸秆转化为生物炭后连续还田能够提高土壤总有机碳和轻组有机碳含量,更有利于土壤有机碳的长期固存。     

玉米秸秆源有机物料对黑土养分有效性与酶活性的提升效应

[目的]研究以玉米秸秆为主要原料制备的不同类型有机物料对东北黑土土壤肥力和玉米产量的影响,为黑土地保护和秸秆资源高效利用提供理论依据.[方法]田间定位试验连续进行了5年.试验设不施肥对照(CK)、单施化肥(NPK)、化肥配施秸秆(NPK+ST)、化肥配施生物炭(NPK+BR)以及化肥配施堆肥(NPK+CP)5个处理,各...     

Effects of straw and its biochar applications on the abundance and community structure of CO2-fixing bacteria in a sandy agricultural soil

Purpose

Crop straw and biochar application can potentially increase carbon sequestration and lead to changes in the microbial community in agricultural soils. Sequestration of CO₂ by autotrophic microorganisms is key to biogeochemical carbon cycling in soil ecosystems. The effects of straw and its biochar, derived from slow pyrolysis, on CO₂ fixation bacteria in sandy soils, remain unclear. Therefore, this study compared the response of abundance and community of CO₂ fixation bacteria to the two straw application methods in a sandy agricultural soil. The overall aim of the study was to achieve an efficient use of straw residues for the soil sustainablility.

Materials and methods

We investigated the soil organic carbon content and autotrophic bacteria over four consecutive years (2014–2018) in a field experiment, including the following four treatments: whole maize straw amendment (S), whole maize straw translated biochar amendment (B), half biochar and half straw amendment (BS), and control (CK) without straw or biochar amendment. The autotrophic bacterial abundance and community structure were measured using molecular methods of real-time PCR, terminal restriction fragment length polymorphisms (T-RFLP), and a clone library targeting the large subunit gene (cbbL) of ribulose-1,5-bisphosphate carboxylase/oxygenase.

Results and discussion

The results showed that the content of soil total organic carbon (TOC), dissolved organic carbon (DOC), and microbial biomass carbon (MBC) in B, S, and BS treatments was significantly increased compared with the CK treatment. Soil TOC and available potassium (AK) in the B treatment significantly increased by 15.4% and 23.3%, respectively, but soil bulk density, DOC, and MBC significantly decreased by 8.5%, 10.6%, and 14.5%, respectively, compared with the S treatment. The abundance of the cbbL gene as well as of the bacterial 16S rRNA gene increased significantly in straw or biochar application treatments as compared to the CK treatment. The B treatment, but not the BS treatment, significantly increased the cbbL gene abundance when compared to the S treatment. No significant differences were observed in the bacterial 16S rRNA gene abundance among the three straw or biochar applications. The application of straw biochar could increase the diversity of the autotrophic bacteria, which also altered the overall microbial composition. Physicochemical properties of the soil, such as soil pH, SOC, and bulk density, can help explain the shift in soil microbial composition observed in the study.

Conclusions

Taken together, our results suggest that straw biochar, rather than straw application, leads to an increase in the abundance and diversity of CO₂-fixing bacteria, which would be advantageous for soil autotrophic CO₂ fixation.

     

施加秸秆与废弃物对茉莉园土壤团聚体及碳氮磷含量的影响

为了研究施加秸秆与废弃物对茉莉园土壤团聚体与碳、氮和磷含量的影响,以福州河滨茉莉园土壤为研究对象,对对照(C)、秸秆(S)、秸秆+石膏(SG)、秸秆+生物炭(SB)和秸秆+炉渣(SS)5种处理样地0—10,10—20,20—30cm土层土壤团聚体分布和稳定性,包括0.25mm团聚体含量(DR0.25)、平均质量直径(MWD)、几何平均直径(GMD)、分形维数(D)以及土壤碳、氮、磷含量和化学计量比进行了测定分析。结果表明:5种处理团聚体均以0.053~0.25,0.25~2 mm粒级为主。与对照相比,单施秸秆团聚体DR0.25、MWD和GMD值分别减小了19.86%,19.18%和37.98%,D增加了14.26%,团聚体稳定性降低;秸秆+石膏、秸秆+生物炭和秸秆+炉渣与单施秸秆相比,DR0.25和MWD相差不大,GMD较单施秸秆分别增加了2.34%,0.63%和12.67%,D分别减少了2.31%,6.26%和5.01%,团聚体稳定性增强。秸秆、秸秆+石膏、秸秆+生物炭和秸秆+炉渣与对照相比,0—10cm表层土壤碳、氮、磷含量均显著增加,10—20,20—30cm土层变化不大,表现为养分向表层富集的现象。综合比较分析,石膏、生物炭和炉渣可以作为秸秆还田配施改良剂,以提高秸秆还田的功效。     

长期连续秸秆还田和生物质炭施用对稻田N2O排放的影响

为了评估麦季多年连续秸秆还田和生物质炭施用对稻麦轮作系统下稻田N₂O排放的影响，于2010年麦季开始开展了为期11 a的麦季秸秆还田和生物质炭施用定位试验。试验共包括5个处理：无玉米秸秆还田和生物质炭施用(CK);6 t/(hm²·a)玉米秸秆还田(CS);2.4 t/(hm²·a)生物质炭施用(BC1);6 t/(hm²·a)生物质炭施用(BC2)和12 t/(hm²·a)生物质炭施用(BC3)。结果表明，BC2和BC3处理较CK均显著提高了土壤碱解氮、有效磷、速效钾、易氧化碳、可溶性有机氮和土壤微生物生物量氮含量。CS、BC1和BC2处理水稻生长季N₂O总排放量与CK没有显著差异，但是BC3处理的N₂O总排放量比CK提高了245.31%，并显著高于其他处理。BC3处理的N₂O总排放量和施氮肥后N₂O排放高峰期的累积排放量分别比CK提高了3.84 kg/hm²和3.3...     

秸秆与生物质炭施用对土壤温室气体排放的影响差异

采用室内培养试验,向土壤中添加小麦秸秆和不同量生物质炭,同时比较探究秸秆与生物质炭施用对土壤温室气体排放及微生物活性的影响差异。试验共设5个处理:土壤(S)、土壤+1%小麦秸秆(WT)、土壤+1%生物质炭(BC1)、土壤+2%生物质炭(BC2)和土壤+4%生物质炭(BC4)。在培养期内,施秸秆处理土壤CO2排放量比对照处理S显著增加约12.60%~2005.63%,而施生物质炭处理降低约51.49%~97.93%。施秸秆处理的温室气体增温潜势(GWP)是对照处理S的1.12~19.24倍,而施生物质炭处理,即处理BC1、BC2和BC4的GWP分别降低了0.27%~64.06%,15.78%~94.01%和29.43%~92.28%。小麦秸秆施用会明显增加土壤温室气体排放,增加温室效应;而添加生物质炭对土壤CO2、N2O排放表现出一定的抑制作用,并明显减弱温室气体增温潜势,即生物质炭能明显减弱温室效应。添加小麦秸秆促进土壤微生物生物量碳的增加,提高FDA水解酶、脲酶、过氧化氢酶、磷酸酶活性;生物质炭施用一段时间后对土壤过氧化氢酶活性表现为显著激活作用。     

Combined effect of biochar and soil moisture on soil chemical properties and microbial community composition in microplastic-contaminated agricultural soil

Accumulation of microplastics (MPs) in agricultural environments has caused growing concern in recent years because of its detrimental impacts on soil quality, crop productivity and ecosystem function. This study was conducted to assess the impact of biochar on soil chemical and microbial properties in a MP-contaminated soil under two moisture regimes. Soil was contaminated with 1% (w/w) of low-density polyethylene MPs. Four types of standard biochar, that is, oil seed rape (OSR) biochar produced at 550°C (OSR 550) and 700°C (OSR 700) and soft wood pellet (SWP) biochar produced at 550°C (SWP 550) and 700°C (SWP 700), were applied at a rate of 5% (w/w). The control was maintained without MP addition. The samples were incubated in soil with two moisture regimes, that is, at 30% and 70% of the water holding capacity, and the soil chemical and microbiological properties were assessed after 100 days of incubation. OSR biochar application significantly increased soil pH (8.53–8.81) and electrical conductivity (0.51–0.58 dS/m) in both moisture regimes. The effect of biochar application on soil enzyme activity and microbial community composition did not show a clear trend. However, SWP 700 biochar improved soil enzyme activity compared with that of the control and improved bacterial diversity and evenness compared with those of other biochars, which was attributed to the high surface area available for microbial colonization. Low soil moisture content significantly reduced enzyme activity and bacterial richness even with biochar amendment, except for SWP 550 biochar. This study implies the suitability of biochar for improvement of soil quality in MP contaminated soil under both moisture regimes. However, further long-term studies are needed to get a clear understanding on the impact of different types of biochar on MP-contaminated soil.     

Application of mixed straw and biochar meets plant demand of carbon dioxide and increases soil carbon storage in sunken solar greenhouse vegetable production

Solar vegetable greenhouse soils show low soil organic carbon content and thus also low rates of soil respiration. Processing vegetable residues to biochar and mixing biochar with maize straw might improve soil respiration and increase soil organic carbon stocks, while preventing the spread of soil-borne diseases carried by vegetable residues. In an incubation experiment, we tested how additions of maize straw (S) and biochar (B) added in varying ratios (100S, 75S25B, 50S50B, 25S75B, 100B and 0S0B (control)) affect soil respiration and fraction of added C remaining in soil. Daily CO₂ emissions were measured over 60 days incubation, the natural abundance of ¹³C in soil and in the added biochar and maize straw were analysed. Our result shows that (a) soil CO₂ emissions were significantly increased compared to soil without the straw additions, while addition of biochar only decreased soil respiration; (b) cumulative CO₂ emissions decreased with increasing ratio of added biochar to maize straw; (c) the abundance of soil ¹³C was significant positively correlated with cumulative CO₂ emissions, and thus with the ratio of straw addition. Our results indicate that incorporation of maize straw in greenhouse soils is a meaningful measure to increase soil respiration and to facilitate greenhouse atmosphere CO₂ limitation while producing vegetables. On the other hand, additions of biochar from vegetable residues will increase soil organic carbon concentration. Therefore, the simultaneous application of maize straw and biochar obtained from vegetable residues is an effective option to maintain essential soil functions for vegetable production in sunken solar greenhouses.     

水分含量对秸秆还田土壤碳矿化和微生物特性的影响

An 80-d incubation experiment was conducted to investigate straw decomposition,the priming effect and microbial characteristics in a non-fertilized soil(soil 1) and a long-term organic manure-fertilized soil(soil 2) with and without13 C-labeled maize straw amendment under different moisture levels. The soil 2 showed a markedly higher priming effect,microbial biomass C(Cmic),and β-glucosidase activity,and more abundant populations of bacteria and fungi than the soil 1. Also,soil CO2 emission,Cmic,β-glucosidase activity,and bacterial and fungal population sizes were substantially enhanced by straw amendment. In the presence of straw,the amount of straw mineralization and assimilation by microbes in the soil at 55% of water holding capacity(WHC) were significantly higher by 31% and 17%,respectively,compared to those at 25% of WHC. In contrast,β-glucosidase activity and fungal population size were both enhanced as the moisture content decreased. Cmicdecreased as straw availability decreased,which was mainly attributed to the reduction of straw-derived Cmic. Amended soils,except the amended soil 2 at 25% of WHC,had a more abundant fungal population as straw availability decreased,indicating that fungal decomposability of added straw was independent of straw availability. Non-metric multidimensional scaling analysis based on fungal denatured gradient gel electrophoresis band patterns showed that shifts in the fungal community structure occurred as water and straw availability varied. The results indirectly suggest that soil fungi are able to adjust their degradation activity to water and straw availability by regulating their community structure.     

Effect of biobed composition, moisture, and temperature on the degradation of pesticides

Biobeds retain and degrade pesticides through the presence of a biobed mixture consisting of straw, peat, and soil. The effects of biobed composition, moisture content, and temperature on pesticide degradation were investigated in laboratory studies. Straw produced the main microbial activity in the biobed mixtures as strong positive correlations were observed between straw, respiration, and phenoloxidase content. Most pesticides investigated were dissipated by cometabolic processes, and their dissipation was correlated with respiration and/ or phenoloxidase content. More pesticides were more dissipated at biobed moisture levels of 60% water holding capacity (WHC) than at 30% and 90% WHC, while 20 degrees C gave higher dissipation rates than 2 and 10 degrees C. A straw:peat:soil ratio of 50:25:25% v/v is recommended in field biobeds since this produces high microbial activity and low pH, favorable for lignin-degrading fungi and phenoloxidase activity.     

生物炭和秸秆对华北农田表层土壤矿质氮和pH值的影响

基于2014-2015年华北农田定位试验,设CK（单施氮磷钾肥）、C1（生物炭4.5t×hm^-2×a^-1+氮磷钾肥）、C2（生物炭9.0t×hm^-2×a^-1+氮磷钾肥）和SR（秸秆还田+氮磷钾肥）4个处理,对施用生物炭和秸秆还田对表层土壤矿质氮（NO₃^--N、NH₄⁺-N）含量以及土壤pH值的影响进行研究。结果表明,不同处理土壤矿质氮的动态变化趋势基本一致,施用生物炭和秸秆还田均可显著提高土壤NO₃^--N含量（P<0.05）,但对土壤NH₄⁺-N含量影响不大。与秸秆还田相比,高量施用生物炭有利于增加土壤NO₃^--N含量。各处理土壤中矿质氮主要以NO₃^--N为主,NH₄⁺-N含量均保持在一个较低水平。将冬小麦整个生育期内各处理土壤NO₃^--N、NH₄⁺-N含量与夏玉米的相比,前者显著高于后者。在整个冬小麦-玉米轮作周期内,高量施用生物炭显著提高了土壤pH值,且各处理土壤NO₃^--N与土壤pH值呈显著负相关（P<0.05）,土壤NH₄⁺-N含量与土壤pH值相关性不显著;而各处理土壤NO₃^--N、NH₄⁺-N含量与土壤含水量均呈显著正相关（P<0.05）。可见,添加生物炭对减少氮素的转化和流失具有较大潜力。     

轮作和微生物菌肥对黄瓜连作土壤理化性状及生物活性的影响

通过周转箱栽培试验,研究了番茄轮作(T1)、木霉菌肥+黄瓜连作(T2)、木霉菌肥+番茄轮作(T3)、护根宝+黄瓜连作(T4)、护根宝+番茄轮作(T5)5种处理方式对黄瓜连作土壤理化性状及生物活性的影响。结果表明,5种处理方式均能不同程度的改善黄瓜连作土壤的理化性状,同时提高土壤酶活性、增加细菌及放线菌数量及降低真菌数量。与番茄轮作相比,微生物菌肥的改良效果更为明显,且番茄轮作结合施用微生物菌肥的复合改良效果好于单一改良。总体来看,T3处理效果最好,其次为T5,T3在改善连作土壤理化性状、提高土壤酶活性方面具有良好效果,而T5在优化连作土壤微生物菌群方面效果较好。两种菌肥相比,木霉菌肥的总体改良效果好于护根宝。     

玉米秸秆炭还田对黑土土壤肥力特性和氮素农学效应的影响

【目的】探索玉米秸秆炭对东北黑土土壤肥力特性和氮素农学效应的影响,可为东北玉米集约化生产区秸秆资源利用和培肥土壤提供理论和实际应用基础。【方法】本研究以东北典型黑土区春玉米种植体系为研究对象,通过连续两年的田间原位试验,研究了添加500℃厌氧条件热解的玉米秸秆炭对土壤养分含量、 微生物和酶活性的影响及玉米秸秆炭对作物产量和氮素农学效应的影响。试验设三个处理: 1)PK+4 t/hm2秸秆还田(CK); 2)NPK+4 t/hm2秸秆还田; 3)NPK+4 t/hm2秸秆还田+2 t/hm2秸秆生产秸秆碳,在玉米成熟期取020 cm土壤样品和植株样品,采用常规方法进行相关项目的测定。【结果】 1)土壤养分分析结果。与秸秆还田相比,秸秆炭处理在2013和2014年土壤碱解氮含量(AN)分别提高了10.1%和9.7%,均达到显著水平(P0.05); 土壤速效磷含量(AP)分别提高了13.7%和27.3%,在2014年达到显著水平(P0.05); 土壤微生物量碳含量(SMBC)分别提高了13.5%和26.9%,土壤脲酶活性(URE)分别提高了22.3%和31.8%,2014年SMBC和URE升高均达显著(P0.05)。秸秆炭对土壤有机质(OM)、 全氮(TN)、 速效钾(AK)、 土壤微生物量氮(SMBN)和蔗糖酶活性(SUC)的提升效果在两年试验中均没有达到显著水平, 2)氮素农学效应影响结果。与处理2相比,处理3肥料氮偏因子生产力(PFPN)分别提高了3.3%和9.6%,肥料氮经济效益(EBN)分别提高了12.9%和27.5%,均在2014年表现出显著提高(P0.05); 而两年间处理3的玉米产量分别提高3.3%和9.5%、 肥料氮利用率(UEN)分别提高了3.9%和14.0%、 肥料氮农学效率(AEN)分别提高了11.6%和23.9%,但均未达显著水平。【结论】2年试验初步表明施用玉米秸秆炭可以提高土壤微生物活性和土壤酶活性,调节土壤与作物之间的养分供需,改善土壤养分状况,对提升氮素农学效应有作用。因此,玉米秸秆炭可作为秸秆资源高效利用的有效形式,其长期效果还需进一步试验。     

不同改良剂对河套灌区盐碱土入渗特性及水盐分布的影响

为对比研究改良剂对河套灌区盐碱土入渗特性及水盐分布的影响,设置对照组及2种施用水平(1%和2%)下的2种改良剂(生物炭和脱硫石膏)共5组处理,进行室内土柱试验。结果表明：(1)相比于对照组,1%施用量的生物炭能使入渗时间延缓8.9%,抑制水分入渗,降低相同时间内的土壤累积入渗量,2%施用量的生物炭对水分入渗过程起到先抑制后促进的作用,能使入渗时间缩短35.6%,2种施用量的脱硫石膏都能使入渗时间缩短91.1%,促进水分入渗,提高相同时间内的累积入渗量;只有2%施用量的生物炭使最终的累积入渗量大幅增加62.8%。(2)湿润锋运移距离与时间呈幂函数关系,用Kostiakov模型对累积入渗量和时间的关系拟合相对于Philip模型效果更好。(3)相比于对照组,只有1%施用量的生物炭使入渗后的土壤含水率降低2.7%,其余各处理均出现不同程度的增加;2种施用量的生物炭分别使入渗后的土壤含盐量显著降低28.5%和52.0%,但2种施用量的脱硫石膏分别使土壤表层含盐量显著提高184.3%和403.7%,其中2%施用量处理使土壤整体平均含盐量显著提高73.0%。综合考虑各处理改良后的入渗特性、土壤含水率...     

不同原料生物质炭复配对土壤镉的赋存形态及小白菜镉吸收的影响

通过生物质炭复配,降低治理成本,为提高秸秆生物质炭对镉污染土壤的治理效果,将秸秆生物质炭（大豆秸秆炭（SSB）、油菜秸秆炭（RSB））与动物屠宰废弃物炭（SWB）复配,设置2.22 g kg?1（B1）、4.44 g kg?1（B2）两个施用量,通过小白菜盆栽试验,研究生物质炭对原位污染土壤镉赋存形态及小白菜镉吸收的影响。研究表明,与对照（CK）相比,生物质炭显著降低小白菜根系和地上部的镉含量。在4.44 g kg?1施炭水平下,SSB2和RSB2处理的小白菜根系镉含量较SWB2处理显著降低、降幅分别达 33.40%和 20.49%。SSB2处理小白菜根系镉的富集系数较SWB2处理显著降低、降幅达31.68%。与 SSB2处理相比,SSB与SWB复配（SSWB2）处理根系和地上部镉含量分别降低22.57%和 36.14%。生物质炭显著降低土壤中镉的生物有效性,其中RSB2和SSB2处理的土壤交换态镉占比（F2）较SWB 2处理分别降低 9.31%和 3.63%,强有机结合态镉占比（F6）分别提高 16.11%和 9.74%。复配生物质炭SSWB2 处理的F2较SSB2 处理降低 11.05%,铁锰结合态镉占比（F5）提高13.50%。因此,秸秆生物质炭与屠宰废弃物炭复配可有效降低污染土壤镉的生物有效性及小白菜对镉的吸收和富集。