盐化土壤微生物区系及理化性状对不同改良剂的响应研究

系统分析了脱硫废弃物、专用改良剂和不同量菌肥对盐化土壤的改良效应,结果表明:单施脱硫废弃物对土壤细菌和放线菌数量影响很小,但可以有效增加真菌数量;单施专用改良剂或菌肥后微生物数量增幅相对较大,改良剂效果优于菌肥;脱硫废弃物、改良剂和菌肥同时施用可以显著增加土壤微生物数量;单施脱硫废弃物和菌肥对土壤有机质和养分含量、作物收获后的指标影响很小;3种物料同时施用则可以显著提高土壤有机质和养分含量,向日葵的株高、径粗、盘径、实粒数和百粒重都有显著增加。在施用脱硫废弃物和改良剂的前提下,菌肥施用量为45 kg hm-2的处理对盐化土壤改良效果最佳,但与施用量为30 kg hm-2的处理差异不显著。     

脱硫废弃物和专用改良剂在碱化土壤改良中的效果

通过大田试验,研究了添加燃煤脱硫废弃物和几种专用改良剂对碱化土壤性质的变化及其对油葵(Helianthusannuus)生长的影响。结果表明:二者配合施用提高了土壤有机质和养分含量,一定程度上降低了碱化度、pH和全盐含量,使油葵出苗率、株高和产量分别提高了116.7%、19.2%和140.7%以上;3种专用改良剂间,改良剂Ⅲ在提高土壤养分含量和降低碱化度和全盐含量等方面的效果最佳,其增产幅度也最高;改良剂Ⅰ的两个施用时期间,秋施显著提高了有机质、全N和碱解N含量,降低了全盐含量,提高了油葵出苗率和产量;改良剂Ⅰ的3个施用水平间,7.50 t hm-2和11.25 t hm-2的施用量下具有较高的全N和碱解N含量、较低的全盐含量和碱化度以及较高的出苗率、株高和产量。以上结果表明脱硫废弃物和改良剂及其配合施用改善了土壤物理化学性质,且有利于油葵的生长和发育。其中,改良剂Ⅲ的改良效果最佳,但其施用技术有待于进一步的研究。     

盐渍化土壤施用有机物-脱硫石膏改良剂效果的研究

研究了在盐渍化园田土壤上施用有机物与脱硫石膏混合改良刺对土壤理化性状和白菜产量的影响.试验采用改良剂的2种配方(成分比例不同)、3个施用量,以不施改良剂处理为对照,7个处理,3次重复.结果表明t施用有机物-脱硫石膏混合改良剂Ⅲ、Ⅳ可降低土壤容重最多为10.34%,11.30%;增加土壤总孔隙度最多达8.94%,9.84%.0-5 cm土壤全盐量由0.72%降至0.26%～0.46%;5-20 cnl土壤全盐量由0.32%降至0.14%～0.19%.改良剂2种配方的不同施用量与对照相比,土壤ESP、pH、土壤交换性Na~+和土壤Cl~-占阴离子总量分别下降了2.59%～16.28%,0.12～0.19,2.87%～24.53%和9.26%～213.05%.增加土壤SO_4~(2-)和Ca~(2+)最多达137.45%和228.24%.与对照相比,白菜增产10.19%～30.99%.施用有机物-脱硫石膏混合改良剂不仅能够改善土壤的理化环境,同时也为作物提供了丰富的腐殖酸及Ca,S等营养物质.     

脱硫废弃物改良宁夏盐渍化土壤对细菌和氨氧化微生物丰度的影响

为探明脱硫废弃物改良盐渍化土壤对微生物群落的影响效果,在2009~2010年,采用田间试验,施用不同量的脱硫废弃物(0、0.74、1.49、2.25、3.00 kg·m-2),研究了脱硫废弃物对盐渍化土壤细菌、氨氧化细菌和氨氧化古菌的影响。试验结果表明:0~20 cm土层,Ca2+和NO-3-N含量随着施用量增加而增加;土壤p H值、电导率值显著下降。实时荧光定量PCR(q PCR)分析结果表明,微生物丰度随着脱硫废弃物的施用发生变化,但这种变化并不与脱硫废弃物的施用量呈线性关系。在0~20 cm土壤层,施脱硫废弃物使得细菌16S rRNA基因拷贝数处理组显著高于对照组。氨氧化古菌与氨氧化细菌基因拷贝数在T2和T4处理高于其它处理。20~40 cm土层各处理间微生物群落没有显著变化,或没有出现规律的变化趋势。因此,脱硫废弃物增加了土壤细菌和氨氧化功能基因丰度,且对上层土壤影响更为显著。本研究中施用脱硫废弃物1.49 kg·m-2(T2)是引起细菌和氨氧化功能基因丰度增加的施用量。     

土壤结构改良剂对重度碱化盐土的改良效果

以宁夏银北重度碱化盐土为研究对象,系统研究生化黄腐酸BFA(Biochemical fulvic acid)和聚合硫酸铁铝PAFS(Polymeric aluminum ferric sulfate)与脱硫石膏FGD(Flue gas desulfurization)配合施用对土壤结构改善及其他理化性状的改良效果。结果表明:施用脱硫石膏和结构改良剂后向日葵出苗率、株高、千粒重和产量较对照均有显著增加。2014年、2015年和2016年脱硫石膏和改良剂配合施用的处理产量比对照平均提高了353.48%、298.82%和411.47%。2014年施用脱硫石膏和结构改良剂的处理0~20 cm土壤容重较对照处理平均降低9.07%,其中T3(FGD+BFA+PAFS)降幅最大。各处理土壤孔隙度变化趋势与容重相反。2015年和2016年0~20 cm脱硫石膏和改良剂配合施用的处理<0.25 mm粒级质量分数比2014年显著降低,1~2 mm粒级质量分数显著增加。整体来讲,改良后T3土壤水稳性团聚体状况最佳。脱硫石膏单独施用或与结构改良剂配合施用均会降低土壤pH值和EC,T3降幅最大;施用脱硫石膏和不同结构改良剂处理差异间不显著。施用脱硫石膏和改良剂后土壤有机质较对照明显增加,其中T3增幅最大,T4(FGD+BFA)次之。施用脱硫石膏和改良剂后土壤碱解氮、速效磷和速效钾变化情况与有机质相似,但增幅略大于有机质增幅。整体来讲,施用FGD+BFA+PAFS可以显著改善碱化盐土土壤结构、提高土壤有机质和养分含量,实现作物显著增产增收。     

脱硫石膏与结构改良剂配合施用对龟裂碱土理化性状和水稻生长的影响

[目的]筛选出最适宜宁夏回族自治区银北灌区盐碱地水稻生长的土壤结构改良剂施用量,为中国同类型地区盐碱地的改良应用提供科学依据。[方法]设置田间定位试验,研究银北灌区龟裂碱土在施用不同剂量土壤结构改良剂(0,150,270,375kg/hm~2)与统一施用定量脱硫石膏(22.5t/hm~2)对土壤基本理化性质及水稻生长的影响。[结果]在施用不同剂量结构改良剂后,0—20cm土层的土层容重、全盐量和pH值呈降低趋势,总孔隙度和水稳性团聚体则呈增加趋势。在0—20cm土层,各处理改良效果均较显著,当深度大于40cm时,所有处理的改良效果不明显。施加改良剂增加了水稻的成活率、株高和产量,且各处理间均差异显著(p0.05)。[结论]脱硫石膏与结构改良剂配合施用能显著改善龟裂碱土理化性状,促进水稻成长。综合考虑经济因素,脱硫石膏(22.5t/hm~2)+土壤结构改良剂(270kg/hm~2)的施用量效果最佳。     

不同改良剂对河套灌区盐渍化土壤性状和葵花生长特性的影响

为了评价不同改良剂对盐渍化土壤的改良效果,以葵花为研究对象,采用大田裂区试验方法,设置生物炭(DC,22.5 t/hm~2)、脱硫石膏(DS,37.5 t/hm~2)、脱硫石膏加有机肥(DSF,各37.5 t/hm~2)、对照(DCK)4种处理。结果表明:施加改良剂均降低了土壤容重,增加了土壤孔隙度,生物炭效果最明显,在耕层(0—20 cm)收获后较播种前土壤容重降低6.11%,是DCK的4倍,孔隙度增加12.89%,是DCK的5倍;脱硫石膏降低土壤pH和电导率效果最优,最大降幅分别为10.09%和28.51%;3种改良剂对盐渍化土壤的肥力效应不同,与对照相比,在收获后生物炭处理显著提高土壤耕层有机质、碱解氮、速效磷含量,脱硫石膏显著提高速效钾含量;各改良剂处理能显著增加葵花株高、茎粗、干物质积累量和百粒重,且生物炭处理的葵花产量最高,为4 539.60 kg/hm~2,较对照增产32.28%。综上所述,在河套灌区盐渍化土壤中施入不同改良剂后,土壤性状得到明显改善,促进葵花的正常生长,提高了产量。其中施入生物炭22.5 t/hm~2对盐渍土壤改良效果最佳,其次是施入脱硫石膏37.5 t/hm~2,能有效地提高土壤肥力和葵花产量。     

施用菜籽饼肥对次生盐渍化温室土壤有效养分、盐分及盐分组成的影响

通过田间试验研究了施用油菜菜籽饼肥处理后,次生盐渍化温室土壤中的有效养分、水溶性盐分含量及盐分离子组成的变化,以评价施用饼肥改良次生盐浈化温室土壤的可行性以及在温室土壤上大量施用油菜籽饼肥可能出现的后果.结果表明:在次生盐浈化温室土壤上施用饼肥会显著增加0～20 cm土壤中的绝大多数有效养分特别是大量元素有效养分的含量和全盐含量.同时,施用饼肥也使得20～30 cm土壤中的部分养分和盐分离子含量显著增加,土壤次生盐渍化程度进一步加重.因此,施用饼肥并不能作为一种改良次生盐溃化温室土壤的有效措施,为避免土壤次生盐渍化程度的形成和发展,应减少设施农业中饼肥的施用量.     

土壤调理剂及其配施微生物菌肥对设施菜田次生盐渍化土壤改良效果研究

针对设施菜田土壤次生盐渍化问题,研究分析不同用量土壤调理剂及其配施微生物菌肥对促进土壤脱盐、改善土壤理化性质及土壤微生物多样性的改良效果。试验结果表明,施用土壤调理剂和微生物菌肥后,土壤理化性质明显改善,土壤容重、EC、全盐量均有不同程度下降,Na+、K+、Ca2+、Cl-、HCO3-含量降低,有效抑制土壤返盐;且施用土壤调理剂和微生物菌肥后,土壤细菌群落多样性和丰富度趋于增加,尤其是固氮菌和分解有机质菌属的数量显著增加,土壤有益菌含量的增加对黄瓜生长起到促进作用。土壤调理剂及其配施微生物菌肥在改善土壤理化性质、降低土壤表层盐分、提高土壤微生物细菌群落多样性方面具有显著效果,可为设施菜田次生盐渍化土壤缓解盐胁迫提供参考。     

三种秸秆有机肥改良土壤次生盐渍化的效果及生物效应

通过盆栽实验的方法,研究了三种秸秆有机肥对次生盐渍化土壤的EC值、硝酸根离子含量和油菜生物量的影响。结果表明,M1有机肥显著增加油菜的生物量,但在一定程度上增加土壤盐分含量;M2有机肥的效果与M1有机肥效果趋势相似,但增加土壤中的盐分含量的程度要小的多;而施用秸秆肥料M3,在增加油菜生物量的同时显著降低土壤盐分含量,减轻了土壤的次生盐渍化程度。结果表明,三种秸秆有机肥均能提高油菜对盐渍化的耐受能力,增加其生物量。采用M3秸秆有机肥改良土壤盐渍化是一条有效途径,但其最佳施用量与土壤盐渍化程度有关,非盐渍化土壤施用过多M3肥料将降低生物量。     

Soil ameliorants alter physicochemical properties and fungal communities in saline-sodic soils of Northeast China

To understand the mechanisms of soil ameliorants affecting microbial communities is important for saline-sodic soils reclamation. High-throughput sequencing was used to characterize the fungal community in soils amended with four types of ameliorants over an 8-year period. Besides a control without any additional ameliorant (CK), other four treatments including 1) amendment with sandy soil (SS), 2) amendment with desulfurization gypsum (DG), 3) amendment with farm manure (FM), and 4) amendment with a mixture of SS, DG, and FM (M) were analyzed. Soil pH and electrical conductivity significantly decreased with the addition of soil ameliorants, whereas the soil organic carbon (SOC), total nitrogen (TN), and SOC/TN ratio (C/N) significantly increased in the FM and M treatments compared with the CK treatment. Fungal richness increased significantly with the mixed ameliorants addition (M). Distinct fungal community structures were observed in the treatments with soil ameliorants. The fungal community composition was significantly associated with the SOC, C/N, aggregate content with a diameter > 0.25 mm and geometric mean diameter. The changes in these soil characteristics were highly correlated with the ameliorants additions, suggesting that the impacts of ameliorants on the soil fungal community occurred indirectly as a result of alterations to soil physiochemical properties.     

脱硫石膏对盐碱土一维水平吸渗特征及水分运动参数的影响

为探明添加脱硫石膏对盐碱土水分运动参数的影响,以改善和提高银川北部地区土壤结构和土地生产力,进行了室内一维水平土柱吸渗试验。选取6种脱硫石膏添加比例0,1.5%,3%,4.5%,6%和7.5%,探究不同脱硫石膏添加比例下盐碱土水平吸渗特征及水分运动参数的变化。结果表明:脱硫石膏添加减缓了土壤水分入渗过程,随着脱硫石膏添加比例增加,各处理累积入渗量与湿润锋运移距离均逐渐减小。幂函数与Philip模型能较好地拟合不同脱硫石膏添加比例下盐碱土水分吸渗特征,吸渗率随脱硫石膏配比增加逐渐减小,毛管力对水的吸持作用减弱。随着脱硫石膏配比增加,土壤饱和含水率依次增加,饱和导水率依次减小,土壤持水能力明显提高。在Brooks—Corey模型中,形状系数n逐渐增加,进气吸力h_d逐渐减小,土壤通气性增强。在相同含水率情况下,随着脱硫石膏配比增加,土壤水分扩散率减小。添加脱硫石膏增加了土壤持水性能,改变了土壤水分分布状况,对土壤水分运动参数有显著影响。研究结果可为合理利用脱硫石膏改良盐碱地提供参考依据。     

Sulfur Fertilization of Canola (Brassica napus) with Flue Gas Desulfurization Gypsum: An Assessment Study

Flue gas desulfurization gypsum, a coal combustion byproduct, may be a viable sulfur source for dryland canola. The objectives of the authors in this research were to evaluate the potential of using flue gas desulfurization gypsum as a sulfur fertilizer source, and also to determine the environmental impact of adding flue gas desulfurization gypsum to soil. Flue gas desulfurization gypsum and ammonium sulfate were applied at comparable rates to canola to two soils in 2008 and one soil in 2009. In 2008 both flue gas desulfurization gypsum and ammonium sulfate supplied adequate amounts of sulfur to the plants and in 2009, canola yields were more variable and depended significantly on sulfur rate, but not on sulfur source. Overall, soil quality was not negatively impacted by the addition of flue gas desulfurization gypsum and although none of the power plants in the northern Great Plains currently produces flue gas desulfurization gypsum, finding agricultural uses for this byproduct is an important step in determining its usefulness in this area.     

Use of langbeinite to reclaim sodic and saline sodic soils

Abstract

Langbeinite is a soluble potassium‐magnesium sulfate mineral (K₂SO₄2MgSO₄) found as an evaporite in many regions of the world. Langbeinite was used as a reclaiming material in a fine textured (clay loam) saline sodic soil (Grabe Series). This amendment can be dissolved and directly into the irrigation water, displacing sodium (Na) quickly with minimal water use. This amendment was superior over gypsum as a reclaiming material for a saline sodic soil in batch, column, and greenhouse studies. Langbeinite required 50% less irrigation water than gypsum to displace and leach exchangeable Na from soils. Langbeinite improved the infiltration rates of saline sodic soils, but not as effectively as gypsum. Significant increases in germination percent dry matter production mass of lima bean (Phaseolus lunatus L.) plants were observed when using langbeinite over the gypsum soil amendment.     

The effect of Gypsum amendment on transport of phosphorus in a sandy soil

The effect of gypsum amendment on transport of phosphorus (P) in a Pineda sand (loamy, silicious, hyperthermic Arenic Glossaqualf) was investigated in a leaching column experiment. Phosphorus was either placed on the surface of the soil or mixed with the surface 2 cm depth of soil in the column. Gypsum amendment decreased the transport of P in soil. Compared to the unamended soil, transport of P decreased by 35 and 54% in soils amended with 4.5 and 9.0 M.T./ha gypsum, respectively. The transport of P was further decreased by 74% when P was premixed with the surface 2 cm of soil. The transport of P was not influenced by the SO₄ ion from gypsum amendment. Instead, formation of Ca-P precipitate appeared to be responsible for the decreased transport of P in the gypsum-amended soil.     

Short-term effects of biochar and gypsum on soil hydraulic properties and sodicity in a saline-alkali soil

Salt and sodicity of saline-alkali soil adversely affect the construction of ecological landscapes and negatively impact crop production. The reclamation potential of biochar (BC, wheat straw biochar applied at 1% by weight), gypsum (G, 0.4% by weight), and gypsum coupled with biochar (GBC) was examined in this laboratory-based study by evaluating their effects on a saline-alkali soil (silt loam) with no amendment as a control (CK). Saline ice and fresh water (simulated rainfall) were leached through soil columns to investigate changes in salt content, sodium adsorption ratio (SAR), alkalinity, and pH of the leachate and the soil. Results showed that saturated water content and field water capacity (FWC) significantly increased by 4.4% and 5.6%, respectively, in the BC treatment after a short incubation time. Co-application of biochar and gypsum (GBC) increased soil saturated hydraulic conductivity (Ks) by 58.4%, which was also significantly higher than the sole addition. Electrical conductivity (EC) of the leachate decreased sharply after saline ice leaching; subsequent freshwater leaching accelerated the removal of the rest of the salts, irrespective of the amendment application. However, the application of gypsum (G and GB) significantly enhanced the removal of exchangeable Na+ and reduced leachate SAR. After leaching, the soil salt content decreased significantly for all treatments. The application of gypsum resulted in a significantly lower soil pH, exchangeable sodium percentage (ESP), SAR, and alkalinity values than those recorded for the CK and BC treatments. These results demonstrated that the co-application of gypsum and biochar could improve saline-alkali soil hydraulic conductivity and decrease leaching-induced sodicity over a short period.     

石膏和腐植酸配施对干旱盐碱区土壤改良及棉花生长影响

针对试验区盐碱土特点，选择石膏和腐殖酸为盐碱土壤改良剂，通过石膏、腐殖酸单施与石膏和腐殖酸不同用量配施试验，分析了改良剂施用后土壤盐分含量和pH值变化、及对棉花株高、茎粗和产量的影响，优选出适宜于该试验区的最佳改良剂。试验结果表明，石膏和腐殖酸9:1组合在200和300 kg/667 m2施用量情况下，0-20 cm土壤降盐效果好于单独施用石膏或腐殖酸处理；而单施腐殖酸处理对棉花增产效果最好，较控制处理棉花产量增加29.8%。综合分析，亩施石膏和腐殖酸9:1组合改良剂200 kg为该地区较优的改良剂用量，可使0-20 cm土壤含盐量较控制处理下降24.3%，棉花增产24%。