微塑料输入与秸秆添加对潮土和黄棕壤氮淋溶的影响

为探究微塑料输入与秸秆添加对农田土壤氮淋溶的影响，以潮土和黄棕壤为研究对象，每种土壤各设置8个处理，包括对照（CK）、低量微塑料（PE1）、中量微塑料（PE2）、高量微塑料（PE3）、秸秆（S）、秸秆+低量微塑料（S+PE1）、秸秆+中量微塑料（S+PE2）、秸秆+高量微塑料（S+PE3），研究了添加秸秆与不添加秸秆条件下，不同微塑料输入量对土壤氮淋溶的影响。结果表明，仅添加微塑料条件下，与对照（CK）相比，潮土PE1、PE2、PE3处理总氮（TN）淋溶量均无显著差异，黄棕壤仅PE1处理显著增加了TN淋溶量。在添加秸秆（S）处理中，与对照（CK）相比，潮土添加秸秆后显著降低了硝态氮（NO₃^--N）、铵态氮（NH₄⁺-N）、TN淋溶量，分别降低了31.15%、13.45%、15.26%，黄棕壤添加秸秆后显著增加了TN淋溶量，增加了22.56%。添加秸秆处理相较于不添加秸秆处理，潮土各浓度微塑料输入下NO₃^--N、NH₄⁺-N、TN的累计淋溶量呈降低趋势，而黄棕壤低量微塑料输入降低了TN淋溶量，高量微塑料输入增加了TN淋溶量。偏最小二乘路径模型（PLS-PM）分析表明，在潮土中添加秸秆主要通过影响淋溶液pH和NO₃^--N淋溶量影响氮素淋溶，微塑料添加量对氮淋溶无显著影响；在黄棕壤中添加秸秆主要通过影响淋溶液NO₃^--N、NH₄⁺-N淋溶量影响氮淋溶，微塑料添加量主要通过影响淋溶液NH₄⁺-N淋溶量影响氮淋溶。研究结果可为农田土壤微塑料污染风险的管控及减少土壤氮素的淋失提供依据。     

水稻秸秆预处理还田对土壤养分淋溶及COD的影响

对秸秆进行预处理可以加快秸秆的腐解,为了探讨秸秆经过不同预处理后还田对土壤养分淋溶及COD淋出量的影响,利用白腐真菌、大球盖菇、尿素分别对秸秆进行预处理,通过室内人工土柱模拟试验方法,对秸秆配施有机肥还田后土壤中氮磷及COD淋出量进行分析。运用(SEM)扫描电镜、(FTIR)傅里叶红外光谱、(XRD)X射线多晶衍射对预处理前后秸秆结构及成分进行分析,并通过比较不同预处理秸秆与有机肥配施淋溶过程中总氮、硝态氮、铵态氮、总磷、溶磷、COD的变化来确定秸秆还田前最佳的预处理方式。结果表明:不同秸秆预处理方法使秸秆表面结构均产生不同程度的变化,分子间氢键集聚力减弱,部分碳水化合物被分解。相比空白对照组(CK),配施有机肥明显增加了淋溶液中养分及COD的含量(p<0.05);在配施有机肥的处理中,处理SF2(白腐真菌预处理秸秆还田+施肥)、SF3(尿素预处理秸秆还田+施肥)、SF4(未预处理秸秆还田+施肥)、SF5(大球盖菇预处理秸秆还田+施肥)相对于只施有机肥的处理SF1,总氮的淋溶量分别降低16.61%,20.42%,13.84%,33.22%,铵态氮的淋溶量分别降低了4.90%,22.77%,18.3%,38.39%,其中大球盖菇对总氮和铵态氮的累计淋溶损失量的降低作用更显著(p<0.05);各处理的淋溶液中硝态氮、总磷、溶磷的淋溶损失量差异不显著。直到淋溶结束,各个处理的COD的累计淋溶损失量从大到小为SF1(不秸秆还田+施肥)>SF4(未预处理秸秆还田+施肥)>SF3(尿素预处理秸秆还田+施肥)>SF2(白腐真菌预处理秸秆还田+施肥)>SF5(大球盖菇预处理秸秆还田+施肥)>CK(空白对照),SF5(大球盖菇预处理秸秆还田+施肥)处理的COD累计淋溶损失量低于其他处理,说明在配施有机肥条件下,大球盖菇预处理秸秆还田可以有效降低COD的累计淋溶损失量。总体来说,大球盖菇预处理秸秆还田对减少土壤氮素的淋溶损失和淋溶液中COD含量均有一定的积极作用。     

田间条件下氮的矿化及硝态氮淋溶研究

采用SRC（Soil-Resin-Core）装置，研究了重庆市主要土壤类型的氮矿化差异以及与硝态氮淋溶的关系。研究结果表明，微酸性紫色土（菜地）的氮索矿化量、硝态氮淋失量和有效氮的变幅均较大，而其它两种坡耕地变化的氮素矿化景和硝态氮的淋失量变幅均较小。相关分析表明：在微酸性紫色土中，影响硝态氮淋失的主要因素是矿化量，且二者呈显著正相关；而其它两种坡耕地土壤的矿化量与硝态氮淋失量不表现相关性。这就表明不同土壤矿化、硝态氮淋失的情况有差异。     

铜在草甸黑土中的淋溶规律及其对不同因素的响应

通过室内土柱试验,模拟研究在扣除地表径流影响的条件下,铜在草甸黑土中的淋溶规律。结果表明:随着淋溶液用量增加,铜的淋出量增大;土壤溶液和腐殖酸溶液作为淋溶液,在一定程度上抑制铜的淋溶,而EDTA会显著促进铜的淋溶;CaCl2、MgSO4、KCl和NaCl 4种无机盐淋溶液均能促进铜的淋溶,促进作用顺序为CaCl2>MgSO4>KCl和NaCl>对照;随着淋溶液pH值的降低,铜的淋出量增加;间断淋溶方式不利于土壤中铜的淋溶。     

不同淋洗方式下滨海沙性盐渍土改良效果

选择对滨海沙性盐渍土进行室内土柱模拟淋洗试验,采用连续淋洗与间歇淋洗2种方式比较不同淋洗方式下沙性盐渍土的改良效果。结果表明,淋出液矿化度随着体积变化急剧下降,直至稳定于很低的水平,连续淋洗与间歇淋洗淋出液矿化度分别从233.8,327.4g/L稳定至2.5,2.2g/L。间歇淋洗单位水量淋洗的盐分要高于连续淋洗。淋出液的各离子随体积变化趋势与矿化度变化相似;淋洗结束后土壤盐分变化显示,随着用水量的增加,淋洗效率逐渐降低,15,20,25,30cm水量下连续淋洗的淋洗效率分别为2.87,2.40,1.98,1.67g/ml;间歇淋洗的淋洗效率为3.10,2.48,2.00,1.68g/ml,间歇淋洗的淋洗效率始终要高于连续淋洗;由于各离子溶脱淋洗速率不同,改变了土壤中盐分离子组成,土壤由原来以Na+-Cl-型转变为以Ca2+-SO24-型。根据淋洗过程中土壤盐分变化与用水量之间的关系拟合出的淋洗曲线效果较好,相关系数分别为0.968和0.970。淋洗试验表明,间歇淋洗具有更高的淋洗效率,节水潜力要高于连续淋洗,由此得出的淋洗曲线可用于指导大田沙性盐渍土改良应用。     

离子型稀土矿体中溶液非均匀性渗透对浸取率的影响

为研究离子型稀土矿体中浸取剂溶液的非均匀渗透对浸取率和浸取深度的影响,在江西安远的离子型稀土矿山开展了亮蓝和硫酸铵混合溶液的注液坑入渗试验,亮蓝用于示踪溶液渗透过程,硫酸铵用于反映渗透过程的离子交换,获取矿体中溶液的非均匀渗透过程,运用形态学图像处理技术,计算染色剖面染色图像指数和多重分形谱谱宽,分析非均匀渗透过程对稀土离子浸取深度的影响。研究结果表明:江西安远离子型稀土矿体非均匀性参数变异系数属于中等变异性,浸取剂溶液在稀土矿体的渗透过程具有多重分形性质,相对于基质流深度、染色深度和染色面积比等剖面染色图像指数,多重分形谱谱宽与优先流比对非均匀渗透过程更灵敏;随优先流比增加,浸取率降低,浸取深度也减小。     

片麻岩新成土中硝态氮垂直运移规律模拟研究

采用室内土柱模拟的方法,研究河北省太行山片麻岩新成土中不同肥料、不同施氮量对硝态氮垂直运移的影响。结果表明,尿素、有机无机混合肥、氮磷复合肥中硝态氮淋失总量比值为1∶0.87∶0.94。中等施氮量下,有机无机复混肥可以降低氮素淋失。尿素硝态氮淋失率平均为29%,氮磷复合肥平均为27.8%,有机无机混合肥平均为23.7%。60 cm和90 cm处硝态氮淋失量比值为1∶1.03,差异不显著。淋溶结束后,有机无机混合肥在不同土层各处理中硝态氮含量最高,尿素硝态氮含量最低。     

中国农田氮淋失相关因素分析及总氮淋失量估算

通过对我国近 10 年 382 组农田 N 素淋失数据进行统计分析,发现水田的 NO3--N 淋失量与土壤体积质量、有机质、全 N（TN）、黏粒含量百分比显著负相关,与施 N 量、灌水量显著正相关;旱地中 NO3--N 淋失量与全 P（TP）、粉粒含量百分比、土层深度显著负相关,与土壤中 TN 含量、砂粒百分比含量、施 N 量、降雨量、灌溉水量显著正相关。水田中总 N 表观淋失率平均值为 2.19%,95% 的置信区间为 1.56% ~ 2.82%;旱地中总 N 表观淋失率平均值为 4.35%,95% 的置信区间 2.88% ~ 5.82%。根据 2008 年中国统计年鉴计算出 2007 年我国总 N 淋失量达到 0.644 Tg,约占我国总施 N 量的2.80%。     

热带亚热带酸性土壤硝化作用与氮淋溶特征

通过室内好气培养和土柱模拟淋洗培养试验,研究了氨基氮肥加入对热带亚热带4种不同性质和利用方式酸性土壤硝化、氮及盐基离子淋溶、土壤及淋出液酸化的影响。4种土壤分别为采自花岗岩发育的海南林地砖红壤(HR)、玄武岩发育的云南林地砖红壤(YR)、第四纪红黏土发育的江西旱地红壤(RU)和第四纪下蜀黄土发育的江苏旱地黄棕壤(YU)。结果表明:4种土壤硝化作用大小表现为YURUYRHR。HR主要以可溶性有机氮(DON)和NH_4~+-N形态淋失,YU土壤的氮淋溶形态以NO_3~–-N为主,YR和RU土壤的氮淋溶形态NO_3~–-N、NH_4~+-N和DON兼而有之。盐基离子总淋失量与NO_3~–-N淋失量显著正相关,但各盐基离子淋失由于离子本性和土壤性质差异并不完全一致。Ca~(2+)在缓冲外源NH_4~+-N硝化致酸和平衡NO_3~–-N淋失所带负电荷过程中起重要作用。在阳离子交换量小、盐基饱和度低的土壤(如RU土壤),外源NH_4~+-N的硝化和淋失不仅导致盐基离子淋失,而且引发NH_4~+-N、甚至是H~+淋失。综上,热带亚热带地区土壤上外源氮输入的增加可能会在更短的时间内导致氮素向系统外的流失,引发环境问题。     

Effects of Irrigation Water Salinity and Leaching Fraction on Yield and Evapotranspiration in Spring Wheat

To determine the effects of irrigation water salinity and leaching fraction on crop evapotranspiration (ETc), grain yield, straw yield, shoot sodium (Na), and chloride (Cl) concentrations of spring wheat (Triticum aestivum L.) cultivar ‘Onfarom 9,’ a pot experiment was conducted using saline soil with electrical conductivity of soil paste extract (ECe) of 13.2 dS m^?1. A factorial experiment with a completely randomized design replicated seven times was used with three levels of saline irrigation water (4, 9, and 12 dS m^?1) and four leaching levels (0, 17, 29, and 37%) included as the factors. The results showed that ETc significantly decreased as a result of an increase in irrigation water salinity (ECi) and decrease in leaching level. Crop evapotranspiration deficit and decreasing irrigation and drainage water effectively resulted in grain and straw yield reduction. Increase in ECi increased accumulation of Cl and Na in crop shoot, but application of leaching decreased this accumulation.     

不同pH淋溶液对猪粪中不同指标溶出的影响

该文研究猪粪在酸雨条件下释放污染物的规律，分析释放物的环境危害性。试验配置pH值为3.60、4.80和5.60的淋溶液，模拟广东省内的酸雨降水环境，对新鲜猪粪进行24d的淋浴，然后对各组淋出液和猪粪残留化学成分进行分析，得出不同pH值淋溶下污染物重金属铜、锌、砷和氨氮、总磷、CODGr等时间－浓度曲线。结果表明，新鲜猪粪在酸性淋溶下，其渗滤液的pH有所降低，在24d淋溶过程中渗滤液重金属（Zn、Cu、As）的浓度总体上呈下降趋势，以pH4.8时滤出重金属的速度较pH3.6、5.6快；COD、氨氮早期溶出较快，以后逐步减缓。新鲜猪粪经酸性淋溶后，渗滤液中铜、砷以及COD、总磷、氨氮含量均显著增加。因此对即使临时堆放亦需采取措施，以防止因雨水等导致的渗滤液污染。     

丁吡吗啉在土壤中的吸附及淋溶特性

化学农药在土壤中的吸附和淋溶特性是评价其环境行为的重要指标,也是新农药登记必须提供的环境影响资料。本文分别采用振荡平衡法、土壤薄层层析法和土柱淋溶法研究了丁吡吗啉在不同土壤中的吸附和淋溶特性。结果表明,丁吡吗啉在3种供试土壤上的吸附规律可以较好地用FreundLich方程描述,吸附常数Kd在10.42~37.72mL.g-1之间,在砂土中较难被吸附,在壤土和粘土中属中等吸附。丁吡吗啉在3种供试土壤中不易移动或不移动,3种土柱淋溶试验的结论均为难淋溶。根据综合试验结果,对相关影响因素进行了讨论,认为影响丁吡吗啉在土壤中吸附性的主要因素为土壤有机质含量和土壤粘粒含量,影响淋溶特性的主要因素为土壤吸附和丁吡吗啉在水中的溶解度。     

亚热带主要耕作土壤硝态氮淋失特征试验研究

本文选取红壤、水稻土、潮土、黄棕壤和紫色土等我国亚热带地区的主要耕作土壤为研究对象,采用土柱模拟试验,研究了在这些土壤中,氮素累积与硝态氮迁移的动态特征,并对氮素的淋失风险进行了定量评价和预测。结果表明,硝态氮在土壤中的淋失过程可分为两个明显的阶段:高浓度快速降低阶段和低浓度缓慢降低阶段。硝态氮淋失过程存在明显的拐点,该点对应的累积入渗量（拐点入渗量）变化范围为38.1 - 219.7 mm,且随土壤硝态氮含量的增加呈幂函数关系增加,表明随硝态氮含量的增高,其淋失风险呈加速增大的趋势。硝态氮淋失强度随土壤硝态氮含量的增加呈显著的线性变化趋势。初步估测,我国亚热带地区年降水入渗量700 mm和土壤硝态氮累积水平为N 20 mg /kg条件下,表层土壤（0-20cm）的硝态氮年平均淋失量为N 484.9 kg /hm2,土壤间的变异系数（CV）分别为26.5%。土壤硝态氮含量是影响硝态氮淋失强度的决定性因素,其它土壤性质的影响均相对较小,因此,控制土壤氮素累积和化肥施用水平是降低其淋失风险的关键环节。     

大沽河流域农田土壤磷有效性及全磷淋失影响因素试验

以青岛市大沽河流域砂壤、河潮土、砂姜土3种农田土壤为研究对象,开展室内土柱试验,研究土壤pH、温度、含水率等理化性质与生物炭和氮肥配施对土壤有效磷(Olsen-P)和全磷(TP)淋失的影响,以期为提高农田土壤磷素有效性、减少全磷淋失提供参考依据。结果表明:3种土壤的pH在偏中性或弱碱性时磷素有效性最高,pH偏酸性时,土壤全磷淋失量较大;3种土壤不同土层中的Olsen-P含量随含水率的增加表现为不同的变化规律;3种土壤的磷素有效性均随温度的升高逐渐增大,全磷淋失量随温度的升高逐渐降低;生物炭和氮肥配施(T1~T7)处理下均能够有效提高土壤磷素有效性,作用效果依次为生物炭和氮肥联合施加>单加生物炭>单加氮肥,当氮肥和生物炭比例为2:1时,土壤磷素有效性最高。生物炭与氮肥联合施加对土壤全磷淋失的抑制效果优于单独施加生物炭,氮肥对全磷淋失的抑制效果不明显。     

第四纪红色粘土发育的红壤中营养元素的淋失

A red soil derived from Quaternary red clay was employed to study nutrient leaching with soil columns repacked in laboratory. The objective was to identify the effects of fertilization practices on leaching patterns and magnitudes of Ca²⁺, Mg²⁺, K⁺, NH₄⁺, and NO₃^-. The treatments were CK (as a control), CaCO₃, CaSO₄, MgCO₃, Ca(H₂PO₄)₂, urea, KCl, and multiple (a mixture of the above-mentioned fertilizers). The fertilizers were added to the bare surface of the soil columns, and then the columns were leached with 120 mL deionized water daily through peristaltic pumps over a period of 92 days. Leaching processes of NH₄⁺, and NO₃^- were only measured in CK, urea, and multiple treatments which were directly related to N leaching. Results showed that sole application of CaSO₄, and Ca(H₂PO₄)₂ scarcely had any effect on the leaching losses of Ca²⁺, Mg²⁺, and K⁺; the application of MgCO₃ stimulated the leaching of Mg²⁺; the application of CaCO₃ promoted the leaching of Ca²⁺, Mg²⁺ and K⁺; urea treatment also promoted the leaching of K⁺ and NH₄⁺, and NO₃^- leaching mainly occurred at late stage of leaching process in particular; under KCl treatment, leaching of Ca²⁺, Mg²⁺, and K⁺ was promoted to a large extent; under multiple treatment, leaching of Ca²⁺, Mg²⁺, K⁺, NH₄⁺, and NO₃^- was all increased and NO₃^- was mainly leached at the end of leaching process and still had a trend of increase.     

硫酸铝对苏打盐碱土中氟迁移规律的影响

采用土柱淋洗法,研究不同铝氟摩尔比下苏打盐碱土中氟的迁移过程及pH值变化情况。结果表明,苏打盐碱土施铝后,能够明显降低淋洗液的pH值,与空白相比,差异均达极显著水平。并且随着淋洗次数和铝相对含量的增加,pH值呈现逐渐降低的趋势。不同铝氟摩尔比作用下,氟在碱土中的迁移动态及总淋失率存在较大的差别。随着淋洗次数的增加,1∶1处理的每次淋失率变化较缓,(1∶2)～(1∶4)处理呈先增加后降低的趋势,而(1∶5)～(1∶7)处理明显下降。与对照相比,苏打盐碱土上施用硫酸铝可以降低氟在土壤中的总淋失量,进而可以减少土体中的氟向地下水中的迁移,降低人畜通过饮用地下水而带来的摄氟量。但是氟总淋失率的降低程度与铝的相对含量有关,其中1∶4铝氟处理的总淋失率相对较高,而1∶1处理的淋失率相对较低。这可能与添加硫酸铝后苏打盐碱土的pH值变化、铝氧化物和氢氧化物数量变化、土壤胶体带电性变化及土壤自身铝的释放有关。     

The effect of grassland renovation on soil mineral nitrogen and on nitrate leaching during winter

Renovation of grassland may increase the mineralization of organic material and leads to a high amount of mineral N in soil which can be leached in the winter period. Soil mineral N (SMN) in autumn and calculated nitrate leaching during winter were measured after the renewal of 8 y–old cut grassland on a sandy soil in NW Germany in 1999 to 2002. Several factors, which may influence the intensity of N mineralization, were investigated in the 2 years following renewal: the season of renovation (spring or late summer/early autumn), the technique (rotary cultivator or direct drilling), and the amount of N fertilization (0 or 320 kg N ha^–1 y^–1 in the 7 years before the renovation). Calculated nitrate‐N leaching losses during winter were significantly higher following renewal in early autumn (36–64 kg N ha^–1) compared to renewal in spring (1–7 kg N ha^–1). This effect was only significant in the first, not in the second winter after renovation. The renovation technique had a significant effect on the nitrate‐N leaching losses only in the first year after the renovation. Direct drilling led to higher leaching losses (35 kg N ha^–1) than the use of a rotary cultivator (30 kg N ha^–1) in the same year. Calculated nitrate losses (on average over 60 kg N ha^–1) were highest after renewal of N‐fertilized grassland in late summer/early autumn. To minimize N leaching losses, it would be more effective to plan grassland renewal in spring rather than in late summer/autumn. Another, however, less effective option is to reduce N fertilization before a renovation in autumn.     

Effects of Mg-Al Layered Double Hydroxide on Nitrate Leaching and Nitrogen Uptake by Maize in a Calcareous Soil

The potential use of a layered double hydroxide (magnesium aluminum nitrate (Mg-Al)-LDH) to suppress the leaching of nitrate from a calcareous sandy loam soil and to enhance the nitrogen utilization efficiency of maize was assessed. The results of column studies showed that nitrate leaching efficiently decreased by 24, 46, and 76% compared to control when 2.5, 5, and 10 g LDH kg^–1 soil were applied, respectively. Nitrate leaching was also reduced by use of LDH in pot experiments. The hindrance effect of LDH in using ammonium nitrate was higher than urea. Application of 2.5, 5, and 10 g LDH kg^–1 soil increased mean nitrogen uptake of maize by 14, 20, and 44% over the control. The studied LDH has a potential to be used as a nitrate-selective exchanger to reduce risks of nitrate leaching. However, the use of Mg-Al-LDH (4:1) can be limited because of its relatively high solubility in soil.     

Application of Fresh and Treated Pig Slurries and a Novel Organic-Mineral Fertilizer in Maize Crop

Lysimeter experiments were carried out during two growing seasons to compare the effect of untreated, digested, codigested, and a novel organic-mineral fertilizer, synthesized with pig slurry by a new-generation technology, on nitrogen (N) and phosphorus (P) leaching when compared with mineral fertilizer at typical rates for maize (Zea mays L.) production in Mediterranean soil. Relationships between application rates and type of fertilizer on maize crop yield, N uptake, and N and P leaching were investigated to assess the efficacy of these fertilizers in Mediterranean areas. Results showed a positive effect of the use of treated slurries, high N uptake of maize plants, and dry-matter production that was crucial for keeping N leaching loads at minimum. Then, not only in terms of production, but also in terms of N conservation in soil and in environmental water quality, slurries showed a better performance than inorganic or the organic-mineral fertilizer.     

石墨烯溶胶配施化肥对土壤中养分流失的影响

通过土柱淋溶试验研究了石墨烯溶胶配施化肥后对土壤中养分流失的影响,以探究石墨烯溶胶的保肥作用。试验共设计5个石墨烯溶胶浓度,进行4次淋溶,测定每次淋溶液以及4次淋溶后的土壤的电导率、氮、磷、钾含量。结果表明:(1)石墨烯溶胶与化肥配施于土壤中后对淋溶液的电导率、氮、磷及钾的含量均有影响,且添加的石墨烯溶胶浓度越大影响越明显。添加石墨烯溶胶处理后的淋溶液中,硝态氮、总氮、磷的含量最大可分别降低88.2%,80.9%和84.7%。(2)4次淋溶后,添加石墨烯溶胶处理的土壤中氮、磷、钾的含量及电导率与对照相比均有增加,其中对总氮、总磷的持留效果最大可提高175.0%和59.3%,但对铵态氮的持留无明显效果。(3)石墨烯溶胶对淋洗液和土壤的pH影响不明显。石墨烯溶胶与肥料施入土壤中,可明显减少土壤中养分的淋溶损失,对土壤中的养分有明显的持留效果,具有保肥的作用。