水作和旱作施用改良剂对蕹菜-土壤系统中铅镉生物有效性的影响差异

为探讨不同农艺调控措施组合对蔬菜-土壤系统重金属生物有效性的影响,以能同时适应水作和旱作两种栽培方式的蕹菜为研究对象,探讨了在人为添加铅镉复合污染情况下,不同栽培方式和施用改良剂(石灰或生物炭)的农艺调控措施组合对蕹菜中铅镉累积规律的影响差异,并从不同处理情况下的土壤理化性质和重金属有效态含量变化特征等方面分析其作用机理。结果发现,旱作和水作两种栽培方式下,蕹菜中重金属累积及土壤重金属有效性等方面出现了不同的变化规律:在水作条件下施用石灰比旱作能更有效地降低土壤铅镉有效态含量,而水作条件下施用石灰和生物炭均能在提高蕹菜产量的情况下降低蕹菜中铅镉含量,且施用6 g·kg~(-1)生物炭的效果最优。总的来说,与旱作模式相比,水作条件下施用改良剂往往对蕹菜-土壤系统中铅镉累积特性的影响效果更明显。     

粉煤灰和石灰对突发性污染土壤中重金属化学形态的影响

利用石灰和粉煤灰对突发性污染土壤中重金属进行修复,采用TCLP法和Tessier浸提法对修复后土壤进行评价。结果表明,当石灰用量为土重的0.1%时,培养1个月,突发性污染土壤中Cu、Cd浸提量(TCLP法)比对照分别下降68.13%和76.67%;当粉煤灰用量为土重的8%时,土壤Cu、Cd浸提量比对照分别下降61.58%和71.67%。两种土壤经修复后,Cu、Cd浸提量均降至国际标准值以下,原因是施用粉煤灰和石灰后,土壤中Cu、Cd的形态由交换态向碳酸态和铁锰态发生转化。     

石灰、生物炭配施硅/多元素叶面肥对水稻Cd积累的影响

为探明钝化剂配合叶面肥对水稻Cd积累的影响,在浙江典型Cd污染稻田,采用小区试验方式分析了对照（CK）、石灰4 500 kg/hm²（LM）、石灰+生物炭1：1混施9 000 kg/hm²（LC）3种模式基础上喷施含Si和多元素（DYS）叶面肥对水稻植株Cd积累的影响。结果表明：与CK相比,LM和LC处理糙米Cd含量分别降低70.1%和88.3%;LM配施含Si和DYS叶面肥使糙米Cd含量进一步降低45.3%和28.9%;LC配施含Si和DYS叶面肥则使糙米Cd含量进一步降低14.5%和13.7%。与LM和LC相比,加喷叶面肥使茎秆—稻谷Cd转运降低42.4%~62.7%,茎秆Cd浓度增加81.9%~123.0%,稻谷Cd浓度降低14.6%~64.2%。与CK相比,LC和LM处理显著提高土壤pH,降低土壤DTPA提取态Cd,且LC处理效果更好;LC处理使壤微生物碳、有机质、脲酶和蔗糖酶活性分别增加6.08%,7.92%,11.90%和0.72%,而LM则分别降低8.33%,14.30%,29.20%和12.10%;LM和LC分别使土壤黏粒含量降低5.73%和4.53%,且LM处理使砂粒含量增加29.70%,粉砂粒含量降低11.70%;LC则使土壤砂粒含量降低1.50%,而粉砂粒含量增加2.17%。综合分析,LC配施含Si或DYS叶面肥能够在有效降低稻米Cd含量的基础上保持土壤质量良性发展。     

防止土法炼锌废渣充填场地重金属污染复垦技术

黔西北赫章县炼锌造成大量的废弃地,土地复垦成为当地面临的主要问题。为大面积的土地复垦提供基础数据,在平整的废渣堆上用0、25和50 kg/m2的碱石灰做隔离层,然后在隔离层上覆以30、45和60 cm的非污染区土壤,共9个处理;选用当地的主要农作物红豆、白菜、玉米和马铃薯进行试验。通过近2 a对红豆、白菜、玉米和马铃薯可食部分和复垦土壤的重金属进行One-Way ANOVA （LSD）分析和富集系数比较得出碱石灰隔离层降低了农作物可食部分的重金属含量;玉米是对重金属富集系数最小的农作物,适合作为土地复垦的首选农作物,而白菜对重金属的富集系数最大,不适合在炼锌区复垦土壤种植;经济有效的碱石灰隔离层厚度为25 kg/m,复垦土壤的厚度为30 cm。     

石灰和硅肥对非污染土壤Cd有效性和花生Cd含量的影响

本文研究了花生盆栽过程中,不同用量石灰及石灰、硅肥配施对非污染土壤有效态Cd和花生籽仁Cd含量的影响。结果表明：（1）在常规施肥条件下,施用石灰及石灰、硅肥配施均能显著提高土壤pH值,同时使得花生叶片细胞膜透性具有降低的趋势;石灰施用量为0.67g·kg-1土时的土壤有效态Cd含量降低了12.6%（显著低于CK）,而石灰、硅肥配施组合对降低土壤有效Cd含量的作用不显著,可能与硅肥中Cd含量较高有关。（2）不同石灰施用量均有降低花生籽仁中Cd含量的趋势,其中石灰施用量为0.67g·kg-1土时花生籽仁Cd含量比CK降低26.1%;但石灰、硅肥配施对降低花生籽仁Cd含量的作用不显著。（3）花生籽仁Cd含量与土壤有效态Cd含量达正相关显著水平,表明土壤Cd有效性是影响花生籽仁Cd含量的主要原因。     

Essential Oils and Antioxidants Derived From Citrus By-Products in Food Protection and Medicine: An Introduction and Review of Recent Literature

After a brief overview of the general production, market value, and uses of citrus by-products, this literature review will focus on the most highly refined “pharmaceutical grade” citrus oils and antioxidants that have been derived from peels or other fruit parts. Citrus oils have been used as a part of the perfume industry and in the practice of alternative medicine for a long time, but now there is a great deal of mainstream food processing and drug industry interest in them owing to the rediscovery or confirmation of some of their beneficial properties, as well their development for entirely new applications. Their roles as antimicrobial, immunomodulatory, and cancer chemopreventive or chemotherapeutic agents appear promising.     

石灰施用对酸性土壤矿物结合有机碳形成的影响

为了解石灰施用对酸性土壤矿物结合有机碳的影响并促进酸性土壤的碳固定,本研究整合已发表的相关研究并在室内设置培养试验探究石灰添加调控酸性红壤矿物结合有机碳形成的可能机制.结果表明:大部分已发表的研究发现石灰添加可以显著促进酸性土壤中矿物结合有机碳的形成.室内控制试验发现石灰添加显著促进了秸秆分解转化为微生物生物量碳,这很...     

Agronomic Implications of the Application of Lime plus Gypsum By‐products to a Hyperdistric Acrisol from Western Spain

Abstract: A laboratory experiment involving the use of leaching columns reproducing the topmost portion of a Hyperdystric Acrisol (FAO 1998 FAO. 1998. World reference base for soil resources, Rome: FAO, ISRIC, and ISSS. (World Soil Resources Report No. 84) [Google Scholar]) or plinthic Palexerult (Soil Survey Staff 2003 Soil Survey Staff. 2003. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys, Washington, D.C.: U.S. Government Printing Office. (Agriculture Handbook No. 436) [Google Scholar]) treated in its Ap horizon with sugar foam wastes and phosphogypsum was conducted. The amendments increased the contents in exchangeable calcium (Ca) of the Ap horizon and, to a lesser extent, also that of the AB horizon. However, the contents in exchangeable magnesium (Mg) and sodium (Na) decreased as much in Ap as they did in AB; by contrast, the potassium (K) content exhibited a less marked decrease. The potassium chloride (KCl)–extractable aluminium (Al) of the Ap horizon was dramatically decreased much more than that of the AB horizon by the amendments. In the soil solution from Ap, the amendments raised the pH and decreased the Al concentration; in that from AB, however, they caused an initial pH decrease, a tendency that reversed as the gypsum was leached and eventually led to the pH exceeding that in the soil solution from control. The first few water extractions exhibited increased Mg concentration. This trend was reversed in the second leaching cycle, where the concentrations of Mg in the amended columns were lower than those in the controls. In the soil solution, the variation of the Ca and sulphate (SO₄ ^2–) concentrations was influenced by the salt‐sorption effect. The total Al content in soil solution from AB increased during the first leaching cycle and then decreased during the second. The amendments decreased the activities of Al³⁺, AlOH⁺², and Al(OH)₂ ⁺ in the Ap horizon and increased those of Al³⁺, AlSO₄ ⁺, Al(SO₄)₂ ^?, and AlF⁺² in the first leaching cycle in the AB horizon. The productivity of the Ap horizon after the treatments was assessed using a wheat crop (T. aestivum, var. ‘Jabato’) in a greenhouse.     

植物篱对石灰土坡耕地理化性质及磷素流失的影响

在三峡库区香溪河流域典型石灰土坡耕地通过修建标准径流小区,设置栀子花(灌木)和黑麦草(草本)植物篱,研究不同类型植物篱对石灰土坡耕地耕层土壤理化性质及磷素流失特征的影响。结果表明:植物篱系统可有效的增加土壤耕层细颗粒含量和减小土壤容重,从而改善土壤分形特征,增强土壤疏通性及含水量,达到增大石灰土坡耕地土壤抗蚀性指数和防治土壤养分流失的目的;2种类型植物篱在不同深度耕层、植物篱带内和带间对石灰土坡耕地理化性质及磷素流失的影响表现出一定的差异性,但总体上差异不显著;土壤耕层黏粒含量与土壤中Ca_8-P、Al-P、Fe-P、O-P和Ca_(10)-P的含量均达到了极显著正相关(r=0.772,0.805,0.603,0.682,0.738),土壤容重与土壤黏粒含量存在显著的负相关关系(r=-0.648),表明植物篱系统是通过对土壤黏粒的有效阻滞和富集,从而减小石灰性土壤容重和磷素的流失,实现改善石灰土坡耕地土壤理化性质和防治农业面源污染的效果。     

长期施肥对砂姜黑土作物产量及土壤物理性质的影响

【目的】保持和提高土壤肥力,提升土壤生产力,是农业持续发展的重要内容。研究无机肥与牛粪、猪粪和小麦秸秆长期配合施用对砂姜黑土作物产量及土物理性质的影响,为培肥改良砂姜黑土、提升砂姜黑土生产力提供理论依据。【方法】利用1982年建立在安徽省蒙城县砂姜黑土上的长期定位试验,分析牛粪、猪粪、秸秆等不同有机物料与无机肥料配施对作物产量、土壤容重和土壤田间持水量的影响,评价有机物料与无机肥配施对砂姜黑土的培肥效果。【结果】长期不施肥处理的小麦、大豆产量持续下降,平均年降低分别为39.0和70.9 kg·hm^-2,25年后产量在极低水平波动。单施无机肥或无机肥与有机物料配施,小麦产量均呈逐年增高的趋势。无机肥和有机物料配施的处理与单施无机肥（NPK）处理相比均表现出增产效果,年均增产率在5%以上。不同有机物料处理间的增产效果是牛粪处理（NPK+CM）优于猪粪处理（NPK+PM）,而猪粪处理优于秸秆处理（NPK+S）。小麦、大豆产量年际间波动幅度较大,长期不施肥处理小麦产量变异系数（CV）最高,增施肥料可以降低CV,有机物料和无机肥配施的处理CV低于单施无机肥处理,牛粪处理CV最小。牛粪、猪粪、秸秆与无机肥料长期配合施用能降低砂姜黑土土壤容重,显著提高土壤田间持水量,小麦、大豆产量与土壤容重呈显著负相关,与土壤田间持水量呈显著正相关,有机物料与无机肥配施可以改善砂姜黑土不良的物理性状。【结论】长期均衡施用无机肥料或有机物料与无机肥配施均能提高土壤肥力水平,小麦产量呈逐年增高的趋势。有机物料与无机肥配施能提高作物产量,降低产量变异,增强产量稳定性,作物高产稳产;能改善砂姜黑土不良的物理性状,提高土壤肥力。有机物料与无机肥配施是安徽省砂姜黑土地区较为适宜的施肥模式。