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1.
采用人工土壤法测定了不同浓度莫能菌素对蚯蚓的急性毒性和对蚯蚓生长、生存、繁殖以及超氧化物歧化酶（SOD）、谷胱甘肽-硫转移酶（GSH-S）、腺三磷酸酶（ATPase）、乙酰胆碱酯酶（T-CHE）活性的影响。结果表明,莫能菌素对蚯蚓14d的LC50为75.883mg·kg-1;当莫能菌素含量达到50mg·kg-1时显著影响蚯蚓的生存（P〈0.05）,死亡率达到20%;当莫能菌素含量达到25mg·kg-1时显著影响蚯蚓的生长（P〈0.05）;药物的染毒浓度与对蚯蚓生存和繁殖的抑制存在明显的剂量-效应关系。染毒21d后,低浓度的兽药莫能菌素就能显著影响蚯蚓体内SOD、GSH-S、ATPase、T-CHE的活性,药物浓度和酶活性间具有明显的剂量-效应关系。莫能菌素对土壤动物蚯蚓显示有毒性作用,对土壤环境具有潜在的生态风险。 相似文献
2.
以皮质远盲蚓（Amynthas corticis）为试验生物,采用一次、叠加的污染方式,研究了毒死蜱在土壤中的残留、蚯蚓体内的累积特征及对蚯蚓生长的影响。结果显示:相同实验浓度条件下,以叠加污染方式进入土壤的毒死蜱残留量低于一次污染方式的残留量。当土壤毒死蜱浓度为12 ~ 20 mg kg?1,暴露55 d时,一次污染条件下,蚯蚓体内毒死蜱蓄积量为3.73 ~ 8.84 mg kg?1,生物－土壤蓄积因子（FBSA）为1.55 ~ 1.70;叠加污染条件下,蚯蚓毒死蜱蓄积量为5.21 ~ 11.04 mg kg?1,FBSA为2.22 ~ 2.46。相同实验浓度条件下,叠加污染方式进入土壤的毒死蜱对蚯蚓的生长抑制显著高于一次污染处理组。该研究结果可为土壤毒死蜱生物毒性和生态风险评价提供基础数据。 相似文献
3.
通过恒温培养试验研究了水溶性高分子材料聚乙烯醇、聚乙二醇和聚丙烯酰胺对P肥(Ca(H2PO4)2)在土壤中有效性的影响.结果表明:水溶性高分子材料改变了P在土壤中的吸附过程.添加聚乙烯醇和聚乙二醇的土壤pH和水溶性P含量随培养时间增加而降低;前者的土壤Olsen P含量随培养时间增加先降低后升高,后者的土壤Olsen P含量则较为恒定,为P 52mg/kg.添加聚丙烯酰胺的土壤水溶性P和Olsen P含量均随培养时间增加而增加,至培养60天时,水溶性P和Olsen P含量分别为P 0.62、60.01 mg/kg;pH变化不显著,约为4.74. 相似文献
4.
聚丙烯酰胺对几种植物种子萌发及生长的影响 总被引：2，自引：0，他引：2
用不同浓度聚丙烯酰胺溶液处理苜蓿、狗尾草、沙棘等8种草本、灌木植物发芽试验结果表明,聚丙烯酰胺溶液浓度为0.1-1.0g/kg时,对鸡眼草、沙棘、苜蓿、草木樨种子萌发有促进作用,对其幼苗苗高、根长的影响除个别有较小抑制作用外,均表现促进作用。当溶液浓度为0.5g/kg时,对兴安胡枝子种子幼苗的根系生长则表现出显著抑制作用,而对荆条种子萌发表现出极显著抑制作用。聚丙烯酰胺各处理浓度均对黄白草、狗尾草萌发表现出极显著或显著抑制作用,而对其幼苗苗高、根长表现出显著促进或较小的抑制作用。 相似文献
5.
《中国生态农业学报》2021,(10)
为解决土壤重金属污染问题,纳米零价铁(nZVI)被广泛应用且备受关注,而nZVI对土壤无脊椎动物、土壤质量、微生物群落等的潜在影响缺乏系统的研究。本文以赤子爱胜蚓(Eisenia foetida)[蚯蚓密度为0、10条?kg-1(土)]为研究对象,探讨不同浓度nZVI (nZVI土壤质量为0、0.05%、0.25%和0.50%)暴露15 d、30 d和45 d后,蚯蚓-微生物-土壤生态系统的响应,为评价nZVI的环境安全性提供参考。结果表明,暴露45 d后, nZVI对蚯蚓存活率和生物量无显著影响, 0.50%nZVI处理的蚯蚓存活率和体内MDA含量与15 d相比分别降低27.66%和0.86 nmol?g-1;而蚯蚓生物量和CAT活性分别增加1.20倍和2.62倍。门或属水平下, nZVI对土壤微生物相对丰度、多样性指数和丰度指数无显著影响;与无添加nZVI处理相比,蚯蚓介导下0.50%nZVI处理土壤中大团聚体(250μm)所占比例、团聚体平均重量直径和速效磷含量分别显著升高15.69%、12.59%和21.20%。蚯蚓介导下nZVI处理中土壤大团聚体所占比例、团聚体平均重量直径显著高于无蚯蚓投加的nZVI处理,可见, nZVI胁迫下蚯蚓活动极显著提高土壤团聚体结构的稳定性(P0.01)。本研究发现长期暴露nZVI对土壤微生物群落特征无显著影响,但可以促进蚯蚓的生长,从而进一步提高了土壤营养元素的生物有效性,为nZVI应用于污染修复与治理的环境安全性评估提供了科学依据。 相似文献
6.
研究把过磷酸钙、硫酸钾、氯化钾作为蚯蚓的饲料添加剂,对蚯蚓生长及蚓粪肥效的影响。试验显示过磷酸钙、硫酸钾、氯化钾都可以作为蚯蚓的饲料添加剂。其中在蚯蚓生存、繁殖和蚓粪肥效这三方面考核上,过磷酸钙添加量都以0.75 mg.kg-1(以P2O5计)效果最好;硫酸钾也是以0.75 mg.kg-1(以K2O计)效果最好;而氯化钾则以0.50 mg.kg-1(以K2O计)效果最好。但添加量过多都会对蚯蚓产生毒害,当过磷酸钙添加量达到2.0 mg.kg-1,硫酸钾添加量达到2.0 mg.kg-1或氯化钾达到0.75 mg.kg-1时,蚯蚓存活量或繁殖量为负值(相对于对照而言)。对于氯化钾而言,2.0 mg.kg-1是蚯蚓的致死量。蚯蚓生长好的蚓粪可以促进菠菜早发芽,提高发芽率。 相似文献
7.
拟除虫菊酯作为全球第三大杀虫剂品种，在农业生产中广泛使用，同时也带来了一系列不利的环境影响。然而，目前有关拟除虫菊酯在土壤环境中的残留行为和风险评估报道较少。以典型拟除虫菊酯类杀虫剂甲氰菊酯(FEN)为研究对象，重点探究其在不同性质土壤中的降解行为以及对典型土壤生物蚯蚓的毒性效应。结果表明，甲氰菊酯在碱性土壤中的降解速度快于酸性土壤，同时在非灭菌土壤中的降解速度为灭菌土壤的4倍。因此，土壤酸碱度和微生物是影响FEN在土壤中降解快慢的主要因素。此外，在降解过程中检测到甲氰菊酯主要代谢物3-苯氧基苯甲酸(3-PBA)的生成。蚯蚓富集结果表明，FEN在蚯蚓体内的含量先升高后降低，最大生物富集因子为0.3。亚急性毒性结果表明，高剂量（5 mg?kg-1）甲氰菊酯暴露14 d后，蚯蚓体内蛋白质含量显著降低（P<0.05），细胞色素P450（CYP450）、羧酸酯酶（CarE）、谷胱甘肽-S-转移酶（GST）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性和丙二醛（MDA）含量均显著增加（P<0.05），同时存在剂量效应，证实土壤中残留的FEN对蚯蚓具有毒性效应。本文对甲氰菊酯在土壤环境中的降解行为研究以及生态毒性风险评估具有重要的指导意义。 相似文献
8.
铜和草甘膦对蚯蚓的毒性效应研究 总被引：3，自引：1，他引：2
污染物的交互作用及其生态毒理效应已成为环境科学研究的主要方向。含铜杀菌剂与除草剂草甘膦[N-(膦酸甲基)甘氨酸]是农业生产中常见的农药,其在土壤中共存可能造成复合污染。草甘膦中含有羧基、氨基、磷酸基等配位基团对重金属阳离子和有机阳离子有很强的络合能力,草甘膦可以影响重金属的生物有效性、毒性以及重金属在生物体内的积累。本文以赤子爱胜蚓(Eisenia fetida)为例,采用室内模拟试验,单一试验设置5个铜浓度25 mg·kg-1、50 mg·kg-1、100 mg·kg-1、200 mg·kg-1和400 mg·kg-1,5个草甘膦浓度25mg·kg-1、50 mg·kg-1、100 mg·kg-1、200 mg·kg-1和500 mg·kg-1,并以去离子水做空白对照;复合试验设置2个铜浓度(低铜浓度25 mg·kg-1和高铜浓度200 mg·kg-1)分别与5个草甘膦浓度(0、25 mg·kg-1、50 mg·kg-1、100 mg·kg-1和200 mg·kg-1)复合;每个处理3次重复,试验期为35 d。研究了铜和草甘膦的单一及复合施用对蚯蚓的亚急性毒性效应。单一毒性试验结果表明,蚯蚓对低浓度铜的响应不敏感,而较高浓度铜使蚯蚓生物量的相对增长率受到显著抑制(α=0.01,r2=0.570),且未出现死亡,并且随着铜浓度的增加蚯蚓体内铜含量显著增加(α=0.01,r2=0.905)。与对照相比草甘膦的添加对蚯蚓的生长无显著影响。复合毒性试验结果表明,草甘膦和铜复合可以降低蚯蚓对铜的吸收,特别是当铜浓度较高时即200 mg·kg-1,草甘膦和铜复合可显著降低蚯蚓对铜的吸收,并且草甘膦能够减轻铜对蚯蚓生物量相对增长率的抑制,但差异并不显著。以上结果表明,铜比草甘膦的毒性大很多,铜与草甘膦复合能够减少蚯蚓对铜的吸收,缓解铜的毒性。因此本研究认为,在草甘膦和重金属共存的污染土壤中,草甘膦能够控制重金属的生物有效性和毒性。 相似文献
9.
通过研究三种不同森林土壤中蚯蚓对莠去津暴露的响应，为莠去津在林业上的科学使用和保护生态环境提供科学依据。采用室内实验的方法研究三种不同类型的森林土壤中莠去津对蚯蚓的影响，以40、80、160、320、480 mg/kg作为暴露浓度，暴露后于第0天，第7天，第14天，第21天，第28天，第35天分别测定土壤中蚯蚓鲜重和死亡率，于第0天和第35天测定土壤中蚯蚓体宽。结果表明，三种森林土壤中莠去津暴露浓度越高，暴露时间越长，对蚯蚓致死效应越强，对蚯蚓鲜重和体宽的抑制效应也越强，呈明显的时间-效应关系和剂量-效应关系。暴露浓度相同时，三种土壤中莠去津对蚯蚓死亡率、鲜重和体重的影响均表现为黄棕壤>雏形土>石灰土。莠去津对蚯蚓的毒性效应与土壤中有机质的含量之间具有明显负相关性，与全磷和有效磷的含量之间具有明显正相关性。研究结果揭示不同类型土壤中莠去津对蚯蚓的毒性作用具有明显差异，且与土壤的肥力具有显著相关性，其可为评估莠去津在农林业上使用的环境风险提供基础参考数据。 相似文献
10.
能源植物荻对铜胁迫的耐性和积累特性 总被引：1，自引：0，他引：1
通过盆栽试验研究不同Cu2+浓度(0,200,400,800,1 600,3 200 mg/kg)和不同时间(50 d和120 d)铜胁迫对荻叶片生理指标、植株生长及Cu积累特征的影响.结果表明:(1)不同生长期荻叶片的O2 产生速率、MDA含量和质膜透性均随Cu胁迫浓度的升高而增大,当Cu≥1 600mg/kg时,与对照相比三者均显著上升(P＜0.05).(2)脯氨酸和可溶性糖含量总体呈先升后降趋势.(3)荻叶片中的SOD、POD及CAT活性随Cu浓度的增加呈先升后降趋势,当Cu≥1 600 mg/kg时,与对照相比酶活性均显著下降(P＜0.05).(4)当Cu≤800 mg/kg时,光合色素含量与对照之间均无显著性差异(P＞0.05),荻的生长也未受到明显影响(P＞0.05);当Cu≥1 600mg/kg时,光合色素含量显著下降(P＜0.05),其生长受到明显抑制(P＜0.05).(5)荻对Cu的积累能力较强且主要分部在地下部,其将Cu运输到地上部的能力较弱.研究表明,荻不是Cu的超积累植物,但是对Cu具有较强的耐性和稳定化能力,在Cu污染土壤修复方面有一定的应用潜力. 相似文献
11.
PAM与不同土壤调理剂混合施用对降雨入渗和土壤侵蚀的影响 总被引：3，自引：2，他引：1
土壤中施用聚丙烯酰胺(PAM)可以提高降雨入渗率,减少土壤侵蚀量。PAM大多施用于土壤表面。为了研究PAM与不同土壤调理剂混合施用对入渗率和侵蚀量的影响,对PAM(22.5kg/hm2)与保水剂(45kg/hm2)、粉煤灰(1 500kg/hm2)、腐殖酸(900kg/hm2)混合的6种施用方法进行了试验。结果表明,施加了PAM的土壤调理剂均能显著提高降雨入渗率和减少土壤侵蚀量。与对照相比,施加了PAM处理的降雨入渗率较对照试验提高了1.8～2.7倍,土壤侵蚀量减少约50%～70%,PAM与粉煤灰和腐殖酸混合施用提高降雨入渗率效果最为显著,PAM和保水剂混合施用减少土壤侵蚀量最多,PAM与粉煤灰和腐殖酸混合施用相比单独施用PAM均没有显著性差异。综合比较结果发现,PAM与粉煤灰混合施用增加降雨入渗率和减少径流的效果最好,PAM与保水剂混合施用抗土壤侵蚀效果最好。 相似文献
12.
Short‐term effects of polyacrylamide and dicyandiamide on C and N mineralization in a sandy loam soil 
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下载免费PDF全文 C. Watson Y. Singh T. Iqbal C. Knoblauch P. Simon F. Wichern 《Soil Use and Management》2016,32(1):127-136
The soil conditioners anionic polyacrylamide (PAM) and dicyandiamide (DCD) are frequently applied to soils to reduce soil erosion and nitrogen loss, respectively. A 27‐day incubation study was set up to gauge their interactive effects on the microbial biomass, carbon (C) mineralization and nitrification activity of a sandy loam soil in the presence or absence of maize straw. PAM‐amended soils received 308 or 615 mg PAM/kg. Nitrogen (N)‐fertilized soils were amended with 1800 mg/kg ammonium sulphate [(NH4)2SO4], with or without 70 mg DCD/kg. Maize straw was added to soil at the rate of 4500 mg/kg. Maize straw application increased soil microbial biomass and respiration. PAM stimulated nitrification and C mineralization, as evidenced by significant increases in extractable nitrate and evolved carbon dioxide (CO2) concentrations. This is likely to have been effected by the PAM improving microbial conditions and partially being utilized as a substrate, with the latter being indicated by a PAM‐induced significant increase in the metabolic quotient. PAM did not reduce the microbial biomass except in one treatment at the highest application rate. Ammonium sulphate stimulated nitrification and reduced microbial biomass; the resultant acidification of the former is likely to have caused these effects. N fertilizer application may also have induced short‐term C‐limitation in the soil with impacts on microbial growth and respiration. The nitrification inhibitor DCD reduced the negative impacts on microbial biomass of (NH4)2SO4 and proved to be an effective soil amendment to reduce nitrification under conditions where mineralization was increased by addition of PAM. 相似文献
13.
Background, Aims and Scope Endpoints in earthworm ecotoxicology scheduled in guidelines are mortality and reproduction rates. However, not only the direct
influence of pollutants on population parameters but also changes in behaviour such as substrate avoidance can have an important
impact on soil ecosystems. In practice two different avoidance response tests are applied in earthworm ecotoxicology: (i)
a six-chamber test system and (ii) a two-chamber test system. Both avoidance response-test systems were compared to establish
their respective advantages and disadvantages in order to advance the standardisation of behavioural tests. The earthworm
avoidance-response tests were applied in addition to the standard acute and chronic earthworm toxicity tests (ISO 11268) in
order to compare the sensitivity of the test endpoints.
Methods Test substrates were contaminated with crude oil and 2,4,6-Trinitrotoluene (TNT), respectively. The test species wasEisenia fetida. The earthworms were exposed to the contaminated substrates and their mortality (14 d), reproduction rates (number of cocoons
after 28 d, juvenile hatching after 56 d), and substrate preference (48 h) determined.
Results and Discussion Whereas 1000 mg/kg TPH (Total Petroleum Hydrocarbons) did not show any lethal effects, 100% mortality occurred in soil with
comparable TNT concentration. The acute tests consistently produced the highest effect concentrations whereas reproduction
and substrate avoidance were the more sensitive test parameters. Both behavioural test systems, when compared, showed similar
substrate avoidance after an incubation time of 48 h. The six-chamber test system provides the potential to test six different
substrates/concentrations at one time. It was observed, however, that earthworms did not migrate among all test chambers within
a test unit in order to select the most appropriate substrate. Orientation was observed only between directly neighbouring
test compartments, which complicates the interpretation of the test results.
Conclusion Substrate avoidance and reproduction variables were clearly more sensitive test endpoints than mortality. Therefore avoidance-response
tests proved to be useful test methods in detecting effects of sublethal concentrations of pollutants on earthworms. The test
duration of the avoidance tests is much shorter compared to the standard acute and chronic earthworm toxicity tests, which
makes them a quick screening tool for identifying potential soil toxicity. Both avoidance-response test systems showed comparable
results regarding the test sensitivity. Nonetheless, the incomplete substrate use in the six-chamber avoidance test due to
the reduced migration possibilities (orientation only to neighbouring chambers) might reduce the distinctness of test results
as it allows only reliable information on the most avoided and therefore most toxic substrate but not on 1 a clear dose-response
pattern. Thus, to gain valid results, the number of replicates and the arrangement of the different substrates must be adopted.
The two-chamber test system is less time-consuming due to easy handling and test results can be quantified more easily.
Recommendations and Outlook In consequence of the better validity of test results, lower expenses for test containers and less time for handling, the
use of the two-chamber system is preferred over the six-chamber test system to assess the toxicity of polluted soil. Because
of the ecosystem consequences of behavioural effects and the fact that avoidance response tests can reveal the toxic potential
of pollutants in low concentrations, such tests should be included into ecotoxicological test protocols. 相似文献
14.
Enhancing the P trapping of pasture filter strips: successes and pitfalls in the use of water supply residue and polyacrylamide 总被引：1，自引：0，他引：1
In intensive pastoral systems the landscape at ground level is clad in dense, filtering vegetation – yet phosphorus losses in overland flow do occur, and pollution of surface waters is a serious consequence. The use of pre‐applied polyacrylamide (PAM) or chitosan to trap particulate phosphorus (PP) and P‐sorbing potable water treatment alum residue (PWTR) to enhance vegetative filtering effects is examined here using field and laboratory overland flow simulation (flows from 0.43 to 0.34 litres s?1 (m width)?1) and analysis. Fitted equations suggest that up to 40% of dissolved reactive P applied (0.75 mg P litre?1) in overland flow could be captured in a flow length of 2.1 m (1 kg PWTR m?2). Unfortunately, drying decreased PWTR effectiveness, though little of the P captured was readily desorbed. This effect did not appear to be the result of gibbsite formation. Compared with the other treatments, there was a strong treatment effect of pre‐applied PAM on the change in PP losses (P < 0.001) over time, though evidence suggests the PAM effect declined during a 44 minute flow period. We showed that the investigated two‐pronged approach to the enhancement of the effectiveness of P trapping by pasture had limitations. Laboratory sheet‐flow simulations suggest that a field‐stable P sorber with sorption characteristics similar to those of the un‐dried PWTR could be an effective retention enhancer for dissolved P. Pre‐applied PAM can have an effect on particulate‐P trapping but was rapidly dissolved and removed by flow. 相似文献
15.
采用人工土壤法，研究重金属镉(Cd2+)对成熟赤子爱胜蚓（Eisenia fetida）的急性毒性,表明蚯蚓对镉具有较强的耐受性。Trizol法提取蚯蚓RNA后，采用Clontech公司的CreatorTM SMARTTM cDNA文库构建试剂盒，成功构建了低剂量Cd2+（200 mg•kg-1）诱导的蚯蚓cDNA文库，其库容量为3.02×105 pfu/mL,扩增后滴度为8.67×109 pfu/mL，重组率为97.3％, 绝大多数的cDNA插入片段≥0•5 kb,平均长度≈1•0 kb。所够建的cDNA质粒文库容量及插入片段大小符合合格文库要求, 为进一步筛选蚯蚓体内解毒、免疫相关基因，寻找生物标志物奠定了基础。 相似文献
16.
《Land Degradation \u0026amp; Development》2017,28(7):2245-2254
Anionic polyacrylamide (PAM) can prevent soil erosion, but its effect on fine particulate phosphorus (P), such as colloidal P, has not been thoroughly examined. The effects of PAM on the release potentials of water‐dispersible colloids (WDC) and total P, molybdenum‐reactive P (MRP), and molybdenum‐unreactive P (MUP) in the colloidal and truly dissolved phases (i.e., TPcoll, MRPcoll, MUPcoll, TPtruly, MRPtruly, and MUPtruly) from six soils across South China were tested in this study. The results showed that the release potentials of TPcoll in the control treatments were 6·9–46·1 mg kg−1 and generally highest in sandy loam soil. Following low (12·5 kg ha−1), middle (25 kg ha−1), and high (50 kg ha−1) levels of PAM application, the release potential of TPcoll decreased by 41·7, 63·2, and 77·4% compared to the control group, respectively. Additionally, PAM may trigger MRPcoll and TPtruly releases in sandy loam and/or silt soils, and for most soils, MRPtruly and MUPtruly showed the highest release potentials at middle or high PAM levels. A significant PAM application level by soil site interaction for the release potentials of WDC and colloidal P was observed. Multiple linear regression showed that the PAM rate combined with soil sand content can successfully predict the release potentials of WDC (R2 = 0·552, p < 0·001) and TPcoll (R2 = 0·738, p < 0·001). Our results suggest that PAM can effectively reduce the loss of soil colloids and colloidal P, while its effects are related to both application level and soil texture. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
17.
Nidal H. Abu-Hamdeh Saleh M. Ismail Randa I. Hatamleh 《Archives of Agronomy and Soil Science》2019,65(2):182-196
A field study was performed for two consecutive seasons to evaluate the effect of polyacrylamide (PAM), tillage systems and particle size on soil physical properties and wheat grain yield. The PAM rates were 0, 10 and 20 kg ha?1 while the tillage treatments included no-tillage (NT), moldboard plowing (CT1), and chisel plowing (CT2). Soil fine particles size of two locations were A (25.2 silt + clay) and B (38.5 silt + clay). Location B reported higher organic matter and total porosity while lower in bulk density. The CT1 and NT treatments denoted better soil organic matter percentage. The CT1 presented maximum infiltration rate compared to other tillage systems. No tillage showed better soil water contents while the minimum was in CT1 of location A and CT2 of location B. Increasing the PAM rate increased total porosity, infiltration rate and soil water content while decreased soil bulk density. Possibly, the presence of compacted layer in location A hindered the effect of PAM. At location B, the CT2 with PAM of 20 kg ha?1 had the highest grain yield compared to other tillage systems. The PAM is beneficial for soil and water conservation and can be used in agriculture. 相似文献
18.
高分子多肽衍生物防治风蚀的风洞试验 总被引：2，自引：1，他引：1
利用高分子化学材料改善地表结构进行化学固沙,是防治风蚀的重要措施之一。为寻找有效的高分子化学材料防治黄土高原北部水蚀风蚀交错区风积沙及沙黄土风蚀,将不同剂量(0(喷清水为对照)、0.4、0.6及1.2 g/m~2)的4种高分子化学材料聚丙烯酰胺(polyacrylamide,PAM)、阳离子羟丙基多糖(cationic hydroxypropyl quito sugar,Jag C162)、羧甲基纤维素(carboxymethyl cellulose,CMC)及羟丙基化多糖(hydroxypropyl polysaccharide,HP-120)喷施于沙黄土及风积沙表面,进行室内风洞试验,测定其风蚀率及表面固积层硬度。结果表明:喷施不同剂量的高分子化学材料PAM、Jag C162、CMC及HP-120于沙黄土及风积沙表面均能显著降低松散扰动沙黄土及风积沙的风蚀率(P0.05)。总体而言,在相同条件下,与其他3种材料相比,PAM防治沙黄土表面风蚀的效果最好,而CMC在防治风积沙风蚀效果最好。喷施4种化学材料于沙黄土和风积沙表面均能显著增加固结层的硬度(0.4 g/m~2 Jag C162除外),且PAM对提高沙黄土表面硬度效果较好,Jag C162、CMC及HP-120对提高风积沙结皮硬度效果较好,其中CMC效果最显著;使用4种高分子化学材料防治风积沙和沙黄土风蚀时,当施用剂量控制在1.2 g/m~2时,几乎可以抵御14 m/s的大风,历时20 min的吹蚀而不产生风蚀。 相似文献
19.
我国主要低产水稻冷浸田养分障碍因子特征分析 总被引：20，自引：0，他引：20
研究我国冷浸田主要分布的7个省份冷浸田土壤样品的养分特征,通过与当地高产田土壤养分特征比较发现:我国冷浸田土壤中有机质含量(13.76～21.52g/kg)和全磷含量(2.78～11.36g/kg)总体高于高产田,部分差异显著(P<0.05);全氮含量(1.39～2.24g/kg)总体略高于高产田,但差异不显著(P<0.05);有效锌含量(4.92～11.03mg/kg)总体高于高产田的含量,且差异显著(P<0.05),表明我国冷浸田的潜在生产力比较高。但是,与高产田相比,我国冷浸田土壤pH值显著偏低(4.47～5.32),致毒因子还原态硫含量(296.12～3 069.33mg/kg)和亚铁含量(160.28～3 786.12mg/kg)却显著偏高(P<0.05),同时,部分地区冷浸田土壤速效磷(1.90～30.20mg/kg)和速效钾(1.30～111.70mg/kg)养分显著缺失(P<0.05),表明这几种养分指标是影响我国冷浸田生产力的重要障碍因子,因此,只要有针对性的改良上述冷浸田养分障碍因子,其必将成为我国粮食生产的巨大战略资源。 相似文献