宜昌市植烟土壤酸化特点与成因分析

[目的]采取措施缓解宜昌市土壤酸化现状,提高烟叶质量.[方法] 对宜昌市植烟土壤1832个土样进行田间调查和土样化验分析,测定其pH值及各种离子含量.[结果]宜昌市植烟土壤徽酸性、强酸性和极强酸性面积已达76.23%,泥质岩土壤与石英质岩土壤下降值相同,土壤pH值与阳离子交换量呈正相关性,土壤酸化早期速效钾增加,后期速效钾含量下降.[结论] 降雨量大,施肥不当及土壤中有效态硫的过高含量是导致土壤酸化的主要原因,施用石灰、施用腐熟有机肥料、施用生理碱性肥料可阻止和减缓土壤酸化.     

脱硫废弃物与有机肥配合对盐碱地的改良效果

[目的] 研究不同施量脱硫废弃物和不同种类有机肥配合施用对盐碱地油菜生长状况的影响.[方法] 在乐都县高庙镇蒲家墩村,采用裂区试验设计,进行盐碱地改良试验.[结果] 脱硫废弃物的不同施量对油菜的生理指标、千粒重、产量影响均未达到显著差异,不同种类有机肥和对照之间对油菜的生理指标、千粒重和产量也没达到显著差异.[结论] 该研究为找到一个适合当地盐碱地的改良方案提供理论依据.     

土壤含水量、容重、光谱反射率之间相伴变化关系研究

[目的]研究土壤含水量变化对容重变化的定量化影响及其与先谱反射率的关系,构建相关模型,为近红外线光谱连续准确监测土壤含水量提供科学依据.[方法]以湖北省黄棕壤、水稻土、潮土为供试土壤,用环刀采样,在土壤脱水干燥过程中,用微型光纤光谱反射仪等连续同步测定土壤质量含水量、容重、土壤体积含水量和光谱反射率的变化.[结果]探讨了土壤含水量-容重变化的关系及相关模型,构建了反映土壤容重变化的土壤体积含水量与土壤光谱反射率的指数关系模型.[结论]所建模型拟合效果好,物理意义明确,形式简单,变量关系清晰.     

施用生物有机肥的土壤养分元素分析

[目的]评价生物有机肥料的环境效应,进一步改善生物有机肥的性能.[方法]施用生物有机肥,研究生物有机肥时土壤氨挥发和土壤氮、磷、钾淋溶的影响.[结果]施用生物有机肥后果园根区域土壤氯挥发损失率减少;与施用化肥相比,氮、磷、钾的淋溶损失率减少.[结论]施用生物有机肥可以减少土壤中氨挥发损失和氮、磷、钾的淋溶损失,增强土壤的保肥性能.     

施肥对潮土养分非匀衡化的土壤修复研究

[目的]研究施肥对不同处理的土壤修复作用.[方法]利用盆栽试验对长期不合理施肥导致土壤养分失衡及生产力下降的土壤进行施肥修复.[结果]试验结果表明:有机、无机肥配合施用是快速修复土壤养分和提高生产力的最佳方法;NP、NPK是既均衡土壤肥力又提高作物产量的无机肥施用方式;对土壤有效磷、氮极度缺乏的土壤,单施磷肥、氮肥效果极显著,其肥效在小麦上与NPK相同.[结论]长期施化肥的土壤对化肥的依赖性更强,停止施肥,玉米产量下降78.6%,小麦产量下降52.8%;而长期施NK和PK肥的土壤,停止施肥反而产量增加,NK处理玉米产量提高112%,小麦产量增加182%,PK处理中玉米产量增加15.1%,小麦产量增加59%;单施有机肥的当季效果不如化肥,但后效明显好于化肥.     

光照强度和温度对三峡水库消落区典型土壤磷释放的影响

[目的]考察3种土壤的释磷量在不同光照和温度下的变化规律.[方法]将采自重庆市涪陵区消落带的沉积物、水稻土、紫色土移至实验室内进行磷释放模拟试验[结果]在不同模拟光照强度下,上覆水总体上偏碱性,pH和总磷均随光照强度的升高而增加.在不同温度下,总体上水体偏碱性,pH随温度的升高而增加,总磷随温度的升高而减小.[结论]光照强度促进土壤微生物把土壤中的有机态磷转化为无机态磷,从而促进内源磷的释放.温度对土壤磷释放的影响主要表现为受温度影响而生长的微生物吸收土壤释放的磷,阻档其进入上覆水中.同一光照强度和温度条件下的土壤释磷量顺序为紫色土>水稻土>沉积物.     

不同配比有机肥和改良剂对土壤理化性质及酶活性的影响

[目的]为快速修复退化土壤提供依据.[方法]以除草剂污染土壤和荒地心土作为材料,利用温室培养试验,研究了不同配比有机肥和改良剂在短期时间内对土壤理化性质及酶活性的影响.[结果]与空白相比,污染土壤的养分和有机质含量经单施改良剂处理后效果不显著,以不同配比的有机肥和改良剂施用于土壤中效果显著提高,土壤的pH值和酶活性经单施改良剂和添加不同配比有机肥+改良剂处理后效果显著提高;而荒地心土养分、有机质含量和酶活性经单施改良剂、混施不同配比的有机肥+改良剂处理后效果均显著提高,土壤的pH值以添加20%有机肥+改良剂处理的效果最为显著.2种土壤的容重均以添加10%和20%有机肥+改良剂处理的效果最为显著.[结论]添加不同配比的有机肥+改良剂可以有效提高土壤的理化性质和酶活性.     

吉林省西部羊草草地土壤类型及土壤质地的微域性特征研究

[目的]为综合研究草原植被的土壤特征以及草原生态的保护与重建提供理论依据.[方法]以吉林省西部地区草原中角碱蓬群落、星星草群落、寸草苔群落、芦苇群落、羊草群落、扁杆蔗草群落、圆叶碱地毛茛群落、鹅绒萎陵菜群落等8个常见"斑块式"植物群落以及光碱斑为研究对象,时其土壤中的可溶性盐离子及土壤机械组成进行研究.[结果]整个养草草地的土壤盐分以苏打为主,且含有一定量碱土金属碳酸盐、少量氯化物及硫酸盐.苏打成分在各个群落中体现出光碱斑>角碱蓬群落>星星草群落>寸草苔群落>芦苇群落>羊草群落>扁杆蔗草群落>圆叶碱地毛茛群落>鹅绒萎陵菜群落的特点,且与土壤中可溶性盐分总量及土壤碱化度变化次序基本一致.[结论]所有土壤都有不同程度的盐碱化现象.     

昌黎县葡萄沟土壤肥力综合评价与对策研究

[目的]研究昌黎县葡萄沟葡萄园的土壤肥力现状,为合理施肥,提高葡萄的产量和品质提供科学依据.[方法]对昌黎县葡萄沟有代表性的葡萄园土壤样品进行理化性状测定和分析,运用修订的内梅罗综合指数法对该地区土壤肥力进行综合评价.[结果]昌黎县葡萄沟土壤pH值偏酸性,容重偏大,有机质含量贫乏,碱解氮含量偏低,速效磷含量丰富,部分葡萄园土壤存在钾素含量偏低,土壤供钾潜力不高的问题,绝大部分土壤处于无盐害的安全区.综合评价结果表明:昌黎县葡萄沟土壤综合肥力系数平均值为1.15,与土壤肥力等级划分指标相比,属三级,土壤肥力一般,其限制因子有有机质、碱解氮、容重、pH值和速效钾.[结论]可通过适量施用石灰,改良土壤酸性;增施有机肥;开展配方施肥,提高化肥利用率等措施提高昌黎县葡萄沟葡萄园土壤肥力.     

施用不同用量钢渣粉对水稻产量和土壤养分的影响

2014年在大田试验条件下,以单施氮磷钾化肥为基准,探讨钢渣粉施用对双季水稻的产量、养分吸收、土壤养分及土壤和稻米中铬含量的影响。结果表明:与单施化肥相比,施用钢渣粉有利于提高早稻产量和促进水稻对硅素养分的吸收,而对晚稻的产量影响较小;可以提高土壤中有效硅的含量和p H值,同时对土壤和稻米中铬含量的影响不大。     

Zinc levels in rice and in soil according to the soil types of Japan, Indonesia, and China

Sustained myocardial ischemia with angina pectoris, electrocardiographic changes and subsequent non-Q-wave infarctions has been reported during percutaneous transluminal rotational atherectomy of complex coronary lesions. The purpose of this study was to evaluate the effect of rotational atherectomy on regional myocardial perfusion as assessed by serial 99mTc-sestamibi SPECT imaging with semiquantitative tracer uptake analysis. METHODS: Twenty-nine consecutive patients with anginal symptoms, complex coronary lesions (all Type B and Type C) and preserved left ventricular function were studied using resting 99mTc-sestamibi SPECT before rotational atherectomy, during and 2 days after the procedure. For semiquantitative computerized analysis, the left ventricular myocardium was divided into 24 regions, and regional perfusion was expressed as percentage of maximal sestamibi uptake. RESULTS: Visual analysis of scintigraphic images revealed transient perfusion defects corresponding to the revascularized vessel in 26 of 29 patients, whereas three patients had no transient hypoperfusion. During rotational atherectomy, perfusion decreased significantly (>2 s.d. below normal mean) in 3.1 +/- 2.4 regions (range 1-10). Perfusion in the territory of the revascularized vessel was 75% +/- 11% at baseline, decreased to 67% +/- 12% during rotational atherectomy (p < 0.001) and normalized again after rotational atherectomy to 78% +/- 8% (p < 0.001). Similarly, perfusion in the region with the maximal reduction decreased from 74% +/- 15% at baseline to 55% +/- 14% (p < 0.001) during the procedure and returned to 74% +/- 16% (p < 0.001) following the intervention. In calcified stenoses, the extent of perfusion defects was larger as compared to noncalcified (4.2 +/- 2.5 versus 2.3 +/- 2.0 regions/patient, p < 0.05). CONCLUSION: During rotational atherectomy, myocardial hypoperfusion occurs. The transient nature of this perfusion defect can be demonstrated and quantified by serial 99mTc SPECT. This model may prove useful to assess the effects of pharmacological approaches to reducing myocardial hypoperfusion during coronary rotational atherectomy.     

Fate and activity of microorganisms introduced into soil

Gastrointestinal (GI) hemorrhage during compromised liver function is known to precipitate portal-systemic encephalopathy (PSE). Hypothetically, the induced hyperammonemia depletes cerebral glutamate pools. To investigate this hypothesis, rats were studied 14 days after portacaval shunt (PCS) or sham surgery (SHAM). Rats received 3 mL bovine erythrocytes or saline at t = 0, 1, 2, and 3h via a previously placed gastrostomy catheter. At t = 0, 2, 4, 6 and 8h arterial blood and at t = 8h cerebral cortex were sampled for determination of ammonia and amino acids. Control rats (NORM) were sampled without previous surgery. Repeated intragastric blood administration increased the already elevated arterial ammonia levels in PCS rats further. This resulted in higher cerebral cortex ammonia and glutamine levels after blood administration. Despite the accumulation of ammonia and glutamine, cerebral cortex glutamate concentrations remained unaltered. Yet, PCS rats became more encephalopathic after blood gavages, suggesting that there is not a clear-cut relation between cerebral cortex glutamate concentrations and degree of PSE. Interestingly, cerebral cortex concentrations of GABA, tyrosine and phenylalanine were markedly increased. Whether these observations are pathogenetically related to PSE remains to be established. The present model of simulated GI hemorrhage in PCS rats seems to be a suitable, clinically valid model for future research regarding hepatic encephalopathy.     

不同植被恢复措施下红壤强度侵蚀区土壤质量的变化

为了探讨生物治理措施对强度红壤侵蚀区土壤质量的影响,对以草促林和乔灌混交2种治理措施下的土壤质量进行比较结果表明:强度红壤侵蚀群落治24a后,土壤的结构、渗透性、蓄水性能、养分特征、微生物性质及其抗侵蚀能力得到了改善,但土壤养分的恢复程度不高,养分的恢复滞后于物理性质的恢复;质量综合指数分析显示,以草促林治理群落的土壤质量综合指数为0.38,恢复程度较低,乔灌混交治理群落达到了0.80,恢复程度较高;2种治理措施下土壤质量的恢复程度差异较大,体现了不同治理措施恢复效果的差异.     

Rapid atrazine mineralisation in soil slurry and moist soil by inoculation of an atrazine-degrading Pseudomonas sp. strain

The evaluation of pesticide-mineralising microorganisms to clean-up contaminated soils was studied with the widely applied and easily detectable compound atrazine, which is rapidly mineralised by several microorganisms including the Pseudomonas sp. strain Yaya 6. The rate of atrazine removal was proportional to the water content of the soil and the amount of bacteria added to the soil. In soil slurry, 6 mg atrazine kg soil-1 was eliminated within 1 day after application of 0.3 g dry weight inoculant biomass kg soil-1 and within 5 days when 0.003 g kg soil-1 was used. In partially saturated soil (60% of the maximal water-holding capacity) 15 mg atrazine kg soil-1 was used. In unsaturated soil, about 60% [U-ring-14C] atrazine was converted to 14CO2 within 14 days. Atrazine was very efficiently removed by the inoculant biomass, not only in soil that was freshly contaminated but also in soil aged with atrazine for up to 260 days. The bacteria exposed to atrazine in unsaturated sterile soil were still active after starvation period of 240 days: 15 mg newly added atrazine kg soil-1 was eliminated within 5 days.     

钨矿区砷污染与土壤微生物及酶活性相关性研究

通过野外采样及室内分析,研究赣南钨矿区的砷污染状况,土壤砷含量和形态对土壤微生物群落以及土壤酶活性的影响．结果表明:钨矿区土壤中砷全量及有效量均显著高于非矿区土壤,矿区土壤中砷以铁锰氧化物结合态为主,生物可给性强的可交换态砷占9.8 %~12 %,尾矿砂中砷以残渣态为主（39.7 %）,交换态砷占16.6 %.矿区土壤砷总量、可利用态砷对矿区土壤微生物数量的影响也呈现负相关,微生物类群对矿区污染的敏感性大小表现为:细菌＞放线菌＞真菌.矿区土壤脲酶、过氧化氢酶、蔗糖酶活性均受到砷污染的抑制,通过相关性分析得出,脲酶活性可以较好的指示钨矿区土壤砷污染程度.钨矿区土壤中微生物区系组成数量及土壤酶活性在一定程度上可反映该矿区砷污染特征.      

某冲积区土壤重金属的分析及评价

为了研究冲积区土壤重金属的累积特征,通过对研究区土壤样品分析,采用地质累积指数法、单项污染指数法和综合污染指数法进行了计算及评价。其计算结果表明,该研究区有20%的土壤重金属累积特征明显,铅有不同程度的累积。其评价结果表明,主要污染元素为汞,其次为铅。     

土壤环境保护与治理策略的研究

紧跟着我国社会主义经济的飞速进步,我国国民的生活品质也获得了飞跃性的提升,但是大部分国民也察觉到身边的生态环境遭受了十分严重的污染和破坏,随着国民对于生态环境重视程度的加深,对生态环境开展保护工作成为了现阶段有关环保机构以及管理部门最重要的工作之一。简单来说,这和我国民生建设的进步过程有着十分紧密的联系,其次也和国民的身体健康有着不可或缺的关系。所以,有关的部门和工作人员要及时增强对土壤环境污染的治理力度。而本篇文章就主要对现阶段的土壤污染困境进行了简单的阐述,并且根据其中出现的部分困境,提出了一系列具有针对性的解决措施,从而在一定程度上促进我国农业以及其余领域的健康发展。