pH值和外加汞浓度对汞在棕土中的吸附-解吸动力学特征的影响

用平衡液吸附和Ca(NO3)2溶液的解吸法,对棕土在pH3-6.5,汞浓度0.2-8mg·kg-1的吸附-解吸动力学进行了研究,以阐明pH和初始浓度对汞有效性的影响。结果表明,pH6.5,浓度8mg·kg-1条件下,60min即可达到汞最大吸附量的93%;10000min达最大解吸量的78.8%。解吸汞占吸附汞的比例随pH升高而升高,在浓度2mg·kg-1,pH3-6.5下,棕土解吸汞占吸附汞的比例为11%-37.4%。Freundlich方程为描述汞吸附-解吸动力学特征的最优模型,其次为Elovich方程。模拟的最大吸附量达84.3mg·kg-1,在此以下,汞的吸附容量随外加汞浓度、时间的递增而升高。解吸速率随初始浓度增加而增加,随解吸时间的延长不断降低。这些结果表明,pH和外加汞浓度影响汞在棕土中的吸附-解吸动力学特征,从而影响在土壤介质中的迁移。

太白山北坡垂直带土壤发生特性与分类──腐棕土

太白山北坡亚高山寒带湿润气候、草甸植被下发育的土壤是土壤垂直带谱中非常重要的组成部分。研究结果表明：此带土壤腐殖质特性明显，淋溶强烈，呈酸性；剖面发育较差，风化度低，粘化作用微弱，具硅铝特性；氧化铁的游离度低，活化度高，潜在移动性大。该带土壤属于系统分类中的腐棕土土类，其中发育在亚高山灌丛草甸的为普通腐棕土，发育在亚高山禾草草甸的为不饱和腐棕土。

人工种植红豆草对灰棕荒漠土改土效应的研究

在甘肃河西走廊的灰棕荒漠土上,进行了人工种植红豆草对灰棕荒漠土改土效应的研究,结果表明：3年生红豆草鲜草产量64.50 t/hm2,折干草22.57 t/hm2,产值为1.47万元/hm2;与CK比较,0～20 cm耕层田间持水量、团聚体、总孔隙度分别增加12.05%、18.33%和15.47%,容重、pH分别降低0.41 g/cm3和0.70,全盐由5.15g/kg降低到2.19g/kg,脱盐率达到57.48%;有机质,速效N、P、K亦随之增加.

不同有机废弃物组合肥对灰棕荒漠土理化性质和玉米产量及经济效益的影响

系统研究了4种不同有机废弃物组合肥对灰棕荒漠土理化性质和玉米产量及经济效益的影响,结果表明:有机废弃物糠醛渣、羊粪、玉米秸秆、菜籽饼按0.50∶0.25∶0.20∶0.05容积比,经高温发酵处理,施用量为45.00t/hm2对灰棕荒漠土理化性质和玉米产量及经济效益有良好的影响,与不施有机废弃物(对照)比较,土壤总孔隙度、团粒结构、贮水量分别增加8.69%、8.73%、91.36 m3/hm2;土壤有机质、碱解N、速效P、速效K、CEC分别增加5.86 g/kg2、1.42 mg/kg7、.47 mg/kg4、2.67 mg/kg1、3.07 cmol/kg;玉米产量、产值、利润分别增加2.03 t/hm2、0.19×104元/hm2、0.08×104元/hm2;土壤容重降低0.28 g/cm3。灰棕荒漠土上施用生活垃圾,重金属离子有富集的趋势,而长期施用糠醛渣、蘑菇渣、锯末则无此效应。

“固废覆绿,棕土新生”生活垃圾填埋场环境再生解读——以鹰潭市生活垃圾填埋场生态封场项目为例

本文以鹰潭市生活垃圾填埋场封场后生态绿地恢复为切入点,从空间、生态、景观的角度诠释了“固废覆绿,棕土再生”的有力途径,深入了解生活垃圾填埋场封场后及生态恢复的关键步骤;剖析在封场再生中,环境污染的治理与风景园林的重生之路。

有机营养功能型土壤改良剂对灰棕荒漠土的改良效果

[目的]进行有机营养功能型土壤改良剂配方筛选,研究灰棕荒漠土改良效果和杂交饲用甜高粱经济效益,解决灰棕荒漠土保水、保肥能力弱,有机质含量低,作物产量低而不稳的瓶颈问题。[方法]选择甘肃省酒泉市肃州区的灰棕荒漠土,采用田间试验的方法进行研究。[结果]不同梯度有机营养功能型土壤改良剂施用量与灰棕荒漠土孔隙度、团聚体、持水量、有机质、速效氮磷钾、杂交饲用甜高粱经济性状和产量呈正相关关系,与灰棕荒漠土容重和pH值呈负相关关系。施用有机营养功能型土壤改良剂与施用传统化肥比较,灰棕荒漠土容重和pH值分别降低4.10%和8.27%;总孔隙度、毛管孔隙度、非毛管孔隙度、总持水量、毛管持水量和非毛管持水量分别增加3.63%,3.60%,3.67%,3.63%,3.60%和3.67%;有机质、碱解氮、速效磷和速效钾分别增加7.03%,0.37%,0.33%和0.29%;真菌、细菌、放线菌、蔗糖酶、脲酶、磷酸酶和多酚氧化酶分别增加121.42%,34.69%,20.00%,61.79%,45.37%,36.00%和63.23%;杂交饲用甜高粱穗粒数、穗粒重、百粒重、产量、施肥利润和投资效率分别增加6.38%,4.17%,4.42%和4.04%,2 390元/hm2和0.40元/元。[结论]施用有机营养功能型土壤改良剂,有效地改善了甘肃省河西走廊灰棕荒漠土理化性质,提高了持水量和杂交饲用甜高粱产量。

灰棕紫泥水稻土油菜高产高效施肥探讨

灰棕紫泥水稻土是四川盆地的主要水稻土,在川东地区占有较大面积.目前,针对该土壤的研究资料较少,为了更好地指导该土壤的平衡配方施肥工作,本文采用三元二次通用旋转设计对该种水稻土的不同施肥水平与油菜产量及经济效益的关系进行了研究,获得了该土壤油菜施肥与产量的数学模型.结果表明,在灰棕紫泥水稻土种植油菜,N、P一次项和NP的交互项均达到了极显著水平,K的一次项达到了显著水平.根据本试验,提出类似地区油菜高产高效配方施肥建议方案为:每公顷施用有机肥15 000 kg,纯N 290.25～323.25 kg,P2O5 110.64～146.28 kg,K2O 66.90 kg.

秸秆还田与施肥对稻田土壤微生物生物量及固氮菌群落结构的影响

利用氯仿熏蒸法和变性梯度凝胶电泳法(PCR-DGGE)研究了秸秆覆盖还田与施肥对灰棕冲积水稻土0—10cm和10—20cm土层土壤微生物生物量碳、氮和固氮菌群落结构的影响。结果表明:土壤微生物量碳、氮和固氮菌多样性从0—10cm土层到10—20cm土层均呈现降低趋势。无秸秆覆盖处理(对照组)的土壤微生物生物量碳(SMB-C)和微生物生物量氮(SMB-N)量最小。在秸秆覆盖还田处理中,低氮和无钾处理的SMB-C和SMB-N都显著低于全量氮磷钾肥处理。虽然无磷处理的SMB-N低于全量氮磷钾处理,但差异不显著。说明秸秆覆盖还田配施充足氮磷钾肥能显著提高土壤微生物生物量碳、氮。由DGGE图谱多样性指数分析得知,配施充足氮磷钾肥的处理土壤的固氮菌多样性最丰富。UPGMA聚类分析显示,10种不同处理的聚类图也不同,对照(无秸秆)处理0—10cm和10—20cm的微生物不同于其它处理单独聚在了一个群里。DGGE条带测序得知,14个条带的近缘种大部分为非培养细菌nifH基因片段,主要优势菌群其归属于变形菌门(Proteobacteria)的β-变形菌纲(Betaproteobacteria)。应用PCR-DGGE技术可以解释灰棕冲积水稻土秸秆覆盖不同肥料用量固氮菌分子群落结构特点。

用石膏改善土壤的透气性

澳大利亚科学家革新了传统的用石膏改善土壤透气性的方法,其不仅提高了施用石膏改良土壤排水性能的效果,而且它的作用效力维持时间较长,从而使得施用石膏变得较为经济。施用石膏能降低土壤的致密度,这是早为人们所知的。由于在澳大利亚的一些灌溉地区土壤排水性很差,除了种植水稻之外。

简论盐田土壤的类型

我国沿海地域辽阔,自然条件复杂,土类繁多,需要有个统一的土壤类型及土质分类标准,以便更有效地研究盐田土壤的属性,总结盐田池板防渗加固的经验,为盐田技术改造提供必要的依据,更好地为盐业生产服务。 1 盐田土壤分类及各土类主要特点 1·1 盐田土壤分类 盐田土壤是在自然土壤的基础上发展演变而成的。笔者根据自然土壤的成土过程、形成条件和属性(物理、生物特性),将我国沿海低地的盐田土划分为褐棕土(棕壤、褐土)、盐土、红壤(砖红壤、赤红壤、红壤、燥红壤)三种不同的土类。各土类分布区域如下:

Vertical variation and storage of nitrogen in an aquic brown soil under different land uses

The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenyang Experimental Station of Ecology, Chinese Academy of Sciences in November of 2003. The results showed that different land uses had different profile distributions of soil total nitrogen (STN), alkali N, ammonium (NH4+-N) and nitrate (NO3--N). The sequence of STN storage was woodland >maize field > fallow field > paddy field, while that of NO3--N content was maize field > paddy field > woodland > fallow field, suggesting the different root biomass and biological N cycling under various land uses. The STN storage in the depth of 0-100 cm of woodland averaged to 11.41 thm-1, being 1.65 and 1.25 times as much as that in paddy and maize fields, respec-tively, while there was no significant difference between maize and fallow fields. The comparatively higher amount of NO3--N in maize and paddy fields may be due to nitrogen fertilization and anthropogenic disturbance. Soil alkali N was significantly related with STN, and the correlation could be expressed by a linear regression model under each land use (R20.929, p<0.001). Such a correlation was slightly closer in nature (woodland and fallow field) than in agro ecosystems (paddy and maize fields). Heavy N fertilization induced an excess of crop need, and led to a comparatively higher amount of soil NO3--N in cultivated fields than in fallow field and woodland. It is suggested that agroforestry practices have the potential to make a significant contribution to both crop production and environment protection.

黑河流域灰棕荒漠土种植耐旱牧草小冠花改土培肥效果的研究

在黑河流域的灰棕荒漠土上种植了耐早牧草小冠花改土培肥效果明显，3年生小冠花与CK比较，0～20cm土层中自然含水量增加73．93gkg^-1、土壤贮水量增加67．17m^3hm^-1、〉0．25mm团粒结构增加12．16％、总孔度增加10．94％、土壤容重降低0．29gcm^-3；pH由8．15降到7，83，全盐含量降低1．72g kg^-1，脱盐率达到58．70％；土壤有机质增加3．01g kg^-1、速效N、P、K分别增加20．9mg kg^-1、5．7mg kg^-1、11．3mg kg^-1，CEC增加7.0cmol kg^-1。3年生小冠花平均株高85．4cm，单株鲜重1074．2g，单株干重343．8g，鲜草产量72．5t hm^-2，干草产量23．2t hm^-2，产值0．93万元hm^-2。

功能型土壤改良剂对灰棕荒漠土的改良效果

选择甘肃河西走廊的灰棕荒漠土,采用田间试验方法,进行了功能型土壤改良剂对灰棕荒漠土改良效果的研究。结果表明:功能型土壤改良剂最佳施用量为24.22 t hm^(-2),杂交玉米理论产量为6.76 t hm^(-2);施用功能型土壤改良剂与传统化肥比较,灰棕荒漠土容重、pH、Hg、Cd、Cr和Pb降低7.20%、5.51%、16.21%、28.85%、15.74%和18.02%;总孔隙度团聚体和总持水量增加6.44%、27.35%和6.44%;有机质、碱解氮、速效磷和速效钾增加20.12%、0.80%、0.96%和0.16%;真菌、细菌和放线菌增加117.31%、34.83%和22.06%;蔗糖酶、脲酶、磷酸酶和多酚氧化酶增加61.48%、45.92%、34.78%和60.32%;施肥利润和肥料投资效率增加29.70%和85.28%。施用功能型土壤改良剂,改善了灰棕荒漠土理化性质和生物学性质,提高了酶活性和杂交玉米的经济效益。

Effects of Long-term Located Fertilization on Wheat Yield and Soil Nutrients of Three Types of Soils in Shandong Province

[Objective] This study aimed to investigate the effects of long-term differ- ent fertilization in three types of soils on wheat yield and soil nutrient variation in Shandong Province. [Method] A 30-year located experiment in Jinan of Shandong Province was selected and the results of soil nutrient and crop yield in 1984, 1987, 1988, 1989, 1990, 2001, 2005, 2006, 2007 and 2010 were measured and collected. In this study, five treatments： CK, NP, NK, PK and NPK of the located experiment were selected. [Result] The three types of soils in wheat yields decreased signifi- cantly in the first several years and in 2006. Wheat yields of the treatments with P fertilizers were obviously higher than those without P fertilizers; it was shown that phosphorus is the primary nutritional factor for high-yielding of wheat. The highest yield is from cinnamon soil, followed by that from brown soil, and the lowest pro- duction is from fluvo-aquic soil. Under the same fertilization, the influence of other factors on wheat yield of brown soil is the smallest, while cinnamon soil is vulnera- ble to the influence of external conditions, resulting in larger fluctuation of annual wheat yield. The alkali-hydro nitrogen contents of three kinds of soils first de- creased, then raised, and at last reduced apparently. Since 2007, the change of al- kali-hydro nitrogen content appeared rebounded. The available P contents of no- phosphorus treatments decreased over time while those of the treatments with P fertilizers increased at first, then decreased, and after that kept relatively stable. The available K contents of no K treatments decreased slowly. The treatments of PK and NK had higher available K content than NPK treatment. [Conclusion] Thus, it is an effective fertilization measure to improve the wheat yield by supplying reasonable phosphate fertilizer and nitrogen fertilizer and making up potassium fertilizer.

Effects of Exogenous Organic Acids on Dehydrogenase Activity in Dark Brown Forest Soils under Nutrient Deficiency

Objective] This study aimed to investigate the effects of exogenous or-ganic acids on dehydrogenase activity in dark brown forest soils under nutrient defi-ciency. [Method] Different proportions of A1 and B horizon dark brown forest soils （A1∶B=1∶2） were utilized to establish soil conditions with nutrient deficiency for cultivation of Larix olgensis seedlings. The effects of oxalic acid, citric acid and succinic acid on dehydrogenase activity in dark brown forest soils under nutrient deficiency were studied systematical y by adding different concentrations of organic acid solutions. [Result] Under nutrient deficiency, dehydrogenase activity in dark brown forest soils was reduced significantly, and the reduction increased with the extension of stress duration. Most organic acid treatments improved dehydrogenase activity in nutrient-deficient dark brown forest soils, and the effects varied with different treatment du-ration and types and concentrations of organic acids. Furthermore, 10.0, 5.0 and 10.0 mmol/L organic acid treatments exhibited the most significant effects on day 10, 20 and 30, respectively. The increment of dehydrogenase activity in different durations showed a downward trend of 30 d〉20 d〉10 d; the improvement effects of three organic acids on dehydrogenase activity showed a downward trend of succinic acid〉 citric acid〉oxalic acid. [Conclusion] Exogenous organic acids improved signifi-cantly dehydrogenase activity in dark brown forest soils under nutrient deficiency and also improved the microbial activity and soil fertility to a certain extent.

Influence of Dark Brown Soil Respiration and Microbial Community under Cadmium Stress

Through laboratory simulation, the influence of cadmium on soil respiratory intensity and microbial community were studied by adding different concentrations of heavy metal cadmium. The results indicated that, the soil respiration had a signifi- cant weakening trend in the same culture days with increasing exogenous cadmium content; the soil respiration intensity was decreased obviously with the increase of culture time, especially after 14 d when the soil exogenous cadmium content was in the range of 0.5-3.0 mg/kg, while the soil respiration had not obvious variation over time when the exogenous cadmium content was in the range of 5.0-10.0 mg/kg. The soil microbial communities decreased significantly and were much lower than that of the control treatment in the same culture days with the increasing of soil exogenous cadmium content; the soil microbial community declined significantly with increasing of culture time for all exogenous cadmium treatments. The number of soil microbial communities in treatment with 10 mg/kg of exogenous cadmium were only 46.43%, 32.26%, 28.74%, 27.39% and 24.62% of that in control treatment on the 7th, 14th, 21st, 28th and 42rd of culture, respectively. It indicated that higher concen- tration of cadmium in dark brown soil had a significant inhibitory effect on soil mi- crobial growth.

吐尔根农场复播成功

新源县吐尔根农场海拔为922～977米,年平均气温为8.5℃,最高气温为39.8℃,最低气温-27℃,光照充足,光照率达65％,无霜期在140～160天,降水量460毫米,上半年多,下半年少,土壤是栗钙土和灰棕土,有机质含量为4～6％,气候是春温多雨,夏高温炎热,适宜喜温作物生长,主要作物有冬、春小麦。其次是玉米、油料、杂粮等作物。也是我县种植冬小麦的东部边缘地区。我场人多地少,现有4000余人,耕地12879亩,劳均地11.5亩,人均地3亩,要想提高产量,必须提高单位面积产量。

兰陵县苍山牛蒡绿色高产栽培技术

兰陵县位于山东省南部,与江苏省邳州市相邻。全县年平均气温14.4℃,年降水量686mm,≥10℃有效积温3 680℃,平均日照时数为2 200小时,无霜期210天,属暖温带季风区半湿润大陆性气候。一年四季分明,日照时数多,降雨量适中,无霜期长,地下水资源丰富,有棕土;褐土;潮土和沙姜黑土四大土壤类型。

Interaction Between Charge Characteristics and Cu^(2+) Adsorption-Desorption of Soils with Variable or Permanent Charge

Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and permanent charge (brown soil) and the relationship between them were studied by means of back-titration and adsorption equilibrium respectively. The amount of variable negative charge was much less in variable-charge soil than in permanent-charge soil and increased with the pH in the system, but the opposite trend occurred in the points of zero charge (PZCs). The amount of Cu2+ ions sorbed by permanent-charge soil was more than that by variable-charge soil and increased with the increase of Cu2+ concentration within a certain range in the equilibrium solution. The amount of Cu2+ ions desorbed with KC1 from permanent-charge soil was more than that from variable-charge soil, but the amount of Cu2+ ions desorbed with de-ionized water from permanent-charge soil was extremely low whereas there was still a certain amount of desorption from variable-charge soil. The increase of PZC of soils with variable or permanent charge varied with the increment of Cu2+ ions added. When the same amount of Cu2+ ions was added, the increments of PZC and variable negative surface charge of permanent-charge soil were different from those of variable-charge soil.

Expert System Land Evaluation for Oil Palm Cultivation （ESLEOP）

Land evaluation assesses the suitability of land for specified land uses. The FAO Framework for Land Evaluation provides guidance for land suitability assessment. An Expert System Land Evaluation for Oil Palm Cultivation （ESLEOP） software was developed using climate, land qualities and land characteristics as diagnostic criteria in order to speed up the process of land assessment for oil palm cultivation in tropical regions. The results showed that ESLEOP evaluated land suitability for oil palm cultivation faster than the conventional method.