最佳养分管理对华北冬小麦养分吸收和利用的影响

针对华北地区小麦施肥过量和不平衡、产量和肥料利用率较低的现象,进行了河南、山东、河北3个小麦主产区最佳养分管理、农民习惯施肥和减素处理对冬小麦产量、养分吸收、利用和经济效益影响的田间试验。结果表明,在山东和河北较高肥力地区,最佳施肥处理(OPT)与农民习惯施肥(FP)处理相比在减少氮肥施用5.4%和43.8%的情况下,分别提高氮肥回收利用率7.7和4.5个百分点;在河南低肥力地区,OPT处理在比FP处理增加10%氮肥施用量的情况下,冬小麦增产12.5%,氮肥回收利用率提高了13.0个百分点。同时,OPT处理钾肥和磷肥的回收利用率也有不同程度的提高。由于地区土壤肥力和养分供应能力变异较大,基于土壤养分测定和目标产量的优化养分管理很有必要且切实可行。     

中国滇池流域土地利用方式对土壤侵蚀和养分状况的影响

Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare soil erosion under four land use types(i.e.,forestland, abandoned farmland, tillage, and grassland) and their effects on soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) in the Shuanglong catchment of the Dianchi Lake watershed, China. There were large variations in the erosion rate and the nutrient distributions across the four land use types. The erosion rates estimated by137 Cs averaged 2 133 t km-2year-1under tillage and abandoned farmland over the erosion rate of non-cultivated sites, and the grasslands showed a net deposition. For all sites, the nutrient contents basically decreased with the soil depth. Compared with tillage and abandoned farmland, grassland had the highest SOC and TN contents within 0–40 cm soil layer, followed by forestland. The significant correlations between137 Cs, SOC and TN were observed. The nutrient loss caused by erosion in tillage was the highest. These results suggested that grassland and forestland would be beneficial for SOC and TN sequestration over a long-term period because of their ability to reduce the loss of nutrients by soil erosion. Our study demonstrated that reduction of nutrient loss in the red soil area could be made through well-managed vegetation restoration measures.     

土地开发对农田土壤养分和盐分变异特征的影响

利用地统计学方法研究了新疆库尔勒市包头湖农场土地开发后土壤空间变异特征。结果表明:土地开发后种植区的土壤有机质和盐分降低,有效磷含量增加,碱解氮含量变化不大;尤其是土地开发后撂荒地土壤有机质含量下降明显。土壤盐分与有机质、碱解氮及速效钾的含量均呈显著正相关,与有效磷呈显著负相关。因此,土地开发后需增施有机肥,补充钾肥,并尽可能不撂荒。     

土壤状况及养分交互作用对棉花产量影响的数学分析

The influence of soil chemical properties and soil nutrition on cotton yields was studied by means of establishing mathematical models. The nultivariate quadratic regression equations developed by a stepwise regression method not only presented the single effect of soil factors but also displayed the interaction (synergistic or antagonistic) of soil nutrients. The effect of individual factor and the way of nutrient interaction were further analysed by the path analysis method. The results showed that among major factors affecting cotton yields, there existed the interactions between macronutrients(available P × available K), and between macronutrients and microelements (N × Zn, P × Mo, P × Cu, P × Zn, K × Mo) besides the single effect of soil pH, total P, available Cu and available Zn.     

添加调节N和P浓度后的植物残体对土壤呼吸作用、微生物量和养分有效性的影响

Microbial activity and nutrient release are known to be influenced by organic matter properties,but it is difficult to separate the effect of C/N ratio from that of C/P ratio because in most plant residues both ratios are either high or low.An incubation experimeut was conducted to investigate the effects of reducing the C/N and C/P ratios of slowly decomposable plant residues (young eucalyptus leaves,mature wheat straw,and sawdust) to those of rapidly decomposable residues (young kikuyu shoots) on soil respiration,microbial biomass,and N and P availability.The C/N and C/P ratios of the former were adjusted to 15 and 89,respectively,by adding N as (NH4)2SO4,P as KH2PO4 or both and residues were added at 10 g C kg-1 to a silt loam.Soil respiration was measured over 21 d;microbial biomass C (MBC) and available N and P were measured on days 0,7,and 21.Compared to the unamended soil,addition of kikuyu increased cumulative respiration 20-fold,MBC concentration 4 to 8-fold,and available P concentration up to 4-fold,whereas the increase in available N concentration was small and transient.Cumulative respiration and MBC concentration were low in the sawdust-amended soil and were not influenced by reducing the C/N and C/P ratios.Cumulative respiration with original wheat and eucalyptus was 30％-40％ of that with kikuyu.Reducing the C/N ratio alone or both C/N and C/P ratios increased cumulative respiration and MBC concentration 2-fold compared to the original wheat and eucalyptus,whereas reducing the C/P ratio had little effect.Throughout the experiment,the available N concentration after addition of residues with reduced C/N ratio increased in the following order of eucalyptus ＜ wheat ＜ sawdust.By independently lowering the C/N and C/P ratios,microbial activity was more limited by C and N than P.However,lowering the C/N ratio of very slowly decomposable sawdust had no effect on soil respiration and MBC concentration,suggesting that other properties such as concentration of poorly decomposable C compounds limited decomposition.     

利用方式和土壤肥力对土壤团聚体和养分的影响

The size distribution of water-stable aggregates and the variability of organic C, N and P contents over aggregate size fractions were studied for orchard, upland, paddy, and grassland soils with high, medium, and low fertility levels. The results showed that > 5 mm aggregates in the cultivated upland and paddy soils were 44.0% and 32.0%, respectively, less than those in the un-tilled orchard soil. Organic C and soil N in different size aggregate fractions in orchard soil with high fertility were significantly higher than those of other land uses. However, the contents of soil P in different size aggregates were significantly greater in the paddy soil as compared to the other land uses. Soil organic C, N and P contents were higher in larger aggregates than those in smaller ones. The amount of water-stable aggregates was positively correlated to their contribution to soil organic C, N and P. For orchard and grassland soils, the > 5 mm aggregates made the greatest contribution to soil nutrients, while for upland soil, the 0.25-0.053 mm aggregates contributed the most to soil nutrients. Therefore, the land use with minimum disturbance was beneficial for the formation of a better soil structure. The dominant soil aggregates in different land use types determined the distribution of soil nutrients. Utilization efficiency of soil P could be improved by converting other land uses to the paddy soil.     

巴西东北部地区土地退化对土壤微生物量和活性的影响

Land degradation causes great changes in the soil biological properties.The process of degradation may decrease soil microbial biomass and consequently decrease soil microbial activity.The study was conducted out during 2009 and 2010 at the four sites of land under native vegetation(NV),moderately degraded land(LDL),highly degraded land(HDL) and land under restoration for four years(RL) to evaluate changes in soil microbial biomass and activity in lands with different degradation levels in comparison with both land under native vegetation and land under restoration in Northeast Brazil.Soil samples were collected at 0-10 cm depth.Soil organic carbon(SOC),soil microbial biomass C(MBC) and N(MBN),soil respiration(SR),and hydrolysis of fluorescein diacetate(FDA) and dehydrogenase(DHA) activities were analyzed.After two years of evaluation,soil MBC,MBN,FDA and DHA had higher values in the NV,followed by the RL.The decreases of soil microbial biomass and enzyme activities in the degraded lands were approximately 8-10 times as large as those found in the NV.However,after land restoration,the MBC and MBN increased approximately 5-fold and 2-fold,respectively,compared with the HDL.The results showed that land degradation produced a strong decrease in soil microbial biomass.However,land restoration may promote short-and long-term increases in soil microbial biomass.     

长江口崇明岛土地利用方式对滨海土壤中重金属和砷的分布和形态特征的影响

The reclamation of tidal flats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the study of heavy metals due to the relative high pollutant concentrations in wetlands. To understand the impact of land use change on heavy metal and arsenic(As) geochemistry by the reclamation of wetlands for agriculture, surface soils and soil profiles were collected from the agricultural land reclaimed in the 1990 s and the intertidal flat wetland at Dongtan on Chongming Island in the Yangtze River Estuary, China. The soil samples were analyzed for total concentrations and chemical speciation of chromium(Cr), zinc(Zn), copper(Cu), lead(Pb), nickel(Ni), cadmium(Cd) and As using inductively coupled plasma mass spectrometry(ICP-MS). Results showed that soil properties(salinity, total organic carbon and grain-size distribution) and the concentrations of heavy metals and As in the soils differed under the different land use types. The conversion of wetland to forest had caused obvious losses of all the measured heavy metals. In paddy field and dryland with frequent cultivation, the concentrations of Cr, Zn, Cu, Ni and As were higher when compared to forest land which was disturbed rarely by human activities. Speciation analysis showed that Cr, Zn, Cu, Ni and As were predominated by the immobile residual fraction, while Pb and Cd showed relatively higher mobility. In general, metal(except Ni) and As mobility decreased in the following order: wetland dryland ≥ paddy field forest land, which suggested that the reclaimed soils had lower metal and As mobility than the intertidal flat wetland. The results of this study contribute to a better understanding of the effects of land use on heavy metals and As in the reclaimed soils of the study area and other similar coastal areas.     

模拟降雨条件下聚丙烯酰胺应用对径流、侵蚀和土壤养分流失的影响

Soil erosion affects soil productivity and environmental quality.A laboratory research experiment under simulated heavy rainfall with tap water was conducted to investigate the effects of anionic polyacrylamide(PAM) application rates(0,0.5,1.0,and 2.0 g m-2) and molecular weights(12 and 18 Mg mol-1) on runoff,soil erosion,and soil nutrient loss at a slope of 5°.The results showed the two lower rates of PAM application decreased runoff while the highest rate increased runoff as compared with the control.Sediment concentration and soil mass loss increased significantly with the increasing PAM application rate.Compared with the control,PAM application decreased K+,NH4+,and NO3-concentrations in sediment and K+ and NH+4 concentrations in runoff,but significantly increased the mass losses of K+,NH4+,and NO-3 over soil surface except for the NH4+ at PAM application rate lower than 1.0 g m-2.PAM application decreased the proportion of K+ loss with runoff to its total mass loss over soil surface from 60.1% to 16.4%.However,it did not affect the NH4+ and NO3-losses with runoff,and more than 86% of them were lost with runoff.A higher PAM molecular weight resulted in less soil erosion and K+ mass loss but had little effect on runoff and NH+4 and NO3-losses.PAM application did not prevent soil erosion and the mass losses of K+ and NO3-under experimental conditions.     

农田土地利用方式对紫色土总砷含量及其垂直分布的影响

为了探讨农田土地利用方式对紫色土总砷含量的影响,采用现场采样及室内分析测试方法,对重庆市旱地、水田、水旱轮作、果园4种土地利用方式下的紫色土总砷含量及其垂直分布进行了比较研究,结果表明:在旱地利用方式下,砷在紫色土剖面层次中呈现的分布规律由耕作层向底土层逐渐递减;在水田利用方式下,砷在土壤剖面层次间分布均衡,其各层次土体总砷平均含量分别为表层9.83mg/kg、犁底层10.00mg/kg、母质层10.51mg/kg;在水旱轮作利用方式下,紫色土剖面中总砷含量呈现从B层→C层→A层依次递减的规律;在园地土地利用方式下,紫色土剖面层次间总砷的含量变化幅度较小。     

基于Web的煤矿废弃地土地复垦决策支持系统设计与实现

为了克服现有煤矿废弃地土地复垦与植被恢复试验法费时费力的缺陷,根据土壤基质和气候相似性原理,采用模糊综合评价一灰色关联优势分析、基于距离的相似算法、基于规则的推理等多种数学方法,分别从植被恢复潜力评价、适生植物品种选择、土地复垦方案选择3个方面建立了相关数学模型,解决了煤矿废弃地恢复潜力的分级、先锋植物选种和土地复垦方案的确定等问题,从而为煤矿废弃地的植被恢复提供了一系列的决策支持.并使用ASENET 等编程语言结合MS Access数据库设计并开发了基于web的煤矿废弃地植被恢复的决策支持系统,该系统能为煤矿废弃地植被恢复工作提供新的研究模式和手段,并已经在辽宁省阜新矿区得到应用,结果表明系统所采用的方法科学、合理、可行.     

矿区土地复垦工程可垦性分析

该文论述了土地复垦规划中可垦性分析的重要性,阐述了可垦性分析的含义和内容,提出可垦性分析的一般程序和多因素综合评价法,即在选定评价单元的基础上,选择可垦性分析的主导因素,采用层次分析法给主导因素打分,采用乘法模型计算评价单元的可垦性综合分值,从而得到待复垦区域的可垦性分析值,通过量化的综合分值可以确定待复垦区域的可垦性。并以山东某矿采煤塌陷地为例进行分析,经验证该方法得出的评价结果能够反应待复垦区的实际情况,为土地复垦规划设计提供参考。     

煤矿区复垦土壤压实时空变异特征

为了揭示煤矿区复垦土壤压实状况的时空变异规律,该文以未塌陷土地为对照,通过实地测定,分析5个复垦年限水平和垂直方面的土壤压实度变异特征。结果表明：复垦土壤表层压实度以复垦1 a（正在复垦）的最大,达到 2050 kPa,随着复垦年限增加逐渐减少,复垦5 a的最小（50 kPa）,基本达到未塌陷土地的压实度。表层土壤压实度空间变异最大的是复垦5 a的土地（变异系数为68.40%）,其次是未塌陷土地（52.58%）,最小的是正在复垦的土地 （22.01%）。从各层的变异情况看,正在复垦的土地各个层次土壤压实度都较大且变异系数较低,其他复垦年限土壤压实度上面3层较小但变异大,至第4层（22.86～30.48 cm）达到较高值,且变异较小,之下压实度基本稳定。     

新疆煤矿土地复垦为草地的适宜性评价方法与应用

土地复垦适宜性评价是土地复垦工作的基础,其评价结果直接决定将来土地复垦的方向和类型。该文以新疆15个煤矿为研究背景,选取了土地待复垦单元土地损毁后的地面坡度、损毁土地深度或压占区堆积物平整量、土地损毁后复垦土源保证率、土壤中黏粒含量、土壤有机质含量、覆土厚度和土地复垦单元可用于灌溉的地表径流量等7个因素作为土地复垦适宜性评价因子,构建了适合新疆煤矿土地复垦为草地的适宜性评价指标体系;以15个煤矿的76个待土地复垦单元作为学习样本,首先采用Q型聚类分析方法将76个样本划为4类,将分类结果与以往结合规范分类结果进行对比,其结果唯一,符合实际且更加精确;然后采用判别分析方法对76个样本进行训练,建立了相应的评价模型,采用回代估计方法对样本逐一进行检验,正确率达到98.7%。将该评价模型应用到新疆尼勒克科尔克煤矿和新疆皮里青煤矿,对2个煤矿的11个待土地复垦单元其复垦为草地的适宜性进行评价,评价分类结果与神经网络模型、因子和聚类联合分析的分类结果一致,分类结果符合规范分类结果范围且更加精确和符合实际。该评价指标体系和评价模型可为新疆煤矿土地复垦工作提供参考。     

不同复垦模式及复垦年限对土壤微生物的影响

为了研究不同复垦年限及复垦植被模式对复垦土壤生物肥力的影响,通过野外调查和采样分析,对平朔安太堡露天煤矿不同复垦年限及复垦植被模式下和原地貌（对照）土壤中细菌、放线菌和真菌3种微生物的数量及变化进行了研究。结果表明：1）从微生物总数来看,随着复垦年限的增加,微生物总数呈增加的趋势,复垦13a的土壤微生物总数达到了624.35×105～1 448.19×105 cfu/g,平均可达1 183.01×105 cfu/g（除自燃地外）,最高的和原地貌已相当。2）在不同复垦年限及复垦模式复垦地0～20 cm表层土壤微生物三大类区系组成中,细菌数量占绝对优势（95%以上）,放线菌数量次之,真菌数量最少。3）不同复垦植被配置方式对复垦土壤微生物数量的增加作用不同。在同一地点不同复垦模式复垦7 a的土壤中微生物数量的变化趋势是紫穗槐＞沙枣＞沙棘。不同复垦模式复垦13 a,从微生物角度评价它们的生态效益是：云杉×油松×落叶松＞刺槐×油松×榆树＞刺槐×柠条＞冰草×刺槐×柠条。4）从土壤微生物与复垦土壤养分的相关系数来看,细菌数量和微生物总数与土壤有机质、碱解氮含量呈显著正相关。     

基于CT分析露天煤矿复垦年限对土壤有效孔隙数量和孔隙度的影响

露天煤矿排土场由于排土过程中大型机械压实等作用会对土壤的孔隙结构产生影响,重构适合于植被生长的土壤孔隙结构是排土场土地复垦的重要工作。为对排土场重构土壤孔隙结构进行定量分析,该文采用高精度无损计算机断层扫描技术（CT）对山西平朔矿区安太堡露天煤矿排土场平台全黄土母质覆盖的不同复垦年限（0、20、23 a）以及原地貌的土壤进行分层扫描成像,并利用Photoshop和Arcgis软件对扫描图像进行处理和统计分析,探讨了排土和复垦对土壤孔隙数量和孔隙度的影响,分析了排土场重构土壤大、中和小孔隙的变化。结果表明：原地貌土壤孔隙数量和孔隙度最大,其次是复垦23和20 a的土壤,排土后未复垦土壤孔隙数量和孔隙度最小。采矿和排土等活动由于大型机械压实作用降低了土壤孔隙数量和孔隙度,尤其是大孔隙数量和大孔隙度;土地复垦对增加土壤孔隙数量和孔隙度有一定的作用,但是过程比较缓慢。采矿和排土等活动对表层土壤孔隙数量和孔隙度的影响要高于底层土壤。该研究可为黄土区大型露天煤矿排土场重构土壤结构的优化与土地复垦措施选择提供依据。     

煤矸石充填复垦地理化特性与重金属分布特征

为研究煤矸石充填复垦地农作物产量达到最佳时的覆土厚度及煤矸石充填复垦地重金属分布状况,该文以新庄孜矿煤矸石充填复垦地作为研究对象,采取室外田间小区试验和室内试验分析方法,选取不同覆土厚度50~60,60~70,70~80,80~90 cm的4类试验地块及对照地块对其土壤理化性质及农作物根系分布、长势产量、重金属元素含量进行调查分析,发现复垦地块各项指标与对照地块差异显著,劣于对照地块;煤矸石充填基质土壤理化性质较差;70~80 cm的厚度是煤矸石充填复垦造地较经济合理的覆土厚度。煤矸石复垦地重金属元素有向上迁移的趋势;复垦土壤及煤矸石基质中Pb、Zn、Cr元素含量处于安全水平;大部分监测的Cu、Ni、Cd元素含量高于淮南土壤背景值,低于中国土壤环境质量标准二级标准,对复垦土壤已构成潜在的威胁性,应予以重视;覆土厚度50~60 cm地块的煤矸石基质中Cu、Ni元素含量处于安全水平,煤矸石基质中Cd元素含量高于淮南土壤土壤背景值,低于中国土壤环境质量标准二级标准,应予以重视。结果表明70~80 cm的厚度是煤矸石充填复垦造地最佳覆土厚度;新庄孜煤矸石充填复垦地重金属有向上迁移的趋势,复垦土壤中重金属含量符合国家二级标准,未出现重金属污染情况,但部分重金属元素含量高于淮南市土壤背景值,应予以重视。     

Phosphorus: a limiting factor for restoration of soil fertility in a newly reclaimed coal mined site in Xuzhou,China

Massive exploration of coal in China has resulted in a significant loss of agricultural land throughout the country. To relieve this increasing shortage, reclamation of abandoned coal mine areas has been prioritized. This study aims to identify the limiting factor(s) affecting the restoration of the soil fertility in a coal-mined area. The work was carried out in a typical area, the Xuzhou coalfield in northern Jiangsu province. Soil fertility parameters showed that the tested soil was very poor, especially in phosphorus. By using soil-pot experiments, it was demonstrated that application of nitrogen and potassium, but without phosphorus fertilizers, did not result in increase in crop yields, while the rational application of organic and inorganic fertilizers improves soil fertility significantly as shown by yields of rice, wheat and green vegetables. By comparing the effectiveness of different treatments, soil phosphorus was identified as the limiting factor in restoring the fertility of this newly reclaimed land. Study on the soil phosphorus speciation further revealed that Ca₂-P was the main source of variation in the supplying capacity of soil phosphorus, whereas Ca₁₀-P remained unchanged. © 1998 John Wiley & Sons, Ltd.     

Potential of mine land reclamation for soil organic carbon sequestration in Ohio

Soils are an effective sink for carbon storage and immobilization through biomass productivity and enhancement of soil organic carbon (SOC) pool. The SOC sink capacity depends on land use and management. Degraded lands lose large amounts of C through SOC decomposition, erosion, and leaching. Thus, restoration of disturbed and degraded mine lands can lead to increase in biomass productivity, improved soil quality and SOC enhancement and sequestration. Reclamation of mined lands is an aggrading process and offers significant potential to sequester C. A chronosequence study consisting of 0‐, 5‐, 10‐, 15‐, 20‐ and 25‐year‐old reclaimed mine soils in Ohio was initiated to assess the rate of C sequestration by pasture and forest establishment. Undisturbed pasture and forest were used as controls. The SOC pool of reclaimed pasture sites increased from 15·3 Mg ha⁻¹ to 44·4 Mg ha⁻¹ for 0–15 cm depth and from 10·8 Mg ha⁻¹ to 18·3 Mg ha⁻¹ for 15–30 cm depth over the period of 25 years. The SOC pool of reclaimed forest sites increased from 12·7 Mg ha⁻¹ to 45·3 Mg ha⁻¹ for 0–15 cm depth and from 9·1 Mg ha⁻¹ to 13·6 Mg ha⁻¹ for 15–30 cm depth over the same time period. The SOC pool of the pasture site stabilized earlier than that of the forest site which had not yet attained equilibrium. The SOC sequestered in 0–30 cm depth over 25 years was 36·7 Mg ha⁻¹ for pasture and 37·1 Mg ha⁻¹ for forest. Copyright © 2000 John Wiley & Sons, Ltd.     

基于面向对象的GF-1遥感影像采煤沉陷区湿地分类

为掌握采煤沉陷区湿地的类别和分布,促进矿区土地的复垦、规划和管理,该文以兖州煤田为例,探讨了基于GF-1遥感影像的面向对象的采煤沉陷区湿地分类方法。对河流湿地和景观湿地的影像进行基于矢量的棋盘分割,采用标准最邻近法进行分类。水产养殖湿地、植被型湿地、未复垦的常年积水湿地和未复垦的季节积水湿地的影像采用基于矢量的多尺度分割,通过反复试验获取最优分割参数,进而进行综合分析得到局部最优分割参数,由此确定分类层次,选取易于区分各类型湿地的影像特征建立分类规则,采用模糊分类法进行分类。选取141个样本点进行实地验证,结果表明分类精度达到96.95%,Kappa系数为0.958 4。该研究为采煤沉陷区湿地的分类提供了借鉴。