新疆水土保持与可持续发展研究

新疆维吾尔自治区作为我国最大及地理位置重要的西北边陲省份,随着人口的增长区域开发进程的进一步加快,水土流失问题日趋严重,水土保持和可持续发展已成为其生态环境建设的重要课题。分析了新疆水土流失的现状、特点和成因以及存在的问题,从可持续发展角度提出了新疆水土保持的对策和建议。     

防治南方土壤侵蚀的新途径——贴地表覆被

在分析南方水土流失特征的基础上 ,对贴地表覆被保持水土效益作了系统评价。由此提出了以贴地表覆被为中心的植被建设防治土壤侵蚀的新途径。     

区域农田土壤质地剖面的随机模拟模型

冲积土壤剖面的质地层次分层是该类土壤的重要特性,对农田水分转化和溶质运移具有重要影响。本文论据已取得的研究结果,采用Ｍａｒｋｏｖ链理论提出了区域冲积土壤质地层次的随机模拟模型－ＭＣ模型和ＭＣ－ＬＮ模型,采用蒙特卡罗方法模拟了研究区的土壤质地剖面,并与实测结果进行了对比。     

尾巨桉引种新区连续年龄序列生长量及土壤理化特性

为探明尾巨桉引种新区林木生长量及土壤理化特性,在桂西北乐里林区设置尾巨桉连续年龄序列观测样地,对林分胸径、树高、蓄积量及其土壤理化性质进行测定。结果如下:1)1～4a生尾巨桉胸径平均总生长依次为5.0,8.0,9.7和10.7cm;树高平均总生长依次5.1,8.8,11.2和12.1m;林分平均总蓄积依次为8.29,31.76,51.45和71.89m3/hm2。2)林地(0～100cm)土壤容重为1.188～1.498g/cm3,总孔隙度为46.79%～59.90%,其中非毛管孔隙度为10.34%～28.50%。3)土壤pH值为5.44～5.60;有机质含量为0.78%～2.51%;全N和全P含量分别为0.04%～0.11%;全K含量为0.40%～0.50%;速效K(42.7～63.5mg/kg)>有效Mn(5.91～22.59mg/kg)>速效P(1.4～6.8mg/kg)>有效Zn(0.61～1.72mg/kg)>有效B(0.07～0.35mg/kg)。研究结果表明,桂西北乐里林区尾巨桉引种新区林地土壤容重较大,土壤主要养分含量普遍缺乏,林木生长量较低。     

广西合浦县水土保持监督执法实践

广西壮族自治区合浦县水土保持监督执法经过一年多的艰苦探索,取得了一系列成果,被评为全国第二批试点先进单位。通过对该县水土保持监督执法工作做法、成效和经验的阐述,指出存在不足之处及今后努力方向。     

硫酸盐对锌和镉在可变电荷土壤上吸附的影响

SO4^2- and Zn^2 or Cd^2 were added to three variable charge soils in different sequences.In one sequence sulfate was added first ,and in the other,Zn^2 or Cd^2 first.The addition of sulfate to the system invariably caused an increase in adsorption of the heavy metal added,with the effect more remarkable whn the soil reacted with the sulfate prior to the metal.the shift in pH50 for both Zn and Cd adsorption was aslo comparatively larger in the first sequence of reactions .It was suggested that the increase in negative charge density and the resultant negative potential of the soil were the primary cause of the pronounced effect of sulfate on adsorption of Zn or Cd,and the formaiton of the ternary surface complex-S-SO4-M might also play a role in the effect.     

我国主要类型土壤的有效态硒及其与某些土壤性质的关系

Forty-eight soil profiles were sampled from different ecological and pedogeochemical areas of China and their available selenium (Av-Se) contents were determined. Results showed that the content of Av-Se in the profiles of soils in China ranged within 2.49~18.10 μg kg^-1, with a mean value of 10.01 μg kg^-1, and was in the sequence of Ferralisols > Luvisols > Isohumisols > Aridisols. The correlation analysis between Av-Se and the soil physical-chemical properties revealed that the correlations between Av-Se and O.M., CEC, Fe₂O₃, Al₂O₃, ignition loss, Co and Zn were positive at a highly significant level, but those between Av-Se and pH, base saturation, CaO, Ba and Sr were all negative at a highly significant level. The reason of some diseases related to the Se deficiency might be the leaching loss of selenium in some soils.     

红壤资源信息系统及其初步应用

Red soil is a very important soil resource in southern China. However, due to being simultaneously of high productive potentialities and severely degraded, it needs harnessing urgently. Red Soil Resource Information System (RSRIS) based on remote sensing and geographic information system (GIST plays an important role in survey, evaluation, utilization and management of red soil resource. RSRIS of Cauzhou City, Zhejiang Province (1:250000) and RSRIS of Longyou County, Zhejiang Province (1:50000) have been made respectively on SUN SPARC station and using ARC/INFO. This paper introduces the system design, database creation and system functions, and it particularly focuses on developing applied models, such as red soil resource division and mapping, suitability evaluation, erosion risk evaluation, plant utilization zone etc. The problems on study of RSRIS and its developing strategy are also discussed.     

第四纪红色粘土发育的红壤中营养元素的淋失

A red soil derived from Quaternary red clay was employed to study nutrient leaching with soil columns repacked in laboratory. The objective was to identify the effects of fertilization practices on leaching patterns and magnitudes of Ca²⁺, Mg²⁺, K⁺, NH₄⁺, and NO₃^-. The treatments were CK (as a control), CaCO₃, CaSO₄, MgCO₃, Ca(H₂PO₄)₂, urea, KCl, and multiple (a mixture of the above-mentioned fertilizers). The fertilizers were added to the bare surface of the soil columns, and then the columns were leached with 120 mL deionized water daily through peristaltic pumps over a period of 92 days. Leaching processes of NH₄⁺, and NO₃^- were only measured in CK, urea, and multiple treatments which were directly related to N leaching. Results showed that sole application of CaSO₄, and Ca(H₂PO₄)₂ scarcely had any effect on the leaching losses of Ca²⁺, Mg²⁺, and K⁺; the application of MgCO₃ stimulated the leaching of Mg²⁺; the application of CaCO₃ promoted the leaching of Ca²⁺, Mg²⁺ and K⁺; urea treatment also promoted the leaching of K⁺ and NH₄⁺, and NO₃^- leaching mainly occurred at late stage of leaching process in particular; under KCl treatment, leaching of Ca²⁺, Mg²⁺, and K⁺ was promoted to a large extent; under multiple treatment, leaching of Ca²⁺, Mg²⁺, K⁺, NH₄⁺, and NO₃^- was all increased and NO₃^- was mainly leached at the end of leaching process and still had a trend of increase.     

非饱和土壤优先流运动特性的染色示踪研究

由于日益增长的环境问题,作为节水灌溉的基础——土壤中优先流的运动特性越来越受到关注。利用亮蓝对初始含水量不同的2组土壤中的非均匀流动进行了示踪研究。通过染色示踪试验采集土壤表平面的溶质迁移动态图像,结合图像分析讨论2种不同初始含水量土壤表平面溶质运移的变异过程。结果表明:2种初始含水量土壤中土样表面的溶质运移分布都不均匀;不同初始含水量土壤中土样表面溶质运移的动态过程不同;随着入渗时间与入渗水量的增大,2种初始含水量土壤中土样表面的分维数呈现非线性增长,染色剂的分布面积非线性扩大,但扩大程度非线性减小。