土壤质量评价指标体系与评价方法研究进展与展望

在过去的10年里,土壤质量评价成为国际研究的热点。综述了土壤质量评价指标体系和土壤质量评价方法。在总结、分析国内外土壤质量评价指标体系与评价方法的最新进展和研究不足的基础上,提出未来我国土壤质量研究工作的建议。     

不同土地利用方式土壤质量评价

通过应用现有的国际通用的土壤质量标准评价体系,对影响土壤质量的物理、化学因子,例如含水量、密度、pH、有机质等采用相应的标准评价方法,结合土壤在不同土地利用方式上的差异,得出不同土地利用方式上土壤质量的显著性差异。     

土壤质量与持续环境——Ⅲ.土壤质量评价的生物学指标

土壤生物是维持土壤质量的重要组分，土壤生物不指标能敏感地反映土壤质量的变化，是土壤质量评价指标体系中不可缺少的组成部分，但目前仍十分缺乏这方面的指标。本文对《土壤质量与持续环境》一书中土壤质量评价的生物学指标进行了评述。     

土壤文化历史档案记录功能评价研究——以河南仰韶村文化遗址为例

目前土壤文化历史档案记录功能研究主要集中于理论和概念,评价指标和标准中定性成分较多,定量成分较少。对此,该研究通过选取遗物遗迹指标(陶片、石器、遗骸、灰坑、灰烬层和文化层)和诊断指标(色度、磁化率、粒度、矿质全量、容重、有机碳同位素、孢粉、植硅体和炭屑),依据指标是否存在或达标,采用定性与定量相结合的方法,建立土壤文化历史档案记录功能评价体系。由于遗物遗迹科研价值明显,所以遗物遗迹指标的重要性大于诊断指标,而遗迹(灰坑、灰烬层和文化层)与遗物(陶片、石器和遗骸)相比,土壤科研价值明显,所以遗迹指标的重要性大于遗物指标,据此将该功能划分为六个等级:一级表示功能完整,发现所有遗物遗迹指标,且数量丰富;二级表示功能明显,发现大量遗迹指标,但遗物指标部分存在;三级表示功能部分明显,发现大量遗物指标,遗迹指标部分存在;四级表示功能不明显,未发现遗物遗迹指标,但诊断指标达标;五级表示功能微弱,未发现遗迹遗物指标,部分诊断指标达标;六级表示无此功能,未发现遗物遗迹指标,诊断指标不达标。运用该评价方法,在河南仰韶村文化遗址内,分别选取一个受到古人类活动干扰的土壤剖面(简称文化剖面)和未受到古人类活动干扰的土壤剖面(简称自然剖面),基于典型剖面的土壤理化性质分析和对比,选取适合该遗址的评价指标和标准,并开展功能评价,从而明确不同级别区域的保护力度和科研价值。     

土壤盐渍化研究展望

介绍了第十五届世界土壤学年会有关土壤盐渍化及盐渍土研究的主要内容和发展趋向，并提出了土壤盐渍化及盐渍进一步深入研究的重要领域。     

上海典型新建绿地的土壤质量评价

本文对上海近年来新建的典型绿地─延中、凯桥、华山、黄兴和公路浦东龙东大道、远东大道沿线的景观绿地进行了土壤现状调查。结果表明:上海典型新建绿地的土壤主要为碱性和强碱性;EC 值基本达标;有机质含量达标率在 60%以上,但含量偏低;土壤容重偏高,通气性差;阳离子代换量总体偏低。使用山泥、泥炭客土的土壤质量较好,可以满足城市绿化造景的需要。建议园林植物要 “适土适栽”、“适地适树”,要充分利用生活垃圾、污泥堆肥等有机质含量高的城市废弃物来改良土壤,对现有的城市绿化土壤质量评价指标需要进一步完善,建议增加 CEC、土壤排水能力等土壤质量评价指标。     

海南岛土壤质量系统评价与区域特征探析

研究建立了海南岛热带地区土壤质量系统评价模型 ,并对该岛土壤质量进行综合评价 ,结果表明海南岛土壤养分有效性为主要限制因子 ,水分有效性和根系适宜性状较好 ,土壤综合质量中等偏上。与林地相比其他土地利用方式土壤质量均有所下降     

宁夏枸杞主产区土壤化学肥力现状及评价

枸杞是著名的中药材,也是宁夏的优势特色作物,为探明宁夏枸杞主产区土壤质量现状,于2021年对宁夏枸杞主产区中宁县7个乡镇的枸杞园土壤进行了多点调查及土壤养分测定,依据我国北方果园养分划分标准及其他产区枸杞园养分状况对宁夏枸杞主产区养分现状进行评价。研究结果表明：（1）在枸杞返青前0～100 cm剖面土壤含水量平均约14.5%;耕层（0～40 cm）pH、EC均值分别为8.02、817.4μS/cm,有机质含量均值为8.59g/kg,碱解氮、有效磷、速效钾含量均值分别为62.2、104.1、273.1 mg/kg。（2）0～100 cm剖面含水量变化较大,其中70～80 cm含水量相对较低;从表层10 cm至下层100 cm土壤盐分含量呈递减趋势,表层EC值达1045.4μS/cm,较下层100 cm处高47.8%;碱解氮、有效磷和速效钾含量从20 cm至100 cm均呈递减趋势,碱解氮含量在40 cm处变化幅度较大,有效磷和速效钾含量在60 cm处变化幅度较大。（3）依据果园养分质量评价标准,耕层0～40 cm土壤质量总体偏碱性,表层0～10 cm轻度盐渍化,20 cm以下虽未达到盐渍...     

土壤质量研究进展与方向

本文在简要介绍和分析土壤质量的概念及其与持续农业的关系，土壤质量的评价方法，土壤质量变化的土壤退化的动因，危害及动态监测方法等方面的最新国际研究进展的基础上，对我国今后土壤质量研究工作的方向和重点领域提出了建议。     

土壤质量与持续环境Ⅱ.土壤质量评价的碳氮指标

土壤质量评价中碳氮指标的表示方法很多，其中生物活性碳、氮能敏感地反映土壤质量的变化，是重要的评价指标，但其测定困难，在土壤质量评价中的认识并不统一。本文对《土壤质量与持续环境》（美国土壤学会１９９４年发行）一书中土壤质量评价在碳氮方面的指标、测定方法以及土壤利用管理对这些指标的影响进行了评述。     

Effects of biodegradable mulch on soil quality

Biodegradable plastic films are desirable alternatives to traditional black polyethylene plastic for use as mulches in agroecosystems. Efforts are ongoing to engineer biodegradable plastic mulches that could be incorporated into the soil at the end of the crop season, and decomposed by microorganisms, ultimately to CO₂, H₂O, and biomass. Whether changes in soil quality occur during or following biodegradation is unknown. An 18-month study evaluated the effects on soil quality following burial of four potentially biodegradable mulches and a no mulch control in high tunnel and open field tomato production systems across three geographically distinct locations (Knoxville, TN; Lubbock, TX; Mount Vernon, WA). The mulch treatments included: two starch-based mulches (BioAgri^® Ag-Film and BioTelo Agri); one experimental 100% polylactic acid mulch (Spunbond-PLA-10); one cellulose-based mulch (WeedGuardPlus; positive control); and a negative control (no mulch). The soil management assessment framework (SMAF) was used to calculate a soil quality index (SQI) according to five dynamic soil properties: microbial biomass carbon, β-glucosidase, electrical conductivity, total organic carbon (TOC), and pH. Within the 18-month evaluation period, the effects of the biodegradable mulches on the SQI were minor, and dependent upon production system and time of incubation at all locations. In general, the SQI was higher in the high tunnel systems for some of the mulch treatments at Knoxville and Lubbock but the opposite was true at Mount Vernon. By the final sampling at 18 months, the SQI was lowest for WeedGuardPlus at Lubbock and Mount Vernon but at Knoxville, the WeedGuardPlus SQI was not significantly different from the no mulch control. Of the five SMAF indicators evaluated, soil microbial biomass and β-glucosidase activity were the most responsive to mulch and production systems, supporting the use of these variables as soil quality indicators for short-term changes due to this agricultural management practice.     

Long-term soil management effects on crop yields and soil quality in a dryland Alfisol

A long-term experiment was conducted with the objective of selecting the appropriate land management treatments and to identify the key indicators of soil quality for dryland semi-arid tropical Alfisols. The experiment was conducted using a strip split–split plot design on an Alfisol (Typic Haplustalf) in southern India under sorghum (Sorghum vulgare (L))-castor (Ricinus communis (L)) bean rotation. The strip constituted two tillage treatments: conventional tillage (CT) and minimum tillage (MT); main plots were three residues treatments: sorghum stover (SS), gliricidia loppings (GL), ‘no’ residue (NR) and sub plots were four nitrogen levels: 0 (N₀), 30 (N₃₀), 60 (N₆₀), and 90 kg ha⁻¹ (N₉₀). Soil samples were collected after the sixth and seventh year of experimentation and were analyzed for physical, chemical and biological parameters. Sustainable yield index (SYI) based on long-term yield data and soil quality index (SQI) using principal component analysis (PCA) and linear scoring functions were calculated. Application of gliricidia loppings proved superior to sorghum stover and no residue treatments in maintaining higher SQI values. Further, increasing N levels also helped in maintaining higher SQI. Among the 24 treatments, the SQI ranged from 0.90 to 1.27. The highest SQI was obtained in CTGLN₉₀ (1.27) followed by CTGLN₆₀ (1.19) and MTSSN₉₀ (1.18), while the lowest was under MTNRN₃₀ (0.90) followed by MTNRN₀ (0.94), indicating relatively less aggradative effects. The application of 90 kg N ha⁻¹ under minimum tillage even without applying any residue (MTNRN₉₀) proved quite effective in maintaining soil quality index as high as 1.10. The key indicators, which contributed considerably towards SQI, were available N, K, S, microbial biomass carbon (MBC) and hydraulic conductivity (HC). On average, the order of relative contribution of these indicators towards SQI was: available N (32%), MBC (31%), available K (17%), HC (16%), and S (4%). Among the various treatments, CTGLN₉₀ not only had the highest SQI, but also the most promising from the viewpoint of sustainability, maintaining higher average yield levels under sorghum–castor rotation. From the view point of SYI, CT approach remained superior to MT. To maintain the yield as well as soil quality in Alfisols, primary tillage along with organic residue and nitrogen application are needed.     

Long-term tillage effects on soil quality

Public interest in soil quality is increasing, but assessment is difficult because soil quality evaluations are often purpose- and site-specific. Our objective was to use a systems engineering methodology to evaluate soil quality with data collected following a long-term tillage study on continuous corn (Zea mays L.). Aggregate characteristics, penetration resistance, bulk density, volumetric water content, earthworm populations, respiration, microbial biomass, ergosterol concentrations, and several soil-test parameters (pH, P, K, Ca, Mg, Total-N, Total-C, NH₄-N, and NO₃-N) were measured on Orthic Luvisol soil samples collected from Rozetta and Palsgrove silt loam (fine-silty, mixed, mesic Typic Hapludalfs) soils. Plots managed using no-till practices for 12 years before samples were collected for this study had surface soil aggregates that were more stable in water and had higher total carbon, microbial activity, ergosterol concentrations, and earthworm populations than either the chisel or plow treatments. Selected parameters were combined in the proposed soil quality index and gave ratings of 0.48, 0.49, or 0.68 for plow, chisel, or no-till treatments, respectively. This indicated that long-term no-till management had improved soil quality. The prediction was supported by using a sprinkler infiltration study to measure the amount of soil loss from plots that had been managed using no-till or mold-board plow tillage. We conclude that no-till practices on these soils can improve soil quality and that the systems engineering methodology may be useful for developing a more comprehensive soil quality index that includes factors such as pesticide and leaching potentials.     

生物质能研究现状及展望

生物质能是当前能源和生态环境领域研究的热点。该文鉴于目前能源、生态环境状况以及生物质能的利用现状、所处的战略地位，对当前生物质能研究的四个热点：生物质能开发利用潜力、生物质能利用对生态环境影响、生物质能开发利用技术研究、生物质能开发利用可行性分析及其发展前景进行了阐述，同时就发展生物质能需要解决的问题作了简要的分析,进而对生物质能开发利用研究有个全面的科学的认识。在能源需求、生态环境保护和发展经济的拉动下，生物质能在未来将具有广阔的发展前景。     

Watershed-scale assessment of soil quality in the loess hills of southwest Iowa

Soil quality is a concept that integrates soil biological, chemical and physical factors into a framework for soil resource evaluation. Conventional tillage practices can result in a loss of soil organic matter and decreased soil quality. The potential for soil quality degradation with tillage may vary depending upon landscape position and the spatial distribution of critical soil properties. Information on how to accurately integrate soil spatial information across fields, landscapes and watersheds is lacking in the literature. The primary objective of this study was to evaluate the long-term effect of conventional and ridge-tillage on soil quality in three small watersheds at the Deep Loess Research Station near the town of Treynor in southwest Iowa. Soil types included Monona silt loams in summit positions, Ida or Dow silt loams in backslope positions, and Napier or Kennebec silt loams in footslope positions. We removed surface soil cores from transects placed along topographic gradients in each watershed and quantified total soil organic C (SOC), total soil N (TN), particulate organic matter C (POM-C) and N (POM-N), microbial biomass C (MB-C), N mineralization potential (PMIN-N), nitrate N, extractable P and K, pH, water-stable macroaggregates (WSA), and bulk density (BD). We used terrain analysis methods to group the data into landform element classes to evaluate the effect of topographic position on soil quality. Results indicate that soil quality is higher under long-term ridge-tillage compared with conventional tillage. Soil quality differences were consistently documented among the three watersheds by: (1) quantification of soil indicator variables, (2) calculation of soil quality index values, and (3) comparison of indicator variable and index results with independent assessments of soil function endpoints (i.e. sediment loss, water partitioning at the soil surface, and crop yield). Soil quality differences under ridge-till were found specifically for the backslope and shoulder landform elements, suggesting that soil quality increases on these landform elements are responsible for higher watershed-scale soil quality in the ridge-tilled watershed.     

Mineralisation and humification of plant matter in soil samples as a tool in the testing of soil quality

Since life is inevitably dependent on the assimilation and dissimilation of carbon, and since most of the organic carbon is bound in soil humic matter, the mineralisation and humification of plant carbon in soil should be monitored, so as to evaluate soil quality and avoid ecological risks. For this reason we suggested an incubation test of thirty days in duration with soil samples amended or not with lucerne meal as a source of plant carbon. During the incubation period, CO₂ release is to be measured repeatedly, and thereafter contents of humic acids (HA) and fulvic acids (FA) should be estimated and compared with those determined in the original soil samples. Our results obtained with samples from non-fertilized or long-term (?>?40 years) fertilized plots of two field trials indicate that fertilization by NPK?+ farm yard manure resulted in (i) a slight enhancement of C mineralisation, i.e., CO₂ release from soil, and (ii) a significant increases of HA and FA contents. Soil samples from a reclaimed mine spoil, and either fertilised or not with sewage sludge did not show distinct differences in the same parameters. The practicability of the incubation test as a tool in the monitoring of soil quality should be further proved using samples from differently affected soils.     

A participatory soil quality assessment in Northern Ethiopia's Mai-Negus catchment

Local communities often have substantial knowledge related to trends in soil quality and the associated limiting factors. Despite this, soil quality (SQ) degradation is a critical problem in Ethiopia and there is little or insufficient scientific information documenting local community experience in assessing SQ. This paper presents experiences of local communities in diagnosis of SQ and assesses the contribution of local knowledge as a strategy for sustainable development decision making within the Mai-Negus catchment of northern Ethiopia. Participatory transect-walks, group discussions and field observation which complemented by household interview were used to acquire data. Farmers identified SQ indicators e.g., crop yield, soil depth, erosion and sedimentation as their basis of categorizing the soils into high, medium and low SQ. They were also able to identify severely degraded areas (hotspots) and underlying causes. Significant variations (P ≤ 0.05) were shown between the proportions of farmers used certain SQ indicator and those who didn't while categorizing SQ. Local farmers involved in this study demonstrated their capability to suggest appropriate land management solutions for specific problems. This study demonstrates the benefit of involving local farmers in both problem identification and solution development so that anti-degradation technologies can easily be implemented and adopted.     

Effect of grinding variables on the NH4HCO3 –dtpa soil test values for Fe,Zn, Mn,Cu, P,and K

Abstract

The effect of grinding force, time, and weight of soil on the NH₄HCO₃ ‐DTPA extractable levels of Fe, Zn, Mn, Cu, P and K from 10 Colorado soils were studied. It was found that the amount of extractable iron and zinc increased, with an increase in force or time of grinding. The significant interaction between time and force of grinding indicates that the combined effect of the larger force and the longer time in increasing the extractable levels of Fe and Zn was greater than the additive effects of these factors. The weight of soil being ground had a small effect on extractable Fe (significant at 10% level) and no effect on other elements. Extractable levels of Mn, Cu, P, and K were not affected by the grinding treatments. Iron was increased 112% and zinc was increased 44% due to the combined effects of the larger force and the longer time of grinding in soils averaging 12.8 and 1.1 ppm in Fe and Zn, respectively. It is concluded that grinding variables should be standardized, otherwise interlaboratory comparisons and standardized interpretations of results are not possible.     

Defining the validity of a biochemical index of soil quality

 The native soils of Galicia (NW Spain) exhibit a biochemical equilibrium such that total soil N is a function of five biochemical and microbiological parameters: microbial biomass C, mineralized N, phosphomonoesterase, β-glucosidase and urease activities. To investigate whether the ratio of the total N calculated from biochemical soil properties (Nc) and the total N as measured by the Kjeldahl method (Nk; Nc/Nk) can be used as an index of soil quality, we determined these variables and consequently the ratio in three kinds of disturbed soils: an artificially Cu-contaminated soil, two lignite mine soils, and a number of arable soils. In none of the studied soils did the individual biochemical parameters respond consistently to the factors influencing soil quality, but in all cases soil degradation was reflected by the Nc/Nk value, which differed more or less markedly from 100%. Nc/Nk can therefore be used for the rapid evaluation of soil degradation, since it distinguishes among biochemically balanced soils, soils in a transient state of high microbiological and biochemical activity and degraded soils. It can also serve as a reliable basis for the rapid calculation of the "ecological dose" (ED₅₀) of soil pollutants. The use of Nc/Nk as an objective index of the biochemical quality of soils is recommended. Received: 20 December 1998