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1.
Eurasian Soil Science - A hypothesis about an increase in the area of waterlogged soils on arable lands of Tambov oblast in the recent decades was tested by the methods of retrospective monitoring...  相似文献   

2.
The current study addressed the spatial variation of soil organic matter (SOM), total nitrogen (TN), extractable phosphorus (EP), and extractable potassium (EK) in agricultural soils of a representative region, northeast China. Soil cation exchange capacity (CEC) and the effects of landscape attributes and land use were also investigated. The techniques used included conventional statistics, geostatistics, and geographic information systems (GIS). Our study demonstrated that EP had the greatest coefficient of variation (CV), and CEC had the least CV. The experimental semivariograms of the five soil chemical properties included in this study were all fitted with exponential models. The five soil variables all showed moderate spatial dependence. The SOM, EK, and CEC decreased with increasing altitude. Significant negative relationships were found between the slope gradient and EP, EK, and CEC. Relatively steeper slopes might result in greater soil erosion, which leads to a decline in soil nutrients. Soil types had significant impacts on all soil chemical properties, which reflect the effect of the parent soil material. In general, the mean values of soil variables for vegetable land were statistically greater than those for upland and paddy fields. After being divided into two parts along the Yinma River, soil samples of the western part have statistically greater SOM, EP, EK, and CEC values than those collected from the eastern part.  相似文献   

3.
Eurasian Soil Science - Active development of the Cis-Ol’khon area in the past decades enhanced the conflicts between land users related to multifunctional land use (residential,...  相似文献   

4.
Soil as a separate natural body occupies certain area with its own set of spectral characteristics within the RED–NIR spectral space. This is an ellipse-shaped area, and its semi-major axis is the soil line for a satellite image. The spectral area for a bare soil surface is neighboring to the areas of black carbon, straw, vegetating plants, and missing RED–NIR values. A reliable separation of the bare soil surface within the spectral space is possible with the technology of spectral neighborhood of soil line. The accuracy of this method is 90%. The determination of the bare soil surface using vegetation indices, both relative (NDVI), and perpendicular (PVI), is incorrect; the accuracy of these methods does not exceed 65%, and for most of the survey seasons it may be lower than 50%. The flat part of the “tasseled cap” described as the soil line, is not a synonym for the area of the bare soil surface. The bare soil surface on the RED–NIR plots occupies significantly smaller areas than the area of soil line according to Kauth and Thomas.  相似文献   

5.
Eurasian Soil Science - The results of a greenhouse experiment with the humus horizon of a sandy loamy soddy-podzolic soil are presented. It was contaminated with heavy metals added with sewage...  相似文献   

6.
The mobility and migration capacity of Zn in the soil-plant system were studied in a series of pot experiments with barley as a test plant. The parameters of Zn accumulation depending on the metal concentrations in soils and soil solutions were estimated by soil and water culture methods. Experiments with barley in water culture were performed on a nutrient (soil) solution extracted from soddy-podzolic soil (Albic Retisol (Loamic, Ochric)) to which Zn2+ was added to reach working concentrations increasing from 0.07 to 430 μM. Different responses of barley plants to changes in the concentration of Zn in the studied soil were identified. Ranges of the corresponding concentrations in the soil and aboveground barley biomass were determined. Parameters of Zn accumulation by test plants were determined depending on the metal content in soddypodzolic soil and the soil solution. A new method was proposed for evaluating the buffer capacity of soils with respect to a heavy metal (Zn) using test plants (BCS(P)Zn). The method was used to evaluate the buffering capacity of loamy sandy soddy-podzolic soil. The considered methodological approach offers opportunities for using data obtained during the agroecological monitoring of agricultural lands with heavy metals (HMs), including the contents of exchangeable HMs and macroelements (C and Mg) in soils and concentrations of HMs and (Ca + Mg) in plants, in the calculation of the buffering capacity of the surveyed soils for HMs.  相似文献   

7.
The effect of amorphous silicon dioxide (SiO2) on cadmium behavior in the soil–plant system was studied in a field experiment on a flooded paddy soil slightly contaminated by cadmium. The application of amorphous SiO2 results in a 1.3- to 1.8-fold smaller cadmium accumulation in the aboveground organs of rice and a 1.8- to 2.6-fold decrease in the content of its available compounds, which can be explained by metal sorption on the surface of applied silicon dioxide and by the reaction of monosilicic acid, which forms in the SiO2 solution, with cadmium. The decrease in cadmium availability is most intensive in the first 2 weeks after SiO2 application. Amorphous silicon causes a 26.6% increase in rice productivity in the first season and 72.9% in the second. The data obtained testify to the fact that the application rates of traditional mineral fertilizers can be decreased without risk to rice productivity if silicon compounds are used. They should become an integral and important part of implementing the 4R-STRATEGY for fertilizer application and plant nutrition optimization.  相似文献   

8.
The issue of agricultural land sustainability is important to every part of the world, especially in the developing countries. Based on the data collected by field investigation and laboratory analysis as well as soil classification theory, the authors discuss the applications of soil series in the arid northwestern China. On the one hand, the application in the layout of rational agricultural of oasis farmlands: (1) two soil series, namely, Lanjiabao (main) and Nijiaxiaying, belong to the moderate and extremely arid region in the study area; accordingly, the layout of crops is the spring wheat and maize (main) and winter wheat;(2) Nijiaxiaying (main) and Lanjiabao, however, fall into the warm-cold and extremely arid region, where the winter wheat (main) and spring wheat grow; and (3) the Shangfusi is part of the warm chilly-arid region, which is used as seasonal pastureland. On the other hand, the application on the soil quality of oasis farmlands, the results indicating that among all soil series, the content of N is very low, however, the content of K is abundant, and the content of P is greatly scarce.  相似文献   

9.
The purpose of this laboratory incubation study was to assess the solubility of phosphorus (P) in alum‐treated poultry litter (ATPL) when applied to three Virginia soils at equivalent P‐based rates. Three poultry litter sources (one that had received no alum additions and two that had received alum additions) were utilized in the study. These litter sources and monopotassium phosphate (KH2PO4) were applied at rates of 66, 132, and 197 mg P kg?1 with a 0‐P check treatment included for each soil. Soils were incubated for 1 year, and samples were collected at 1, 3, 6, and 12 months after treatment application. Data collected were used to calculate the relative extractability of P applied in the three litter sources. Results indicated that ATPL applications reduced P solubility compared to untreated poultry litter (NPL); this effect was most significant at 1 month after application. However, at 12 months, significant differences in extractable P between NPL and ATPL treatments were limited at the 66 mg P kg?1 rate. This resulted from continuous decline in the extractability of P applied in the NPL, whereas the extractability of P applied in the ATPL source changed little with time and in some cases increased slightly between the 1‐ and 3‐month sampling periods. Calculated values of relative extractability were influenced not only by litter source but also P application rate, soil type, and incubation time. Therefore, use of relative extractability values as P source coefficients should be done with caution, because experimental protocol can have profound effects on their magnitude.  相似文献   

10.
This paper has investigated the ratios of closely related elements such as Mn, Cr, V, Ni, Co, Cu, Pb, Cd, Ba, Sr, La and Ce in the major soils of China, and the factors affecting them, and explored their use as indicators in soil formation, material transport and environmental pollution. Results show that the effect of soil-forming processes on the ratios of closely related elements varied with different elements, and became greater in the sequence of Ce/La <V/Cr=Ni/Co<Zn/Cu=Zn/Pb<Zn/Cd <Mn/Cr <Ba/Sr. The magnitude of the variation in the ratios of closely related elements depended on the chemical properties of the elements themselves, on the one hand, and the parent material and climatic conditions on the other.  相似文献   

11.
The effects of seven amendments on the distribution and accumulation of copper and cadmium in a soil–rice system were investigated using a pot experiment. Results showed that application of limestone, calcium magnesium phosphate (Ca–Mg–P fertilizer), calcium silicate (silicon fertilizer), Chinese milk vetch, pig manure, and peat significantly decreased the concentrations of Cu and Cd in rice roots by 24.8–75.3% and 9.7–49.9%, respectively. However, no significant difference was observed between zinc sulfate (zinc fertilizer) and the control treatment. The concentrations of Cu and Cd in different parts of rice followed the order: root > straw > grain, and all amendments restrained the transfer of Cu and Cd from rice root to stem. Copper and Cd concentrations in rice stems at the tillering stage were the highest, and then decreased from the tillering stage to the heading stage. However, they increased again at the ripening stage. The results also showed that application of amendments changed Cu and Cd solubility in soil and decreased their bioavailability, which resulted in the reduction of Cu and Cd uptake by rice. Significant correlations between the concentrations of Cu and Cd in soil solutions and in rice stems were found. The result demonstrated that limestone has the best efficiency among all the amendments used in reducing Cu and Cd contamination to rice production.  相似文献   

12.
ABSTRACT

After reviewing previously published literature in citation analysis and literature mapping, this study mapped the literature of food science and explored the relationships found within it. Using articles published in the Journal of Food Science from 2003 through 2005, a stratified random sample of citations was studied to yield a ranked list of the thirteen most frequently cited journals, which formed a core set for further analysis. Using the Science Citation Index and a standard statistical package (SPSS13), a two-dimensional map was created, relationships between the journals were studied, and the discipline of food science was explored. The study is an extension of previously published research covering the years 2000–2002 and attempts to analyze and compare the results across time frames.  相似文献   

13.
Eurasian Soil Science - This article presents the results of the study of a new soil structuring agent—the interpolymer complex of a chitosan biopolymer and a synthetic polymer of polyacrylic...  相似文献   

14.
A New Fusion Technique of Remote Sensing Imagesfor Land Use/Cover   总被引:1,自引:0,他引:1  
In China, accelerating industrialization and urbanization following high-speed economic development and populationincreases have greatly impacted land use/cover changes, making it imperative to obtain accurate and up to date informationon changes so as to evaluate their environmental effects. The major purpose of this study was to develop a new methodto fuse lower spatial resolution multispectral satellite images with higher spatial resolution panchromatic ones to assistin land use/cover mapping. An algorithm of a new fusion method known as edge enhancement intensity modulation(EEIM) was proposed to merge two optical image data sets of different spectral ranges. The results showed that the EEIM image was quite similar in color to lower resolution multispectral images, and the fused product was better able topreserve spectral information. Thus, compared to conventional approaches, the spectral distortion of the fused images wasmarkedly reduced. Therefore, the EEIM fusion method could be utilized to fuse remote sensing data from the same ordifferent sensors, including TM images and SPOT5 panchromatic images, providing high quality land use/cover images.  相似文献   

15.
以田间实验为基础,分析了在不同厚度的有机物覆盖层下土壤温度变化的机制并与未覆盖条件下的土壤温度进行了比较。实验结果表明,有机物覆盖使土壤的日最高温度和日平均温度降低,但却使土壤的日最低温度得以提高。  相似文献   

16.
Abstract

A small‐plot field experiment on microelement pollution (Aluminum (Al), Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Lead (Pb), Zinc (Zn)) was initiated in 1994 at Tass‐puszta Model Farm of Gyöngyös College, Hungary. The experimental plants were winter wheat (Triticum aestivum L. emend. Fiori et Pool.) in 1995, maize (Zea mays L.) in 1996, and sunflower (Helianthus annuus L.) in 1997. Plant samples were taken each year during the vegetation period at phenophases characterized by intensive nutrient uptake. The Al content of crops was not influenced by Al load of the soil. Arsenic accumulation was not considerable in the grain with the highest As load. Cadmium accumulation was significant both in vegetative and reproductive parts of crops with increasing Cd loads of the soil. The Cd content was about 10–40 times higher in treated sunflower seeds than in the control; as a result the seeds were not suitable for consumption. Cadmium can accumulate in the reproductive tissue, so it is a real risk in the food chain. In the first year, Cr(VI) had a toxic effect on wheat, but it was not mobile in the soil–plant system. Vegetative parts of winter wheat accumulated significant amounts of Hg, but maize and sunflower seeds did not accumulate Hg. Lead, Cu, and Zn showed only moderate enrichment in crops following increasing loads in the soil.  相似文献   

17.
18.
Eurasian Soil Science - The paper focuses on the interactions among the components of urban natural complex (surface soil layer, rhizosphere, and aboveground phytomass of herbaceous plants)...  相似文献   

19.
Chloris virgata, a naturally alkali-resistant halophyte, was studied. Various salt–alkali conditions with different salinities and pHs were established by mixing sodium chloride (NaCl), sodium bicarbonate (NaHCO3), sodium sulfate (Na2SO4), and sodium carbonate (Na2CO3), in various proportions. The effects of these salt–alkali conditions on the state of mineral elements in nutrient solutions were analyzed using the GEOCHEM-PC program. The relative growth rate (RGR) and tillering rate of stressed C. virgata were determined. The activities of metal ions in nutrient solutions, apart from potassium (K+), decreased with both increased salinity and pH, and high pH resulted in precipitation of metal ions and phosphate. Consequently, the high pH of salt–alkaline mixed stress could cause severe nutrient stress in plants. However, when pH was 6.40–8.74, the effects of pH on RGR and tillering rate were not significant, and the high pH surrounding roots might be resisted by the root cells and prevented from invading the intracellular environment. Only when pH > 8.74 did the harmful action of high pH emerge, and the increased pH induced the severe decreases of RGR and tillering rate at the same salinity. The results indicated that pH adjustment outside the roots might be a key physiological mechanism for C. virgata resisting alkali stress.  相似文献   

20.
Soil sieving is an essential laboratory procedure in every soil investigation. Soil tillage and mineralogy are critical factors to soil mechanical properties. The implication of tillage and mineralogy on the settings and sieving efficiency of FTLHV–0200 filtra electromagnetic sieve shaker was studied in soils of 13 ecotopes in Eastern Cape Province. The sieve shaker had T = time, I = interval, and P = power settings. The tillage systems were conventional tillage (CT) and no tillage (NT), while the soil mineralogy was mainly quartz and kaolinite. After sieving, 72% of the aggregates were retained on the 2 mm sieve for soils under CT and 69% were retained on the 2 mm sieve for soils under NT. Soils under NT required sieving for at least 5 min to be broken into particle sizes, while soils under CT required at least 35 min. The setting T4I4P4 (time = 35 min, sieving interval = 9 s, and power level = 9) significantly (p ≤ 5%) affected the percentage of aggregates passing through the stack for all the soils irrespective of mineralogy. Quartz-dominated soils required a sieving time of 15 min to disintegrate, while kaolinite-dominated soils required a sieving time of more than 35 min. Sieving efficiency for aggregate analysis was achieved at T4I4P4 setting for soils under CT and at T2I4P3 (time = 5 min, interval = 9 s, power level = 6) setting for soils under NT. While sieving efficiency was achieved at T3I4P3 (time = 15 min, interval = 9 s, power level = 6) setting for quartz-dominated soils and at T4I4P3 (time = 35 min, interval = 9 s, power level = 6) setting for kaolinite-dominated soils.  相似文献   

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