Spatial distribution and influencing factors of farmland soil organic matter and trace elements in the Nansihu Region

2014 ◽  
Vol 34 (6) ◽  
Author(s):  
武婕 WU Jie ◽  
李玉环 LI Yuhuan ◽  
李增兵 LI Zengbing ◽  
方正 FANG Zheng ◽  
钟豫 ZHONG Yu
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Organic Matter ◽  
Influencing Factors ◽  
Farmland Soil

scholarly journals Assessment of Potato Farmland Soil Nutrient Based on MDS-SQI Model in the Loess Plateau

2021 ◽  
Vol 13 (7) ◽  
pp. 3957
Author(s):  
Yingying Xing ◽  
Ning Wang ◽  
Xiaoli Niu ◽  
Wenting Jiang ◽  
Xiukang Wang
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Fertility ◽  
Soil Quality ◽  
Soil Nutrients ◽  
Organic Matter Content ◽  
Soil Nutrient ◽  
Matter Content ◽  
Soil Organic Matter Content ◽  
Farmland Soil

Soil nutrients are essential nutrients provided by soil for plant growth. Most researchers focus on the coupling effect of nutrients with potato yield and quality. There are few studies on the evaluation of soil nutrients in potato fields. The purpose of this study is to investigate the soil nutrients of potato farmland and the soil vertical nutrient distributions, and then to provide a theoretical and experimental basis for the fertilizer management practices for potatoes in Loess Plateau. Eight physical and chemical soil indexes were selected in the study area, and 810 farmland soil samples from the potato agriculture product areas were analyzed in Northern Shaanxi. The paper established the minimum data set (MDS) for the quality diagnosis of the cultivated layer for farmland by principal component analysis (PCA), respectively, and furthermore, analyzed the soil nutrient characteristics of the cultivated layer adopted soil quality index (SQI). The results showed that the MDS on soil quality diagnosis of the cultivated layer for farmland soil included such indicators as the soil organic matter content, soil available potassium content, and soil available phosphorus content. The comprehensive index value of the soil quality was between 0.064 and 0.302. The SPSS average clustering process used to classify SQI was divided into three grades: class I (36.2%) was defined as suitable soil fertility (SQI < 0.122), class II (55.6%) was defined as moderate soil fertility (0.122 < SQI < 0.18), and class III (8.2%) was defined as poor soil fertility (SQI > 0.186). The comprehensive quality of the potato farmland soils was generally low. The proportion of soil nutrients in the SQI composition ranged from large to small as the soil available potassium content = soil available phosphorus content > soil organic matter content, which became the limiting factor of the soil organic matter content in this area. This study revolves around the 0 to 60 cm soil layer; the soil fertility decreased gradually with the soil depth, and had significant differences between the respective soil layers. In order to improve the soil nutrient accumulation and potato yield in potato farmland in northern Shaanxi, it is suggested to increase the fertilization depth (20 to 40 cm) and further study the ratio of nitrogen, phosphorus, and potassium fertilizer.

scholarly journals Spatial control of carbon dynamics in soil by microbial decomposer communities

2020 ◽  
Author(s):  
Holger Pagel ◽  
Björn Kriesche ◽  
Marie Uksa ◽  
Christian Poll ◽  
Ellen Kandeler ◽  
...  
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Organic Matter ◽  
Distribution Patterns ◽  
Microbial Succession ◽  
Thin Sections ◽  
Spatial Control ◽  
Soil Organic Matter Turnover ◽  
Microbial Decomposer ◽  
Modelling Approach

&lt;p&gt;Trait-based models have improved the understanding and prediction of soil organic matter dynamics in terrestrial ecosystems. Microscopic observations and pore scale models are now increasingly used to quantify and elucidate the effects of soil heterogeneity on microbial processes. Combining both approaches provides a promising way to accurately capture spatial microbial-physicochemical interactions and to predict overall system behavior. The present study aims to quantify controls on carbon (C) turnover in soil due to the mm-scale spatial distribution of microbial decomposer communities in soil. A new spatially explicit trait-based model (SpatC) has been developed that captures the combined dynamics of microbes and soil organic matter (SOM) by taking into account microbial life-history traits and SOM accessibility. Samples of spatial distributions of microbes at &amp;#181;m-scale resolution were generated using a spatial statistical model based on Log Gaussian Cox Processes which was originally used to analyze distributions of bacterial cells in soil thin sections. These &amp;#181;m-scale distribution patterns were then aggregated to derive distributions of microorganisms at mm-scale. We performed Monte-Carlo simulations with microbial distributions that differ in mm-scale spatial heterogeneity and functional community composition (oligotrophs, copiotrophs and copiotrophic cheaters). Our modelling approach revealed that the spatial distribution of soil microorganisms triggers spatiotemporal patterns of C utilization and microbial succession. Only strong spatial clustering of decomposer communities induces a diffusion limitation of the substrate supply on the microhabitat scale, which significantly reduces the total decomposition of C compounds and the overall microbial growth. However, decomposer communities act as functionally redundant microbial guilds with only slight changes in C utilization. The combined statistical and process-based modelling approach derives distribution patterns of microorganisms at the mm-scale from microbial biogeography at microhabitat scale (&amp;#181;m) and quantifies the emergent macroscopic (cm) microbial and C dynamics. Thus, it effectively links observable process dynamics to the spatial control by microbial communities. Our study highlights a powerful approach that can provide further insights into the biological control of soil organic matter turnover.&lt;/p&gt;

The changes in soil organic matter in a forest-cultivation sequence traced by stable carbon isotopes

Soil Research ◽  
2003 ◽  
Vol 41 (7) ◽  
pp. 1317 ◽  
Author(s):  
Q. M. Liu ◽  
S. J. Wang ◽  
H. C. Piao ◽  
Z. Y. Ouyang
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Forest Soil ◽  
C3 Plants ◽  
Organic Carbon Content ◽  
Photosynthetic Pathway ◽  
Δ13c Values ◽  
Size Fractions ◽  
Density Fractions ◽  
Farmland Soil

There is an obvious difference in δ13C values between plants that assimilate carbon via the C3 photosynthetic pathway and those that do so by the C4 photosynthetic pathway. In terms of this characteristic, we analysed the organic carbon content and δ13C values of total soil and δ13C values in different size and density fractions of profile-soil samples either in farmland or in forestland near the Maolan Karst virgin forest, south-west China. This is an area where C3 plants grew previously, now replaced by C4 plants. Deforestation has accelerated the decomposition rate of soil organic matter and reduced the proportion of active components in soil organic matter and thus soil fertility. The δ13C values of different size fractions in forest soil are δ13Ccoarse sand < δ13Cfine sand < δ13Ccoarse silt < δ13Cclay < δ13Cfine silt, and the δ13C values of different size fractions in farmland soil are δ13Ccoarse sand > δ13Cfine sand > δ13Ccoarse silt > δ13Cclay > δ13Cfine silt, indicating that soil organic matter is fresh in coarse sand and oldest in fine silt. The δ13C values of different density fractions in forest soil are δ13Clight < δ13Cheavy, and the δ13C values of different density fractions in farmland soil are δ13Clight > δ13Cheavy, indicating that the soil organic matter is fresh in light fractions and old in heavy fractions.

scholarly journals Comparison of Different Spatial Regression Methods for Predicting Organic Matter Content in Soil

2022 ◽  
Author(s):  
Xumeng Zhang ◽  
Wuping Zhang ◽  
Mingjing Huang ◽  
Li Gao ◽  
Lei Qiao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Organic Matter ◽  
Land Use Planning ◽  
Prediction Accuracy ◽  
Meteorological Data ◽  
Organic Matter Content ◽  
Spatial Prediction ◽  
Matter Content ◽  
Soil Organic Matter Content

Abstract Dynamic changes in soil organic matter content affects the sustainable supply of soil water and fertilizer and impacts the stability of soil ecological function. Understanding the spatial distribution characteristics of soil organic matter will help deepen our understanding of the differences in soil organic matter content, soil formation law; such understanding would be useful for rational land use planning. Taking terrain data, meteorological data, and remote sensing data as auxiliary variables and the ordinary Kriging (OK) method as a control, this study compares the spatial prediction accuracies and mapping effects of various models (MLR, RK, GWR, GWRK, MGWR, and MGWRK) on soil organic matter. Our results show that the spatial distribution trend of soil organic matter predicted by each model is similar, but the prediction of composite models can reflect more mapping details than that of unitary models. The OK method can provide better support for spatial prediction when the sampling points are dense; however, the local models are superior in dealing with spatial non-stationarity. Notably, the MGWR model is superior to the GWR model, but the MGWRK model is inferior to the GWRK model. As a new method, the prediction accuracy of MGWRK reached 47.72% for the OK and RK methods and 40.08% for the GWRK method. The GWRK method achieved a better prediction accuracy. The influence mechanism of soil organic matter is complex, but the MGWR model more clearly reveals the complex nonlinear relationship between soil organic matter content and factors influencing it. This research can provide reference methods and mapping technical support to improve the spatial prediction accuracy of soil organic matter.

Distribution of metallic trace elements (ETM) in surface soils around the Mediouna discharge (southern of Casablanca)

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Samples ◽  
The Other ◽  
Surface Soils ◽  
Other Hand ◽  
Metallic Trace Elements ◽  
Low Concentrations ◽  
Uncontrolled Landfill

The objective of present research was to characterize the surface soils located at 300, 600 and 1000 m of an uncontrolled landfill. The work also aims to evaluate the levels and spatial distribution of metallic trace elements (Cd, Pb, Cu, Ni, Zn, Cr, Co and As) in these soils. Soil samples were collected in 36 points around the landfill. Results showed that Cd, Pb, Zn are concentrated in the soils rich in clay and carbonates, and in organic matter, located at 300 m from the landfill. The basic pH of all soils enhances the retention of these metals. On the other hand, As present in soils at 300, 600 and 1000 m at concentrations slightly higher than those of referenced soils were apparently mobilized by water from the solid/water interfaces. The other metals Cu, Ni, Co, Cr are present at very low concentrations.

Influence of humus acids on mobility and biological availability of iron, zinc and copper

2015 ◽  
Vol 2 (1) ◽  
pp. 73-78
Author(s):  
A. Fateev ◽  
D. Semenov ◽  
K. Smirnova ◽  
A. Shemet
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Sand Culture ◽  
Humic And Fulvic Acids ◽  
Cultivation Medium ◽  
Mobile Forms

Soil organic matter is known as an important condition for the mobility of trace elements in soils, their geo- chemical migration and availability to plants. However, various components of soil organic matter have differ- ent effect on these processes due to their signifi cant differences in structure and properties. Aim. To establish the role of humic and fulvic acids in the process of formation of microelement mobility in soils and their accu- mulation in plants. Methods. A model experiment with sand culture was used to investigate the release of trace elements from preparations of humic and fulvic acids and their uptake by oat plants. Results. It was found that among biologically needed elements humic acids are enriched with iron, fulvic acids – with zinc, and copper distribution between these two groups of substances may be characterized as even. These elements have un- equal binding power with components of soil organic matter, as evidenced by their release into the cultivation medium and accumulation in plants. In the composition of fulvic acids zink has the most mobility – up to 95 % of this element is in the form, accessible for plants; the lowest mobility was demonstrated by copper in the composition with humic acids, for which no signifi cant changes in the concentration of mobile forms in the substrate and in the introduction to the test culture were registered. Despite signifi cantly higher iron content in humic acids, the application of fulvic acids in the cultivation medium provides a greater increase in the con- centration of mobile forms of this element. Conclusions. The results confi rm the important role of organic sub- stances of fulvic nature in the formation of zinc and iron mobility in the soil and their accumulation in plants.

Sign in / Sign up

Export Citation Format

Share Document