scholarly journals Soil gross nitrogen transformations in forestland and cropland of Regosols

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Ren ◽  
Jinbo Zhang ◽  
Hamidou Bah ◽  
Christoph Müller ◽  
Zucong Cai ◽  
...  
Keyword(s):  
Land Use ◽  
Southwest China ◽  
Nitrification Rate ◽  
Land Uses ◽  
Nitrogen Transformations ◽  
N Losses ◽  
Retention Capacity ◽  
N Transformations ◽  
Autotrophic Nitrification ◽  
Land Use Types

AbstractSoil gross nitrogen (N) transformations could be influenced by land use change, however, the differences in inherent N transformations between different land use soils are still not well understood under subtropical conditions. In this study, an 15N tracing experiment was applied to determine the influence of land uses on gross N transformations in Regosols, widely distributed soils in Southwest China. Soil samples were taken from the dominant land use types of forestland and cropland. In the cropland soils, the gross autotrophic nitrification rates (mean 14.54 ± 1.66 mg N kg−1 day−1) were significantly higher, while the gross NH4+ immobilization rates (mean 0.34 ± 0.10 mg N kg−1 day−1) were significantly lower than those in the forestland soils (mean 1.99 ± 0.56 and 6.67 ± 0.74 mg N kg−1 day−1, respectively). The gross NO3− immobilization and dissimilatory NO3− reduction to NH4+ (DNRA) rates were not significantly different between the forestland and cropland soils. In comparison to the forestland soils (mean 0.51 ± 0.24), the cropland soils had significantly lower NO3− retention capacities (mean 0.01 ± 0.01), indicating that the potential N losses in the cropland soils were higher. The correlation analysis demonstrated that soil gross autotrophic nitrification rate was negatively and gross NH4+ immobilization rate was positively related to the SOC content and C/N ratio. Therefore, effective measures should be taken to increase soil SOC content and C/N ratio to enhance soil N immobilization ability and NO3− retention capacity and thus reduce NO3− losses from the Regosols.

The effect of dicyandiamide addition to cattle slurry on soil gross nitrogen transformations at a grassland site in Northern Ireland

2013 ◽  
Vol 152 (S1) ◽  
pp. 125-136 ◽  
Author(s):  
K. L. McGEOUGH ◽  
C. MÜLLER ◽  
R. J. LAUGHLIN ◽  
C. J. WATSON ◽  
M. ERNFORS ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Nitrification Inhibitor ◽  
Organic N ◽  
Ammonium Oxidation ◽  
Nitrogen Transformations ◽  
Cattle Slurry ◽  
N Losses ◽  
N Transformations ◽  
Dominant Process ◽  
Grassland Site

SUMMARYMany studies have shown the efficacy of the nitrification inhibitor dicyandiamide (DCD) in reducing nitrous oxide (N2O) emissions and nitrate (NO3−) leaching. However, there is no information on the effect of DCD on gross soil N transformations under field conditions, which is key information if it is to be used as a mitigation strategy to reduce N losses. The current field study was conducted to determine the effect of DCD on ten gross nitrogen (N) transformations in soil following cattle slurry (CS) application to grassland in Northern Ireland on three occasions (June 2010, October 2010 and March 2011).Ammonium (NH4+) oxidation (ONH4) was the dominant process in total NO3− production (ONH4+ONrec (oxidation of recalcitrant organic N to NO3−)) following CS application, accounting for 0·894–0·949. Dicyandiamide inhibited total NO3− production from CS by 0·781, 0·696 and 0·807 in June 2010, October 2010 and March 2011, respectively. The lower inhibition level in October 2010 was thought to be due to the higher rainfall and soil moisture content in that month compared to the other application times. As DCD strongly inhibited NH4+ oxidation following CS application, it also decreased the rate of total NO3− consumption, since less NO3− was formed. The rates of mineralization from recalcitrant organic-N (MNrec) were higher than from labile organic-N (MNlab) on all occasions. The DCD significantly increased total mineralization (MNrec+MNlab) following CS application in June 2010 and March 2011, but had no significant effect in October 2010. In contrast, the rate of immobilization of labile organic-N (INH4_Nlab) was higher than from recalcitrant organic-N (INH4_Nrec) on all occasions, accounting for 0·878–0·976 of total NH4+ immobilization from CS. The DCD significantly increased total immobilization (INH4_Nrec+INH4_Nlab) when CS was applied in June 2010, but had no significant effect at other times of the year.Dicyandiamide was shown to be a highly effective inhibitor of ammonium oxidation at this grassland site. Although there was evidence that it increased both NH4+ mineralization and immobilization following CS application, its effect on these processes was inconsistent. Further work is required to understand the reason for these inconsistent effects: future improvements in 15N tracer models may help.

scholarly journals Analysis of land stability and land-use change processes in the 19–20th centuries: a case study in Gödöllő Hillside, Hungary

2016 ◽  
Vol 8 (1) ◽  
pp. 39-49
Author(s):  
Krisztina Demény ◽  
Csaba Centeri ◽  
Dániel Szalai
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Change Processes ◽  
Anthropogenic Influence ◽  
Land Uses ◽  
Corine Land Cover ◽  
Land Use Types ◽  
Arable Fields ◽  
Land Cover Map

Abstract The manuscript presents land-use change processes based on former military map analyses. Military maps were derived from the 1770s until the 1890s and later from the CORINE Land Cover map. I observed the transition direction of areal distribution of various land uses. Digitalized maps showed 19-20th century land-use conditions; besides them, we created a grouping system which is based on the intensity of land use. We distinguished six land-use types, ranking them according to the anthropogenic influence (1. built-up areas; 2. arable fields; 3. orchards and vineyards; 4. meadows and pastures; 5. forests; 6. wetlands).

The nitrification inhibitor dicyandiamide increases mineralization–immobilization turnover in slurry-amended grassland soil

2014 ◽  
Vol 152 (S1) ◽  
pp. 137-149 ◽  
Author(s):  
M. ERNFORS ◽  
F. P. BRENNAN ◽  
K. G. RICHARDS ◽  
K. L. MCGEOUGH ◽  
B. S. GRIFFITHS ◽  
...  
Keyword(s):  
Nitrification Inhibitor ◽  
Organic N ◽  
Nitrification Inhibitors ◽  
N Losses ◽  
N Transformations ◽  
Autotrophic Nitrification ◽  
Gross Mineralization ◽  
Soil N Mineralization ◽  
Inhibition Of Nitrification ◽  
Gross N Transformation

SUMMARYNitrification inhibitors are used in agriculture for the purpose of decreasing nitrogen (N) losses, by limiting the microbially mediated oxidation of ammonium (NH4+) to nitrate (NO3−). Successful inhibition of nitrification has been shown in numerous studies, but the extent to which inhibitors affect other N transformations in soil is largely unknown. In the present study, cattle slurry was applied to microcosms of three different grassland soils, with or without the nitrification inhibitor dicyandiamide (DCD). A solution containing NH4+and NO3−, labelled with15N either on the NH4+or the NO3−part, was mixed with the slurry before application. Gross N transformation rates were estimated using a15N tracing model. In all three soils, DCD significantly inhibited gross autotrophic nitrification, by 79–90%. Gross mineralization of recalcitrant organic N increased significantly with DCD addition in two soils, whereas gross heterotrophic nitrification from the same pool decreased with DCD addition in two soils. Fungal to bacterial ratios were not significantly affected by DCD addition. Total gross mineralization and immobilization increased significantly across the three soils when DCD was used, which suggests that DCD can cause non-target effects on soil N mineralization–immobilization turnover.

scholarly journals A signature-based approach to quantify soil moisture dynamics under contrasting land-uses

2021 ◽  
Author(s):  
Ryoko Araki ◽  
Flora Branger ◽  
Inge Wiekenkamp ◽  
Hilary McMillan
Keyword(s):  
Land Use ◽  
Time Series ◽  
Soil Moisture ◽  
Shallow Groundwater ◽  
Storm Event ◽  
Land Uses ◽  
Soil Moisture Dynamics ◽  
Land Use Types ◽  
Event Based ◽  
Moisture Dynamics

Soil moisture signatures provide a promising solution to overcome the difficulty of evaluating soil moisture dynamics in hydrologic models. Soil moisture signatures are metrics that represent catchment dynamics extracted from time series of data and enable process-based model evaluations. To date, soil moisture signatures have been tested only under limited land-use types. In this study, we explore soil moisture signatures’ ability to discriminate different dynamics among contrasting land-uses. We applied a set of nine soil moisture signatures to datasets from six in-situ soil moisture networks worldwide. The dataset covers a range of land-use types, including forested and deforested areas, shallow groundwater areas, wetlands, housing areas, grazed areas, and cropland areas. These signatures characterize soil moisture dynamics at three temporal scales: event, seasonal, and time-series scales. Statistical and visual assessment of extracted signatures showed that (1) storm event-based signatures can distinguish different dynamics for most land-uses, (2) season-based signatures are useful to distinguish different dynamics for some types of land-uses (forested vs. deforested area, greenspace vs. housing area, and deep vs. shallow groundwater area), (3) timeseries-based signatures can distinguish different dynamics for some types of land-uses (forested vs. deforested area, deep vs. shallow groundwater area, non-wetland vs. wetland area, and ungrazed vs. grazed area). We compared signature-based process interpretations against literature knowledge: event-based and time series-based signatures were generally matched well with previous process understandings from literature, but season-based signatures did not. This study demonstrates the best practices of extracting soil moisture signatures under various land-use and climate environments and applying signatures for model evaluations.

scholarly journals Discrepancies in Karst Soil Organic Carbon in Southwest China for Different Land Use Patterns: A Case Study of Guizhou Province

2019 ◽  
Vol 16 (21) ◽  
pp. 4199
Author(s):  
Zhenming Zhang ◽  
Xianfei Huang ◽  
Yunchao Zhou ◽  
Jiachun Zhang ◽  
Xubo Zhang
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Type ◽  
Southwest China ◽  
Potassium Dichromate ◽  
Soil Samples ◽  
Guizhou Province ◽  
Land Uses ◽  
Karst Areas

The assessment of soil organic carbon (SOC) in mountainous karst areas is very challenging, due to the high spatial heterogeneity in SOC content and soil type. To study and assess the SOC storage in mountainous karst areas, a total of 22,786 soil samples were collected from 2,854 soil profiles in Guizhou Province in Southwest China. The SOC content in the soil samples was determined by the oxidation of potassium dichromate (K2Cr2O7), followed by titration with iron (II) sulfate (FeSO4). The SOC storage was assessed based on different land uses. The results suggested that the average SOC density in the top 1.00 m of soil associated with different land uses decreased in the following order: Croplands (9.58 kg m−2) > garden lands (9.07 kg m−2) > grasslands (8.07 kg m−2) > forestlands (7.35 kg m−2) > uncultivated lands (6.94 kg m−2). The SOC storage values in the 0.00–0.10 m, 0.00–0.20 m, 0.00–0.30 m and 0.00–1.00 m soil layers of Guizhou Province were 0.50, 0.87, 1.11 and 1.58 Pg, respectively. The SOC in the top 0.30 m of soil accounted for 70.25% of the total within the 0.00–1.00 m layer in Guizhou Province. It was concluded that assessing SOC storage in mountainous karst areas was more accurate when using land use rather than soil type. This result can supply a scientific reference for the accurate assessment of the SOC storage in the karst areas of southwestern China, the islands of Java, northern and central Vietnam, Indonesia, Kampot Province in Cambodia and in the general area of what used to be Yugoslavia, along with other karst areas with similar ecological backgrounds.

scholarly journals Soil quality evaluation under different land use types in Kersa sub-watershed, eastern Ethiopia

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yared Mulat ◽  
Kibebew Kibret ◽  
Bobe Bedadi ◽  
Muktar Mohammed
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Quality Indicators ◽  
Management Practices ◽  
Land Uses ◽  
Grazing Land ◽  
Data Set ◽  
Eastern Ethiopia ◽  
Land Use Types ◽  
Significant Difference

Abstract Background Soil quality, which can be inferred using indicators that interact synergistically, is affected by land use types and agricultural management practices. This study assessed the status of soil quality under three adjacent land uses (cultivated, grazing, and fallow) in Kersa subwatershed (622 ha). Soil samples were collected from the surface soil (0–20 cm depth) of the identified land uses with three replications and the soil quality parameters were analyzed. A minimum data set of soil quality indicators were selected from physical, chemical, and biological parameters using the literature review and expert opinion method. Linear scoring functions were used to give the unitless scores for the selected data sets, which were then integrated into a soil quality index (SQI). Results The results revealed that bulk density, aggregate stability, pH, cation exchange capacity (CEC), available P, and soil organic carbon (SOC) had a significant difference in SQI among the different land uses. The soil quality indices were 0.69 for grazing land, 0.62 for cultivated land, and 0.59 for the fallow land. The SQI of all the land uses falls in the intermediate soil quality (0.55 < SQI < 0.70) class. Conclusion In almost all the quality indicators assessed, the grazing land was superior to the cultivated and fallow lands. Therefore, implementing management practices that enhance soil quality like organic matter-controlled systems is imperative for sustainable agricultural production in the study area.

Revegetation modifies patterns of temporal soil respiration responses to extreme-drying-and-rewetting in a semiarid ecosystem

2020 ◽  
Author(s):  
Wenhao Sun
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Soil Respiration ◽  
C Sequestration ◽  
Extreme Drought ◽  
Strongly Correlated ◽  
Land Uses ◽  
Drought Period ◽  
Drying And Rewetting ◽  
Land Use Types

&lt;p&gt;Changes in climate and land-use are altering soil respiration patterns and thus affecting C sequestration rates globally. This study aims to understand the effect of revegetation induced land-use change on the response of soil respiration to precipitation pulses during an extreme-drying-and-rewetting period. Soil respiration (SR) in cropland, grassland, shrubland, and orchard were intensively monitored along with environmental variables during an extreme drought period with precipitation pulse on China&amp;#8217;s Loess Plateau. SR was strongly correlated to soil water content for all land-uses. However, the relationship was highly dependent on land-use types: SR was only strongly suppressed in cropland and orchard when moisture content exceeded 10.8% and 13.7%, respectively, whereas no clear suppression was observed under other land-uses. As a result, the C loss in grassland and shrubland was 49.1-78.9% higher than in cropland following significant precipitation events. In addition, SR was negatively and weakly correlated with soil temperature, indicating the change in the dominant control on SR due to extreme drought. Land-use change alters the response of soil respiration to soil moisture during extreme-drying-and-rewetting periods in this revegetated ecosystem. Its effect on respiration pulses will amplify as extreme climate events increase in the future, which may potentially alter the existing C balance.&lt;/p&gt;

scholarly journals Comparing and modelling land use organization in cities

2015 ◽  
Vol 2 (12) ◽  
pp. 150449 ◽  
Author(s):  
Maxime Lenormand ◽  
Miguel Picornell ◽  
Oliva G. Cantú-Ros ◽  
Thomas Louail ◽  
Ricardo Herranz ◽  
...  
Keyword(s):  
Land Use ◽  
Information And Communication Technologies ◽  
Spatial Organization ◽  
Communication Technologies ◽  
Land Uses ◽  
Land Use Patterns ◽  
Use Patterns ◽  
Land Use Types ◽  
Information And Communication ◽  
Simple Interaction

The advent of geolocated information and communication technologies opens the possibility of exploring how people use space in cities, bringing an important new tool for urban scientists and planners, especially for regions where data are scarce or not available. Here we apply a functional network approach to determine land use patterns from mobile phone records. The versatility of the method allows us to run a systematic comparison between Spanish cities of various sizes. The method detects four major land use types that correspond to different temporal patterns. The proportion of these types, their spatial organization and scaling show a strong similarity between all cities that breaks down at a very local scale, where land use mixing is specific to each urban area. Finally, we introduce a model inspired by Schelling's segregation, able to explain and reproduce these results with simple interaction rules between different land uses.

Sign in / Sign up

Export Citation Format

Share Document