Soil properties are not only influenced by geographical factors, such as parent material, location and latitude. Often differences in land uses (forest, rubber plantation, paddy field, bare land) are known to have specific effects on soil properties. In the context of the project Living Landscapes China (LILAC) these effects were evaluated and the characteristics of soil types under changing conditions in two transects (altitude and parent material in transect 1, land uses in transect 2) in the Naban River Watershed National Nature Reserve were classified. We used field investigations to classify the soil types, as well as laboratory analyses to quantify specific characteristics in samples, taken from the profiles. Soil physical (bulk density, water content, texture) and chemical parameters (total contents of carbon, nitrogen and macro nutrients, ECEC) were investigated.
While differences in altitude did not seem to have profound influences on the soils, effects of land uses were pronounced especially in the first 10 to 20 cm of soil profiles. Soils under forests contain between 1.3 % - 2 % SOC and 0.15 % - 0.17 % TN in the Ah horizon. With contents of 1.2 % SOC and 0.11 % TN (Ah horizon) the profile under agricultural use (paddy rice) clearly contains less SOC and TN than the forest profiles. Fertilization also seemed to have an influence resulting in higher contents of Ca (6 - 12 times) and Mg (up to 4 times) for the topsoil as well as a higher effective CEC (7.9 - 9.3 cmolc/kg) for subsoil horizons of the paddy field compared to forest and rubber sites. The profile under bare land (transect 1) showed higher leaching of nutrients due to the missing soil cover. Thus, Al and Fe contents were enriched, while the effective CEC (5.1 cmolc/kg) was reduced and dominated by Al (> 80 %) compared to the other profiles. Differences between forest sites and the rubber stand (>25 years) were less obvious.
Table of Contents
1 The Naban River Watershed National Nature Reserve
1.1 General introduction
1.2 Geology
1.3 Soils and nutrients
2 Material and methods
2.1 Field investigations
2.1.1 Site selection
2.1.2 Soil profile description
2.1.3 Soil sampling
2.2 Laboratory analysis
2.2.1 Bulk density, fine earth density, water content
2.2.2 Texture
2.2.3 pH value
2.2.4 Soil organic carbon (SOC) and total nitrogen (TN)
2.2.5 Nutrients
2.2.6 Cation exchange capacity
3 Results
3.1 World Reference Base
3.2 Soil profile description
3.2.1 Profile 1
3.2.2 Profile 2
3.2.3 Profile 3
3.2.4 Profile 4
3.2.5 Profile 5
3.2.6 Profile 6
3.2.7 Profile 7
3.2.8 Profile 8
3.2.9 Profile 9
3.3 Transect 1
3.3.1 Depth and fine earth density
3.3.2 Texture
3.3.3 pH value
3.3.4 SOC and TN
3.3.5 Nutrients
3.3.6 Effective CEC and base saturation
3.4 Transect 2
3.4.1 Depth and fine earth density
3.4.2 Texture
3.4.3 pH value
3.4.4 SOC and TN
3.4.5 Nutrients
3.4.6 Effective CEC and base saturation
Research Objectives and Themes
The primary objective of this report is to characterize the soil types within the Naban River Watershed National Nature Reserve by examining the influence of geomorphological factors, such as altitude and geology, alongside various land-use patterns including forest, rubber plantations, and paddy fields.
- Scientific soil classification based on the World Reference Base (WRB).
- Comparative analysis of soil properties across two distinct geographical transects.
- Assessment of physical parameters including bulk density and soil texture.
- Evaluation of chemical characteristics such as pH values, SOC, total nitrogen, and nutrient contents.
- Determination of effective cation exchange capacity (ECEC) and base saturation levels.
Excerpt from the Book
3.2.1 Profile 1
P1: Hui Lao Xin Zhai
Ferralic Cambisol (sodic, humic, eutric, chromic)
According to WRB (FAO, 2006) a cambic horizon was defined as diagnostic horizon. As prefix ferralic was chosen because of a very low ECEC. Sodic and eutric were identified as suffixes indicating a higher percentage of Na and Mg on the exchange complex and a base saturation > 50 %.
Summary of Chapters
1 The Naban River Watershed National Nature Reserve: Provides an introduction to the nature reserve, detailing its geographical location, landscape features, and general geological and pedological context.
2 Material and methods: Details the methodologies used for field investigations, site selection, and laboratory analysis, including physical and chemical soil testing protocols.
3 Results: Presents the comprehensive data gathered from soil profile descriptions and two specifically defined transects, comparing parameters like texture, pH, nutrients, and exchange capacity.
Keywords
Naban River Watershed, Soil classification, World Reference Base, WRB, Ferralic Cambisol, Acrisol, Land-use change, Soil properties, Cation exchange capacity, Soil organic carbon, Nutrient leaching, Geomorphology, Subtropical soils, Xishuangbanna, Pedology.
Frequently Asked Questions
What is the core focus of this research?
This report focuses on the classification and characterization of soil types within the Naban River Watershed National Nature Reserve, investigating how environmental factors and land use influence soil quality.
What are the central thematic areas covered in the report?
The core themes include soil morphology, physical properties like density and texture, and chemical properties, specifically organic carbon, nitrogen content, and nutrient availability.
What is the primary goal of the study?
The primary goal is to provide a baseline data set for the region and to understand how different land-use strategies affect soil health and land-cover dynamics in Southwest China.
Which scientific methods were employed?
The study utilized field-based soil profile descriptions, laboratory chemical analyses including dry combustion for carbon, ICP-AES for nutrients, and established soil classification guidelines (WRB, KA5).
What topics are discussed in the main body?
The main body covers the detailed results from two study transects, comparing profiles across various altitudes and land-use types, including forests, rubber plantations, and agricultural land.
Which keywords define this work?
Key terms include soil classification, WRB, Naban River Watershed, land-use, pedology, and nutrient dynamics.
What is the significance of the "ferralic" suffix in the profiles?
The suffix "ferralic" is used to classify soils with very low effective cation exchange capacity (ECEC), which indicates high degrees of weathering and nutrient leaching characteristic of tropical and subtropical regions.
How does land-use affect the soil properties in the Naban River Watershed?
The findings indicate that intensive land use, such as in rubber plantations or cleared wastelands, often leads to lower organic carbon levels and increased nutrient leaching compared to natural forest sites.
- Quote paper
- Maria Wolff (Author), Lulu Zhang (Author), Gerhard Langenberger (Series editor), 2010, Soil classification in the Naban River Watershed National Nature Reserve, Munich, GRIN Verlag, https://www.grin.com/document/157695
