soil_data: Hypothetical Soil Quality Dataset

In SQIpro: Comprehensive Soil Quality Index Computation and Visualization

Hypothetical Soil Quality Dataset

Description

A hypothetical dataset representing soil physicochemical and biological properties across five land-use systems and two soil depths, generated using realistic parameter ranges reported in the soil quality literature. This dataset is intended for demonstrating the functions in the SQIpro package and for pedagogical purposes.

Usage

soil_data

Format

A data frame with 100 rows and 14 variables:

LandUse

Character. Land-use system: Natural_Forest, Agroforestry, Cropland, Grassland, Degraded_Land.

Depth

Character. Soil depth: Surface_0_15cm or Subsurface_15_30cm.

pH

Numeric. Soil pH (1:2.5 water suspension). Unitless. Optimal range 6.0–7.0 for most crops (Brady & Weil, 2008).

EC

Numeric. Electrical Conductivity (dS m^{-1}). Lower values indicate less salinity stress; <0.2 dS m^{-1} considered non-saline (Richards, 1954).

BD

Numeric. Bulk Density (g cm^{-3}). Lower values indicate better soil structure and aeration; >1.6 g cm^{-3} restricts root growth (Arshad et al., 1996).

CEC

Numeric. Cation Exchange Capacity (cmol(+) kg^{-1}). Higher values indicate greater nutrient-holding capacity (Sparks, 2003).

OC

Numeric. Organic Carbon (%). Higher values indicate greater soil organic matter, a key indicator of soil health (Doran & Parkin, 1994).

MBC

Numeric. Microbial Biomass Carbon (mg kg^{-1}). Indicator of soil biological activity (Brookes, 1995).

PMN

Numeric. Potentially Mineralizable Nitrogen (mg kg^{-1}). Indicates N-supplying capacity of soil (Stanford & Smith, 1972).

Clay

Numeric. Clay content (%). Optimal range 20–35% for water and nutrient retention (Arshad et al., 1996).

WHC

Numeric. Water Holding Capacity (%). Higher values indicate better moisture retention (Reynolds et al., 2009).

DEH

Numeric. Dehydrogenase Enzyme Activity (\mug TPF g^{-1} day^{-1}). Indicator of overall microbial metabolic activity (Casida et al., 1964).

AP

Numeric. Available Phosphorus (mg kg^{-1}). Higher values indicate better P availability for plants (Olsen & Sommers, 1982).

TN

Numeric. Total Nitrogen (%). Higher values indicate greater N reserves (Bremner, 1996).

Details

Parameter ranges were informed by values reported in:

• Doran and Parkin (1994) for biological indicators

• Andrews et al. (2004) for MDS indicator ranges

• Masto et al. (2008) for land-use comparison ranges

The dataset is entirely synthetic and does not represent any specific geographic location.

Source

Synthetically generated for the SQIpro package.

References

Andrews, S.S., Karlen, D.L., & Cambardella, C.A. (2004). The soil management assessment framework: A quantitative soil quality evaluation method. Soil Science Society of America Journal, 68(6), 1945–1962. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2136/sssaj2004.1945")}

Arshad, M.A., Lowery, B., & Grossman, B. (1996). Physical tests for monitoring soil quality. In J.W. Doran & A.J. Jones (Eds.), Methods for Assessing Soil Quality, pp. 123–141. SSSA Special Publication 49. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2136/sssaspecpub49.c7")}

Brady, N.C., & Weil, R.R. (2008). The Nature and Properties of Soils (14th ed.). Prentice Hall, New Jersey.

Doran, J.W., & Parkin, T.B. (1994). Defining and assessing soil quality. In J.W. Doran et al. (Eds.), Defining Soil Quality for a Sustainable Environment, pp. 1–21. SSSA Special Publication 35. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2136/sssaspecpub35.c1")}

Masto, R.E., Chhonkar, P.K., Singh, D., & Patra, A.K. (2008). Alternative soil quality indices for evaluating the effect of intensive cropping, fertilisation and manuring for 31 years in the semi-arid soils of India. Environmental Monitoring and Assessment, 136, 419–435. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1007/s10661-007-9697-z")}

Examples

data(soil_data)
head(soil_data)
summary(soil_data)
table(soil_data$LandUse, soil_data$Depth)

SQIpro documentation built on April 20, 2026, 5:06 p.m.