Determining soil indicators for soil sustainability assessment using principal component analysis of astan quds- east of mashhad- Iran

Abstract

Soil quality indicators are measurable soil attributes that reveal the soil productivity response or soil-environment functionality that are used to know whether soil quality is improving, remain constant, or declining. These characteristics could be assessed by different indices such as sustainability index approach (SI) based on the threshold levels of soil indicators and cumulative rating approach (CR) based on crop production limitations, which show the sustainability of soil ecosystem in terms of soil degradation. Since Iran is situated in arid and semi-arid climatic conditions, this research was conducted in agriculture fields of southeast of Mashhad, Iran for comparing these two approaches. Sixty three soil samples (0-30 cm) were collected and nine soil properties such as pH, electrical conductivity (EC), soil organic carbon (SOC), soil particle-size distribution, available water holding capacity (AWHC), bulk density (BD), air capacity (AC), relative field capacity (RFC) and sodium adsorption ratio (SAR) were measured. All these measurements were considered as total data set (TDS). Principal component analysis (PCA) was used to select more effective indicators to conform the minimum data set (MDS). There was a strong correlation between SI and CR (R 2 =0.69, p <0.05). Only six soil indicators selected as MDS (pH, SOC, AWC, BD and SAR) were correlated (p<0.01) significantly with SI and CR. These SI and CR results showed more promising effects on soil sustainability. PCA was found a suitable method for selecting the more effective indicators having R 2 = 0.77 (p <0.05) (CR-MDS versus CR-TDS) comparable with R 2 = 0.80 (p <0.05) (CR-MDS versus SI) to use less soil data input in assessing soil quality in arid zone.

Effects of zeolite and organic fertilizers on soil quality and yield of sugarcane

“…In today's agricultural world much value has been given to organic matters and their relations with the structure and stability (Ghaemi et al, 2014), as these have direct influence on the quality of soil and its management under general degradation condition (Lal, 2015). Fig 2 and 3 show a close relationship and dependence (r> 0.80) between organic matter and water stable aggregation and soil permeability.…”

“…Table 2 shows the trends of the properties studied when applying statistical tools and sensitivity to category change. Ghaemi et al (2014) stated that the use of principal components can contribute to the assessment of soil quality and the sustainable management of an agricultural system. The properties that best demonstrate the qualities of indicators of soil quality are organic matter, stable aggregates, degree of soil aggregation, permeability log 10K and lower plastic limit.…”

“…Soil is one of the most important environmental factors and is considered the main source in providing essential plant nutries, water reserves and a medium for plant growth (Ghaemi et al, 2014). Maintaining or improving soil quality is crucial for agricultural productivity and environmental safety which are to be preserved for future generations (Reeves, 1997;Lal, 2015).…”

Robust Soil Quality Index for Tropical Soils Influenced by Agricultural Activities

“…Once the correlated variables were found, a Principal Components Analysis (PCA) was developed. This analysis reduced the existing data set, transforming it into a new set of variables (main components) which retain most of the variation present in the original variables [7] The indicators with the highest weights in the PCA will represent the parameters that have the greatest influence on the quality of the agricultural soils.…”

“…They should be selected on the basis of the climate, soil type, hydrology and other aspects of study area. Many indicators of soil quality have been proposed, but few have been tested and validated [7] [8].…”