Comparison of two soil quality indices using two methods based on geographic information system

Abstract

This study was conducted to assess Soil Quality Indicators (SQIs) in some cultivated soils in North Delta, Egypt. Two methodologies were implemented (Simple additive SQI1 and Weighted additive SQI2) to assess Soil Quality (SQ) status. SQ was determined qualitatively and quantitatively based on field study and laboratory analysis. In addition the results of both methods were evaluated statistically. Soil Quality Indices (SQI) were examined based on vertical and horizontal soil properties. Twenty potential physiochemical SQIs of sixty soil profiles were assessed. The physiochemical parameters considered in this study were given SQ rate based on each parameter standard rate. The results demonstrated that the assessment of soil Quality based on both methods are similar with significant correlation in the case of well distributed soil samples. SQI2 Outperform SQI1 in comprising all indicators, while SQI1 is timely appreciated economically preferable. The differences in results of SQI1 and SQI2 are mainly due to the numbers of SQIs considered in the calculations and the variations of soil properties through the soil profile. The results indicated that north part of the area characterized by low SQ while the south portion is high SQ whilst the eastern part is moderate. However the low value of SQ in north Nile Delta is mainly associated with the levels of soil salinity, soil compaction and waterlogging. Keywords: Geostatistics, GIS, Model builder, Nile Delta, Soil quality