Assessing Quality of Rice Producing Soils Using Two Methods of Quantification (Published)
Many estimates of soil quality index (SQI) assumed to be similar in their measurement have been suggested across the world. This assumption needs to be proved through comparison of various methods. This study therefore aimed at comparing two quantitative SQIs determined by Soil Management Assessment Framework (SMAF) and Relative Soil Quality Index (RSQI), in two rice – intensive cultivation local government areas (Katcha and Gassol) in Nigeria. A semi-detailed soil survey was conducted and seven modal profile pits dug. Soil samples were collected for laboratory analysis of selected indicators. Data were subjected to quantification using SMAF and RSQI procedures, and results subjected to correlation analysis. Based on SMAF, SQI are 66.75 – 84.3 % in Gassol and 55.9 – 77.65 % in Katcha. With RSQI, 68.06 – 73.03 % in Gassol and 66.14 – 81.84 % in Katcha. Positive correlation occurs between them (r = 0.68 in Gassol and 0.74 in Katcha) indicating that both methods are similar in assessing soil quality. However, in computation RSQI is less subjective because the values for scoring and relative weights were calculated rather than experts’ opinions used in SMAF. Therefore, RSQI is consistent even with different researchers, thus is more reliable.
Keywords: Quantification, RSQI, SMAF, rice intensive, soil quality index