Soil Quality Assessments in Some Iranian Saffron Fi elds

Abstract

Little information is available about Soil Quality (SQ) in Iran, especially in saffron [ Crocus sativus ( L.) Iridaceae ] fields. The objectives of this research were to: (i ) Establish a Minimum Data Set (MDS) for quantifying soil quali ty in saffron fields; (ii) Evaluate soil quality status using two indices of Integrated Qual ity Index (IQI) and Nemoro Quality Index (NQI), and (iii) Investigate the relationship between soil quality and the economics of saffron production. Thirty soil samples were col lected from the Ghayen area of South Khorasan, Iran, and analyzed for soil physical and chemical properties. Principal Component Analysis (PCA) was used to identify a Min imum Data Set (MDS) consisting of sand, Relative Field Capacity (RFC), zinc, SAR , Ca, CaCO 3 , Fe and Bulk Density (BD). Soil Quality was evaluated using the IQI and the NQI for both the Total Data Set (TDS), and MDS . Four SQ indices i.e., IQI TDS , IQI MDS , NQI TDS , and NQI MDS were used to evaluate soil quality in saffron fields in the study area. A significant cor relation (P< 0.05) was shown between the IQI TDS (r= 0.44), NQI TDS (r= 0.41) and economic yield of saffron. Correlation analysis indicated that the IQI TDS performed better compared to the NQI TDS for evaluating the soil quality. Use of the TDS with the IQI index was the most effective approach for evaluating SQ in saffron fields. Keywords: Economic yield, Integrated quality index, Minimum data set, Nemoro quality index