Influence of Soil Organic Carbon, Water Holding Capacity, and Moisture Content on Heavy Metals in Rice Paddy Soils of Western Ghats of India

Abstract

Analysis of soil samples collected from 16 rice paddy elds located in Western Ghats region was made to quantify the heavy metals concentration. Heavy metal analysis was done for Cu, Zn, Mn, Fe, Ni, Cr, Cd, and Pb using atomic absorption spectroscopy. High concentration of these heavy metals was found in rice paddy elds regularly being cultivated using agrochemicals. We compared this concentration with soils of rice paddy eld that was not under cultivation. Cu, Zn, Mn, Fe, Cr, Ni, Pb, and Cd showed a build up at an order of 1.2, 1.3, 2.3, 2.2, 1.8, 2.8, 1.8, and 8.5 times higher in the rice paddy elds cultivated with agrochemical applications. Heavy metals exhibited maximum association (PCA) with soil moisture content (Zn, Fe, Cr, Ni, and Cd), organic carbon content (Fe, Cr, Ni, and Cd) and water holding capacity (Cu, Pb, and Cd). Such associations were absent in the reference site. This indicates the build-up of heavy metals in rice paddy soils under the strong in uence of moisture content, water holding capacity, and organic carbon content of the soil.

A Comparative Study on the Bioavailability and Soil-to-Plant Transfer Factors of Potentially Toxic Element Contamination in Agricultural Soils and Their Impacts: A Case Study of Dense Farmland in the Western Region of Saudi Arabia

“…In soil samples in which arugula and dill were grown, Fe levels were found to be high, suggesting that the physicochemical conditions of the soil, e.g., redox potential, humidity, morphological conditions, flows, The levels of Zn, Fe, Cu, and Ni in NPK fertilizer were 1.86, 7.39, 1.88, and 0.02 mg/kg, respectively. These values were found to be higher than those measured in urea for Zn (0.41), Fe (0.06), Cu (0.02), and Ni (0.003 mg/kg), whereas the average Ni level in phosphatic fertilizers in Saudi Arabia was in the range of 52.80 to 85.8 mg/kg [52]. The average levels of Pb and Cr contents were below the limit of detection in NPK and urea fertilizers.…”