The Relation of Soil Magnetic Properties with Coconut Yield: A Study from Kanyakumari District, Tamil Nadu

ABSTRACT Soil magnetic studies were carried out for a total of 38 samples collected from different coconut farms with varying yield patterns in the Eathamozhi area, Kanyakumari District, Tamil Nadu. An attempt has been made to assess the relationship between soil magnetic parameters (magnetic susceptibility and magnetic mineralogy) and the coconut yield. The soil samples collected from the low coconut yield area show the magnetic susceptibility (χLF) ranges from 32.1 × 10-8 to 67.0 × 10-8m3/kg with a mean value of 47.33 × 10-8 m3/kg, while it varies from 15.98 × 10-8 to 36.15 × 10-8m3/kg for the high yield soils where, the mean susceptibility value was recorded as 21.76 × 10-8 m3/ kg. The moderate yield soils bear a modest range of magnetic susceptibility values with a mean value of 28.90 × 10-8 m3/kg. It is pertinent to note that samples from the low coconut yield area show a high range of magnetic susceptibility values, while the low range values are associated with the high yield soil samples and thus indicate an inverse relationship between magnetic susceptibility and the coconut yield. Moreover, the hysteresis and temperature-dependent magnetisation studies revealed that the high coconut yield soils are characterised by mixed mineralogy of hard and soft magnetic minerals, whereas the soft magnetic minerals are predominant in the soils of low coconut yield. Thus, the magnetic susceptibility and the magnetic mineralogy are distinctly characterised for the low and high coconut yield soils. Therefore, the soil magnetic studies would probably be utilised as innovative yet simple and content techniques to assess the yield of particular crop.