Modeling of microwave dielectric properties of rice growth stages in Zhaoqing test site of Southern China

This paper presents the modeling results of dielectric constants from different rice growth stages in Zhaoqing test site using Debye-Cole dual-dispersion model of vegetation. In the test site, two crops of early season rice and late season rice are planted in 1997 and 1996, and the growing period of rice crop is divided into five major stages: transplant, seedling developing, ear differentiation, heading and mature period. Based on the results, the paper discussed the influences from microwave frequency, gravimetric moisture content of rice, temperature, salinity and bulk density of dry vegetation materials on dielectric constant. The rice crops of different growth stages have the various dielectric constants, and the dielectric constants of early and late season rice crops show the diverse changes. The parameters, including in microwave frequency, gravimetric moisture content of rice, temperature and bulk density of dry vegetation materials, made the influence on dielectric constant, but salinity had no effect on the dielectric constant.