Water Retention and Pore Size Distribution of a Biopolymeric‐Amended Loam Soil

Abstract

The results revealed that T2 spectra provided a good proxy to determine the PSD, showing good agreement between the PSD from T2 spectra and that calculated from the water retention curve (WRC) (R2 > 0.78; RMSE <1.38 μm). The application of CH also increased the zeta potential of the soil to −18.5 mV, compared with −20 mV obtained for the reference soil. The WRC measurements revealed that AG decreased the available water content for plant use compared with the reference soil, whereas CH increased the available water in comparison to the reference soil. Considering the parameters of the van Genuchten model, the application of AG and CH mainly affected the parameter α, confirming the dominant changes in macropores. This finding was confirmed by NMRR relaxation spectra. Furthermore, the application of CH and AG stimulated the microbial activity of the amended soil, leading to an increase in soil respiration.