Effect of application of bentonite from Tam Bo (Lam Dong province) to improve sandy soil for asparagus and maize cultivation

Abstract

This work included an experimental study of sandy soil reclamation in the coastal area of ​​Ninh Phuoc district, Ninh Thuan province by adding bentonite clay which was produced from Tam Bo mine (Lam Dong province). The quality of bentonite was determided by the assessment of analysed mineral and chemical composition. The soil of experimental site was analysed with 25 parameters which showed a lack of nutrition and ability to retain moisture from the soil. With 3% bentonite mixing, soil moisture content was raised above 10% and cation exchange capacity increased over 20%. In-situ experiments of asparagus and maize cultivation resulted in irrigation water savings and crop yields increase. By mixing bentonite with the soil at the rate of 20 tons/ha, 40 tons/ha, and 60 tons/ha, the asparagus yield increased by 10.1%, 15.5%, and 18.6% respectively. With the same percentage of bentonite concentration, the yield of maize increased by 10.5%, 17.9%, and 22.2%, respectively.