Elemental dynamics in porewater of an acid sulfate paddy soil as affected by sodium bentonite and dolomite amendments: insights from field study

¹ Department of Soil Science, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
² Project Environmental Management Department, PTT Public Company Limited, Bangkok 10900, Thailand

^* Corresponding author: saowanuch.t@ku.th

Abstract

Rice productivity in acid sulfate soils are frequently limited due primarily to strong acidity, low phosphorus (P) availability and metal toxicity. A recent study has documented that the use of sodium bentonite (NaB), non-hazardous material uses in natural gas pipeline construction, could be a promising soil amendment for mitigating major concerns experiencing in acid sulfate soils. Here we examined the effects of NaB and dolomite (DL) on dynamics in dissolved contents of both nutrient and associated elements in an acid sulfate soil and rice yield from paddy field in natural gas pipeline Rights-of-Way. The results demonstrated that the NaB and DL utilization significantly alleviated soil acidity and metal (Al, Fe, and Mn) toxicity (α = 0.05). Both soil amendments also significantly improved readily available P. Nonetheless, the soil NaB incorporation did elevate soluble sodium and did plummet soluble K, Ca, and Mg. Therefore, appropriate ratios and amounts of the K, Ca, and Mg along with N fertilizers are indisputable needed to maintain the nutrient balance when applying NaB as a soil amendment. Our finding implies that combined use of NaB and DL are suggested to soil amendment and could alleviate nutrient imbalance as compared to the sole NaB utilization.