Effects of Oyster Shell Powder on Leaching Characteristics of Nutrients in Latosol

Abstract

In this study, we analyzed the effect of oyster shell powder of different proportions on the nutrient leaching characteristics of latosol, using an indoor soil column simulation test. Based on the optimized fertilizer application amount, we tested five different amounts of oyster shell powder in the test [0 % (control, CK), 0.1 % (T1), 0.2 % (T2), 0.4 % (T3), and 0.8 % (T4)] for analyzing the intermittent and dynamic leaching characteristics of nutrients in the soil samples. The results indicated that the loss of nutrients in urea, superphosphate, and potassium chloride (due to leaching) increased linearly with the amount of fertilizer. By adding oyster shell powder, the leaching loss reduced by 23.90–57.25 % for ammonium nitrogen, 6.31–10.07 % for phosphorus, and 17.08–26.58 % for potassium. However, the leaching loss for nitrate nitrogen increased by 2.5–5.8 times. In addition, the application of oyster shell powder to latosol provided acid adjustment and water retention enhancement, which increased the pH value of the soil by 3.77 (from pH 4.15 to 7.92) and reduced water loss by 2.52 %. Thus, the application of oyster shell powder can reduce the acidity of the surface soil and retain water and fertilizer to a certain extent; however, it may increase the potential risk of nitrate nitrogen pollution in groundwater.