Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China.
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Int J Environ Res Public Health. 2023 Feb 22;20(5):3919. doi: 10.3390/ijerph20053919.
Excessive N fertilizer application has aggravated soil acidification and loss of N. Although oyster shell powder (OSP) can improve acidic soil, few studies have investigated its ability to retain soil N. Here, the physicochemical properties of latosol after adding OSP and calcined OSP (COSP) and the dynamic leaching patterns of ammonium N (NH-N), nitrate N (NO-N), and Ca in seepage, were examined through indoor culture and intermittent soil column simulation experiments. Various types of N fertilizer were optimized through the application of 200 mg/kg of N, urea (N 200 mg/kg) was the control treatment (CK), and OSP and COSPs prepared at four calcination temperatures-500, 600, 700, and 800 °C-were added to the latosol for cultivation and leaching experiments. Under various N application conditions, the total leached N from the soil followed ammonium nitrate > ammonium chloride > urea. The OSP and COSPs had a urea adsorption rate of 81.09-91.29%, and the maximum reduction in cumulative soil inorganic N leached was 18.17%. The ability of COSPs to inhibit and control N leaching improved with increasing calcination temperature. Applying OSP and COSPs increased soil pH, soil organic matter, total N, NO-N, exchangeable Ca content, and cation exchange capacity. Although all soil enzyme activities related to N transformation decreased, the soil NH-N content remained unchanged. The strong adsorption capacities for NH-N by OSP and COSPs reduced the inorganic N leaching, mitigating the risk of groundwater contamination.
过量施氮肥会加剧土壤酸化和氮素损失。虽然牡蛎壳粉（OSP）可以改善酸性土壤，但很少有研究探讨其保氮能力。本研究通过室内培养和间歇土柱模拟实验，考察了添加牡蛎壳粉（OSP）和煅烧牡蛎壳粉（COSP）后土壤的理化性质以及渗漏水铵态氮（NH-N）、硝态氮（NO-N）和 Ca 的动态淋失特征。通过施加 200mg/kg 的 N 优化了各种类型的氮肥，尿素（N200mg/kg）作为对照处理（CK），并向原状土中添加在四个煅烧温度（500、600、700 和 800°C）下制备的 OSP 和 COSP 进行培养和淋溶实验。在各种氮素施加条件下，土壤中总淋失氮的顺序为硝酸铵>氯化铵>尿素。OSP 和 COSP 对尿素的吸附率为 81.09%-91.29%，累积土壤无机氮淋失量的最大减少量为 18.17%。COSP 抑制和控制氮淋失的能力随煅烧温度的升高而提高。施加 OSP 和 COSP 会增加土壤 pH 值、土壤有机质、全氮、NO-N、可交换钙含量和阳离子交换量。虽然与氮转化有关的所有土壤酶活性都降低了，但土壤 NH-N 含量保持不变。OSP 和 COSP 对 NH-N 的强吸附能力减少了无机氮的淋失，降低了地下水污染的风险。
