| 可溶性磷径流时间关系模拟研究 |
| 摘要点击 2606 全文点击 2346 投稿时间：2007-09-14 修订日期：2007-11-13 |
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| 中文关键词 磷 径流损失 径流时间 Olsen-P |
| 英文关键词 phosphorus runoff loss runoff time Olsen-P |
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| 中文摘要 |
| 利用Heckrath分段回归（split-line）模型，对潮褐土Olsen-P、CaCl2-P含量进行拟合，得到潮褐土环境敏感磷临界点对应的土壤Olsen-P含量为69.4 mg/kg.采用循环水法模拟地表径流，研究了不同施磷水平土壤通过径流流失到水体中的可溶性磷(dissoluble phosphorus，DP)与径流时间的关系.利用一级动力学方程模型对径流发生时土壤向水体输入DP总量的动态变化进行模拟分析，结果表明模型能够较好地描述径流发生时磷素从土壤向水体的转移.当施磷量低于400 kg/hm2时，速率常数，K没有发生变化，其平均值为1.095 h-1；而当施磷量为800和1 600 kg/hm2时，K值分别减小了17.2%和38.9%.利用指数函数模型对径流发生时土壤向水体输入DP速率随时间的动态变化进行模拟分析，结果表明，当施磷量低于400 kg/hm2时，速率常数K′没有发生变化，其平均值为1.037h-1；而当施磷量高于800 kg/hm2时，K′值却有所降低.土壤Olsen-P和CaCl2-P与径流发生时土壤的可溶性磷流失潜势（dissoluble phosphorus loss potential，DPLP）和可溶性磷流失初始速率（dissoluble phosphorus loss initial velocity，VP0）间存在明显的线性关系，因此土壤Olsen-P含量和CaCl2-P含量可以作为土壤环境影响评价的指标来指示土壤DP径流损失的风险. |
| 英文摘要 |
| The environmental sensitive phosphorus point of a cinnamon fluvo-aquic soil was 69.4 mg/kg (Olsen-P) evaluated by fitting soil Olsen-P and CaCl2-P content using Heckrath split-line model. The relationship between dissoluble phosphorus (DP) lost from runoff in soils applied different P rate and runoff time was studied using circular water method. The first-order kinetics model was used to simulate the dynamics of DP transported from soil to water with time. The results indicated that this model could simulate the transport suitably. When the applied P less than 400 kg/hm2, the velocity constant K which is average 1.095 h-1 unchanged; while when the applied P rates were 800 and 1 600 kg/hm2, K decreased by 17.2% and 38.9%, respectively. The exponent function was used to simulate the velocity of DP from soil to water with time and the results showed that it was a suitable model. When the applied P less than 400 kg/hm2, the velocity constant K′ which is average 1.037 h-1 unchanged; while when the applied P rate was higher than 800 kg/hm2, a declining tendency was found for K′. There was significant relationship between soil Olsen-P or CaCl2-P content and soil DPLP or VP2 when surface runoff occurred. This result showed that soil Olsen-P or CaCl2-P content could be used to direct the runoff risk as a gist of estimate soil environment. |
