Turfgrass systems have been identified as potential sources of nitrate leaching and subsequent groundwater contamination. The HYDRUS (2D/3D) model was used to quantify nitrate leaching from bermudagrass [Cynodon dactylon (L.) Pers.] and buffalograss [Buchloe dactyloides (Nutt.) Engelm] established by either seed or sod and irrigated with either tailored (defined as reclaimed water with an N concentration of 15 mg L⁻¹) or potable water and fertilized with calcium nitrate. A parameter sensitivity analysis conducted prior to model calibration revealed that soil texture, denitrification rate, and plant uptake all affected nitrate leaching. Simulated nitrate flux matched the experimental data more accurately when denitrification rate varied by soil depth. Moreover, nitrate leaching also differed between turfgrass species and between establishment methods. Leaching was higher from grasses propagated by seed than from sod at the beginning of the establishment period. Increasing the concentration of nitrate in tailored water from 0 to 200 mg L^–1 increased concentrations at 50-cm depths for both species but the increase was significantly higher under buffalograss than bermudagrass and was attributed to lower nutrient uptake and denitrification rates under buffalograss. Nitrate concentrations at 50-cm depth were significantly higher for coarse sand compared with loamy sand, which was attributed to differences in retention times of the two soil types. Soil texture was even more important than nitrate application rate in predicting nitrate leaching losses and the results of the sensitivity analysis demonstrated that nitrate leaching was affected more by denitrification than by plant uptake.

中文翻译：

---

模拟用定制再生水灌溉的草坪草建立过程中的 NO3-N 浸出

草坪系统已被确定为硝酸盐浸出和随后地下水污染的潜在来源。HYDRUS (2D/3D) 模型用于量化从百慕大草 [ Cynodon dactylon (L.) Pers.] 和水牛草[ Buchloe dactyloides (Nutt.) Engelm] 中的硝酸盐浸出量作为 N 浓度为 15 mg L ^{-1 的}再生水) 或饮用水并用硝酸钙施肥。在模型校准之前进行的参数敏感性分析表明，土壤质地、反硝化率和植物吸收都会影响硝酸盐的浸出。当反硝化率随土壤深度变化时，模拟的硝酸盐通量与实验数据更准确地匹配。此外，硝酸盐浸出在草坪草种类之间和建立方法之间也不同。在建立初期，种子繁殖的草的浸出率高于草皮。将定制水中的硝酸盐浓度从 0 增加到 200 mg L ^–1两种物种在 50 厘米深度处的浓度增加，但水牛草下的浓度增加明显高于狗牙根，这归因于水牛草下较低的养分吸收和反硝化率。与壤土砂相比，粗砂在 50 厘米深度处的硝酸盐浓度显着更高，这是由于两种土壤类型的保留时间不同。在预测硝酸盐浸出损失方面，土壤质地比硝酸盐施用率更重要，敏感性分析的结果表明，反硝化作用比植物吸收对硝酸盐浸出的影响更大。