| 黎会仙,王文娥,胡笑涛.滴灌施肥条件下土壤水氮运移数值模拟[J].干旱地区农业研究,2019,37(2):10~17 |
| 滴灌施肥条件下土壤水氮运移数值模拟 |
| Numerical simulation of soil water and nitrogen distribution under the integration of drip irrigation and fertilization |
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| DOI：10.7606/j.issn.1000-7601.2019.02.02 |
| 中文关键词: 滴灌施肥 水氮运移 数值模拟 |
| 英文关键词:drip fertilization water and nitrogen transport numerical simulation |
| 基金项目:公益性行业（农业）科研专项（201503125）；“十三五”国家重点研发计划（2016YFC0400200） |
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| 中文摘要: |
| 为了研究滴灌施肥条件下土壤水、氮的运移分布规律，本文通过室内土柱滴灌水氮入渗试验，研究了滴灌结束时及再分布过程中土壤水、氮的运移变化规律；同时用HYDRUS软件建立了土柱滴灌水氮入渗的几何模型，用来模拟滴灌土壤水氮运移过程。对试验及模拟中12个观测点测得的土壤含水率、土壤铵态氮、硝态氮质量浓度进行对比分析，结果表明：土壤含水率模拟值与实测值的相对误差变化在10%以内；土壤铵态氮、硝态氮质量浓度的模拟值与实测值变化范围在20%以内。滴灌结束时土体剖面内土壤含水率随距滴头距离的增大而减小，再分布72 h土层25~30 cm土壤含水率增大到0.2 cm3·cm-3，120 h后土体剖面内土壤含水率较滴灌结束时下降了18%。土壤铵态氮质量浓度主要分布于距滴头20 cm的范围；24 h土壤铵态氮质量浓度最大，且随着时间的推移逐渐减小，到120 h时减少了40%；各观测点24 h至120 h土壤硝态氮质量浓度随着时间的推移逐渐增大，且硝态氮质量浓度在滴头20 cm的范围内由0.442 mg·cm-3增加到1.2 mg·cm-3。各观测点24 h土壤硝态氮质量浓度在空间分布上差异不大，其中观测点1，3，6，8，5的土壤硝态氮质量浓度分别为0.437，0.467，0.451，0.482 mg·cm-3和0.447 mg·cm-3，差值均小于0.05 mg·cm-3；48 h后土体剖面内土壤硝态氮质量浓度空间分布随离滴头距离的增加而减小，垂直方向上从距滴头5 cm的观测点1到距滴头25 cm的观测点8减少了53%。依据研究结果，可用数值模型模拟滴灌施肥条件下土壤水氮运移的变化规律。 |
| 英文摘要: |
| In order to study soil water and nitrogen (N) transport and distribution under drip irrigation and fertilization, the soil water and N transport in the process of drip irrigation and redistribution was studied with a water and N infiltration experiment with soil column under drip irrigation. At the same time, the geometric model of water and N infiltration in soil column under drip irrigation was established by using HYDRUS software to simulate the soil water and nitrogen transport. The soil water content, ammonium nitrogen (NH+4-N), and nitrate nitrogen (NO-3-N) concentration collected at 12 observation points in the experiment and simulation were analyzed. The result showed that: the relative error between simulated and measured values of soil moisture content was less than 10%, and the simulated and measured values of NH+4-N and NO-3-N were less than 20%.At the end of drip irrigation, soil water content in soil profile decreased with the increase in distance from the emitter, and increased to 0.2 cm3·cm-3 in soil layer of 25~30 cm after 72 hours of redistribution. After 120 hours, soil water content in soil profile decreased by 18% compared with that at the end of drip irrigation. The content of NH+4-N was mainly distributed in the zone within 20 cm from emitter. The concentration of NH+4-N in soil reached the maximum value at 24 h and gradually decreased with time, and decreased by 40% at 120 h. The concentration of NO-3-N in soil increased gradually with time from 24 h to 120 h, and the concentration of NO-3-N increased from 0.442 mg·cm-3 to 1.2 mg·cm-3 in the zone of 20 cm from the emitter. At 24 h, the spatial distribution of soil NO-3-N concentrations was not significant, with the concentration of soil NO-3-N concentrations at observation points 1, 3, 6, 8, and 5 being 0.437, 0.467, 0.451, 0.482 and 0.447 mg·cm-3, respectively, the difference was less than 0.05 mg·cm-3. After 48 h, the spatial distribution of soil NO-3-N concentration in soil profile decreased with the increase in distance from the emitter, as the vertical distribution decreased 53% from observation point 1 that was 5 cm away from emitter to observation point 8 that was 25 cm away from the emitter. Based on the results, the numerical model can be used to simulate the soil water and N transport under drip irrigation and fertilization. |
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