Discharging of moisture and salt from unsaturated soil has always been a difficult problem. Therefore, a laboratory experiment in unsaturated soil, under drip irrigation, on subsurface drainage and soil desalination through subsurface drainage pipes (SDP) was conducted for using soil flume, where artificial macropore flow tubes (MFT) were deployed and connected to SDP. We conducted seven different deployment treatments of the artificial MFT, including four deployment tube densities (0, 3, 4, and 5) and two deployment arrangements (curved and straight). The results showed that no flow was observed in the SDP under the base treatment without MFT, increasing flow rates to 9.71 L, 10.7 L, and 12.3 L under the three straight line treatments and 7.81 L, 9.81 L, and 11.2 L under the three curved line treatments. Water content in both the upper and lower soil layers was almost uniform in the treatments with MFT, and an overall desalination trend was observed; the average desalination rate of curved MFT treatments was lower than that of the straight MFT treatments under the same MFT density. The findings serve as the foundation for future studies on drainage and desalination in unsaturated soil and facilitate the design of tile drainage under drip irrigation.

中文翻译：

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非饱和土壤大孔隙流动对地下排水和土壤脱盐影响的试验研究*

从不饱和土壤中排出水分和盐分一直是一个难题。因此，在不饱和土壤中，在滴灌下，通过地下排水管（SDP）对地下排水和土壤脱盐进行了实验室试验，以使用土壤水槽，其中部署了人工大孔流管（MFT）并连接到 SDP。我们对人工 MFT 进行了七种不同的部署处理，包括四种部署管密度（0、3、4 和 5）和两种部署安排（弯曲和直线）。结果表明，在没有 MFT 的基础处理下，SDP 中没有观察到流动，三种直线处理下的流速分别增加到 9.71 L、10.7 L 和 12.3 L，而三种直线处理下的流速分别增加到 7.81 L、9.81 L 和 11.2 L。曲线处理。MFT处理的上、下土层含水量基本一致，总体呈淡化趋势；在相同的MFT密度下，弯曲MFT处理的平均脱盐率低于直线MFT处理。研究结果为未来非饱和土壤排水和脱盐研究奠定了基础，并有助于滴灌下瓷砖排水的设计。