Subsurface drip irrigation is the most efficient irrigation technology available to agricultural producers. The dimensions of wetted areas, affected by subsurface drip irrigation (SDI) system design and initial soil moisture conditions, were evaluated around emitters in three different indoor soil bins with a growing alfalfa (Medicago sativa L.) crop. To investigate the dynamics of soil moisture an emitter flow rate of 0.432 L hr⁻¹ was implemented for 3, 4, 5, 6, 7 h of continuous irrigation application in all three bins. Moreover, a normal single pulse application (6 h) to three multi-pulse [three 2-h pulses separated by 4 h (3 × 2 h), a 2-h and 4-h pulse separated by 6 h (2 + 4 h), a 4-h and 2-h pulse separated by 6 h (4 + 2 h)] were compared. The results showed that at applications of five or more hours, single irrigation events in the Clay loam (CL) and Loamy sand (LS) bins could generate connected wetted areas around emitters along driplines with width (W) values larger than 60 cm. In the LS bin, without separation between dry and wet initial conditions, the increase of height (H) as a function of application duration was steeper than in the CL and C bins. Soil moisture differences between multi-pulse and single-pulse irrigation applications disappeared within 24 h after the start of the first irrigation event. Therefore, sub-daily multi- pulse irrigation is not relevant for crop water management.

地下滴灌是农业生产者可用的最有效的灌溉技术。受地下滴灌 (SDI) 系统设计和初始土壤湿度条件影响的湿润区域的尺寸在三个不同的室内土壤箱中的发射器周围进行评估，其中种植苜蓿 ( Medicago sativa L.) 作物。为了研究土壤水分的动态，发射器流速为 0.432 L hr ^-1在所有三个垃圾箱中实施了 3、4、5、6、7 小时的连续灌溉应用。此外，一个正常的单脉冲应用 (6 h) 到三个多脉冲 [三个 2-h 脉冲间隔 4 h (3 × 2 h)，一个 2-h 和 4-h 脉冲间隔 6 h (2 + 4 h)，比较了相隔 6 小时 (4 + 2 小时)] 的 4 小时和 2 小时脉冲。结果表明，在 5 小时或更长时间的应用中，黏土 (CL) 和壤土 (LS) 箱中的单次灌溉事件可以沿着宽度 ( W)值大于 60 厘米的滴灌线在排放器周围产生连接的湿润区域。在 LS bin 中，不区分干湿初始条件，高度 ( H)的增加作为应用持续时间的函数，比在 CL 和 C 仓中更陡峭。在第一次灌溉事件开始后 24 小时内，多脉冲和单脉冲灌溉应用之间的土壤水分差异消失。因此，次日多脉冲灌溉与作物水分管理无关。