Waterlogging and salinity can occur together in salinised landscapes and restrict crop production. Drainage can alleviate waterlogging and salinity, but previous research suggested the need for deep drains, which may not be acceptable to smallholder farmers. Consequently, for the first time to our knowledge, we tested the usefulness of shallow drains in sunflower cultivation for smallholder farmers in a salt-affected, waterlogged coastal clay soil in the Ganges Delta. Experimental treatments were as follows: undrained, open surface drains (SD; 0.1 m deep, 1.8 m apart), slotted-pipe subsoil drains (SSD; 0.5 m deep, 4.5 m apart) and SSD+SD. All plots were inundated (2–3 cm above the soil surface) for 24 h before opening drains, at vegetative emergence and then at the V8 stage of plants. Relative to the most-drained (SSD+SD) treatment, the SD and SSD treatments gave 15–29% less yield, while the undrained treatment depressed yield by 48%. Soil water content (SWC) at 0–60 cm depth early in the season was 6–21, 4–10 and 3–5% less in SSD+SD treatment than in the undrained, SD and SSD treatments, respectively, while from flowering to harvest, SWC in SSD+SD was 2–4, 4–8 and 4–10% higher than in the undrained, SD and SSD treatments, respectively. In addition, soil electrical conductivity EC_1:5 at 0–60 cm depth in SSD+SD treatment was 31–52, 16–38 and 11–32% lower than in the undrained, SD and SSD treatments, respectively. Across all treatments, the increases in yield due to drainage were associated with decreases in waterlogging (in the 0–30 cm layer) early in the growing season, increases in SWC late in the growing season and decreases in EC_1:5 throughout the cropping season. While the shallow surface drains alone increased the yield, additional shallow subsoil drains further increased crop yield on coastal saline soils.

在盐渍化的景观中，涝渍和盐分可能同时发生并限制作物生产。排水可以缓解内涝和盐分，但之前的研究表明需要深排水，小农可能无法接受。因此，据我们所知，我们第一次在恒河三角洲受盐渍影响的沿海粘土土壤中测试了浅水渠对小农种植向日葵的有用性。实验处理如下：不排水、开放地表排水沟（SD；0.1 m 深，1.8 m 间距）、槽管底土排水沟（SSD；0.5 m 深，4.5 m 间距）和 SSD+SD。在打开排水沟之前，在植物出苗时，然后在植物的 V8 阶段，所有地块都被淹没（高于土壤表面 2-3 厘米）24 小时。相对于最排水 (SSD+SD) 处理，SD 和 SSD 处理减产 15-29%，而不排水处理减产 48%。从开花期开始，SSD+SD 处理在 0-60 cm 深度的土壤含水量 (SWC) 分别比不排水、SD 和 SSD 处理低 6-21、4-10 和 3-5%收获时，SSD+SD 中的 SWC 分别比不排水、SD 和 SSD 处理高 2-4、4-8 和 4-10%。此外，土壤电导率 EC_{SSD+SD 处理在 0-60 cm 深度处的1:5}分别比不排水、SD 和 SSD 处理低 31-52、16-38 和 11-32%。在所有处理中，由于排水导致的产量增加与生长季节早期的涝渍减少（在 0-30 厘米层中）、生长季节后期 SWC 的增加和整个种植过程中 EC _1:5的减少有关季节。虽然仅浅表排水沟增加了产量，但额外的浅底土排水沟进一步增加了沿海盐渍土的作物产量。