Data from: Controlled drainage and subirrigation suitability in the United States: A meta-analysis of crop yield and soil moisture effects

Controlled drainage and subirrigation (CDSI) is an important water
management strategy in many regions, but the conditions under which CDSI
is most likely to increase crop yield and soil moisture are not
fully understood. A meta-analysis, consisting of 154 pairwise
observations from replicated and randomized trials in 30 peer-reviewed
primary research articles on CDSI (6 controlled drainage, 24
CDSI, analyzed together due to data scarcity), was conducted to
study the responses of yield and soil moisture to CDSI, and
investigate how crop type, soil texture, and cumulative growing
season precipitation (PGS) influence these responses. Based
on the yield response to these moderating factors, we used a
fuzzy-logic approach to map potentially suitable locations for CDSI in the
conterminous United States. On average, CDSI increased yield by
8.0% (95% CI = 1.8–14.7%) compared with conventional free
drainage. The yield response to CDSI did not differ among
crops. However, a greater yield response to CDSI was observed in
medium-textured soils (19.4% increase; 95% CI = 12.4–27.0%) than
in coarse- or fine-textured soils. The positive effect of CDSI on
yield increased with decreasing PGS in coarse-
and medium-textured soils. There was no clear effect of CDSI on
soil moisture, nor did any moderators influence this
relationship, though this may be attributed to the scarcity of
studies on CDSI reporting soil moisture. The fuzzy-logic-based
approach revealed that while potentially suitable areas are
mostly concentrated in the well studied U. S. Midwest, these
areas also exist in other regions where CDSI may warrant further
study.

控制排水与地下灌溉（Controlled Drainage and Subirrigation, CDSI）是诸多地区广泛应用的重要水分管理策略，但目前尚未完全明确CDSI在何种条件下最易提升作物产量与土壤含水率。本研究针对CDSI开展了一项元分析（meta-analysis），共纳入来自30篇同行评议原创研究论文中的154组成对观测样本，这些数据均来自重复随机试验（其中包含6项控制排水试验、24项CDSI试验，因数据稀缺将二者合并分析）；旨在探究作物产量与土壤含水率对CDSI的响应规律，并解析作物类型、土壤质地以及生长季累计降水量（PGS）对上述响应的调控作用。基于产量对这些调控因子的响应特征，本研究采用模糊逻辑（fuzzy logic）方法，绘制了美国本土范围内CDSI的潜在适宜应用区域分布图。相较于常规自由排水，CDSI可使作物产量平均提升8.0%（95%置信区间：1.8%~14.7%）。不同作物类型的产量响应无显著差异，但相较于粗质地或细质地土壤，中等质地土壤上的CDSI产量提升效果更为显著（增幅达19.4%，95%置信区间：12.4%~27.0%）。在粗质地与中等质地土壤中，CDSI对产量的正向效应随生长季累计降水量（PGS）的降低而增强。CDSI对土壤含水率未表现出明确的调控效应，各类调控因子也未对该关联产生显著影响，不过这一结果可能受限于当前CDSI相关研究中土壤含水率观测数据的匮乏。基于模糊逻辑的分析结果显示，尽管CDSI潜在适宜区域主要集中在研究较为充分的美国中西部地区，但在其他区域也存在此类适宜区域，这些区域的CDSI应用值得开展进一步研究。