Effects of Controlled Drainage on the Content Change and Migration of Moisture, Nutrients, and Salts in Soil and the Yield of Oilseed Sunflower in the Hetao Irrigation District

Abstract

Controlled drainage (CD) is an important agricultural measure for maintaining soil moisture and nutrients, controlling groundwater level, and increasing crop yield. In arid regions, CD can be used to improve the water supply in agriculture and reduce environmental pollution. In this study, we investigated the effects of CD, including drainage depths of 40 cm (CWT1) and 70 cm (CWT2) during the plant growth stages, free drainage (FD), and open-ditch drainage (OD), on the migration of water, nutrients, and salts in the soil, the dynamics of the groundwater level, the loss of soil nitrogen, and the growth of oilseed sunflower plants. Compared with FD, CD increased the water and nutrient content in the soil, reduced nitrogen loss, and enhanced the ability of the soil to continuously supply nitrogen to the oilseed sunflower plants, which benefited plant growth at later growth stages and reduced environmental pollution. During the period between irrigation at the budding stage and the harvest stage, the average soil water content in the 0–20 cm soil layer in CWT1 increased by 3.67%, 4.78%, and 0.55%, respectively, compared with that in CWT2, FD, and OD. The soil mineral content in CWT1 was 25.17%, 35.05%, and 17.78% higher than that in CWT2, FD, and OD, respectively, indicating that higher soil salinity occurred at the later stage of plant growth in CWT1, which actually had little effect on the plants due to their enhanced salt tolerance and increased need for water and nutrients at that stage. In addition, CD delayed the decline in groundwater level, which allowed the plants to use groundwater at later growth stages, and as a result, the yield and water-use efficiency were improved. CWT1 significantly increased oilseed sunflower yield by 4.52–11.14% and increased water-use efficiency by 1.16–10.8%. Moreover, CWT1 also increased the survival rate of the oilseed sunflower plants by 2.62–2.92%, and the plants demonstrated good growth. Therefore, under CD conditions, plants used soil water and nitrogen more efficiently and, as a result, their productivity was increased, and the water quality was improved.

The Effect of Controlled Tile Drainage on Growth and Grain Yield of Spring Barley as Detected by UAV Images, Yield Map and Soil Moisture Content

“…The probability of retaining plant-available soil water due to CTD is lower in our drier study site than in humid sites, but even a small increase in soil water availability associated with the elimination of drainage runoff is important for stabilizing or slightly increasing crop yields. For instance, Dou et al [74] identified a delay in groundwater table decline through CTD (drainage depth of 40 cm) in a dryland area, which allowed sunflower to use groundwater at later growth stages, resulting in yield and water use efficiency improvements of 4.52-11.14% and 1.16-10.8%, respectively. Accordingly, the grain yield of spring barley in our study was increased by 4% in relation to CTD.…”

Effect of Autumn Irrigation on Salt Leaching under Subsurface Drainage in an Arid Irrigation District

“…The effective utilization of water resources and reduction of soil salinization levels have become important influencing factors to achieve high-quality development in agriculture and maintain sustainability in ecology [8,9]. Salinity gradually accumulates in soil during the crop growing season in the Hetao Irrigation District, and the soil can reach moderate or severe salinization by the end of the crop growth period [10]. Ren et al [11] found that the temporal variation in soil salinity was also significant, with the proportion of salt-affected soil at the regional scale increasing from 28% to 42% by the end of the growing season.…”

Canola yield and quality under tile drainage in the Canadian Prairies

“…Agricultural drainage is an important water management practice that provides a conducive growing environment for root development and crop growth by lowering the water table and removing excess water within the root zone. Although drainage is mainly practiced in humid climates, it is also important in semi-arid climates such as the Canadian Prairies in controlling salinization (Dou et al 2021). The benefits of agricultural drainage are well documented in several textbooks, including increased crop yield and decreased nutrients and drainage outflow (Natural Resources Conservation Service, NRCS 2001, Huffman et al 2011.…”

“…Early studies on CD can be traced to the United States in the 1970s. Due to its enormous benefits, it has been recommended and adopted in various countries, including Canada, Italy, Sweden, Australia, China, and Iran (Wesström et al 2014, Sunohara et al 2016, Tolomio and Borin 2018, Jouni et al 2018, Dou et al 2021.…”

“…Numerous studies have reported varying results on the agronomic and environmental impacts of different water management systems. Using CD, for example, which is regarded as one of the best management practices (BMPs), several studies have reported positive benefits, including increased yield and income, decrease in drainage flow, drop in nitrate and phosphorus export, disease control, salinity control, and improved soil structure (Tan et al 1999, Fausey 2005, Satchithanantham et al 2014, Darzi et al 2007, Drury et al 2009, Skaggs et al 2012, Awale et al 2015, Gunn et al 2015, Mehring et al 2015, Sunohara et al 2016, Smith et al 2019, Wang et al 2020, Mourtzinis et al 2021, Dou et al 2021, Helmers et al 2022). On the contrary, negative results have also been reported for CD, including lower yield, increase in surface runoff, alternative routes to nutrients losses, increased potential for salinization and increased GHG emissions (Tan et al 1998, Hornbuckle et al 2005, Nangia et al 2013, Kumar et al 2014, Hanke 2018.…”