Soil salinization after long‐term mulched drip irrigation poses a potential risk to agricultural sustainability

Abstract

Summary Prevention of soil salinization is key to agriculture in arid and semiarid regions. Because of the desert climate and extensive demand for irrigation, mulched drip irrigation (MDI) has been practised across Xinjiang, the largest cotton‐planting region in China, since the early 1990s, reaching 2 × 106 ha in 2014. Although MDI can minimize irrigation‐induced soil salinization, long‐term practice of MDI causes salts to accumulate in the root zone and on the bare soil surface between mulches, which leads to unsustainable crop yields. Here, we summarize the mechanisms and factors that affect soil salinization under MDI management. A proper MDI scheme that meets the requirements for crop growth and the flushing of excessive salts is essential for agricultural sustainability in Xinjiang and other oasis agroecosystems around the world. Highlights Long‐term mulched drip irrigation causes salt accumulation in the subsoil and on the surface. A proper irrigation scheme that sustains crop growth and flushes excessive salts is crucial.

Drip irrigation with organic fertilizer application improved soil quality and fruit yield

“…Some studies have suggested that short‐term drip irrigation flushes salts to the deeper subsoil and soil salinity appeared to accumulate in the area far from the tape (Liu, Yang, Li, Yu, & Wang, ; Wang, Yang, & Zheng, ). However, other studies have claimed that long‐term (>5 yr) drip irrigation could induce soil salinization, and caused salts to accumulate in the root zone and on the bare soil surface (Mai et al., ; Wang et al., ). Some suggested that the long‐term use of mineral fertilizers can also lead to the accumulation of salt, while the use of organic fertilizers reduced the degree of soil salinization (Cha‐um & Kirdmanee, ; Walker & Bernal, ).…”

“…Some studies have shown that drip irrigation can save 25-60% of irrigation water relative to surface irrigation (Aujla, Thind, & Buttar, 2007;Bashour & Nimah, 2004;Evans & Zaitchik, 2008;Ibragimov et al, 2007). Compared with flood and furrow irrigation, drip irrigation distributes water more evenly through the crop seasons and inhibits deep penetration (Karlberg, Rockstrom, Annandale, & Steyn, 2007;Wang, Fan, & Guo, 2019). In Xinjiang, drip irrigation has been widely used in cotton cultivation, with more than 3 million ha of arable land irrigated using this technology (Xinjiang Statistical Bureau, 2018).…”

Quantitative Evaluation of Spatial and Temporal Variation of Soil Salinization Risk Using GIS-Based Geostatistical Method

“…On the basis of the existing research results and referring to the actual situation and historical data of the research area [26][27][28], the intensity and range of various salinization risk sources were summarized, and the risk factors that represent the actual situation of the research area were selected. Considering many factors such as the integrity of the data in the study area and its representativeness, the authors chose the surface temperature, the surface elevation, the surface slope, the surface aspect, the normalized differential vegetation index, the plant senescence reflectance index, the land-use and land-cover change, the surface soil water content, the shallow soil salt content (20-40 cm, g/kg), the shallow soil water content (20-40 cm, %), the deep soil salt content (60-80 cm, g/kg), and the deep soil water content (60-80 cm, %) as risk sources, for a total of 12 factors.…”

“…On the basis of the existing research results and referring to the actual situation and historical data of the research area [26][27][28], the intensity and range of various salinization risk sources were Figure 2. Topographic map of the study area: (a) The DEM data of the study area; (b) the surface aspect of the study area; and (c) the surface slope of the study area.…”

Investigating the Proper Application Rate of Nitrogen under Mulched Drip Irrigation to Improve the Yield and Quality of Tomato in Saline Soil

“…However, the absorption of nitrogen by crops is heavily influenced by site-specific conditions. Drip irrigation has a leaching effect on the salt present in the root zone, which can create a good water and salt environment for the root system [21]. Previous studies have examined salt and nitrogen, but most of them have focused on water-salt movement [22] or water-nitrogen coupling.…”