Long-term effects of combining gypsuming with brackish ice irrigation on soil desalinization and crop growth in abandoned saline-sodic land

ABSTRACT

Salinity-sodicity may be reduced by freezing and melting (FM) brackish ice irrigation combined with gypsum for the highly saline-sodic soils. A 5-year field study was carried out in the Songnen Plain, northeast China, to investigate the effects of FM brackish ice irrigation in combination with phosphogypsum on soil salinity-sodicity. The treatments consisted of no amendment, no irrigation (CK) and FM brackish ice irrigation using the local brackish water (SW), and required phosphogypsum application to fully reclaim the 0–10 cm, 0–20 cm, 0–30 cm and 0–40 cm soil layer, combined with SW (10GR + SW, 20GR + SW, 30GR + SW and 40GR + SW), respectively. The findings showed that five FM brackish ice irrigation significantly decreased soil salinity–sodicity, and the lowest value of electrical conductivity (EC) (0.49 dS m⁻¹) in the soil layer of 0–40 cm was observed in 30GR + SW treatment. Maximum sunflower and tomato yields (2670.28 kg ha⁻¹ and 31,854.28 kg ha⁻¹) were observed in the 30GR + SW treatment. Results indicate that FM brackish ice irrigation in combination with the phosphogypsum required for reclaiming 30 cm depth of soil is a cost-effective scenario for the abandoned saline-sodic land.

KEYWORDS:

• Soil
• freezing and melting
• saline-sodic soil
• phosphogypsum
• Songnen Plain

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the National Key Research and Development Program of China [2016YFC0501200], the National Natural Science Foundation of China [Nos. 41971066 and 41771250], and the Science-technology Development Initiative of Jilin Province [20180201012SF].