Background In the agricultural planting system in western areas of Northeast China, the drought during the growing season greatly restricts the water and fertilizer use efficiency of crops, threatens food security and the sustainability of water and land resources in China. The rational application of super absorbent polymers (SAP) has great potential to improve the soil available water-holding capacity of low yield farmland in addition to engineering measures.

Methods Pot experiments were conducted on a typical aeolian sandy soil in the western part of Jilin province, to explore the responses of soil and water conservation characteristics such as field water-holding capacity, wilting coefficient, and soil water capacity to SAP types (Dijin, Anxin, Wote and Hanbaobei), particle size (big and small) and the application dosage (0, 0.2%, 0.5%, 1.0%, 2.0%, 4.0% and 6.0%) of SAP.

Results 1) The water-holding capacity of SAP was significantly affected by its type, particle size, application dosages, and their interactions, among them, application dose was the key factor on water retention. 2) The soil water status was closely related to the type of SAP, e.g., soil water-holding capacity (Dijin>Anxin>Wote>Hanbaobei). The content of potassium and sodium ions in SAP may be the main factors affecting water retention, rather than calcium and magnesium ions. 3) The field water-holding capacity, wilting coefficient, and available soil water capacity significantly increased with increasing of SAP application, the increment was up to 15.53, 1.95, and 17.75 times more than control, respectively, which enhanced the competition between plant and SAP in severe dry soil. 4) SAP with small particles significantly enhanced available soil field capacity (1.21 times) and water-holding capacity (1.23 times) compared with the large ones, whereas it showed negative effect on the wilting coefficient.

Conclusions The reasonable application of SAP has a positive effect on promoting the sustainability of soil and water resources in arid areas, improving the water status, and achieving the goal of "yield improvement" in low production planting system.