Soil temperature modeling in topsoil with plastic film mulching and low spring temperatures

ABSTRACT

Mulching has been widely used to increase soil temperature and promote seedling emergence in areas with cold springs. However, soil temperature regulation with mulching is not well controlled, which often leads to failure in crop establishment. A two-year field study was conducted to determine and simulate the effect of transparent plastic film mulching on soil temperatures at 5 cm depth (T₅) using the Denitrification-Decomposition (DNDC) model in the cold Hetao Irrigation District in north-western China. Four treatments were used: no mulch (CK), full mulching with plastic film at 140 cm width (PMF), and partial plastic film mulching at 60 cm width (PM60) and 30 cm width (PM30). Mulching did not result in a sinusoidal phase change in diurnal air temperature (T_a) between mulch and the soil surface (T_ms). T_ms decreased with a decrease in film width. Values of the daily averaged T_ms and T₅ were significantly correlated (R² > 0.70). Simulated T₅ matched the observed T₅ well, with marginal overestimation in both no-mulch and mulch conditions (NSE > 0.7). Embedding a simple empirical approach for T_ms calculation can reduce parameter input into the DNDC model, and result in acceptable T₅ simulation.

KEYWORDS:

• Plastic film mulch
• chilling stress
• DNDC model
• soil temperature

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Second Tibetan Plateau Scientific Expedition and Research (STEP) program [2019QZKK0303] and the Strategic Priority Research Program of the Chinese Academy of Sciences [XDA23060302] .