Exploring crop root-soil heat relationships to optimally predict soil temperatures in greenhouse spaces

Considering the direct or indirect influence of crops on greenhouse soil, we improved the traditional greenhouse prediction of soil temperature, and established an accurate greenhouse soil temperature prediction model for the research gap of crop-soil thermal relationship in the climate of subtropical region. Multiple sets of replicated experiments were conducted to verify the hypothesis of crop-root-soil thermal relationship and compared with the model predictions.

The direct or indirect effects of crops on soil temperature are considered in the analysis of soil energies, in particular the effects of the results of the study of the crop-root-soil heat relationship. A new soil heat balance equation was re-established to correct the original greenhouse soil prediction model based on the soil heat balance equation. After experimental validation and model comparison verification, the model performance was evaluated by calculating two indicators, root mean square error (rRMSE) and mean bias error (MBE).

The experimental results show that there is a relatively stable temperature difference between the crop root system-soil. At ambient temperatures below sub-high temperatures, a stable temperature difference existed at all soil depths; at sub-high temperatures, this temperature difference became so small as to be almost negligible.

Comparison of the simulated data with the experimental data showed that the changes in soil temperature were consistent with the crop activities and the model simulated with higher accuracy than the original model. This provides an accurate method of predicting soil boundary conditions for studying the greenhouse thermal environment in the subtropics.