Limiting water range: Crop responses related to in‐season soil water dynamics, weather conditions, and subsoil compaction

Abstract

AbstractThe least limiting water range (LLWR) has been used as a soil structural quality indicator for identifying in‐season water dynamics, yet studies focusing on its use for detecting in‐season water stresses and their effect on crop response on severely compacted subsoils are scarce. The objectives of this study were, therefore, to examine the in‐season water dynamics on a tile‐drained soil with compacted subsoil in the light of two different approaches for calculating LLWR (standard LLWR by da Silva et al. [1994] and refined LLWR by Pulido‐Moncada & Munkholm [2019]) and to evaluate the crop response to aboveground and belowground conditions. Information on LLWRs was obtained from soil sampling in the most contrasting treatments of a compaction experiment: with and without compaction. In‐season water dynamics were measured from 2017 to 2019. The refined LLWR approach defined a wider range of water content nonlimiting for plant growth compared with the da Silva et al. approach. Compaction affected the LLWRs (p < .05), yet no significant effect of subsoil compaction on crop yield was found. Cumulative aeration and water stress day indicators identified from the refined LLWR were significantly related to grain yield (p < .05). The lower winter wheat yield in 2018 compared with 2019 seemed to be related to the direct impact of weather factors on aboveground growth and to aeration and water stresses. The apparent lack of compaction effect suggests further studies are needed to determine if in‐season stresses derived from the LLWRs can be related to crop development and yield under different soil and weather conditions.