Root architecture development in stony soils

Shehan Morandage,Andrea Schnepf,Daniel Leitner,Mirjam Zörner,Jan Vanderborght,Harry Vereecken,Gaochao Cai

doi:10.1002/vzj2.20133

Shehan Morandage, Andrea Schnepf + Show 5 more

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https://doi.org/10.1002/vzj2.20133

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Abstract

AbstractSoils with high stone content represent a challenge to root development, as each stone is an obstacle to root growth. A high stone content also affects soil properties such as temperature or water content, which in turn affects root growth. We investigated the effects of all soil properties combined on root development in the field using both experiments and modeling. Field experiments were carried out in rhizotron facilities during two consecutive growing seasons (wheat [Triticum aestivum L.] and maize [Zea mays L.]) in silty loam soils with high (>50%) and low (<4%) stone contents. We extended the CPlantBox root architecture model to explicitly consider the presence of stones and simulated root growth on the plot scale over the whole vegetation period. We found that a linear increase of stone content resulted in a linear decrease of rooting depth across all stone contents and developmental stages considered, whereas rooting depth was only sensitive to cracks below a certain crack density and at earlier growth stages. Moreover, the impact of precipitation‐influenced soil strength had a relatively stronger impact on simulated root arrival curves during the vegetation periods than soil temperature. Resulting differences between stony and non‐stony soil of otherwise the same crop and weather conditions show similar trends as the differences observed in the rhizotron facilities. The combined belowground effects resulted in differences in characteristic root system measures of up to 48%. In future work, comparison of absolute values will require including shoot effects—in particular, different carbon availabilities.

Highlights

More than 10% stone content is found in 41% of Europe’s soils (Stendahl et al, 2009), affecting both forested and agricultural areas (Cai, Vanderborght, et al, 2018; Hlaváčiková et al, 2018)
Wheat roots arrived at 120-cm depth after 120 d, whereas there were hardly any roots observed at this depth in the stony soil
We showed that simulated differences of characteristic root system measures between stony and cracked soils of otherwise same crop and weather conditions show similar trends as in the measurements obtained in the rhizotron facilities in Selhausen

Summary

Introduction

More than 10% stone content is found in 41% of Europe’s soils (Stendahl et al, 2009), affecting both forested and agricultural areas (Cai, Vanderborght, et al, 2018; Hlaváčiková et al, 2018). The effect of stones on root architecture development is even less well known (Cai, Vanderborght, et al, 2018) and has only been explicitly incorporated in few root architectural models (Jin et al, 2020; Schnepf et al, 2018). The combined effect of stones and corresponding soil properties on root architecture development at the plot scale has not yet been explicitly simulated. In order to identify parameters that characterize the RSA and how it develops as a function of the soil conditions and properties, experimental field sampling data have been combined with model simulations using an inverse modeling framework (Garré et al, 2012; Morandage et al, 2019; Pagès et al, 2012; Vansteenkiste et al, 2014; Ziegler et al, 2019).

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