TY - JOUR

T1 - Root growth of cauliflower (Brassica oleracea L. botrytis) under unstressed conditions

T2 - Measurement and modelling

AU - Kage, H.

AU - Kochler, M.

AU - Stützel, H.

PY - 2000

Y1 - 2000

N2 - Root observations were carried out on cauliflower using the minirhizotron and the soil core method in two years on two locations with different soil types, a loess loam and a humic loamy sand. Total root length (RL) (cm cm-2) of cauliflower was correlated to total shoot dry weight (W(sh)) (g m-2) RL=0.0124(±0.005)*W(sh), r2=0.76. There was an acceptable correlation (r2=0.88) between the minirhizotron and the soil core methods for the sub-soil data, whereas the minirhizotron method underestimated rooting intensity for the top soil. Changes in rooting depth over time could be described for both soil types using a segmented function of temperature sum, consisting of an early exponential and a later linear phase. The increase of rooting depth during the linear phase was 0.107(±0.01) cm °C-1 d-1. A simple descriptive root growth model based on the assumptions of a negative exponential decline of root length density (RLD) with soil depth, of a fixed ratio of RLD at the top of the soil profile and at rooting depth (r(RLD)) and of a fixed fraction of dry matter increase allocated to fine-roots (f(fR)) was formulated and used to describe the temporal and spatial variation of RLD found in the field. Slightly diffent estimates of f(fR) and of r(RLD) could be found for the different soil types, indicating a higher fraction of fine-root dry matter for the loess loam soil and a somewhat deeper root system for the humic loamy sand soil. A cross validation using the parameter values obtained from adjusting to the rooting data of one soil type for predicting RLD values of the other soil type, however, indicated that still quite satisfactory estimates (r2=0.91 and 0.95) of RLD could be obtained.

AB - Root observations were carried out on cauliflower using the minirhizotron and the soil core method in two years on two locations with different soil types, a loess loam and a humic loamy sand. Total root length (RL) (cm cm-2) of cauliflower was correlated to total shoot dry weight (W(sh)) (g m-2) RL=0.0124(±0.005)*W(sh), r2=0.76. There was an acceptable correlation (r2=0.88) between the minirhizotron and the soil core methods for the sub-soil data, whereas the minirhizotron method underestimated rooting intensity for the top soil. Changes in rooting depth over time could be described for both soil types using a segmented function of temperature sum, consisting of an early exponential and a later linear phase. The increase of rooting depth during the linear phase was 0.107(±0.01) cm °C-1 d-1. A simple descriptive root growth model based on the assumptions of a negative exponential decline of root length density (RLD) with soil depth, of a fixed ratio of RLD at the top of the soil profile and at rooting depth (r(RLD)) and of a fixed fraction of dry matter increase allocated to fine-roots (f(fR)) was formulated and used to describe the temporal and spatial variation of RLD found in the field. Slightly diffent estimates of f(fR) and of r(RLD) could be found for the different soil types, indicating a higher fraction of fine-root dry matter for the loess loam soil and a somewhat deeper root system for the humic loamy sand soil. A cross validation using the parameter values obtained from adjusting to the rooting data of one soil type for predicting RLD values of the other soil type, however, indicated that still quite satisfactory estimates (r2=0.91 and 0.95) of RLD could be obtained.

KW - Cauliflower

KW - Dry matter production

KW - Minirhizotron method

KW - Model

KW - Roots

UR - http://www.scopus.com/inward/record.url?scp=0033815812&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0033815812

VL - 223

SP - 131

EP - 145

JO - Plant and soil

JF - Plant and soil

SN - 0032-079X

IS - 1-2

ER -