Cotton root growth in a compacted Vertisol (Grey Vertosol). I. Prediction using strength measurements and 'limiting water ranges'

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 1157 ◽  
Author(s):  
D. C. McKenzie ◽  
A. B. McBratney
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Published Data ◽  
Cotton Production ◽  
Compacted Soil ◽  
Cotton Root ◽  
Least Limiting Water Range ◽  
Content Range ◽  
Water Contents ◽  
Better Than

The shear strength of a Vertisol under a broad range of compaction conditions has been related to ‘non-limiting water range’ (NLWR), ‘partially limiting water range’ (PLWR), and ‘least-limiting water range’ (LLWR) estimates for the growth of cotton roots. These factors indicate the soil water content range that land managers should aim to maintain so that root growth limitations caused by excessive hardness and poor aeration are minimised. The proportion of macropores available for root extension as the bulk soil becomes too anaerobic and/or hard for their growth has been quantified via a re-assessment of published data that relate oxygen flux density to air-filled porosity. A shear vane was shown to be better than a penetrometer for distinguishing compacted and non-compacted soil under a broad range of soil water contents on a Vertisol used for irrigated cotton production. Published critical limits for cotton root growth based on penetrometer data are of limited value. Nevertheless, these data have been converted for use with a shear vane. The NLWR and PLWR estimates have also been related to the SOILpak score, core bulk density, a clod shrinkage parameter, and a SOLICON image analysis factor.

EFFECT OF SOIL WATER AND TEMPERATURE ON CORN (Zea mays L.) ROOT GROWTH DURING EMERGENCE

1986 ◽  
Vol 66 (1) ◽  
pp. 51-58 ◽  
Author(s):  
H. W. CUTFORTH ◽  
C. F. SHAYKEWICH ◽  
C. M. CHO
Keyword(s):  
Root Growth ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Zea Mays L ◽  
Rate Sensitivity ◽  
Corn Hybrids ◽  
Soil Water Stress ◽  
Soil Temperatures ◽  
Water Contents

Root growth between germination and emergence for the corn hybrids Pioneer 3995, Northrup King 403 and Pride 1108 was studied. Soil temperatures of 15, 19, 25 and 30.5 °C and a range of soil water contents were used. Decreases in soil temperature and water content both decreased root growth rate. Sensitivity to water content decreased with decreasing soil temperature. All three hybrids responded to soil temperature in the same way. By contrast, Pioneer 3995 was less sensitive to soil water stress than was Northrup King 403, while Pride 1108 was the most sensitive. Key words: Soil water, soil temperature, root growth (early), corn

scholarly journals Comparison of Soil Hydraulic Parameterizations for Mesoscale Meteorological Models

2005 ◽  
Vol 44 (7) ◽  
pp. 1116-1132 ◽  
Author(s):  
Frank J. Braun ◽  
Gerd Schädler
Keyword(s):  
Soil Water ◽  
Atmospheric Model ◽  
Surface Data ◽  
Rhine Valley ◽  
Soil Hydraulic ◽  
Cover Up ◽  
Meteorological Models ◽  
Water Contents ◽  
Soil Water Contents ◽  
Better Than

Abstract Soil water contents, calculated with seven soil hydraulic parameterizations, that is, soil hydraulic functions together with the corresponding parameter sets, are compared with observational data. The parameterizations include the Campbell/Clapp–Hornberger parameterization that is often used by meteorologists and the van Genuchten/Rawls–Brakensiek parameterization that is widespread among hydrologists. The observations include soil water contents at several soil depths and atmospheric surface data; they were obtained within the Regio Klima Projekt (REKLIP) at three sites in the Rhine Valley in southern Germany and cover up to 3 yr with 10-min temporal resolution. Simulations of 48-h episodes, as well as series of daily simulations initialized anew every 24 h and covering several years, were performed with the “VEG3D” soil–vegetation model in stand-alone mode; furthermore, 48-h episodes were simulated with the model coupled to a one-dimensional atmospheric model. For the cases and soil types considered in this paper, the van Genuchten/Rawls–Brakensiek model gives the best agreement between observed and simulated soil water contents on average. Especially during episodes with medium and high soil water content, the van Genuchten/Rawls–Brakensiek model performs better than the Campbell/Clapp–Hornberger model.

The uptake of zinc-65 by oats in relation to soil water content and root growth

Soil Research ◽  
1976 ◽  
Vol 14 (1) ◽  
pp. 67 ◽  
Author(s):  
EKS Nambiar
Keyword(s):  
Root Growth ◽  
Thin Layer ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
65Zn Uptake ◽  
Access To Water ◽  
Seminal Roots ◽  
Dry Soil ◽  
Water Contents

Effects of water content of the topsoil on root growth and 65Zn absorption by oats were measured. Seminal roots of oats grew through a labelled uptake layer that had been initially wetted to various water contents. The uptake layer was separated from adjacent layers of wet sand or soil by a thin layer of wax. When the uptake layer was wetted initially and allowed to dry during the uptake period, water content affected root growth and 65Zn uptake similarly. 65Zn absorption by unbranched seminal roots decreased linearly as soil water suction increased from 0.3 to 5 bar. Nevertheless significant amounts of 65Zn were absorbed (40% of that from wet soil) even when the soil water suction exceeded 15 bar, with negligible concomitant uptake of water. Provided the roots had access to water in a subjacent layer, rates of 65Zn absorption from dry soil increased with the age of the plants. The exudation of mucilage from the root was enhanced locally where the soil was dry. The mucilage may facilitate the transfer of zinc to the root in dry soil.

Cotton Root Growth and Soil Water Extraction

1989 ◽  
Vol 53 (6) ◽  
pp. 1850-1855 ◽  
Author(s):  
William L. Bland ◽  
William A. Dugas
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Water Extraction ◽  
Cotton Root ◽  
Soil Water Extraction

Effects of Soil Water Content on Cotton Root Growth and Distribution Under Mulched Drip Irrigation

2009 ◽  
Vol 8 (6) ◽  
pp. 709-716 ◽  
Author(s):  
Xiao-tang HU ◽  
Hu CHEN ◽  
Jing WANG ◽  
Xiao-bin MENG ◽  
Fu-hong CHEN
Keyword(s):  
Root Growth ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Drip Irrigation ◽  
Cotton Root ◽  
Mulched Drip Irrigation

scholarly journals The Effect of Irrigation Rate on the Water Relations of Young Citrus Trees in High-Density Planting

2021 ◽  
Vol 13 (4) ◽  
pp. 1759
Author(s):  
Said A. Hamido ◽  
Kelly T. Morgan
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Soil Salinity ◽  
Planting Density ◽  
Stem Water Potential ◽  
Irrigation Rate ◽  
Biological Stress ◽  
Stem Water ◽  
Water Contents ◽  
Soil Water Contents

The availability and proper irrigation scheduling of water are some of the most significant limitations on citrus production in Florida. The proper volume of citrus water demand is vital in evaluating sustainable irrigation approaches. The current study aims to determine the amount of irrigation required to grow citrus trees at higher planting densities without detrimental impacts on trees’ water relation parameters. The study was conducted between November 2017 and September 2020 on young sweet orange (Citrus sinensis) trees budded on the ‘US-897’ (Cleopatra mandarin x Flying Dragon trifoliate orange) citrus rootstock transplanted in sandy soil at the Southwest Florida Research and Education Center (SWFREC) demonstration grove, near Immokalee, Florida. The experiment contained six planting densities, including 447, 598, and 745 trees per ha replicated four times, and 512, 717, and 897 trees per ha replicated six times. Each density treatment was irrigated at 62% or 100% during the first 15 months between 2017 and 2019 or one of the four irrigation rates (26.5, 40.5, 53, or 81%) based on the calculated crop water supplied (ETc) during the last 17 months of 2019–2020. Tree water relations, including soil moisture, stem water potential, and water supplied, were collected periodically. In addition, soil salinity was determined. During the first year (2018), a higher irrigation rate (100% ETc) represented higher soil water contents; however, the soil water content for the lower irrigation rate (62% ETc) did not represent biological stress. One emitter per tree regardless of planting density supported stem water potential (Ψstem) values between −0.80 and −0.79 MPa for lower and full irrigation rates, respectively. However, when treatments were adjusted from April 2019 through September 2020, the results substantially changed. The higher irrigation rate (81% ETc) represented higher soil water contents during the remainder of the study, the lower irrigation rate (26.5% ETc) represents biological stress as a result of stem water potential (Ψstem) values between −1.05 and −0.91 MPa for lower and higher irrigation rates, respectively. Besides this, increasing the irrigation rate from 26.5% to 81%ETc decreased the soil salinity by 33%. Although increasing the planting density from 717 to 897 trees per hectare reduced the water supplied on average by 37% when one irrigation emitter was used to irrigate two trees instead of one, applying an 81% ETc irrigation rate in citrus is more efficient and could be managed in commercial groves.

Water stress affects the productivity, growth components, competitiveness and water relations of phalaris and white clover growing in a mixed pasture

1992 ◽  
Vol 43 (3) ◽  
pp. 659 ◽  
Author(s):  
L Guobin ◽  
DR Kemp ◽  
GB Liu
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
White Clover ◽  
Leaf Growth ◽  
Leaf Water ◽  
Water Potentials ◽  
Relative Water ◽  
Dry Conditions ◽  
Leaf Appearance ◽  
Water Contents

The effect of water stress during summer and recovery after rain on herbage accumulation, leaf growth components, stomatal conductance and leaf water relations of white clover (Trifolium repens cv. Haifa) and phalaris (Phalaris aquatica cv. Australian Commercial) was studied in an established mixed pasture under dryland (dry) or irrigated (wet) conditions. Soil water deficits under dry conditions reached 150 mm and soil water potentials in the top 20 cm declined to nearly -2 MPa after 50 days of dry weather. Water stress severely restricted growth of both species but then after rain fell, white clover growth rates exceeded those of phalaris. Under irrigation, white clover produced twice the herbage mass of phalaris but under dry conditions herbage production was similar from both species. Leaf appearance rates per tiller or stolon were slightly higher for white clover than phalaris but were reduced by 20% under water stress in both species. Leaf or petiole extension rates were more sensitive to water stress than leaf appearance rates and declined by 75% in phalaris and 90% in white clover. The ratio of leaf or petiole extension rates on dry/wet treatments was similar for both species in relation to leaf relative water contents, but in relation to leaf water potentials phalaris maintained higher leaf growth rates. Phalaris maintained a higher leaf relative water content in relation to leaf water potentials than did white clover and also maintained higher leaf water potentials in relation to the soil water potential in the top 20 cm. Stomata1 conductances for both species declined by 80-90% with increasing water stress, and both species showed similar stomatal responses to bulk leaf water potentials and leaf relative water contents. It is suggested that the poorer performance of white clover under water stress may be due principally to a shallower root system than phalaris and not due to any underlying major physiological differences. The white clover cultivar used in this study came from the mediterranean region and showed some different responses to water stress than previously published evidence on white clover. This suggests genetic variation in responses to water stress may exist within white clover. To maintain white clover in a pasture under dry conditions it is suggested that grazing practices aim to retain a high proportion of growing points.

Soil aggregate breakdown in a field experiment with different rainfall intensities and initial soil water contents

2017 ◽  
Vol 68 (6) ◽  
pp. 853-863 ◽  
Author(s):  
P. Shi ◽  
S. Thorlacius ◽  
T. Keller ◽  
M. Keller ◽  
R. Schulin
Keyword(s):  
Field Experiment ◽  
Soil Water ◽  
Soil Aggregate ◽  
Aggregate Breakdown ◽  
Initial Soil ◽  
Water Contents ◽  
Soil Water Contents
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