Effect of Soil Water on GPR Estimation of Bulked Roots, Methods, and Suggestions

Abstract Background: Root phenotyping methods are of increasing importance as researchers seek to understand belowground productivity and breeders work to select for root traits. Effective non-destructive root phenotyping methods do not exist for bulked-root and tuber crops such as potato and cassava. Cassava is a tropical crop widely grown by subsistence farmers throughout the tropics and is the fourth most important staple food crop in the world, yet lags in research. It has an extensive growth period sometimes exceeding 12 months. Early maturity is a major goal for breeders, but the ability to select for it is hampered by the lack of non-destructive yield estimation methods. GPR is a tool with potential to aid in bulked root selection, but standard methods have yet to be developed. In this study, we demonstrate good practice in GPR estimation of root mass, which was used as a proxy for cassava root mass, and investigate the effect of soil water content on measurement.Results: Significant correlation between GPR data and daikon root mass was found for three of the five irrigation treatments. Correlation strength improved with increased soil water content and decreased variation of soil water content between plots. Pearson correlation coefficient varied from 0.53 – 0.79.Conclusions: GPR can be used to estimate bulked root mass. Wet soil can improve the predictive quality of GPR data, but water content needs to be homogeneous throughout the study site and period. Determining the optimal soil water content will require further research.

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Canopy Solar-Induced Chlorophyll Fluorescence and Its Link to Transpiration in a Temperate Evergreen Needleleaf Forest during the Fall Transition

Forests ◽

10.3390/f13010074 ◽

2022 ◽

Vol 13 (1) ◽

pp. 74

Author(s):

Weiwei Cong ◽

Kaijie Yang ◽

Feng Wang

Keyword(s):

Chlorophyll Fluorescence ◽

Soil Temperature ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Air Temperature ◽

Pearson Correlation ◽

Evergreen Forest ◽

Spatiotemporal Resolution ◽

The Relationship

Northern hemisphere evergreen needleleaf forest (ENF) contributes a significant fraction of global water exchange but regional transpiration (T) observation in ENF ecosystems is still challenging. Traditional remote sensing techniques and terrestrial biosphere models reproduce the transpiration seasonality with difficulty, and with large uncertainties. Solar-induced chlorophyll fluorescence (SIF) emission from vegetation correlates to photosynthesis at multiple spatial and temporal scales. However, how SIF links to transpiration of evergreen forest during seasonal transition is unclear. Here, we explored the relationship between canopy SIF and T retrieved from ground observation towers in ENF. We also examined the role of meteorological and soil factors on the relationship between SIF and T. A slow decrease of SIF and T with a fast reduction in photosynthetically active radiation (PAR), air temperature, vapor pressure deficit (VPD), soil temperature and soil water content (SWC) were found in the ENF during the fall transition. The correlation between SIF and T at hourly and daily scales varied significantly among different months (Pearson correlation coefficient = 0.29–0.68, p < 0.01). SIF and T were significantly linearly correlated at hourly (R2 = 0.53, p < 0.001) and daily (R2 = 0.67, p < 0.001) timescales in the October. Air temperature and PAR were the major moderating factors for the relationship between SIF and T in the fall transition. Soil water content (SWC) influenced the SIF-T relationship at an hourly scale. Soil temperature and VPD’s effect on the SIF-T relationship was evident at a daily scale. This study can help extend the possibility of constraining ecosystem T by SIF at an unprecedented spatiotemporal resolution during season transitions.

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Management of corm size and soil water content for gladiolus flower production

Ornamental Horticulture ◽

10.14295/oh.v23i2.972 ◽

2017 ◽

Vol 23 (2) ◽

pp. 152

Author(s):

Renata Bachin Mazzini-Guedes ◽

Osvaldo Guedes Filho ◽

Edna Bonfim-Silva ◽

Jean Couto ◽

Marcel Pereira ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Field Capacity ◽

One Pot ◽

Early Maturity ◽

Flower Production ◽

Production Factors ◽

The Family ◽

Water Contents

Gladiolus grandiflorus Andrews, in the family Iridaceae, is one of the most produced and marketed flowers in the world. In general, however, research results on gladioli production factors are scarce and divergent. The objective of this work was to evaluate the influence of corm size and soil water content on gladiolus flower production. The experimental design, using the early maturity cultivar ‘White Friendship’, was entirely randomized, arranged in a 5 x 2 factorial scheme (five soil water contents: 25; 50; 75; 100; and 125% field capacity, combined with two corm sizes: medium and big), with four replications per treatment. Each replication, composed of one pot, comprised three corms, totaling 40 pots and 120 plants. Both vegetative and flowering characteristics were evaluated. Gladiolus cultivation at 80% soil field capacity presents best results for commercialization, generating longer flower stems with greater diameter and flower number, plus larger flowers. Furthermore, such soil water content promotes the shortest cultivation period

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The use of computer assisted tomography to determine spatial distribution of soil water content

Soil Research ◽

10.1071/sr9830435 ◽

1983 ◽

Vol 21 (4) ◽

pp. 435 ◽

Cited By ~ 110

Author(s):

JM Hainsworth ◽

LAG Aylmore

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Plant Root ◽

Computer Assisted ◽

X Ray ◽

Computer Assisted Tomography ◽

Spatial Changes ◽

Exciting Possibility ◽

Non Destructive

To date no experimental technique has been capable of directly and repetitively measuring spatial distributions of soil water content in a non-destructive manner. The potential of computer assisted tomography (CAT) to overcome this problem has been examined in this paper. The results obtained from a commercially-produced X-ray CAT scanner and a conventional gamma scanner suggest that CAT scanning can be used to determine spatial changes in soil water content with adequate resolution for soil-plant studies. The technique can clearly be used to resolve spatial changes in soil water content with time. Application of the technique to water uptake by a single plant root shows that CAT scanning presents an extremely exciting possibility for studies of soil-plant water relations.

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Effect of Stoniness on the Hydraulic Properties of a Soil from an Evaporation Experiment Using the Wind and Inverse Estimation Methods

Water ◽

10.3390/w11030440 ◽

2019 ◽

Vol 11 (3) ◽

pp. 440

Author(s):

Nerea Arias ◽

Iñigo Virto ◽

Alberto Enrique ◽

Paloma Bescansa ◽

Riley Walton ◽

...

Keyword(s):

Hydraulic Conductivity ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Hydraulic Properties ◽

Estimation Methods ◽

Fine Earth ◽

Rock Fragments ◽

Stony Soil ◽

Inverse Estimation

Stony soils are distributed all over the world. The study of their characteristics has gained importance lately due to their increasing use as agricultural soils. The effect that rock fragments exert on the soil hydraulic properties is difficult to measure in situ, and is usually derived from the fine earth properties. However, the corrections used so far do not seem accurate for all types of stony soils. Our objective was to assess the adequacy of estimating the hydraulic properties of a stony soil from the fine earth ones by correcting the latter by the volume occupied by rock fragments. To do that, we first assessed the validity of different approaches for estimating the hydraulic properties of a stone-free and a stony (40% rock fragments) cylinder prepared with samples from the same silt loam soil. The functions relating to the soil hydraulic properties (θ-h, K-h-θ) were estimated by the Wind method and by inverse estimation, using data from an evaporation experiment where the soil water content and pressure head were measured at different soil depths over time. Results from the evaporation experiment were compared to those obtained by applying the equation that corrects fine earth properties by the rock fragments volume. Wind and the Inverse Estimation methods were successfully applied to estimate soil water content and hydraulic conductivity from the stony soil experiment, except for some uncertainties caused by the limited range of suction in which the experiment was conducted. The application of an equation for adjusting the soil water content at different pressure heads (allowing for defining the soil water retention curve, SWRC), and the unsaturated hydraulic conductivity (K) directly from the stone content was not satisfactory. K values obtained from the measured data were higher than those inferred by the correcting equation in the wet range, but decreased much faster with a decreasing pressure head. The use of this equation did therefore not take into account the effect that the creation of lacunar pores by the presence of rock fragments likely exerts on water flow processes. The use of such correction needs therefore to be revised and new approaches are needed for estimating the hydraulic conductivity in stony soils. In relation to SWRC, a new equation to calculate the water content of a stony soil accounting for the influence of possible lacunar pores is proposed.

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A Non-Destructive Method for Determining the Distribution of Soil Water Content by Measuring Fast Neutron Transmission Using an NE-213 Organic Scintillator

Japanese Journal of Applied Physics ◽

10.1143/jjap.23.1124 ◽

1984 ◽

Vol 23 (Part 1, No. 8) ◽

pp. 1124-1128 ◽

Cited By ~ 7

Author(s):

Toshihiko Ohnuki ◽

Tadatoshi Yamamoto ◽

Yoshiki Wadachi

Keyword(s):

Water Content ◽

Fast Neutron ◽

Soil Water ◽

Soil Water Content ◽

Neutron Transmission ◽

Organic Scintillator ◽

Non Destructive

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Image analysis for non-destructive and non-invasive quantification of root growth and soil water content in rhizotrons

Journal of Plant Nutrition and Soil Science ◽

10.1002/1522-2624(200210)165:5<573::aid-jpln573>3.0.co;2-w ◽

2002 ◽

Vol 165 (5) ◽

pp. 573-581 ◽

Cited By ~ 21

Author(s):

Rolf O. Kuchenbuch ◽

Keith T. Ingram

Keyword(s):

Image Analysis ◽

Root Growth ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Non Invasive ◽

Non Destructive

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SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1985.46.1696 ◽

1985 ◽

pp. 185-189

Author(s):

M.C.H.Mouat Pieter Nes

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Solution ◽

Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

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Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

Agrokémia és Talajtan ◽

10.1556/agrokem.59.2010.1.19 ◽

2010 ◽

Vol 59 (1) ◽

pp. 157-164 ◽

Cited By ~ 1

Author(s):

E. Tóth ◽

Cs. Farkas

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Carbon Dioxide Emission ◽

Nutrient Content ◽

Soil Disturbance ◽

Biological Properties ◽

Soil Tillage ◽

Favourable Effect ◽

Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

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