Quantification of the length and diameter of root segments with public domain software

Dowdy, R. H.; Nater, Edward A.; Dolan, M. S.

doi:10.1080/00103629509369311

Cited by 35 publications

(32 citation statements)

References 16 publications

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“…11). Although methods for its determination have been proposed (Majdi et al 1992;Dowdy et al 1995;Kucke et al 1995), establishing an average value is often cumbersome. The analysis of digitalized root images indicated an average value for the root radius of 0.0003 m. It is, however, possible that this value overestimates the real value of r 0 due to information loss both in the sieving/washing process and in the digitalizing process.…”

Section: Root System Analysismentioning

confidence: 99%

A split-pot experiment with sorghum to test a root water uptake partitioning model

et al. 2009

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Correct modeling of root water uptake partitioning over depth is an important issue in hydrological and crop growth models. Recently a physically based model to describe root water uptake was developed at single root scale and upscaled to the root system scale considering a homogeneous distribution of roots per soil layer. Root water uptake partitioning is calculated over soil layers or compartments as a function of respective soil hydraulic conditions, specifically the soil matric flux potential, root characteristics and a root system efficiency factor to compensate for within-layer root system heterogeneities. The performance of this model was tested in an experiment performed in two-compartment split-pot lysimeters with sorghum plants. The compartments were submitted to different irrigation cycles resulting in contrasting water contents over time. The root system efficiency factor was determined to be about 0.05. Release of water from roots to soil was predicted and observed on several occasions during the experiment; however, model predictions suggested root water release to occur more often and at a higher rate than observed. This may be due to not considering internal root system resistances, thus overestimating the ease with which roots can act as conductors of water. Excluding these erroneous predictions from the dataset, statistical indices show model performance to be of good quality.

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Section: Root System Analysismentioning

confidence: 99%

A split-pot experiment with sorghum to test a root water uptake partitioning model

et al. 2009

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“…Roots were separated from soil in a hydropneumatic elutriator (Smucker et al, 1982). The washed roots were stained, scanned, and analyzed using a public domain software package (Dowdy et al, 1995).…”

Section: Planting and Harvestingmentioning

confidence: 99%

Fine root demography in alfalfa (Medicago sativa L.)

Goins

Russelle

1996

Plant Soil

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In perennial forages like alfalfa (Medicago sativa L.), repeated herbage removal may alter root production and mortality which, in turn, could affect deposition of fixed N in soil. Our objective was to determine the extent and patterns of fine-diameter root production and loss during the year of alfalfa stand establishment. The experiment was conducted on a loamy sand soil (Udorthentic Haploboroll) in Minnesota, USA, using horizontally installed minirhizotrons placed directly under the seeded rows at 10, 20, and 40 cm depths in four replicate blocks. We seeded four alfalfa germplasms that differed in N2 fixation capacity and root system architecture: Agate alfalfa, a winter hardy commercially-available cultivar; Ineffective Agate, which is a non-N2-fixing near isoline of Agate; a new germplasm that has few fibrous roots and strong tap-rooted traits; and a new germplasm that has many fibrous roots and a strongly branched root system architecture, Video images collected biweekly throughout the initial growing season were processed using C-MAP-ROOTS software.More than one-half of all fine roots in the upper 20 cm were produced during the first 7 weeks of growth. Root production was similar among germplasms, except that the highly fibrous, branch-rooted germplasm produced 29% more fine roots at 20 cm than other germplasms. In all germplasms, about 7% of the fine roots at each depth developed into secondarily thickened roots. By the end of the first growing season, greatest fine root mortality had occurred in the uppermost depth (43%), and least occurred at 40 cm (36%). Survival of contemporaneous root cohorts was not related to soil depth in a simple fashion, although all survivorship curves could be described using only five rates of exponential decline. There was a significant reduction in fine root mortality before the first herbage harvest, followed by a pronounced loss (average 22%) of fine roots at the 10-and 20-cm depths in the 2-week period following herbage removal. Median life spans of these early-season cohorts ranged from 58 to 131 days, based on fitted exponential equations. At all depths, fine roots produced in the 4 weeks before harvest (early-to mid-August) tended to have shorter median life spans than early-season cohorts. Similar patterns of fine root mortality did not occur at the second harvest. Germplasms differed in the pattern, but not the ultimate extent, of fine root mortality. Fine root turnover during the first year of alfalfa establishment in this experiment released an estimated 830 kg C ha -1 and 60 kg N ha -1, with no differences due to N2 fixation capacity or root system architecture.

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“…Farrel et al (1993) showed that comparable results could be had with either manual or digital measurement of root lengths using the line intersect method. Dowdy et al (1995) and Kimura and Yamasaki (2001) found that easily-obtained public domain image analysis software could be used to quantify the length and diameter of root segments. Kokko et al (1993) used a slightly different approach to quantify roots from a soil sample by counting the number of pixels projected on a 2-dimensional image to determine root surface area.…”

Section: Introductionmentioning

confidence: 99%

A method to separate plant roots from soil and analyze root surface area

Benjamin

Nielsen

2004

Plant Soil

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Analysis of the effects of soil management practices on crop production requires knowledge of these effects on plant roots. Much time is required to wash plant roots from soil and separate the living plant roots from organic debris and previous years' roots. We developed a root washer that can accommodate relatively large soil samples for washing. The root washer has a rotary design and will accommodate up to 24 samples (100 mm diam. by 240 mm long) at one time. We used a flat-bed scanner to digitize an image of the roots from each sample and used a grid system with commercially-available image analysis software to analyze each sample for root surface area. Sensitivity analysis and subsequent comparisons of 'dirty' samples containing the roots and all the organic debris contained in the sample and 'clean' samples where the organic debris was manually removed from each sample showed that up to 15% of the projected image could be covered with debris without affecting accuracy and precision of root surface area measurements. Samples containing a large amount of debris may need to be partitioned into more than one scanning tray to allow accurate measurements of the root surface area. Sample processing time was reduced from 20 h, when hand separation of roots from debris was used, to about 0.5 h, when analyzing the image from an uncleaned sample. The method minimizes the need for preprocessing steps such as dying the roots to get better image contrast for image analysis. Some information, such as root length, root diameter classes and root weights, is not obtained when using this technique. Root length measurements, if needed, could be made by hand on the digital images. Root weight measurement would require sample cleaning and the advantage of less processing time per sample with this method would be lost. The significance of the tradeoff between information not obtained using this technique and the ability to process a greater number of samples with the time and personnel resources available must be determined by the individual researcher and research objectives.

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Quantification of the length and diameter of root segments with public domain software

Cited by 35 publications

References 16 publications

A split-pot experiment with sorghum to test a root water uptake partitioning model

A split-pot experiment with sorghum to test a root water uptake partitioning model

Fine root demography in alfalfa (Medicago sativa L.)

A method to separate plant roots from soil and analyze root surface area

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