ROOTING CHARACTERISTICS OF CORN, SOYBEANS AND BARLEY AS A FUNCTION OF AVAILABLE WATER AND SOIL PHYSICAL CHARACTERISTICS

1988 ◽  
Vol 68 (1) ◽  
pp. 121-132 ◽  
Author(s):  
L. M. DWYER ◽  
D. W. STEWART ◽  
D. BALCHIN
Keyword(s):  
Extinction Coefficient ◽  
Root Distribution ◽  
Physical Characteristics ◽  
Root Density ◽  
Rooting Depth ◽  
Exponential Equation ◽  
Nonlinear Fitting ◽  
Available Water ◽  
Soil Physical Characteristics ◽  
Maximum Root

Root densities of field-grown corn, soybeans and barley were measured as functions of depth in four soils of different textures for 1 yr, and root depths were monitored for 2 additional years. General relationships were established between root depth, available soil water and soil texture. Maximum root depths were found to be inversely related to available water within the limits imposed by crop rooting habits and soil physical characteristics. Roots continued to develop during the reproductive growth phase and maximum root densities were found about the time of physiological maturity. Root distribution with depth was described for each crop on each soil using a modified exponential equation with an extinction coefficient specific to crop, growth stage and soil. Reasonable estimates of root distribution can be predicted from root density in the top layer using a crop-specific extinction coefficient in this modified exponential equation. Key words: Maximum root density, root distribution, rooting depth, nonlinear fitting

Root distribution of lychee trees growing in acid soils of subtropical Queensland

1990 ◽  
Vol 30 (5) ◽  
pp. 699 ◽  
Author(s):  
CM Menzel ◽  
RL Aitken ◽  
AW Dowling ◽  
DR Simpson
Keyword(s):  
Soil Properties ◽  
Root Distribution ◽  
Chemical Properties ◽  
Acid Soils ◽  
Sampling Technique ◽  
Exchange Capacity ◽  
Root Density ◽  
Rooting Depth ◽  
Ph Values ◽  
Vertical Root Distribution

A core sampling technique was used to investigate the vertical root distribution of 8-10-year-old lychee trees (Litchi chinensis cv. Tai So) growing on 5 acid soils in subtropical Queensland (lat. 27�s.). At each site, soil and roots were sampled at 10 cm depth intervals to 100 cm, the root density determined and a range of soil chemical and physical properties measured. Eighty percent of the feeder roots were located within the top 0-20 cm (1 site), 0 4 0 cm (2 sites) or 0-60 cm (2 sites). The depth of rooting was greatest in the fine textured soils, while the greatest total root density was recorded in the coarse textured soils. The data suggest that the placement of tensiometers for water scheduling needs to take into account the effective rooting depth of lychee because it may vary with soil type. At all sites, pH values were acidic (pH<6.0) and subsoil pH values were below 5.5, and exchangeable Ca decreased and exchangeable A1 increased with depth. Four of the 5 sites had subsoil with >30% Al saturation of the cation exchange capacity. Although root density (all sites) was correlated with a number of soil chemical properties, stepwise multiple linear regression showed that 62% of the variation in root density could be explained by a curvilinear function of depth. The intercorrelations between soil properties and the correlation of depth with some properties demonstrate the difficulties in separating the effects of depth per se from those of soil properties in reducing root growth.

Dual effect of fruit tree cultivation on soil physical characteristics

2011 ◽  
Vol 19 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Lei SUN ◽  
Yi-Quan WANG ◽  
Yu-Lin ZHANG ◽  
Jian-Bo LI ◽  
Hai-Yan HU
Keyword(s):  
Fruit Tree ◽  
Physical Characteristics ◽  
Dual Effect ◽  
Soil Physical Characteristics

Fine-root distribution of coniferous plantations in relation to site in southern Buenos Aires, Argentina

1992 ◽  
Vol 22 (11) ◽  
pp. 1575-1582 ◽  
Author(s):  
Adrián Ares ◽  
Norman Peinemann
Keyword(s):  
Organic Matter ◽  
Vertical Distribution ◽  
Root Distribution ◽  
Fine Roots ◽  
Buenos Aires ◽  
Fine Root ◽  
Organic Matter Content ◽  
Root Density ◽  
Site Quality ◽  
Coniferous Plantations

A study was conducted to determine the amounts and vertical distribution of fine roots <2 mm as a function of site quality in a temperate, hilly zone of Argentina. Fine roots were sampled in autumn from 0.2-ha plots established in 12 coniferous plantations of Pinushalepensis Mill., Pinusradiata D. Don, Cedrusdeodara (D. Don) G. Don, and Cupressussempervirens L.f. horizontalis, located in Sierra de la Ventana, southern Buenos Aires. Generally, root density was found to be higher under low-growth stands. The distance from a tree sometimes had an effect on root density, but no clear pattern within stands could be observed. Root density commonly decreased with depth, but slight irregularities in some profiles were observed. Site quality and soil type influenced root distribution. Belowground biomass up to a depth of 50 cm ranged from 1600 to 9800 kg•ha−1 in high-growth stands and from 5400 to 40 700 kg•ha−1 in low-growth stands. Soil organic matter content provided the best correlation with root density. A possible practical implication would be the use of indices related to vertical distribution of organic matter, among other variables, as complementary estimators of effective depth of rooting. The results strongly suggest that trees maintain a large fine-root system in poor sites at the expense of aboveground growth.

SOIL CONDITIONS ASSOCIATED WITH ABSENCE OR SPARSE DEVELOPMENT OF APPLE ROOTS

1978 ◽  
Vol 58 (4) ◽  
pp. 961-969 ◽  
Author(s):  
D. H. WEBSTER
Keyword(s):  
Soil Condition ◽  
Soil Strength ◽  
Rooting Depth ◽  
Soil Porosity ◽  
Soil Conditions ◽  
Increase With Increase ◽  
Or Groups ◽  
Maximum Root ◽  
M 12 ◽  
Root Abundance

Within orchards or groups of similar samples, the abundance of apple roots [Formula: see text] diameter was related to total soil porosity (Sta). Below a boundary soil porosity, roots were sparse or absent, and above this porosity, maximum root abundance tended to increase with increase in soil porosity. Depending upon soil texture, this boundary porosity varied from 29 to 39%. A previously derived model, which estimates boundary soil porosity (Stc) as a function of texture, accounted for most of these differences. If the model was correct, all boundary Sta – Stc values should have been zero and in four of six groups of samples the derived values were zero, + 1 or − 1. The greater departures from the expected in the remaining two groups (− 2 and + 4) may have been due to a tolerance of M. 12 rootstock to poor aeration and incomplete exploitation of potential rooting depth, respectively. With the exception of M. 12, apple roots were sparse or absent in samples with less than 10% air porosity at a tension of 100 cm (S100 cm). Poor development of roots in these samples was predicted by the model. In many samples with S100 cm > 10% there were few or no roots. Soil strength of many samples was within the range known to interfere with root development. For the purpose of recognizing a soil condition that will prevent apple root growth, Sta – Stc appears to be superior to the other criteria examined, i.e. Sta, S100 cm or soil strength.

Soil physical characteristics of peat soils

2002 ◽  
Vol 165 (4) ◽  
pp. 479 ◽  
Author(s):  
Kai Schwärzel ◽  
Manfred Renger ◽  
Robert Sauerbrey ◽  
Gerd Wessolek
Keyword(s):  
Physical Characteristics ◽  
Peat Soils ◽  
Soil Physical Characteristics

Seed-bed cultivations and sugar-beet seedling emergence

1989 ◽  
Vol 112 (2) ◽  
pp. 159-169 ◽  
Author(s):  
R. J. Gummerson
Keyword(s):  
Sugar Beet ◽  
Time Course ◽  
Seedling Emergence ◽  
Physical Characteristics ◽  
Thermal Time ◽  
Fine Aggregates ◽  
Soil Physical Characteristics

SummaryExperiments are described in which a range of seed beds was created in each of 5 years. The weather in these years produced wet, dry and capping seed-bed conditions. The time course of sugar-beet seedling emergence on each seed bed was recorded each year and the differences were considered in terms of soil physical characteristics: much of the year-to-year variation was accounted for by considering thermal time above 3 °C. The differences in emergence between seed beds were large only when conditions were dry, but in all years it was advantageous to level the seed bed in autumn or winter. Seed beds with a dense soil below the seed and fine aggregates above gave the most suitable conditions for rapid and successful emergence.

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