scholarly journals Relationship between Deep Root Distribution and Root Penetration Capacity Estimated by Pot Experiments with a Paraffin and Vaseline Layer for Landraces and Recent Cultivars of Wheat

2008 ◽  
Vol 11 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Katashi Kubo ◽  
Hiroshi Uchino ◽  
Yutaka Jitsuyama ◽  
Kazuto Iwama
1984 ◽  
Vol 35 (1) ◽  
pp. 31 ◽  
Author(s):  
RJK Myers ◽  
MA Foale ◽  
AA Done

Four grain sorghum cultivars (Quicksilver, Texas 610SR, E57 and Q7844), representing early-to-late maturity types, were grown under different irrigation frequencies (7-day, 14-day, 28-day or 42-day intervals or once-only-at-sowing) in the dry season in the Ord Irrigation Area. Soil water distribution, root distribution and evapotranspiration were determined periodically. Frequent irrigation resulted in shallow root development and most water use was from the surface 40 cm of soil. Depth of water extraction increased with plant age and with less frequent irrigation. The depth of root penetration determined by direct measurement was similar to that inferred from soil water profiles. Water uptake per unit length of root was related to soil water content only in the 0-40 cm soil layers. Ea/Ep (actual evapotranspiration/pan evaporation) was classified into three stages according to the degree of soil drying after irrigation. During the first stage, immediately after irrigation, Ea/Ep was generally close to 0.75 irrespective of cultivar, leaf area index (LAI) or irrigation interval. During the second stage, linear functions adequately described Ea/Ep as a function of LA1 for LA1 less than 5. During the third stage, which commenced when total soil water to 1.8 m declined to 545 mm, poor relationships between Ea/Ep. Following an analysis of the soil water use data, it is believed that maximum yields of sorghum may be attainable with irrigation at sowing followed by three carefully timed irrigations.


2014 ◽  
Vol 31 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Vincent Freycon ◽  
Christelle Wonkam ◽  
Adeline Fayolle ◽  
Jean-Paul Laclau ◽  
Eric Lucot ◽  
...  

Abstract:Despite the important functional role of deep roots in withdrawing water during drought, direct measurements of root distribution are very rare in tropical rain forests. The aim of this study was to investigate the root distribution of Entandrophragma cylindricum, a common tree species in the Central African semi-deciduous rain forest, in Ferralsols and Arenosols. We dug two pits to a depth of 6 m in Ferralsols and two pits to a depth of 3 m in Arenosols, close to E. cylindricum trees. The vertical soil profiles were divided into 10 × 10-cm grid cells and the roots counted were distributed in three diameter classes. We fitted a root distribution model to our dataset. We found that vertical root distribution was shallower in Arenosols than in Ferralsols. Root penetration was not stopped even by a Ferralsol with high gravel content in its subsoil. Overall, our measurements showed that 95% of all roots were distributed to depths of between 258 and 564 cm from the soil surface, which is much deeper than the 95 cm depth previously reported in the literature for tropical rain forests. As sampling depth could explain this discrepancy, we recommend a sampling depth of at least 3–5 m to accurately estimate root distribution. The drier the dry season, the deeper the sampling depth should be. Our results are consistent with global models of root distribution in forest ecosystems, which are driven by climate variables. We thus suggest that deep rooting could be common in rain forests with a marked dry season.


1996 ◽  
Vol 121 (4) ◽  
pp. 644-648 ◽  
Author(s):  
Maria do Rosário G. Oliveira ◽  
António M. Calado ◽  
Carlos A. Martins Portas

Tomato (Lycopersicon esculentum Mill.) root distribution was evaluated by the trench profile wall method at four trickle irrigation regimes (irrigation at soil water potential -10, -20, -40, and -60 kPa) in a 2-year field trial. Total root length intensity (m·m-2), final yield (t·ha-1) and fruit size (g/fruit) decreased with decrease in amount of water applied. In both years, tomato water use efficiency (kg·ha-1·mm-1) was significantly lower with irrigation at -10 kPa than with any other irrigation regime studied. The largest proportion of tomato roots, 88% for 1989 and 96% for 1990, was found in the top 40 cm of the soil and rapidly decreased with depth. The high concentration of roots in the 30 to 40 cm layer was attributed to an horizon with high soil bulk density values, immediately below 40 cm, impeding deeper root penetration. Most roots occurred in the emitter area, close to the plant. In rows 1.5 m apart, between 12% and 21% of total root length was found more than 0.5 m from the stem, which may have resulted from the interpenetration of roots from plants of adjoining rows.


Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 307 ◽  
Author(s):  
M. S. Lorimer ◽  
L. A. Douglas

The effects of 5 management practices (native forest, native pasture, phalaris pasture, crop-pasture rotation, and continuous cropping), applied prior to sowing wheat seeds, on the distribution of wheat roots and associated grain yields were studied. The grain yield from the 5 treatments decreased in the following order: crop-pasture rotation > native pasture > phalaris pasture > native forest > continuous cropping, and this was directly related to the distribution of the wheat roots in the respective treatment plots. A high incidence of root disease in the phalaris pasture plots severely restricted root distribution and grain yield despite the apparent ‘ideal’ soil conditions for plant growth. The implications of current land management practices, which lead to the formation of plough-pans and reduced root penetration into the subsoil, are discussed in terms of future wheat production on this soil type.


1990 ◽  
Vol 20 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Marcel Prévost ◽  
Hassan A. Bolghari

As part of a study to determine the parameters for effective scarification and promotion of black spruce natural regeneration, an invitro experiment was conducted to assess growth and rooting ability in sandy soils of four bulk densities (0.85, 1.05, 1.25, and 1.45 g cm−3). The experiment included seeds from two origins, one representative of a well-drained upland site and the other, of a poorly drained lowland site. Results show that black spruce successfully established itself in all bulk densities under study. Shoot growth was best in bulk density 1.25 g cm−3 with the seeds of upland origin. It was also good for seeds of both origins in the 0.85 and 1.05 g cm−3 soils. However, seedlings established in the soil compacted to 1.45 g cm−3 showed reduced growth. Bulk densities of 0.85 and 1.05 g cm−3 favored deep root penetration, whereas densities of 1.25 and 1.45 g cm−3 restricted rooting. As a whole, upland seedlings developed better rooting than lowland seedlings, indicating that the selected sites of origin could represent two distinct ecotypes. As to allocation between shoots and roots, an interaction was found between bulk density and seed origin.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 451a-451
Author(s):  
Eric J. Biddinger ◽  
Robert D. Berghage ◽  
David J. Beattie

There is an increasing interest in the use of fiber pots to grow containerized nursery plants. Of particular interest is the ability to incorporate chemicals to modify plant growth, reduce microbial decomposition, and alter fiber structure. Four perennial plants Forsythia `Spring Glory', Baptisia australis, Ilex × meserveae `Blue Girl', and Coreopsis rosea were grown in 2.3-L fiber containers. Containers were treated with Cu(OH)2 (Spin Out®, Griffin Corp.) at 1500 or 3000 ppm, TCMBT (Busan® 30WB fungicide, Buckman Lab.) at 1700 or 3400 ppm, and combinations of Cu(OH)2 and TCMBT. Untreated plastic and untreated fiber pots were used as controls. Plants were grown in a commercial nursery in central Pennsylvania for 5 months during the 1997 growing season. Plants were harvested in the fall. Data included: root penetration of pot walls, plant growth, pot strength, medium root distribution, and root zone temperatures. Results with TCMBT were inconclusive. However, Cu(OH)2-treated pots had fewer penetrating roots and were stronger. Root zone temperatures in fiber pots were lower.


1965 ◽  
Vol 16 (5) ◽  
pp. 785 ◽  
Author(s):  
PG Ozanne ◽  
CJ Asher ◽  
DJ Kirton

The distribution of roots and the uptake of 42K from various depths in soil were studied in glasshouse and field experiments on 12 temperate annual pasture species. Root/top weight ratios were mostly higher in grasses than in legumes or herbs. This ratio decreased with increasing maturity of the plants. The concentration of roots under field swards decreased exponentially with depth, from 10 cm downwards. Large differences in root distribution were noted between species. The most shallow-rooted were lotus, subterranean clover, and silver grass. The deep-rooted species were cape-weed, erodium, oats, lupins, and serradella. Some ecological implications of these differences in rooting depth are discussed. The effective rooting depth in the field was correlated with root penetration rates measured on young plants. The possibility of using root penetration rate as a means of predicting potential rooting depth is discussed. All species had a high proportion of their roots in the top 10 cm of soil and took up most 42K from this layer. As the depth increased, both the concentration of roots in the soil and the amount of potassium absorption decreased. The amount of roots at the sites of 42K placement was closely related to both the concentration and the total amount of 42K in the tops.


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