Root development and growth of oilseed, wheat and pea crops on tilled and non-tilled soil

Whiteley, G. M.; Dexter, A. R.

doi:10.1016/0167-1987(82)90006-x

Cited by 60 publications

(24 citation statements)

References 6 publications

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“…Em solos onde as raízes finas podem explorar canais radiculares e fissuras existentes, culturas com raízes pivotantes são mais afetadas pela compactação que aquelas com raízes fasciculadas mais finas (Whiteley & Dexter, 1982). Entretanto, raízes de maior diâmetro apresentam maior resistência ao encurvamento quando entram em solo compactado (Whiteley & Dexter, 1984), o que, segundo Henderson (1989) A terra foi coletada na camada superficial (0-20 cm) de um Latossolo Vermelho-Escuro álico textura média (Carvalho et al, 1983) e, após secagem ao ar, foi passada em peneira com malha de 4 mm.…”

Section: Introductionunclassified

Influência da compactação do solo em subsuperfície sobre o crescimento aéreo e radicular de plantas de adubação verde de inverno

Müller

Ceccon

Rosolem

2001

Rev. Bras. Ciênc. Solo

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RESUMOA compactação do solo é um problema comum nas lavouras e que influi tanto no crescimento e na produtividade das culturas, como na conservação do solo e da água. A fim de estudar esse problema, cinco espécies de plantas de adubação verde de inverno (ervilhaca, nabo forrageiro, tremoço branco, aveia preta e aveia branca) foram cultivadas em quatro perfis de solo com crescentes níveis de compactação em subsuperfície (Ds: 1,31, 1,43, 1,58 e 1,70 Mg m -3 ). O experimento foi realizado em vaso e sob condição de casa de vegetação na FCA/ UNESP, em Botucatu (SP), em 1998, utilizando um LE de textura média. Com o aumento da compactação do solo, o comprimento e a matéria seca das raízes aumentaram acima da camada compactada e diminuíram abaixo dela, concentrando o sistema radicular das plantas próximo à superfície. O diâmetro radicular médio do tremoço e das duas aveias aumentou na camada compactada com o aumento da densidade do solo, diminuiu para o caso da ervilhaca e não se alterou para o caso do nabo. O nabo forrageiro e a aveia preta sobressaíram-se com maiores valores de densidade de comprimento radicular na camada compactada e inferior e no vaso como um todo, mesmo com o aumento da compactação. Concluiu-se, neste estudo, que o nabo forrageiro e a aveia preta apresentaram-se como bons materiais, para melhorar as características de solos com compactação subsuperficial, mostrando vigor no crescimento de raízes dentro e abaixo da camada compactada do solo, devendo-se, entretanto, validar estes resultados no campo, em condições diferentes de clima e solo.Termos de indexação: camada compactada, plantas de cobertura, raiz.

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Section: Introductionunclassified

Influência da compactação do solo em subsuperfície sobre o crescimento aéreo e radicular de plantas de adubação verde de inverno

Müller

Ceccon

Rosolem

2001

Rev. Bras. Ciênc. Solo

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“…Hettiaratchi & Reece, 1969;Graf & Cook, 1980). Root thickening is not merely the result of damage but can be a benefit to the plant since species showing good soil penetration often display thicker roots m response to the stress (Whiteley & Dexter, 1982). Generally, the increase in root radius is due to an increase in cell diameter and not to an increase in cell number (i.e.…”

Section: Soil Penetrationmentioning

confidence: 99%

The control of cell expansion in roots

Pritchard¹

1994

New Phytologist

153

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SUMMARY The expansion of roots is considered at the level of the single cell. The water relations of cell expansion are discussed. Water entry, solute import and cell wall properties are considered as possible regulatory points. It is argued that root cell expansion can be understood in terms of cell turgor pressure and the physical properties of the cell wall, provided solute supply is not limiting. Various measurements of cell wall properties in roots are presented and the assumptions underlying their measurements are presented. It is concluded that cell wall properties must be measured over short time periods to prevent alterations in wall properties during the experiment. The radial location of the load‐bearing layers is discussed and it is concluded that, unlike aerial tissue, growth is limited by the properties of the inner layer of the root cortex. Evidence is presented to show that cell wall properties can change both during development and following turgor perturbation. In general, however, turgor itself is tightly regulated, particularly towards the root tip. A number of environmental situations are presented in which root growth is altered. The mechanism of the alteration is discussed at the single cell level. These 'stresses’include osmotic stress, low temperature and soil compaction. In many cases the alteration of root growth is consistent with changes in the ceil wall properties of the growing ceils. Severe stress, resulting in near cessation of root cell extension, can result in a change (usually an increase) in turgor pressure. The change in turgor pressure of the cells in the growing zone is smaller than that which would be expected from a continuation of an unstressed solute import rate. This exemplifies both the change in cell wall properties and the tight turgor homeostasis of root tips. The biochemical processes which underlie the modulation of cell wall properties are presented as they are currently understood in roots. Measurements of the chemical composition of the wall have not revealed any useful differences which can explain the developmental or stress‐induced changes in cell wall properties. Recent work on cell wall enzymes and proteins may provide information about control of cross‐linkages within the wall. In the last section the relative importance of apoplastic and symplastic solute transport to the expanding cells is considered. At present the consensus appears to favour the symplastic route, but the apoplastic pathway may also operate, possibly as a scavenging mechanism for leaked ions. The regulation of turgor pressure by linking solute import with wall loosening is discussed.

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“…These differences in soils often contribute to altered root growth in crops grown without tillage compared with those grown under conventional tillage (Goins & Russelle, 1996). Roots of crop plants grown without tillage typically concentrate a greater proportion of their root system at shallow soil depths than do root systems in conventional tillage (Whiteley & Dexter, 1982 ;Cheng et al, 1990 ;Rasse & Smucker, 1998), perhaps because of greater surface soil moisture availability and lower soil bulk density without tillage. Although a substantial quantity of data indicate that root spatial distributions are significantly affected by tillage practices, it is still unclear whether root temporal distribution or demography differ consistently in conventional compared with sustainable systems.…”

Section: Tillagementioning

confidence: 99%

Spatial and temporal deployment of crop roots in CO₂‐enriched environments

2000

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 Growth of crops in CO# -enriched atmospheres typically results in significant changes in root growth and development. Increased root carbohydrates stimulate root growth either directly (functioning as substrates) or indirectly (functioning as signal molecules) by enhancing cell division or cell expansion, or both. Although highly variable, the literature suggests that, generally, initiation and stimulation of lateral roots is favored over the elongation of primary roots, leading to more highly branched, shallower root systems. Such architectural shifts can render root systems less efficient, perhaps contributing to the lower specific root activities often reported. Allocation of carbon (C) to roots fluctuates through the life of the plant ; root functional and growth responses should therefore not be viewed as static. In annual crops, C allocation to belowground processes changes as vegetative growth switches to reproduction and maturation. Reductions in C allocation to roots over time might cause temporal shifts in root deployment, perhaps affecting root demography. However, significant changes in root turnover (defined here as root flux or mortality relative to total root pool size) as a result of decreased root longevities in crop plants are unlikely. Consideration of changing C allocation to roots, a more thorough understanding of the mechanistic controls on root longevity, and a better characterization of the rooting habits (life histories) of different crop species will further our understanding of how increasing atmospheric [CO # ] will affect root demography. This knowledge will lead the way toward a more thorough understanding of the linkage of atmosphere with belowground plant function and also that of plant function with soil biology and structure. Ultimately, successful modeling of global C and nitrogen (N) cycles will require empirical data concerning spatial and temporal deployment of roots for a range of crop species grown under different agricultural management systems.

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Root development and growth of oilseed, wheat and pea crops on tilled and non-tilled soil

Cited by 60 publications

References 6 publications

Influência da compactação do solo em subsuperfície sobre o crescimento aéreo e radicular de plantas de adubação verde de inverno

Influência da compactação do solo em subsuperfície sobre o crescimento aéreo e radicular de plantas de adubação verde de inverno

The control of cell expansion in roots

Spatial and temporal deployment of crop roots in CO₂‐enriched environments

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Root development and growth of oilseed, wheat and pea crops on tilled and non-tilled soil

Cited by 60 publications

References 6 publications

Influência da compactação do solo em subsuperfície sobre o crescimento aéreo e radicular de plantas de adubação verde de inverno

Influência da compactação do solo em subsuperfície sobre o crescimento aéreo e radicular de plantas de adubação verde de inverno

The control of cell expansion in roots

Spatial and temporal deployment of crop roots in CO2‐enriched environments

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Spatial and temporal deployment of crop roots in CO₂‐enriched environments