scholarly journals Genotypic variation in soil penetration by maize roots is negatively related to ethylene-induced thickening

2021 ◽  
Author(s):  
Dorien J. Vanhees ◽  
Hannah M. Schneider ◽  
Kenneth W. Loades ◽  
A. Glyn Bengough ◽  
Malcolm J. Bennett ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Genotypic Variation ◽  
Soil Layer ◽  
Cortical Cell ◽  
Mechanical Impedance ◽  
Radial Expansion ◽  
Compacted Soil ◽  
Nodal Roots ◽  
Maize Roots ◽  
Exogenous Ethylene

AbstractRadial expansion is a classic response of roots to mechanical impedance that has generally been assumed to aid penetration. We analysed the response of maize nodal roots to impedance to test the hypothesis that radial expansion is not related to the ability of roots to cross a compacted soil layer. Genotypes varied in their ability to cross the compacted layer, and those with a steeper approach to the compacted layer or less radial expansion in the compacted layer were more likely to cross the layer and achieve greater depth. Root radial expansion was due to cortical cell size expansion, while cortical cell file number remained constant. Genotypes and nodal root classes that exhibited radial expansion upon encountering the compacted soil layer also thickened in response to exogenous ethylene in hydroponic culture, i.e. radial expansion in response to ethylene was correlated with the thickening response to impedance in soil. We propose that ethylene insensitive roots, i.e. those that do not thicken and are able to overcome impedance, have a competitive advantage under mechanically impeded conditions as they can maintain their elongation rates. We suggest that prolonged exposure to ethylene could function as a stop signal for axial root growth.

scholarly journals Root anatomical traits contribute to deeper rooting of maize under compacted field conditions

2020 ◽  
Vol 71 (14) ◽  
pp. 4243-4257
Author(s):  
Dorien J Vanhees ◽  
Kenneth W Loades ◽  
A Glyn Bengough ◽  
Sacha J Mooney ◽  
Jonathan P Lynch
Keyword(s):  
Genotypic Variation ◽  
Cortical Cell ◽  
Mechanical Impedance ◽  
Field Conditions ◽  
Root Anatomy ◽  
Rooting Depth ◽  
Field Site ◽  
Compacted Soil ◽  
Penetrometer Resistance

Abstract To better understand the role of root anatomy in regulating plant adaptation to soil mechanical impedance, 12 maize lines were evaluated in two soils with and without compaction treatments under field conditions. Penetrometer resistance was 1–2 MPa greater in the surface 30 cm of the compacted plots at a water content of 17–20% (v/v). Root thickening in response to compaction varied among genotypes and was negatively associated with rooting depth at one field site under non-compacted plots. Thickening was not associated with rooting depth on compacted plots. Genotypic variation in root anatomy was related to rooting depth. Deeper-rooting plants were associated with reduced cortical cell file number in combination with greater mid cortical cell area for node 3 roots. For node 4, roots with increased aerenchyma were deeper roots. A greater influence of anatomy on rooting depth was observed for the thinner root classes. We found no evidence that root thickening is related to deeper rooting in compacted soil; however, anatomical traits are important, especially for thinner root classes.

scholarly journals A ‘nodemap’ to sustainable maize roots: linking nitrogen and water uptake improvements

2019 ◽  
Vol 70 (19) ◽  
pp. 5036-5039
Author(s):  
Beatriz Lagunas ◽  
Ian C Dodd ◽  
Miriam L Gifford
Keyword(s):  
Water Uptake ◽  
Nitrogen Uptake ◽  
Shoot Growth ◽  
Genotypic Variation ◽  
Root Anatomy ◽  
Nitrogen Stress ◽  
Deep Roots ◽  
Stress Effects ◽  
Nodal Roots ◽  
Maize Roots

This article comments on:Guo H, York LM. 2019. Maize with fewer nodal roots allocates mass to more lateral and deep roots that improve nitrogen uptake and shoot growth. Journal of Experimental Botany70, 5299–5309.Yang JT, Schneider HM, Brown KM, Lynch JP. 2019. Genotypic variation and nitrogen stress effects on root anatomy in maize are node-specific. Journal of Experimental Botany70, 5311–5325.

scholarly journals The ability of maize roots to grow through compacted soil is not dependent on the amount of roots formed

2021 ◽  
Vol 264 ◽  
pp. 108013
Author(s):  
Dorien J. Vanhees ◽  
Kenneth W. Loades ◽  
A.Glyn Bengough ◽  
Sacha J. Mooney ◽  
Jonathan P. Lynch
Keyword(s):  
Compacted Soil ◽  
Maize Roots

scholarly journals Growth and Yield Sensitivity of Four Vegetable Crops to Soil Compaction

1995 ◽  
Vol 120 (6) ◽  
pp. 956-963 ◽  
Author(s):  
David W. Wolfe ◽  
Daniel T. Topoleski ◽  
Norman A. Gundersheim ◽  
Betsy A. Ingall
Keyword(s):  
Field Study ◽  
Sweet Corn ◽  
Soil Layer ◽  
Growth And Yield ◽  
Yield Response ◽  
Yield Reduction ◽  
Total Biomass ◽  
Snap Bean ◽  
Rainfall Events ◽  
Compacted Soil

A 3-year field study conducted on an Eel silt loam soil (Aquic Udifluvent) compared cabbage (Brussica oleracea L. capitata group), cucumber (Cucumis sativus L.), snap bean (Phaseolus vulgaris L.), and sweet corn (Zea mays L.) for their growth and yield response to an artificially compacted soil layer beginning at about the 10-cm depth. Slower growing cabbage seedlings in compacted plots were more subject to flea beetle damage than the uncompacted controls. Prolonged flooding after heavy rainfall events in compacted areas had a more adverse effect on cabbage and snap bean than on cucumber or sweet corn. Sweet corn showed almost no growth reduction in one of the three years (1993) when relatively high fertilizer rates were applied and leaf nitrogen deficiencies in compacted plots were prevented. Maturity of cabbage, snap bean, and cucumber was delayed, and the average reduction in total marketable yield in (direct-seeded) compacted plots was 73%, 49%, 41%, and 34% for cabbage, snap bean, cucumber and sweet corn, respectively. Yield reduction in transplanted cabbage (evaluated in 1993 only) was 29%. In a controlled environment greenhouse experiment using the same soil type and similar compaction treatment as the field study, compaction caused a reduction in total biomass production of 30% and 14% in snap bean and cabbage, respectively, while cucumber and sweet corn showed no significant response. The growth reductions of snap bean and cabbage in the greenhouse could not be attributed to compaction effects on soil water status, leaf turgor, nutrient deficiency, or net CO, assimilation rate of individual leaves. Root growth of sweet corn was least restricted by the compacted soil layer. The contrast between our field and greenhouse results indicates that the magnitude of yield response to compaction in the field was often associated with species sensitivity to secondary effects of compaction, such as prolonged flooding after rainfall events, reduced nutrient availability or uptake, and prolonged or more severe pest pressure.

scholarly journals Soil compaction by the tractor in spring and its effect on soil porosity 

1983 ◽  
Vol 55 (2) ◽  
pp. 91-107
Author(s):  
Erkki Aura
Keyword(s):  
Soil Compaction ◽  
Theoretical Calculations ◽  
Soil Surface ◽  
Mechanical Impedance ◽  
Soil Samples ◽  
Soil Porosity ◽  
Sowing Time ◽  
Compacted Soil ◽  
Core Soil ◽  
Porosity Measurements

The effect on soil porosity of tractor compaction of soil in the spring was studied by taking cylindrical core soil samples. The profile samples showed that the tractor most seriously compacts the soil below the harrowed layer at the depth of 10-25 cm. Soil was compacted most severely when till age and drilling were performed under wet conditions about one week be for enormal sowing time. The sub soil at the depth of 35-40 cm was compacted only under very wet conditions. The grain yield of wheat was significantly reduced when the volume of large pores was reduced to about 10 % or less. Porosity measurements showed that the severely compacted soil almost completely recovered from one spring to the next. Theoretical calculations suggested that compaction by normal traffic does not cause a shortage of oxygen at least in the inter-crumb pores of soil if the soil surface structure is not dispersed and encrusted. The decrease in crop growth by compaction is primarily due to mechanical impedance, which slows down development of the root system.

scholarly journals WINTER WHEAT GROWTH IN ARTIFICIALLY COMPACTED SOIL

1988 ◽  
Vol 68 (3) ◽  
pp. 527-535 ◽  
Author(s):  
W. W. WILHELM ◽  
L. N. MIELKE
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Bulk Density ◽  
Leaf Area ◽  
Plant Height ◽  
Soil Layer ◽  
Triticum Aestivum L ◽  
Thin Layers ◽  
Normal Density ◽  
Compacted Soil

Dense soil tillage pans can develop from the improper use of tillage tools. The influence of compacted layers or pans on plant growth and development, although much studied, is not clearly understood. This greenhouse experiment evaluated the influence of uniformly compacted soil and thin layers of compacted soil placed at various depths on early growth of winter wheat (Triticum aestivum L.). Artificially compacted soil [Alliance silt loam, Aridic Argiustoll (Eluviated Brown Chernozem); A horizon] profiles were constructed in polyvinyl chloride tubes of 150-mm diameter by 350 mm long. Treatments were: (1) uniformly noncompacted (bulk density 1.30 Mg m−3) soil; (2) uniformly compacted (bulk density 1.80 Mg m−3) soil; (3) a compacted (bulk density 1.80 Mg m−3) soil layer at 100- to 120-mm depth with the remaining soil noncompacted (bulk density 1.30 Mg m−3); or (4) a compacted (bulk density 1.80 Mg m−3) soil layer at 180- to 200-mm depth with the remaining soil noncompacted (bulk density 1.30 Mg m−3). Generally, winter wheat grown in cores that were uniformly compacted or compacted in the upper layer responded similarly. Plant height, at the end of the experiment (32 d after planting), for the uniformly compacted and upper compacted layer treatments was 280 mm, compared to 323 mm for the control (uniformly noncompacted). Leaf area development was similar to the response indicated for plant height throughout the growth period. Root mass and length tended to be less in layered or compacted soil than in noncompacted soil. Roots accumulated within or immediately above compacted soil layers. Higher bulk density or a shallow compacted layer produced winter wheat with reduced height, leaf area, and dry matter compared with soil of normal density or with a deeper compacted layer. Key words: Bulk density, Triticum aestivum L., tillage pan, wheat (winter)

scholarly journals Water Hummer Technology for Soil Destruction on Dredgers

2020 ◽  
Vol 9 (3) ◽  
pp. 3570-3576
Keyword(s):  
Surface Layer ◽  
Dynamic Equilibrium ◽  
Technical Problem ◽  
Soil Layer ◽  
Soil Surface ◽  
High Energy ◽  
Water Hammer ◽  
Mechanical Equipment ◽  
Compacted Soil ◽  
Ambient Temperatures

The present investigation aims to propose a solution of the problem which is connected with slurry processing during the dredger’s operation under difficult conditions. On dredgers, depending on the degree of air dryness or low ambient temperatures very often arises technical problem that creates difficulties for the crew. It is connected with the fact that soil surface layer is very dense. It is very difficult to dredge the soil during extraction under water surface or unloading from the hold of a vessel at low ambient temperatures. The top layer of the very soil is characterized by a high degree of compaction and can be destroyed in two ways only. The first way is to use very powerful mechanical equipment (percussion mechanisms, vibration equipment, etc.). This method is associated with high energy spending and its use on a vessel is technically difficult. The second way is to use the soil cutting process with the use of mechanical cutters. Dredger’s operation with the use of milling equipment is always characterized by the fact that during soil mechanical treatment there is always occurs breakage of the cutter teeth or rapid wear of the cutting surfaces. A similar problem occurs when sandy or clay soil is extracted under water, which is compacted by its properties. In investigation a non-trivial solution was used to solve the problem of destruction of the compacted soil layer during the operation of the dredger. It was proposed to use the hydrodynamic method based on water hammer as the main mechanism for the destruction of compacted soil. As a result of the interaction of the compacted soil layer and high pressurized directed water jets, good performance of the dredger can be achieved. The two-dimensional mechanism of destruction of the compacted soil layer can be described by the condition of dynamic equilibrium of the three main flows - the jet, which flows from the conical nozzle and two flows along the soil surface. For these streams, a reactive force evaluation has been performed. Destructive jets can be generated by standard marine pumps in combination with the use of water hammer. Based on the results of the experiments, it was found that the qualitative destruction of the surface layer of compacted soil occurs using two or three phases of hydraulic water hummer.

Assessment of spatial variability of penetration resistance and hardpan characteristics in a cassava field

Soil Research ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 210 ◽  
Author(s):  
Osama Mohawesh ◽  
Tomoyasu Ishida ◽  
Kazunari Fukumura ◽  
Kunihiko Yoshino
Keyword(s):  
Spatial Variability ◽  
Soil Compaction ◽  
Soil Layer ◽  
Penetration Resistance ◽  
Management Information ◽  
Management Zones ◽  
Compacted Soil ◽  
Natural Density ◽  
Field Variability ◽  
Range Of Values

Soil compaction is generally defined as an increase of the natural density of soil at a particular depth. This compacted soil layer spatially varies over the field. Describing within-field variability is a fundamental first step towards determining the size of management zones. The purpose of the study was to explain the spatial variability of penetration resistance (PR) and hardpan characteristics. Soil PR, dry bulk density (BD), and water content (WC) were measured on the nodes of a mesh. Statistical and geostatistical analysis were used to analyse the spatial variability of PR at 5 depths: 0.0–0.1, 0.1–0.2, 0.2–0.3, 0.3–0.4, and 0.4–0.5 m, and hardpan characteristics. PR had the maximum variability among the measured properties. Hardpan lower edge depth varied from 0.297 to 0.714 m, having a mean and CV of 0.411 m and 20.43, respectively. PR was inversely related to WC. Correlation between BD and WC and PR for the same layer was relatively high. PR and hardpan characteristics showed spatial variability across the field, except PR at depth 0.1–0.2 m. Spherical isotropic models fitted all the measured properties. The range of values of the spatial structure was greater than 7.6 m. The results showed that hardpan and PR spatially varied across the field. These results are important in determining the necessary tillage technique as well as the tillage depth and the target compacted area for a suitable land management. These results also have important implications for how site-specific management information should be collected and explained.

Root Response to Water Stress in Rainfed Lowland Rice

1990 ◽  
Vol 26 (3) ◽  
pp. 287-296 ◽  
Author(s):  
M. Thangaraj ◽  
J. C. O'Toole ◽  
S. K. De Datta
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Root Length Density ◽  
Soil Layer ◽  
Sprinkler Irrigation ◽  
Mechanical Impedance ◽  
Field Studies ◽  
Soil Drying ◽  
Rainfed Lowland ◽  
Response To Water

SUMMARYThe relation between soil mechanical impedance as a result of soil drying, and root system growth (mass and length density) of rice was investigated in greenhouse and field studies. In a greenhouse experiment, soil drying for 16 days increased mechanical impedance in the 0–20 cm soil layer from near 0 to 2.5 MPa, and decreased root growth by 47% compared to the continuously flooded control. Root length density decreased with decreasing soil moisture and increasing soil mechanical impedance. In a lowland field experiment using a sprinkler irrigation gradient treatment for 19 days during the vegetative growth stage, soil mechanical impedance as low as 0.01 MPa inhibited root growth while values greater than 0.3–0.5 MPa decreased root growth and extension by 75%. The relative loss of potential root growth was continued after reflooding. Root length density, measured at flowering, was linearly related to yield.

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