scholarly journals Plant roots sense soil compaction through restricted ethylene diffusion

Science ◽  
2021 ◽  
Vol 371 (6526) ◽  
pp. 276-280 ◽  
Author(s):  
Bipin K. Pandey ◽  
Guoqiang Huang ◽  
Rahul Bhosale ◽  
Sjon Hartman ◽  
Craig J. Sturrock ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Compaction ◽  
Warning Signal ◽  
Gas Diffusion ◽  
Wild Type ◽  
Compacted Soils ◽  
Compacted Soil ◽  
Modern Agriculture ◽  
Hormone Responses ◽  
Root Tissues

Soil compaction represents a major challenge for modern agriculture. Compaction is intuitively thought to reduce root growth by limiting the ability of roots to penetrate harder soils. We report that root growth in compacted soil is instead actively suppressed by the volatile hormone ethylene. We found that mutant Arabidopsis and rice roots that were insensitive to ethylene penetrated compacted soil more effectively than did wild-type roots. Our results indicate that soil compaction lowers gas diffusion through a reduction in air-filled pores, thereby causing ethylene to accumulate in root tissues and trigger hormone responses that restrict growth. We propose that ethylene acts as an early warning signal for roots to avoid compacted soils, which would be relevant to research into the breeding of crops resilient to soil compaction.

Root responses of triticale and soybean to soil compaction in the field are reproducible under controlled conditions

2016 ◽  
Vol 43 (2) ◽  
pp. 114 ◽  
Author(s):  
Tino Colombi ◽  
Achim Walter
Keyword(s):  
Root Growth ◽  
Soil Compaction ◽  
Root Systems ◽  
Oxygen Availability ◽  
Compacted Soils ◽  
Root Branching ◽  
Controlled Conditions ◽  
Glycine Max L ◽  
Limited Oxygen

Soil compaction includes a set of underlying stresses that limit root growth such as increased impedance and limited oxygen availability. The aims of the present study were to (i) find acclimations of triticale (× Triticosecale) and soybean (Glycine max L.) roots to compacted soils in the field; (ii) reproduce these under controlled conditions; and (iii) associate these responses with soil physical properties. To this end, plants were grown at two different soil bulk densities in the field and under controlled conditions representing mature root systems and the seedling stage respectively. Diameters, lateral branching densities, the cortical proportion within the total root cross-section and the occurrence of cortical aerenchyma of main roots were quantified. Soil compaction caused decreasing root branching and increasing cortical proportions in both crops and environments. In triticale, root diameters and the occurrence of aerenchyma increased in response to compaction in the field and under controlled conditions. In soybean, these acclimations occurred at an initial developmental stage but due to radial root growth not in mature roots. These results showed that responses of root systems to compacted soils in the field are, to a large extent, reproducible under controlled conditions, enabling increased throughput, phenotyping-based breeding programs in the future. Furthermore, the occurrence of aerenchyma clearly indicated the important role of limited oxygen availability in compacted soils on root growth.

scholarly journals Root and shoot growth in safflower as affected by soil compaction

2020 ◽  
pp. 1443-1448
Author(s):  
Caroline Beal Montiel ◽  
Deonir Secco ◽  
Araceli Ciotti Marins ◽  
Luiz Antônio Zanão Junior ◽  
Jeikson Rafael Deggerone ◽  
...  
Keyword(s):  
Root Growth ◽  
Crop Yield ◽  
Soil Compaction ◽  
Shoot Growth ◽  
Soil Bulk Density ◽  
Carthamus Tinctorius ◽  
Field Conditions ◽  
Compacted Soils ◽  
Tillage Practices ◽  
Root And Shoot Growth

Soil compaction, induced by no-tillage practices, can negatively impact soil properties important for plant growth. Compacted soils can restrict root growth depth, resulting in reduced crop yield. Although safflower (Carthamus tinctorius) has a deep root system, yield may still be affected by soil compaction. Therefore, this study aimed to evaluate safflower root and shoot growth when submitted to soil compaction in an Oxisol soil under controlled (greenhouse) and field conditions. Five soil bulk density measures were performed in a greenhouse (1.1, 1.2, 1.3, 1.4 and 1.5 Mg m–3). Four compaction levels (established by the number of passes of a farm tractor: 0, 1, 3, and 5 passes consecutively) were performed to evaluate the effect of soil compaction in the field. Root and shoot growth were measured after harvesting the plants. Safflower root growth was reduced when soil compaction increased from 1.1 to 1.5 Mg m–3 under controlled (greenhouse) conditions. In field conditions, we observed a decrease in root length, and fresh and dry matter in roots and shoots of safflower as the soil compaction increased to 5P (1.28 Mg m–3). The results of our study suggest safflower root and shoot growth can be impacted by soil compaction which could affect crop yield.

Effect of Microbial Seed Treatment on Root Growth of Wheat under Compacted Soil Condition

2019 ◽  
Vol 6 (02) ◽  
Author(s):  
SURAJIT MONDAL ◽  
DEBASHIS CHAKRABORTY ◽  
SANGEETA PAUL
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Soil Compaction ◽  
Seed Treatment ◽  
Root Length Density ◽  
Average Diameter ◽  
Soil Condition ◽  
Microbial Culture ◽  
Compacted Soil ◽  
Microbial Cultures

Soil compaction can seriously restrict root growth both in surface and subsurface soil layers, preventing the root system to uptake water and nutrients from deeper layers in wheat due to intensive puddling in rice. To understand the effect of compaction (BD1 = bulk density 1.4 g cm-3 and BD2 = 1.8 g cm-3) on root growth of wheat, a pot experiment was conducted in ambient condition during wheat growing period (November-April) in 2017-18. This experiment was done with microbially treated wheat seeds (M1 to M6) to observe the effects of microbial cultures on root growth under compacted soil condition in comparison to control where no seed treatment was done. BD1 registered a marginally 28% higher root length density than BD2. Among seed treatment with microbial cultures (MC), MC5 resulted in highest root length density (23% higher than the control). Unlike root length density, root volume density was influenced significantly (p less than 0.05) by microbial seed inoculation, although soil compaction had marginal impact. Average diameter of root varied significantly among treatments due to both soil compaction and microbial seed treatment (p less than 0.01). Average diameter was significantly higher (20%, p less than 0.01) in BD2 than BD1. MC2 recorded higher (45-33%, p less than 0.01) root diameter than other treatments but was comparable with MC3. It can be concluded that Seed treatment with suitable microbial culture can promote the crop growth in general and root growth in particular under compacted soil condition.

Root growth altered by compaction of a sandy loam soil affects severity of rhizoctonia root rot of wheat seedlings

2004 ◽  
Vol 44 (6) ◽  
pp. 595 ◽  
Author(s):  
J. S. Gill ◽  
S. Hunt ◽  
K. Sivasithamparam ◽  
K. R. J. Smettem
Keyword(s):  
Root Growth ◽  
Rhizoctonia Solani ◽  
Soil Profile ◽  
Soil Compaction ◽  
Anastomosis Group ◽  
Soil Conditions ◽  
Wheat Seedlings ◽  
Bare Patch ◽  
Compacted Soil ◽  
The Impact

Rhizoctonia solani Anastomosis Group 8 damages seedling roots of wheat, causing the 'bare-patch' disease. This makes the first 4 weeks after germination the most critical period for disease development. As the field inoculum of the pathogen is mainly concentrated in the surface 10 cm of soil, the rate of root growth becomes critical for the vulnerable tissues of the root to escape the attack from the inoculum zone. To evaluate the effect of alteration of root growth by soil compaction on disease severity, a study was undertaken in 40-cm-deep pots made from PVC pipes (8.7 cm diameter). Four depths of soil compaction (whole soil profile compacted, whole soil loose, upper 10 cm loose and compacted below, upper 20 cm loose and compacted below) were tested using sieved soil. Effective root length of infected seedlings was higher in the pots where the whole soil profile was compacted than others. Reduction in dry root weights, where soil was compacted to heights of 0, 17.5, 27.5 or 37.5 cm following inoculation, were 68, 30, 74 and 56%, respectively. Reduction in shoot weights was 52, 22, 66 and 44%, respectively. Eight days after incubation, microbial activity was greater where the soil was highly compacted than where there was a low level of soil compaction. Saprophytic growth in soil of Rhizoctonia solani Anastomosis Group 8 was higher in loosely packed soil than in compacted soil. This shows that higher impact of disease under compacted soil conditions is due to reduced root growth and that disturbing the soil below seeds can reduce the impact of disease.

scholarly journals Reducing nitrous oxide emissions from grazed winter forage crops

2012 ◽  
pp. 57-62 ◽  
Author(s):  
T.J. Van der Weerden ◽  
T.M. Styles
Keyword(s):  
Nitrous Oxide ◽  
Soil Compaction ◽  
Nitrification Inhibitor ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Gaseous Emissions ◽  
Forage Crops ◽  
Compacted Soils ◽  
Compacted Soil

Wintering cows on forage crops leads to urine being excreted onto wet, compacted soils. This is likely to result in significant gaseous emissions of nitrous oxide (N2O), which may be reduced through strategic applications of nitrification inhibitors. A study was established on a winter swede crop to (i) determine N2O emissions from compacted soil treated with cattle urine, and (ii) quantify the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in reducing these emissions. Nitrous oxide emissions from the urine + compacted soil were significantly greater (P < 0.001) than from compacted soil without urine, with 3.2% of the urine-N being lost as N2O. DCD application significantly reduced this loss (P < 0.05) to 0.8% of the applied urine-N. Expressed at a paddock scale, total N2O emissions from the winter-grazed swede crop were 7.9 kg N ha-1, which was reduced to 3.4 kg N ha-1 when DCD was applied. Keywords: urine, dicyandiamide, nitrification inhibitor, soil compaction, nitrous oxide.

scholarly journals Low ABA concentration promotes root growth and hydrotropism through relief of ABA INSENSITIVE 1-mediated inhibition of plasma membrane H+-ATPase 2

2021 ◽  
Vol 7 (12) ◽  
pp. eabd4113
Author(s):  
Rui Miao ◽  
Wei Yuan ◽  
Yue Wang ◽  
Irene Garcia-Maquilon ◽  
Xiaolin Dang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Root Growth ◽  
Experimental System ◽  
Aba Signaling ◽  
Wild Type ◽  
Normal Medium ◽  
C Terminus ◽  
Quadruple Mutant ◽  
Aba Insensitive ◽  
Aba Receptors

The hab1-1abi1-2abi2-2pp2ca-1 quadruple mutant (Qabi2-2) seedlings lacking key negative regulators of ABA signaling, namely, clade A protein phosphatases type 2C (PP2Cs), show more apoplastic H+ efflux in roots and display an enhanced root growth under normal medium or water stress medium compared to the wild type. The presence of low ABA concentration (0.1 micromolar), inhibiting PP2C activity via monomeric ABA receptors, enhances root apoplastic H+ efflux and growth of the wild type, resembling the Qabi2-2 phenotype in normal medium. Qabi2-2 seedlings also demonstrate increased hydrotropism compared to the wild type in obliquely-oriented hydrotropic experimental system, and asymmetric H+ efflux in root elongation zone is crucial for root hydrotropism. Moreover, we reveal that Arabidopsis ABA-insensitive 1, a key PP2C in ABA signaling, interacts directly with the C terminus of Arabidopsis plasma membrane H+-dependent adenosine triphosphatase 2 (AHA2) and dephosphorylates its penultimate threonine residue (Thr947), whose dephosphorylation negatively regulates AHA2.

scholarly journals Evaluation of Leaf Litter Mulching and Incorporation on Skid Trails for the Recovery of Soil Physico-Chemical and Biological Properties of Mixed Broadleaved Forests

Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Meghdad Jourgholami ◽  
Azadeh Khoramizadeh ◽  
Angela Lo Monaco ◽  
Rachele Venanzi ◽  
Francesco Latterini ◽  
...  
Keyword(s):  
Soil Properties ◽  
Soil Compaction ◽  
Biological Properties ◽  
Soil Protection ◽  
Natural Soil ◽  
Compacted Soils ◽  
Beneficial Effects ◽  
Physico Chemical ◽  
Forest Logging ◽  
Soil Recovery

Engineering applications can be used to mitigate the adverse effects of soil compaction and amend compacted soils. Previous literature has highlighted the beneficial effects of interventions such as litter mulching and incorporation on skid trails. However, little is known about the effectiveness of these alternatives in restoring forest soil quality after forest logging. The objective of this study was to properly elucidate the effects of the above mentioned soil protection methods, litter incorporation before skidding (LI) and litter mulching after skidding (LM), on the recovery of compacted soil’s physico-chemical and biological properties on skid trails over a 2-year period in the Hyrcanian forests of Iran to identify the best option for restoration intervention. The litter used in both methods consisted of dried leaves of the hornbeam and maple tree in three intensities of 3, 6, and 9 Mg ha−1. The results showed that the application of both methods (LI and LM) significantly improved the soil properties when compared to the untreated skid trail. Results showed that the recovery values of soil properties in the LI treatments were significantly higher than those of the LM. The recovery values of soil properties by 6 and 9 Mg ha−1 were significantly higher than those of 3 Mg ha−1, while the differences were not significant between 6 and 9 Mg ha−1. Our findings showed that soil properties were partially recovered (70–80%) over a 2-year period from treatment, compared to untreated, but the full recovery of soil properties required more time to return to the pre-harvest value. Overall, the results of this study demonstrated that the application of soil protection methods accelerates the process of recovering soil properties much faster than natural soil recovery, which can take more than 20 years in these forests.

The influence of forest site on rate and extent of soil compaction and profile disturbance of skid trails during ground-based harvesting

2000 ◽  
Vol 30 (8) ◽  
pp. 1196-1205 ◽  
Author(s):  
J R Williamson ◽  
W A Neilsen
Keyword(s):  
Root Growth ◽  
Soil Compaction ◽  
Forest Type ◽  
Soil Bulk Density ◽  
Parent Material ◽  
Forest Site ◽  
Undisturbed Soil ◽  
Soil Parent Material ◽  
Wet Forests

Soil compaction has been considered a principal form of damage associated with logging, restricting root growth and reducing productivity. The rate and extent of soil compaction on skid trails was measured at six field locations covering a range of dry and wet forests. Data was collected for up to 21 passes of a laden logging machine. A similar extent of compaction, averaging 0.17 g·cm-3 increase in total soil bulk density (BD), was recorded for all field sites despite substantial site and soil differences. On average, 62% of the compaction in the top 10 cm of the soil occurred after only one pass of a laden logging machine. The environment under which soils had formed played a major role in determining the BD of the undisturbed soil. Compaction was strongly related to the original BD, forest type, and soil parent material. Soil strengths obtained in the field fell below levels found to restrict root growth. However, reduction in macropores, and the effect of that on aeration and drainage could reduce tree growth. On the wettest soils logged, machine forces displaced topsoils rather than causing compaction in situ. Recommended logging methods and implications for the development of sustainability indices are discussed.

scholarly journals Evaluation of Pigeon Pea Lines for Biological Soil Decompaction

2009 ◽  
Vol 2009 ◽  
pp. 1-7
Author(s):  
Rodolfo Godoy ◽  
Osny Oliveira Santos Bacchi ◽  
Fernando Almeida Moreira ◽  
Klaus Reichardt
Keyword(s):  
Root Growth ◽  
Pigeon Pea ◽  
Soil Resistance ◽  
Biological Processes ◽  
Soil Layers ◽  
Compacted Soil ◽  
Cultivation Practices ◽  
Series Of Experiments ◽  
Growth Development ◽  
Resistance To Penetration

Soil decompaction is generally achieved through mechanical cultivation practices; however biological processes can significantly add to this process through root growth, development, and later senescence. This study was carried out in Piracicaba, SP, Brazil and had the purpose of selecting, among forty one pure pigeon pea lines, the most efficient genotypes that promote soil decompaction by roots penetrating compacted soil layers. Utilizing artificially compacted 30 mm high soil blocks, in a series of experiments, these lines were compared to the cultivar Fava Larga taken as a standard. Three lines were preliminarily selected out of the initial group, and afterwards, in more detailed screenings by monitoring soil resistance to penetration and also evaluating the behavior of Tanzania grass plants seeded after pigeon pea, two of them, g5-94 and g8-95, were selected as possessing the most fit root system to penetrate compacted soil layers.

Characterisation of three shoot apical meristem mutants of Arabidopsis thaliana

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 397-403 ◽  
Author(s):  
H. M. Ottoline Leyser ◽  
I. J. Furner
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Growth ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Floral Development ◽  
Wild Type ◽  
Recessive Mutations ◽  
Phenotypic Characterisation ◽  
Dicotyledonous Plants ◽  
And Function

The shoot apical meristem of dicotyledonous plants is highly regulated both structurally and functionally, but little is known about the mechanisms involved in this regulation. Here we describe the genetic and phenotypic characterisation of recessive mutations at three loci of Arabidopsis thaliana in which meristem structure and function are disrupted. The loci are Clavata1 (Clv1), Fasciata1 (Fas1) and Fasciata2 (Fas2). Plants mutant at these loci are fasciated having broad, flat stems and disrupted phyllotaxy. In all cases, the fasciations are associated with shoot apical meristem enlargement and altered floral development. While all the mutants share some phenotypic features they can be divided into two classes. The pleiotropic fas1 and fas2 mutants are unable to initiate wild- type organs, show major alterations in meristem structure and have reduced root growth. In contrast, clv1 mutant plants show near wild-type organ phenotypes, more subtle changes in shoot apical meristem structure and wild-type root growth.

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