There were strong relationships between exchangeable aluminium (Al) and relative top yield, and between soil pH and relative top yield in the Garret and Bisinella soils. Sweet potato plants produced maximum top yields at soil exchangeable Al <3.0 cmol ((+)/kg, with a 10% yield reduction coinciding with a value of approximately 5.0 cmol (+)/kg. The value was lower for the Bisinella soil than the Garret soil. In the case of pH, maximum yield in both soils was evident at a soil pH of 5.0 with 90% of maximum yield being achieved at about pH 4.7. These results suggest that soil pH would be a good index for Al toxicity. The close relationships between sweet potato growth and both exchangeable Al and soil pH need to be explored further to determine whether it will hold across a wide range of acid soil groups.
", "keywords": ["2. Zero hunger", "Manganese", "Multidisciplinary", "Ph", "Cultivars", "Agriculture", "04 agricultural and veterinary sciences", "C1", "Land and Farm Management", "Subsoil Horizons", "0401 agriculture", " forestry", " and fisheries", "Calcium", "Root Elongation", "Aluminum", "0701 Agriculture"], "contacts": [{"organization": "Ilaava, Vele P., Blamey, Pax, Asher, Colin J.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1071/ar00043"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Australian%20Journal%20of%20Agricultural%20Research", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1071/ar00043", "name": "item", "description": "10.1071/ar00043", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1071/ar00043"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2000-01-01T00:00:00Z"}}, {"id": "10.1071/fp14125", "type": "Feature", "geometry": null, "properties": {"license": "unspecified", "updated": "2026-06-23T16:18:42Z", "type": "Journal Article", "created": "2014-12-03", "title": "Intraspecific Variation In Leaf Growth Of Wheat (Triticum Aestivum) Under Australian Grain Free Air Co2 Enrichment (Agface): Is It Regulated Through Carbon And/Or Nitrogen Supply?", "description": "Underlying physiological mechanisms of intraspecific variation in growth response to elevated CO2 concentration [CO2] were investigated using two spring wheat (Triticum aestivum L.) cultivars: Yitpi and H45. Leaf blade elongation rate (LER), leaf carbon (C), nitrogen (N) in the expanding leaf blade (ELB, sink) and photosynthesis (A) and C and N status in the last fully expanded leaf blade (LFELB, source) were measured. Plants were grown at ambient [CO2] (~384\uffc2\uffb5molmol\uffe2\uff80\uff931) and elevated [CO2] (~550\uffc2\uffb5molmol\uffe2\uff80\uff931) in the Australian Grains Free Air CO2 Enrichment facility. Elevated [CO2] increased leaf area and total dry mass production, respectively, by 42 and 53% for Yitpi compared with 2 and 13% for H45. Elevated [CO2] also stimulated the LER by 36% for Yitpi compared with 5% for H45. Yitpi showed a 99% increase in A at elevated [CO2] but no A stimulation was found for H45. There was a strong correlation (r2=0.807) between LER of the ELB and soluble carbohydrate concentration in LFELB. In ELB, the highest spatial N concentration was observed in the cell division zone, where N concentrations were 67.3 and 60.6mg g\uffe2\uff80\uff931 for Yitpi compared with 51.1 and 39.2mg g\uffe2\uff80\uff931 for H45 at ambient and elevated [CO2]. In contrast, C concentration increased only in the cell division and cell expansion zone of the ELB of Yitpi. These findings suggest that C supply from the source (LFELB) is cultivar dependent and well correlated with LER, leaf area expansion and whole-plant growth response to elevated [CO2].
", "keywords": ["Diurnal regulation of LER", "580", "0106 biological sciences", "0301 basic medicine", "2. Zero hunger", "070303 Crop and Pasture Biochemistry and Physiology", "leaf blade elongation rate", "diurnal regulation of LER", "gas exchange", "Growth analysis", "15. Life on land", "01 natural sciences", "Leaf blade elongation rate", "03 medical and health sciences", "Elevated (CO2)", "elevated [CO2]", "Gas exchange", "growth analysis"]}, "links": [{"href": "https://doi.org/10.1071/fp14125"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Functional%20Plant%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1071/fp14125", "name": "item", "description": "10.1071/fp14125", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1071/fp14125"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2015-01-01T00:00:00Z"}}, {"id": "10.1073/pnas.2201072119", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:18:46Z", "type": "Journal Article", "created": "2022-07-18", "title": "Ethylene inhibits rice root elongation in compacted soil via ABA- and auxin-mediated mechanisms", "description": "Soil compaction represents a major agronomic challenge, inhibiting root elongation and impacting crop yields. Roots use ethylene to sense soil compaction as the restricted air space causes this gaseous signal to accumulate around root tips. Ethylene inhibits root elongation and promotes radial expansion in compacted soil, but its mechanistic basis remains unclear. Here, we report that ethylene promotes abscisic acid (ABA) biosynthesis and cortical cell radial expansion. Rice mutants of ABA biosynthetic genes had attenuated cortical cell radial expansion in compacted soil, leading to better penetration. Soil compaction-induced ethylene also up-regulates the auxin biosynthesis gene OsYUC8 . Mutants lacking OsYUC8 are better able to penetrate compacted soil. The auxin influx transporter OsAUX1 is also required to mobilize auxin from the root tip to the elongation zone during a root compaction response. Moreover, osaux1 mutants penetrate compacted soil better than the wild-type roots and do not exhibit cortical cell radial expansion. We conclude that ethylene uses auxin and ABA as downstream signals to modify rice root cell elongation and radial expansion, causing root tips to swell and reducing their ability to penetrate compacted soil.
Soil adjacent to roots has distinct structural and physical properties from bulk soil, affecting water and solute acquisition by plants. Detailed knowledge on how root activity and traits such as root hairs affect the three\uffe2\uff80\uff90dimensional pore structure at a fine scale is scarce and often contradictory.
Roots of hairless barley (Hordeum vulgare L. cv Optic) mutant (NRH) and its wildtype (WT) parent were grown in tubes of sieved (<250\uffc2\uffa0\uffce\uffbcm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron\uffe2\uff80\uff90based X\uffe2\uff80\uff90ray computed tomography to visualise pore structure at the soil\uffe2\uff80\uff93root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1\uffc2\uffa0mm of the root surface.
Less dense packing of particles at the root surface was hypothesised to cause the observed increased pore volume fraction immediately next to the epidermis. The pore size distribution was narrower due to a decreased fraction of larger pores. There were no statistically significant differences in pore structure between genotypes or moisture conditions.
A model is proposed that describes the variation in porosity near roots taking into account soil compaction and the surface effect at the root surface.
Soil compaction represents a major agronomic challenge, inhibiting root elongation and impacting crop yields. Roots use ethylene to sense soil compaction as the restricted air space causes this gaseous signal to accumulate around root tips. Ethylene inhibits root elongation and promotes radial expansion in compacted soil, but its mechanistic basis remains unclear. Here, we report that ethylene promotes abscisic acid (ABA) biosynthesis and cortical cell radial expansion. Rice mutants of ABA biosynthetic genes had attenuated cortical cell radial expansion in compacted soil, leading to better penetration. Soil compaction-induced ethylene also up-regulates the auxin biosynthesis gene OsYUC8 . Mutants lacking OsYUC8 are better able to penetrate compacted soil. The auxin influx transporter OsAUX1 is also required to mobilize auxin from the root tip to the elongation zone during a root compaction response. Moreover, osaux1 mutants penetrate compacted soil better than the wild-type roots and do not exhibit cortical cell radial expansion. We conclude that ethylene uses auxin and ABA as downstream signals to modify rice root cell elongation and radial expansion, causing root tips to swell and reducing their ability to penetrate compacted soil.Soil adjacent to roots has distinct structural and physical properties from bulk soil, affecting water and solute acquisition by plants. Detailed knowledge on how root activity and traits such as root hairs affect the three\uffe2\uff80\uff90dimensional pore structure at a fine scale is scarce and often contradictory.
Roots of hairless barley (Hordeum vulgare L. cv Optic) mutant (NRH) and its wildtype (WT) parent were grown in tubes of sieved (<250\uffc2\uffa0\uffce\uffbcm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron\uffe2\uff80\uff90based X\uffe2\uff80\uff90ray computed tomography to visualise pore structure at the soil\uffe2\uff80\uff93root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1\uffc2\uffa0mm of the root surface.
Less dense packing of particles at the root surface was hypothesised to cause the observed increased pore volume fraction immediately next to the epidermis. The pore size distribution was narrower due to a decreased fraction of larger pores. There were no statistically significant differences in pore structure between genotypes or moisture conditions.
A model is proposed that describes the variation in porosity near roots taking into account soil compaction and the surface effect at the root surface.