The Experts below are selected from a list of 13512 Experts worldwide ranked by ideXlab platform
Tino Colombi - One of the best experts on this subject based on the ideXlab platform.
-
cortical cell diameter is key to energy costs of root growth in wheat
Plant Physiology, 2019Co-Authors: Tino Colombi, Anke M Herrmann, Pernilla Vallenback, Thomas KellerAbstract:Root growth requires substantial amounts of energy and thus carbohydrates. The energy costs of root growth are particularly high in both dry and compacted Soil, due to high Soil Penetration Resistance. Consequently, more carbon must be allocated from aboveground plant tissue to roots, which limits crop productivity. In this study, we tested the utility of root cortical cell diameter as a potential selection target to reduce the energy costs of root growth. Isothermal calorimetry was adopted for in situ quantification of the energy costs of root growth of 16 wheat (Triticum aestivum) genotypes under three levels of Penetration Resistance. We show that cortical cell diameter is a pivotal and heritable trait, which is strongly related to the energy costs of root growth. Genotypic diversity was found for cortical cell diameter and the energy costs of root growth. A large root cortical cell diameter correlated with reduced energy costs of root growth, particularly under high Soil Penetration Resistance. Moreover, significant correlations were found between the ability to radially enlarge cortical cells upon greater Penetration Resistance (i.e. phenotypic plasticity) and the responsiveness in the energy costs of root growth. A higher degree of phenotypic plasticity in cortical cell diameter was associated with reduced energy costs of root growth as Soil Penetration Resistance increased. We therefore suggest that genotypic diversity and phenotypic plasticity in cortical cell diameter should be harnessed to adapt crops to dry and compacted Soils.
-
feedbacks between Soil Penetration Resistance root architecture and water uptake limit water accessibility and crop growth a vicious circle
Science of The Total Environment, 2018Co-Authors: Tino Colombi, Lorena Chagas Torres, Achim Walter, Thomas KellerAbstract:Abstract Water is the most limiting resource for global crop production. The projected increase of dry spells due to climate change will further increase the problem of water limited crop yields. Besides low water abundance and availability, water limitations also occur due to restricted water accessibility. Soil Penetration Resistance, which is largely influenced by Soil moisture, is the major Soil property regulating root elongation and water accessibility. Until now the interactions between Soil Penetration Resistance, root system properties, water uptake and crop productivity are rarely investigated. In the current study we quantified how interactive effects between Soil Penetration Resistance, root architecture and water uptake affect water accessibility and crop productivity in the field. Maize was grown on compacted and uncompacted Soil that was either tilled or remained untilled after compaction, which resulted in four treatments with different topSoil Penetration Resistance. Higher topSoil Penetration Resistance caused root systems to be shallower. This resulted in increased water uptake from the topSoil and hence topSoil drying, which further increased the Penetration Resistance in the uppermost Soil layer. As a consequence of this feedback, root growth into deeper Soil layers, where water would have been available, was reduced and plant growth decreased. Our results demonstrate that Soil Penetration Resistance, root architecture and water uptake are closely interrelated and thereby determine the potential of plants to access Soil water pools. Hence, these interactions and their feedbacks on water accessibility and crop productivity have to be accounted for when developing strategies to alleviate water limitations in cropping systems.
Thomas Keller - One of the best experts on this subject based on the ideXlab platform.
-
cortical cell diameter is key to energy costs of root growth in wheat
Plant Physiology, 2019Co-Authors: Tino Colombi, Anke M Herrmann, Pernilla Vallenback, Thomas KellerAbstract:Root growth requires substantial amounts of energy and thus carbohydrates. The energy costs of root growth are particularly high in both dry and compacted Soil, due to high Soil Penetration Resistance. Consequently, more carbon must be allocated from aboveground plant tissue to roots, which limits crop productivity. In this study, we tested the utility of root cortical cell diameter as a potential selection target to reduce the energy costs of root growth. Isothermal calorimetry was adopted for in situ quantification of the energy costs of root growth of 16 wheat (Triticum aestivum) genotypes under three levels of Penetration Resistance. We show that cortical cell diameter is a pivotal and heritable trait, which is strongly related to the energy costs of root growth. Genotypic diversity was found for cortical cell diameter and the energy costs of root growth. A large root cortical cell diameter correlated with reduced energy costs of root growth, particularly under high Soil Penetration Resistance. Moreover, significant correlations were found between the ability to radially enlarge cortical cells upon greater Penetration Resistance (i.e. phenotypic plasticity) and the responsiveness in the energy costs of root growth. A higher degree of phenotypic plasticity in cortical cell diameter was associated with reduced energy costs of root growth as Soil Penetration Resistance increased. We therefore suggest that genotypic diversity and phenotypic plasticity in cortical cell diameter should be harnessed to adapt crops to dry and compacted Soils.
-
feedbacks between Soil Penetration Resistance root architecture and water uptake limit water accessibility and crop growth a vicious circle
Science of The Total Environment, 2018Co-Authors: Tino Colombi, Lorena Chagas Torres, Achim Walter, Thomas KellerAbstract:Abstract Water is the most limiting resource for global crop production. The projected increase of dry spells due to climate change will further increase the problem of water limited crop yields. Besides low water abundance and availability, water limitations also occur due to restricted water accessibility. Soil Penetration Resistance, which is largely influenced by Soil moisture, is the major Soil property regulating root elongation and water accessibility. Until now the interactions between Soil Penetration Resistance, root system properties, water uptake and crop productivity are rarely investigated. In the current study we quantified how interactive effects between Soil Penetration Resistance, root architecture and water uptake affect water accessibility and crop productivity in the field. Maize was grown on compacted and uncompacted Soil that was either tilled or remained untilled after compaction, which resulted in four treatments with different topSoil Penetration Resistance. Higher topSoil Penetration Resistance caused root systems to be shallower. This resulted in increased water uptake from the topSoil and hence topSoil drying, which further increased the Penetration Resistance in the uppermost Soil layer. As a consequence of this feedback, root growth into deeper Soil layers, where water would have been available, was reduced and plant growth decreased. Our results demonstrate that Soil Penetration Resistance, root architecture and water uptake are closely interrelated and thereby determine the potential of plants to access Soil water pools. Hence, these interactions and their feedbacks on water accessibility and crop productivity have to be accounted for when developing strategies to alleviate water limitations in cropping systems.
Ciro Antonio Rosolem - One of the best experts on this subject based on the ideXlab platform.
-
Safflower root and shoot growth affected by Soil compaction
2018Co-Authors: Marcos Vinicius Mansano Sarto, Ciro Antonio Rosolem, Jaqueline Rocha Wobeto SartoAbstract:ABSTRACT Safflower (Carthamus tinctorius L.) is a commercial seed crop grown for its good yield of high-quality oil. It is tolerant to water stress but may be sensitive to Soil compaction. The aim of this study was to assess safflower growth under different degrees of Soil compaction at depths of 0.15 m to 0.20 m. The experiment was carried out in PVC pots constructed from three rings. Five levels of Penetration Resistance (0.20, 0.33, 0.50, 0.93, and 1.77 MPa) were applied in the intermediate ring, and two safflower genotypes, IMA-4904 and IMA-2106, were examined. There was no difference between safflower genotypes with respect to their Resistance to Soil compaction, which reduced root length density in the compacted layer and changed the root distribution in the Soil profile, but did not prevent the roots from crossing the compacted layer and developing in depth. Increased Soil bulk density in the compacted layer increased root diameter of the IMA-2106 genotype. Penetration Resistance levels over 0.20 MPa (density of 1.2 mg.dm–3) limited safflower root development. The maximum safflower growth occurred when the Soil Penetration Resistance was 0.86 MPa. In this study, the Q1/2 index was higher than 1.77 and 1.55 for the IMA-2106 and IMA-4904 genotypes, respectively. Hence, safflower has proven to be tolerant to Soil compaction, and stands out as a species with potential to decrease Soil bulk density.
-
Guar root and shoot growth as affected by Soil compaction
Universidade Federal de Goiás, 2018Co-Authors: Marcos Vinicius Mansano Sarto, Ciro Antonio Rosolem, Jaqueline Rocha Wobeto SartoAbstract:Guar (Cyamopsis tetragonoloba L.) is commonly grown in arid lands, because of its high drought-tolerance. However, Soil compaction may be a limiting factor to its growth. This study aimed to evaluate the guar growth, according to the Soil Penetration Resistance (0.20 MPa, 0.33 MPa, 0.50 MPa, 0.93 MPa and 1.77 MPa, in a layer with depth between 0.15 m and 0.20 m), in a Rhodic Acrudox Soil. The shoot and root dry mass, root length by the Q1/2 index (mechanical Soil Penetration Resistance in which the root growth is reduced by 50 %) and root diameter were evaluated. The impairment of the guar shoot growth begins when the Penetration Resistance is greater than around 1 MPa. The Soil compaction alters the distribution of guar roots in the Soil profile, concentrating them in the 0.15 m layer, but it does not prevent roots from penetrating this layer and developing in depth. The root diameter increases in the compacted layer. A Soil Penetration Resistance of up to 1.77 MPa does not influence the root length density below the compacted layer, as well as the total root length density of guar. Although the guar Q1/2 index is greater than 1.58, the shoot and root dry mass are impaired
-
soybean root growth and yield in rotation with cover crops under chiseling and no till
European Journal of Agronomy, 2010Co-Authors: Juliano Carlos Calonego, Ciro Antonio RosolemAbstract:Compacted subSoil layers result in shallow root systems hindering the absorption of water and nutrients by plants. Disruption of Soil compacted layers can be promoted by mechanical and/or biological methods, using plants with strong root systems. The immediate and medium term effects of mechanical chiseling and crop rotations on soybean root growth and yield were evaluated during four years in Brazil. Triticale (X Triticosecale Wittmack) and sunflower (Helianthus annuus L.) were grown in the autumn–winter (April–August). In the next spring (September–October/early November), designated plots were chiseled down to 0.25 m or planted to millet (Pennisetum glaucum L.), sorghum (Sorghum bicolor (L.) Moench) and sunn hemp (Crotalaria juncea L.), grown as cover crops, preceding soybean (Glycine max (L.) Merrill). Chiseling was done only in the first year, and these plots were left fallow during the spring (September–October/early November) for the rest of the experiment. Chiseling resulted in lower Soil Penetration Resistance and higher soybean yields in the first year. However, in the following years soybean root growth in depth was increased under rotation with triticale and pearl millet due to the presence of biopores and a decrease in Soil Penetration Resistance. Soybean yields tended to decrease over the years in plots that were chiseled when compared with plots under crop rotation. Chiseling can be replaced by crop rotations involving species with aggressive root systems in order to alleviate deleterious effects of Soil compaction on soybean yields in tropical Soils. This effect is gradual, thus crop rotation will be fully effective in remediating Soil compaction in a 3- to 4-year term.
-
Root growth and nutrient accumulation in cover crops as affected by Soil compaction
Soil and Tillage Research, 2002Co-Authors: Ciro Antonio Rosolem, J S S Foloni, C S TiritanAbstract:Crop rotation using cover crops with vigorous root systems may be a tool to manage Soils with some degree of compaction. Root and shoot growth as well as nutrient accumulation by summer species suitable for crop rotation in tropical areas were studied at different subSoil compaction levels. Crotalaria juncea (Indian hemp), Crotalaria spectabilis (showy crotalaria), Helianthus annuus (sunflower), Pennisetum americanum (pearl millet) and Sorghum bicolor (guinea sorghum) were grown for 40 days in pots 33.5 cm high with 10 cm internal diameter. Soil in the pots had uniform bulk density of 1.25 Mg m-3 for the top and bottom 15 cm sections. Bulk densities of 1.31, 1.43, 1.58 and 1.70 Mg m-3 were established in the 3.5 cm middle section. H. annuus and P. americanum had the highest early macronutrient accumulation. The grasses S. bicolor and P. americanum yielded twice as much shoot dry matter as the other species. Root growth generally decreased with increasing Soil bulk density with C. spectabilis less affected than other species. Although the grasses were more sensitive to high Soil Penetration Resistance, they showed higher root length densities at all compaction levels. P. americanum had the highest potential to be used as cover crop due to its high root density at high Soil Penetration Resistances, vegetative vigour and ability to accumulate macronutrients.
C M P Vaz - One of the best experts on this subject based on the ideXlab platform.
-
modeling and correction of Soil Penetration Resistance for varying Soil water content
Geoderma, 2011Co-Authors: C M P Vaz, J M Manieri, Isabella C De Maria, Markus TullerAbstract:article i nfo For this study Penetration Resistance (PR) was measured within the pro! les of four Oxisols for a wide range of water contents (! ) and bulk densities. Obtained data were utilized to parameterize 23 previously applied regression models. The most promising models were selected to illustrate effects of Soil texture on PR. Finally, a new correction method based on normalization of PR with ! corresponding to a matric potential of ! 10 kPa was introduced. Evaluation of texture effects revealed that for very wet Soils PR was lowest, but increased with clay content. PR at ! 1500 kPa exhibited a maximum at clay content of 35% and at ! 10 kPa PR was least affected by texture. From all regression models three- and two-parametric exponential and power functions yielded closest matches to measured data. The proposed correction signi! cantly dampened the in" uence of ! on PR, which allows better comparison for a speci! c Soil or among different Soils.
-
simultaneous measurement of Soil Penetration Resistance and water content with a combined penetrometer tdr moisture probe
Soil Science Society of America Journal, 2001Co-Authors: C M P Vaz, Jan W HopmansAbstract:and nutrient exploration have been obtained (Stelluti et al., 1998), and cone penetrometers have been used Soil mechanical impedance affects root growth and water flow, extensively in Soil science studies to identify natural and controls nutrient and contaminant transport below the rooting and induced compacted layers (Henderson, 1989) or to zone. Among the Soil parameters affecting Soil strength, Soil water content and bulk density are the most significant. However, field predict related Soil properties (Ayers and Bowen, 1987). water content changes both spatially and temporally, limiting the Among the Soil parameters that affect PR, Soil water application of cone penetrometers as an indicator of Soil strength. content and bulk density are the most significant (VazConsidering the presence of large water content variations within a quez et al., 1991). For example, Stitt et al. (1982) conSoil profile and across a field and the large influence of water content ducted a comprehensive study of factors affecting PR on Soil strength, there is need for a combined penetrometer‐moisture in coarse-textured Soils in the Atlantic Coastal Plain, probe to provide simultaneous field water content and Soil Resistance and used stepwise regression to relate mechanical immeasurements. Such a probe was developed, which uses the time pedance to various measured Soil properties. The highdomain reflectometry (TDR) technique to determine water content est correlation coefficients were found for a regression and its influence on Soil Penetration Resistance. The coiled TDR moismodel that included Soil water content, Soil particle ture probe consists of two parallel copper wires, each 0.8 mm in roughness and bulk Soil density. Shaw et al. (1942) condiameter and 30 cm long, coiled around a 5-cm-long polyvinyl chloride (PVC) core with a 3-mm separation between wires. Calibration curves cluded that Soil moisture is the dominant factor influencrelating the Soil bulk dielectric constant measured by the coiled probe ing the force required to push a penetrometer into the to water content were obtained in the laboratory for a Columbia Soil, with PR increasing as the moisture content define sand loam (coarse-loamy, mixed, superactive, nonacid, thermic creased. In an experimental study by Henderson et al. Oxyaquic Xerofluvent), a Yolo silt clay loam (fine-silty, mixed, non- (1988) it was found that PR was only slightly affected acid, thermic Typic Xerorthent), and washed sand, and data were with a decrease of Soil water content to ∪70% of field analyzed based on a mixing model approach. Subsequently, field ex- capacity. However, the PR increased exponentially with periments were conducted to measure simultaneously the Penetration a further reduction of the water content of the sandy Soil. Resistance (PR) and water content along a Soil profile. Results showed This study showed that PR increased with an increase of a detailed water content profile with excellent correlation with the bulk density across the whole measured water content gravimetric method, whereas the depth distribution of PR was similar range. However, because Soil moisture varies both spato that of dry bulk density as determined from Soil cores. tially and temporally and is only one of the Soil variables related to PR, the utility of using PR to determine compaction effects is marginal. Moreover, interpretation of
Jan W Hopmans - One of the best experts on this subject based on the ideXlab platform.
-
contribution of water content and bulk density to field Soil Penetration Resistance as measured by a combined cone penetrometer tdr probe
Soil & Tillage Research, 2001Co-Authors: L H Bassoi, Jan W HopmansAbstract:Abstract Soil strength as measured by cone penetrometers depends on several parameters, but it is mostly affected by the Soil water content ( θ ) and bulk density ( ρ ). In order to better understand the effect of the water content and bulk density on Soil strength we developed a combined penetrometer–coiled TDR probe to determine simultaneously the depth distribution of Penetration Resistance and water content in a Soil profile. Field experiments carried out for a Yolo Soil allowed the fitting of the effect of θ and ρ using a combined power–exponential equation. Using the combined cone penetrometer–TDR probe data, the fitted equation may be used to estimate Soil bulk density.
-
simultaneous measurement of Soil Penetration Resistance and water content with a combined penetrometer tdr moisture probe
Soil Science Society of America Journal, 2001Co-Authors: C M P Vaz, Jan W HopmansAbstract:and nutrient exploration have been obtained (Stelluti et al., 1998), and cone penetrometers have been used Soil mechanical impedance affects root growth and water flow, extensively in Soil science studies to identify natural and controls nutrient and contaminant transport below the rooting and induced compacted layers (Henderson, 1989) or to zone. Among the Soil parameters affecting Soil strength, Soil water content and bulk density are the most significant. However, field predict related Soil properties (Ayers and Bowen, 1987). water content changes both spatially and temporally, limiting the Among the Soil parameters that affect PR, Soil water application of cone penetrometers as an indicator of Soil strength. content and bulk density are the most significant (VazConsidering the presence of large water content variations within a quez et al., 1991). For example, Stitt et al. (1982) conSoil profile and across a field and the large influence of water content ducted a comprehensive study of factors affecting PR on Soil strength, there is need for a combined penetrometer‐moisture in coarse-textured Soils in the Atlantic Coastal Plain, probe to provide simultaneous field water content and Soil Resistance and used stepwise regression to relate mechanical immeasurements. Such a probe was developed, which uses the time pedance to various measured Soil properties. The highdomain reflectometry (TDR) technique to determine water content est correlation coefficients were found for a regression and its influence on Soil Penetration Resistance. The coiled TDR moismodel that included Soil water content, Soil particle ture probe consists of two parallel copper wires, each 0.8 mm in roughness and bulk Soil density. Shaw et al. (1942) condiameter and 30 cm long, coiled around a 5-cm-long polyvinyl chloride (PVC) core with a 3-mm separation between wires. Calibration curves cluded that Soil moisture is the dominant factor influencrelating the Soil bulk dielectric constant measured by the coiled probe ing the force required to push a penetrometer into the to water content were obtained in the laboratory for a Columbia Soil, with PR increasing as the moisture content define sand loam (coarse-loamy, mixed, superactive, nonacid, thermic creased. In an experimental study by Henderson et al. Oxyaquic Xerofluvent), a Yolo silt clay loam (fine-silty, mixed, non- (1988) it was found that PR was only slightly affected acid, thermic Typic Xerorthent), and washed sand, and data were with a decrease of Soil water content to ∪70% of field analyzed based on a mixing model approach. Subsequently, field ex- capacity. However, the PR increased exponentially with periments were conducted to measure simultaneously the Penetration a further reduction of the water content of the sandy Soil. Resistance (PR) and water content along a Soil profile. Results showed This study showed that PR increased with an increase of a detailed water content profile with excellent correlation with the bulk density across the whole measured water content gravimetric method, whereas the depth distribution of PR was similar range. However, because Soil moisture varies both spato that of dry bulk density as determined from Soil cores. tially and temporally and is only one of the Soil variables related to PR, the utility of using PR to determine compaction effects is marginal. Moreover, interpretation of