scholarly journals Relationship between Very Fine Root Distribution and Soil Water Content in Pre- and Post-Harvest Areas of Two Coniferous Tree Species

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1227
Author(s):  
Moein Farahnak ◽  
Keiji Mitsuyasu ◽  
Takuo Hishi ◽  
Ayumi Katayama ◽  
Masaaki Chiwa ◽  
...  
Keyword(s):  
Water Content ◽  
Root System ◽  
Soil Water ◽  
Soil Water Content ◽  
Tree Species ◽  
Fine Roots ◽  
Fine Root ◽  
Soil Depth ◽  
Tree Cutting ◽  
Coniferous Tree Species

Tree root system development alters forest soil properties, and differences in root diameter frequency and root length per soil volume reflect differences in root system function. In this study, the relationship between vertical distribution of very fine root and soil water content was investigated in intact tree and cut tree areas. The vertical distribution of root density with different diameter classes (very fine <0.5 mm and fine 0.5–2.0 mm) and soil water content were examined along a slope with two coniferous tree species, Cryptomeria japonica (L.f.) D. Don and Chamaecyparis obtusa (Siebold et Zucc.) Endl. The root biomass and length density of very fine roots at soil depth of 0–5 cm were higher in the Ch. obtusa intact tree plot than in the Cr. japonica intact plot. Tree cutting caused a reduction in the biomass and length of very fine roots at 0–5 cm soil depth, and an increment in soil water content at 5–30 cm soil depth of the Ch. obtusa cut tree plot one year after cutting. However, very fine root density of the Cr. japonica intact tree plot was quite low and the soil water content in post-harvest areas did not change. The increase in soil water content at 5–30 cm soil depth of the Ch. obtusa cut tree plot could be caused by the decrease in very fine roots at 0–5 cm soil depth. These results suggest that the distribution of soil water content was changed after tree cutting of Ch. obtusa by the channels generated by the decay of very fine roots. It was also shown that differences in root system characteristics among different tree species affect soil water properties after cutting.

Root length density and soil water distribution in drip-irrigated olive orchards in Argentina under arid conditions

2009 ◽  
Vol 60 (3) ◽  
pp. 280 ◽  
Author(s):  
Peter S. Searles ◽  
Diego A. Saravia ◽  
M. Cecilia Rousseaux
Keyword(s):  
Water Content ◽  
Root System ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Length ◽  
Root Length Density ◽  
Soil Depth ◽  
Drip Line ◽  
North West ◽  
Intensively Managed

Several studies have evaluated many above-ground aspects of olive production, but essential root system characteristics have been little examined. The objective of our study was to evaluate root length density (RLD) and root distribution relative to soil water content in three commercial orchards (north-west Argentina). Depending on the orchard, the different drip emitter arrangements included either: (1) emitters spaced continuously at 1-m intervals along the drip line (CE-4; 4 emitters per tree); (2) 4 emitters per tree spaced at 1-m intervals, but with a space of 2 m between emitters of neighbouring trees (E-4); or (3) 2 emitters per tree with 4 m between emitters of neighbouring trees (E-2). All of the orchards included either var. Manzanilla fina or Manzanilla reina trees (5–8 years old) growing in sandy soils, although the specific characteristics of each orchard differed. Root length density values (2.5–3.5 cm/cm3) in the upper soil depth (0–0.5 m) were fairly uniform along the drip line in the continuous emitter (CE-4) orchard. In contrast, roots were more concentrated in the E-4 and E-2 orchards, in some cases with maximum RLD values of up to 7 cm/cm3. Approximately 70% of the root system was located in the upper 0.5 m of soil depth, and most of the roots were within 0.5 m of the drip line. For each of the three orchards, significant linear relationships between soil water content and RLD were detected based on 42 sampling positions that included various distances from the trunk and soil depths. Values of RLD averaged over the entire rooting zone and total tree root length per leaf area for the three orchards were estimated to range from 0.19 to 0.48 cm/cm3 and from 1.8 to 3.5 km/m2, respectively. These results should reduce the uncertainty associated with the magnitude of RLD values under drip irrigation as intensively managed olive orchards continue to expand in established and new growing regions.

scholarly journals SURFACE RESIDUES: EFFECTS ON SOIL MOISTURE AND TEMPERATURE1

2021 ◽  
Vol 34 (4) ◽  
pp. 887-894
Author(s):  
GUSTAVO HADDAD SOUZA VIEIRA ◽  
ARILDO SEBASTIÃO SILVA ◽  
ARUN DILIPKUMAR JANI ◽  
LUSINERIO PREZOTTI ◽  
PAOLA ALFONSA VIEIRA LO MONACO
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Block Design ◽  
Soil Disturbance ◽  
Dry Season ◽  
Depth Range ◽  
Sunn Hemp

ABSTRACT This study aimed to determine how crop residue placement and composition would affect soil water content and temperature during the dry season in the central region of Espírito Santo state, Brazil. A 19-week field study was conducted from April to August 2017. A 2 x 4 factorial study with four replications was implemented using a randomized complete block design. Factors were soil management [conventional tillage (CT) and no soil disturbance (ND)] and residue amendment [maize (Zea mays L.), sunn hemp (Crotalaria juncea L.), a maize-sunn hemp mixture, and a no amendment control]. Soil water content and temperature were measured weekly at predetermined soil depth intervals. Soil water content was higher in ND plots amended with surface residues than under all other treatments in the 0 to 0.05 m depth range. All residue amendments in this range were equally effective in conserving soil water. Surface residues reduced soil temperature by up to 8.4 °C relative to the control in ND plots. Incorporating residue amendments by CT cancelled all temperature-moderating benefits provided by surface residues. These results indicate that surface residues from cereals, legumes, or cereal/legume mixtures are equally effective in conserving soil water and moderating soil temperature during the dry season. Additional research is needed to determine how improved soil environmental conditions, generated by surface residues, would affect nutrient acquisition and crop performance.

scholarly journals Effects of different biomass materials as a salt-isolation layer on water and salt migration in coastal saline soil

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11766
Author(s):  
Mao Yang ◽  
Runya Yang ◽  
Yanni Li ◽  
Yinghua Pan ◽  
Junna Sun ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Salt Concentration ◽  
Saline Soil ◽  
Soil Depth ◽  
Soil Layer ◽  
Thick Layer ◽  
Peat Layer ◽  
Salt Accumulation

The aim of this study was to find a material suited for the prevention of evaporative water loss and salt accumulation in coastal saline soils. One-dimensional vertical water infiltration and phreatic evaporation experiments were conducted using a silty loam saline soil. A 3-cm-thick layer of corn straw, biochar, and peat was buried at the soil depth of 20 cm, and a 6-cm-thick layer of peat was also buried at the same soil depth for comparison. The presence of the biochar layer increased the upper soil water content, but its ability to inhibit salt accumulation was poor, leading to a high salt concentration in the surface soil. The 3-cm-thick straw and 6-cm-thick peat layers were most effective to inhibit salt accumulation, which reduced the upper soil salt concentration by 96% and 93%, respectively. However, the straw layer strongly inhibited phreatic evaporation and resulted in low water content in the upper soil layer. Compared with the straw layer, the peat layer increased the upper soil water content. Thus, burying a 6-cm-thick peat layer in the coastal saline soil is the optimal strategy to retain water in the upper soil layer and intercept salt in the deeper soil layer.

Laboratory and field evaluation of five soil water sensors

2004 ◽  
Vol 84 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Q. Huang ◽  
O. O. Akinremi ◽  
R. Sri Rajan ◽  
P. Bullock
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Field Evaluation ◽  
Soil Bulk Density ◽  
Laboratory Evaluation ◽  
Engineering Sciences ◽  
Probe Calibration

Accurate in situ determination of soil water content is important in many fields of agricultural, environmental, hydrological, and engineering sciences. As numerous soil water content sensors are available on the market today, the knowledge of their performance will aid users in the selection of appropriate sensors. The objectives of this study were to evaluate five soil water sensors in the laboratory and to determine if laboratory calibration is appropriate for the field. In this study, the performances of five sensors, including the Profile Probe™ (PP), ThetaProbe™ , Watermark™, Aqua-Tel™, and Aquaterr™ were compared in the laboratory. The PP and ThetaProbe™ were more accurate than the other soil water sensors, reproducing soil water content using factory recommended parameters. However, when PP was installed on a loamy sand in the field, the same soil that was used for the laboratory evaluation, it overestimated field soil water, especially at depth. Another laboratory experiment showed that soil water content readings from the PP were strongly influenced by soil bulk density. The higher the soil bulk density, the greater was the overestimation of soil water content. Two regression parameters, a0 and a1, which are used to convert the apparent dielectric constant to volumetric water content, were found to increase linearly with the soil bulk density in the range of 1.2 to 1.6 Mg m-3. Finally, the PP was calibrated in the field and a good calibration function was obtained with an r2 of 0.87 and RMSE of 2.7%. The values of a0 and a1 obtained in the field were different from factory recommended parameters (a0 = 2.4 versus 1.6 while a1 = 12.5 versus 8.4) and were independent of soil depth, bulk density, and texture. As such, individual field calibration will be necessary to obtain precise and accurate measurement of soil water content with this instrument. Key words: Soil water content, Profile Probe, calibration, soil water content sensor

Distribution of carbon and nutrients and fluxes of mineral nitrogen after clear-felling a Pinusradiata plantation

1990 ◽  
Vol 20 (9) ◽  
pp. 1490-1497 ◽  
Author(s):  
P. J. Smethurst ◽  
E. K. S. Nambiar
Keyword(s):  
Organic Matter ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
N Mineralization ◽  
Soil Depth ◽  
Mineral N ◽  
Southeastern Australia ◽  
Nutrients Fluxes

The effects of clear-felling and slash removal on the distribution of organic matter and nutrients, fluxes of mineral N, and soil water and temperature were studied in a 37-year-old Pinusradiata D. Don plantation, on a sandy Podzol in southeastern Australia. Slash, litter, and the top 30 cm of soil combined contained 1957 kg N•ha−1, of which slash and litter contained 12 and 25%, respectively. Therefore, loss of slash and litter due to burning or other intensive site preparation practices would substantially reduce the N capital at the site. During the first 18 months after clear-felling, soil water content in the clear-felled area was up to 50% higher than in the uncut plantation, but there were only minor differences in soil temperature. Slash removal decreased the water content of litter, but had little effect on the water content or temperature of the soil. In the uncut plantation, N mineralized in litter and soil was completely taken up by the trees. Following clear-felling, rates of N mineralization increased in litter after 4 months, and in soil after 12 months, but changes were less pronounced with slash removal. After clear-felling, increased mineralization and the absence of trees (no uptake) led to increased concentrations of mineral N in both litter and soil, 64–76% of which was leached below the 30 cm soil depth prior to replanting. Despite leaching, concentrations of mineral N after clear-felling remained higher than those in the uncut plantation for at least 3 years.

Influence of temperature on soil water content measured by ECH2O-TE sensors

2012 ◽  
Vol 26 (3) ◽  
pp. 259-269 ◽  
Author(s):  
M. Kočárek ◽  
R. Kodešová
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Regression Equations ◽  
Influence Of Temperature ◽  
Reference Soil ◽  
Guideline Values ◽  
Influence Of Temperature On

Influence of temperature on soil water content measured by ECH2O-TE sensorsThe aim of this study was to investigate the influence of temperature on water content value measured by ECH2O-TE sensors. The influence of temperature on measured soil water content values was clearly demonstrated. Soil water content values measured during the day apparently oscillated with oscillating soil temperatures. Average daily temperature and soil water content were calculated for selected periods. Regression relationships between deviations of soil temperature and soil water content from their daily average values were evaluated. Correlation between the soil water content and temperature deviations increase with the soil depth due to the lower influence of rainfall and evaporation at the soil surface on measured soil water content values in deeper soil layersegsoil water content oscillation was controlled mostly by oscillating temperature. The guideline values of linear regression equations (R2>0.8) were very similar, close to value 0.002 and the intercept values were equal to zero. The equation for recalculation of measured soil water content values at given temperature to reference soil water content for reference soil temperature, was propozed on the basis of this analysis.

scholarly journals Physiological and climate controls on foliar mercury uptake by European tree species

2021 ◽  
Author(s):  
Lena Wohlgemuth ◽  
Pasi Rautio ◽  
Bernd Ahrends ◽  
Alexander Russ ◽  
Lars Vesterdal ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Tree Species ◽  
Physiological Activity ◽  
Growing Season ◽  
Relevant Parameter ◽  
Uptake Rates ◽  
Mercury Uptake

Abstract. Despite the importance of vegetation uptake of atmospheric gaseous elemental mercury (Hg(0)) within the global Hg cycle, little knowledge exists on the physiological, climatic and geographic factors controlling stomatal uptake of atmospheric Hg(0) by tree foliage. We investigate controls on foliar stomatal Hg(0) uptake by combining Hg measurements of 3,569 foliage samples across Europe with data on tree species traits and environmental conditions. To account for foliar Hg accumulation over time, we normalized foliar Hg concentration over the foliar life period from the simulated start of the growing season to sample harvest. The most relevant parameter impacting daily foliar stomatal Hg uptake was tree functional group (deciduous versus coniferous trees). On average, we measured 3.2 times higher daily foliar stomatal Hg uptake rates in deciduous leaves than in coniferous needles of the same age. Across tree species, for foliage of beech and fir, and at two out of three forest plots with more than 20 samples, we found a significant (p < 0.001) increase in foliar Hg values with respective leaf nitrogen concentrations. We therefore suggest, that foliar stomatal Hg uptake is controlled by tree functional traits with uptake rates increasing from low to high nutrient content representing low to high physiological activity. For pine and spruce needles, we detected a significant linear decrease of daily foliar stomatal Hg uptake with the proportion of time, during which vapor pressure deficit (VPD) exceeded the species-specific threshold values of 1.2 kPa and 3 kPa, respectively. The proportion of time within the growing season, during which surface soil water content (ERA5-Land) in the region of forest plots was low correlated negatively with corresponding foliar Hg uptake rates of beech and pine. These findings suggest that stomatal uptake of atmospheric Hg(0) is inhibited under high VPD conditions and/or low soil water content due the regulation of stomatal conductance to reduce water loss under dry conditions. We therefore propose, that foliar Hg measurements bear the potential to serve as proxy for stomatal conductance. Other parameters associated with forest sampling sites (latitude and altitude), sampled trees (average age and diameter at breast height) or regional satellite observation-based transpiration product (GLEAM) did not significantly correlate with daily foliar Hg uptake rates. We conclude that tree physiological activity and stomatal response to VPD and soil water content should be implemented in a stomatal Hg model, to assess future Hg cycling under different anthropogenic emission scenarios and global warming.

scholarly journals Spatial variability of soil penetration resistance influenced by season of sampling

Bragantia ◽  
2010 ◽  
Vol 69 (suppl) ◽  
pp. 163-173 ◽  
Author(s):  
Juan José Bonnin ◽  
José Manuel Mirás-Avalos ◽  
Kléber Pereira Lanças ◽  
Antonio Paz González ◽  
Sidney Rosa Vieira
Keyword(s):  
Spatial Distribution ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Indicator Kriging ◽  
Data Series ◽  
Soil Resistance ◽  
Inverse Distance ◽  
Cone Index

The aim of this work was to analyze the spatial distribution of soil compaction and the influence of soil water content on the resistance to penetration. The latter variable was described by the cone index. The soil at the study site was a Nitisol and the cone index data were obtained using a penetrometer. Soil resistance was assessed at 5 different depths, i.e. 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm and deeper than 40 cm, whereas soil water content was measured at 0-20 cm and 20-40 cm. Soil water conditions varied during the different samplings. Coefficients of variation for cone index ranged from 16.5% to 45.8% while those for soil water content varied from 8.96% to 21.38%. Results suggested a high correlation between soil resistance, as assessed by the cone index, and soil depth. However, the expected relation with soil water content was not observed. Spatial dependence was observed in 31 out of 35 data series, both cone index and soil water content. This structure was fitted to exponential models with nugget effect varying from 0 to 90% of the sill value. Four of the data series showed a random behaviour. Inverse distance technique was used in order to map the distribution of the variables when no spatial structure was observed. Ordinary kriging showed a smoothing of the maps compared to those from inverse distance weighing. Indicator kriging was used to map the cone index spatial distribution for recommendation of further soil management.

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