scholarly journals A comparison of root growth dynamics of silver maple and flowering dogwood in compacted soil at differing soil water contents

2000 ◽  
Vol 20 (4) ◽  
pp. 257-263 ◽  
Author(s):  
S. D. Day ◽  
J. R. Seiler ◽  
N. Persaud
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Growth Dynamics ◽  
Compacted Soil ◽  
Flowering Dogwood ◽  
Silver Maple ◽  
Water Contents ◽  
Soil Water Contents

Cotton root growth in a compacted Vertisol (Grey Vertosol). I. Prediction using strength measurements and 'limiting water ranges'

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 1157 ◽  
Author(s):  
D. C. McKenzie ◽  
A. B. McBratney
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Published Data ◽  
Cotton Production ◽  
Compacted Soil ◽  
Cotton Root ◽  
Least Limiting Water Range ◽  
Content Range ◽  
Water Contents ◽  
Better Than

The shear strength of a Vertisol under a broad range of compaction conditions has been related to ‘non-limiting water range’ (NLWR), ‘partially limiting water range’ (PLWR), and ‘least-limiting water range’ (LLWR) estimates for the growth of cotton roots. These factors indicate the soil water content range that land managers should aim to maintain so that root growth limitations caused by excessive hardness and poor aeration are minimised. The proportion of macropores available for root extension as the bulk soil becomes too anaerobic and/or hard for their growth has been quantified via a re-assessment of published data that relate oxygen flux density to air-filled porosity. A shear vane was shown to be better than a penetrometer for distinguishing compacted and non-compacted soil under a broad range of soil water contents on a Vertisol used for irrigated cotton production. Published critical limits for cotton root growth based on penetrometer data are of limited value. Nevertheless, these data have been converted for use with a shear vane. The NLWR and PLWR estimates have also been related to the SOILpak score, core bulk density, a clod shrinkage parameter, and a SOLICON image analysis factor.

scholarly journals The Effect of Irrigation Rate on the Water Relations of Young Citrus Trees in High-Density Planting

2021 ◽  
Vol 13 (4) ◽  
pp. 1759
Author(s):  
Said A. Hamido ◽  
Kelly T. Morgan
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Soil Salinity ◽  
Planting Density ◽  
Stem Water Potential ◽  
Irrigation Rate ◽  
Biological Stress ◽  
Stem Water ◽  
Water Contents ◽  
Soil Water Contents

The availability and proper irrigation scheduling of water are some of the most significant limitations on citrus production in Florida. The proper volume of citrus water demand is vital in evaluating sustainable irrigation approaches. The current study aims to determine the amount of irrigation required to grow citrus trees at higher planting densities without detrimental impacts on trees’ water relation parameters. The study was conducted between November 2017 and September 2020 on young sweet orange (Citrus sinensis) trees budded on the ‘US-897’ (Cleopatra mandarin x Flying Dragon trifoliate orange) citrus rootstock transplanted in sandy soil at the Southwest Florida Research and Education Center (SWFREC) demonstration grove, near Immokalee, Florida. The experiment contained six planting densities, including 447, 598, and 745 trees per ha replicated four times, and 512, 717, and 897 trees per ha replicated six times. Each density treatment was irrigated at 62% or 100% during the first 15 months between 2017 and 2019 or one of the four irrigation rates (26.5, 40.5, 53, or 81%) based on the calculated crop water supplied (ETc) during the last 17 months of 2019–2020. Tree water relations, including soil moisture, stem water potential, and water supplied, were collected periodically. In addition, soil salinity was determined. During the first year (2018), a higher irrigation rate (100% ETc) represented higher soil water contents; however, the soil water content for the lower irrigation rate (62% ETc) did not represent biological stress. One emitter per tree regardless of planting density supported stem water potential (Ψstem) values between −0.80 and −0.79 MPa for lower and full irrigation rates, respectively. However, when treatments were adjusted from April 2019 through September 2020, the results substantially changed. The higher irrigation rate (81% ETc) represented higher soil water contents during the remainder of the study, the lower irrigation rate (26.5% ETc) represents biological stress as a result of stem water potential (Ψstem) values between −1.05 and −0.91 MPa for lower and higher irrigation rates, respectively. Besides this, increasing the irrigation rate from 26.5% to 81%ETc decreased the soil salinity by 33%. Although increasing the planting density from 717 to 897 trees per hectare reduced the water supplied on average by 37% when one irrigation emitter was used to irrigate two trees instead of one, applying an 81% ETc irrigation rate in citrus is more efficient and could be managed in commercial groves.

Soil aggregate breakdown in a field experiment with different rainfall intensities and initial soil water contents

2017 ◽  
Vol 68 (6) ◽  
pp. 853-863 ◽  
Author(s):  
P. Shi ◽  
S. Thorlacius ◽  
T. Keller ◽  
M. Keller ◽  
R. Schulin
Keyword(s):  
Field Experiment ◽  
Soil Water ◽  
Soil Aggregate ◽  
Aggregate Breakdown ◽  
Initial Soil ◽  
Water Contents ◽  
Soil Water Contents

MITIGATION YIELD SCALED METHANE EMISSION FROM RICE GROWN IN WATER STRESS CONDITIONS WITH BIOCHAR AND SILICATE AMENDMENTS

2021 ◽  
Author(s):  
MUHAMMAD ASLAM ALI ◽  
SANJIT CHANDRA BARMAN ◽  
MD. ASHRAFUL ISLAM KHAN ◽  
MD. BADIUZZAMAN KHAN ◽  
HAFSA JAHAN HIYA
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Field Capacity ◽  
Saturated Soil ◽  
Rice Grain ◽  
Standing Water ◽  
Water Contents ◽  
Soil Water Contents

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.

scholarly journals Effect of Nano-Carbon on Water Holding Capacity in a Sandy Soil of the Loess Plateau

2017 ◽  
Vol 21 (4) ◽  
pp. 189-195 ◽  
Author(s):  
Beibei Zhou ◽  
Xiaopeng Chen
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Loess Plateau ◽  
Sandy Soil ◽  
Water Retention ◽  
Soil Mixture ◽  
Cumulative Infiltration ◽  
Nano Carbon ◽  
Water Contents ◽  
Soil Water Contents

The poor water retention capacity of sandy soils commonly aggregate soil erosion and ecological environment on the Chinese Loess Plateau. Due to its strong capacity for absorption and large specific surface area, the use of nanocarbon made of coconut shell as a soil amendment that could improve water retention was investigated. Soil column experiments were conducted in which a layer of nanocarbon mixed well with the soil was formed at a depth of 20 cm below the soil surface. Four different nanocarbon contents by weight (0%, 0.1%, 0.5%, and 1%) and five thicknesses of the nanocarbon- soil mixture layer ranging from 1 to 5 cm were considered. Cumulative infiltration and soil water content distributions were determined when water was added to soil columns. Soil Water Characteristic Curves (SWCC) were obtained using the centrifuge method. The principal results showed that the infiltration rate and cumulative infiltration increased with the increases of nanocarbon contents, to the thicknesses of the nano carbon-soil mixture layer. Soil water contents that below the soil-nano carbon layer decreased sharply. Both the Brooks-Corey and van Genuchten models could describe well the SWCC of the disturbed sandy soil with various nano carbon contents. Both the saturated water content (θs), residual water content (θr) and empirical parameter (α) increased with increasing nano carbon content, while the pore-size distribution parameter (n) decreased. The available soil water contents were efficiently increased with the increase in nanocarbon contents.

Diffusivity and sorptivity determination at different soil water contents from horizontal infiltration

Geoderma ◽  
2019 ◽  
Vol 338 ◽  
pp. 88-96 ◽  
Author(s):  
Rafael Villarreal ◽  
Luis A. Lozano ◽  
Esteban M. Melani ◽  
María Paz Salazar ◽  
María Florencia Otero ◽  
...  
Keyword(s):  
Soil Water ◽  
Horizontal Infiltration ◽  
Water Contents ◽  
Soil Water Contents

Soil water contents for tillage: A comparison of approaches and consequences for the number of workable days

2019 ◽  
Vol 195 ◽  
pp. 104384 ◽  
Author(s):  
Peter Bilson Obour ◽  
Thomas Keller ◽  
Johannes L. Jensen ◽  
Gareth Edwards ◽  
Mathieu Lamandé ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Contents ◽  
Soil Water Contents

scholarly journals An empirical model for describing the influence of water content and concentration of sulfamethoxazole (antibiotic) in soil on the total net CO2 efflux

2020 ◽  
Vol 68 (4) ◽  
pp. 351-358
Author(s):  
Miroslav Fér ◽  
Radka Kodešová ◽  
Barbora Kalkušová ◽  
Aleš Klement ◽  
Antonín Nikodem
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Solution Treatment ◽  
Soil Microbial Activity ◽  
Soil Samples ◽  
Co2 Efflux ◽  
The Impact ◽  
Water Contents ◽  
Soil Water Contents

AbstractThe aim of the study was to describe the impact of the soil water content and sulfamethoxazole, SUL, (antibiotic) concentration in soil on the net CO2 efflux. Soil samples were taken from topsoils of a Haplic Fluvisol and Haplic Chernozem. Soil samples were packed into the steel cylinders. The net CO2 efflux was measured from these soil columns after application of fresh water or SUL solution at different soil water contents. The experiments were carried out in dark at 20°C. The trends in the net CO2 efflux varied for different treatments. While initially high values for water treatment exponentially decreased in time, values for solution treatment increased during the first 250–650 minutes and then decreased. The total net CO2 effluxes measured for 20 hours related to the soil water content followed the second order polynomial functions. The maximal values were measured for the soil water content of 0.15 cm3 cm−3 (Haplic Fluvisol with water or solution, Haplic Chernozem with solution) and 0.11 cm3 cm−3 (Haplic Chernozem with water). The ratios between values measured for solution and water at the same soil water contents exponentially increased with increasing SUL concentration in soils. This proved the increasing stimulative influence of SUL on soil microbial activity.

scholarly journals Application of the Bayesian calibration methodology for the parameter estimation in CoupModel

2009 ◽  
Vol 21 ◽  
pp. 13-24 ◽  
Author(s):  
Y. Conrad ◽  
N. Fohrer
Keyword(s):  
Soil Water ◽  
Parameter Space ◽  
Mineral Nitrogen ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Bayesian Calibration ◽  
Soil Temperatures ◽  
Simulation Results ◽  
Water Contents ◽  
Soil Water Contents

Abstract. This study provides results for the optimization strategy of highly parameterized models, especially with a high number of unknown input parameters and joint problems in terms of sufficient parameter space. Consequently, the uncertainty in model parameterization and measurements must be considered when highly variable nitrogen losses, e.g. N leaching, are to be predicted. The Bayesian calibration methodology was used to investigate the parameter uncertainty of the process-based CoupModel. Bayesian methods link prior probability distributions of input parameters to likelihood estimates of the simulation results by comparison with measured values. The uncertainty in the updated posterior parameters can be used to conduct an uncertainty analysis of the model output. A number of 24 model variables were optimized during 20 000 simulations to find the "optimum" value for each parameter. The likelihood was computed by comparing simulation results with observed values of 23 output variables including soil water contents, soil temperatures, groundwater level, soil mineral nitrogen, nitrate concentrations below the root zone, denitrification and harvested carbon from grassland plots in Northern Germany for the period 1997–2002. The posterior parameter space was sampled with the Markov Chain Monte Carlo approach to obtain plot-specific posterior parameter distributions for each system. Posterior distributions of the parameters narrowed down in the accepted runs, thus uncertainty decreased. Results from the single-plot optimization showed a plausible reproduction of soil temperatures, soil water contents and water tensions in different soil depths for both systems. The model performed better for these abiotic system properties compared to the results for harvested carbon and soil mineral nitrogen dynamics. The high variability in modeled nitrogen leaching showed that the soil nitrogen conditions are highly uncertain associated with low modeling efficiencies. Simulated nitrate leaching was compared to more general, site-specific estimations, indicating a higher leaching during the seepage periods for both simulated grassland systems.

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