A SOIL WATER BUDGET MODEL WITH A NEARLY IMPERMEABLE LAYER

1981 ◽  
Vol 61 (2) ◽  
pp. 361-371 ◽  
Author(s):  
R. DE JONG ◽  
C. F. SHAYKEWICH
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Budget ◽  
Budget Model ◽  
Sink Term ◽  
Impermeable Layer ◽  
Homogeneous Soil ◽  
Potential Transpiration ◽  
System Water ◽  
Water Contents

A soil water budget model which accounted for a nearly impermeable layer in the profile was developed to describe the water content in a non-homogeneous soil-root system. Water uptake by the roots was represented by a sink term which was dependent upon the root distribution, the soil water content and the potential transpiration. The chosen boundary conditions, precipitation, evapotranspiration and a nearly impermeable layer at the bottom of the soil profile approximated those existing in the field. A submodel to calculate interception was included in the model. Data obtained from a field experiment on a clay soil were compared with calculated results for the period 1 May to 30 Sept. 1975. The overall agreement between daily measured and calculated soil water contents was excellent; all calculated values fell within 10% of the measured data. The model also yielded acceptable results in predicting the distribution of soil water through the profile.

Utility of a simple soil water budget model in agronomic research. 2. Estimates of available soil water in relation to profile changes of soil water content and potential

1974 ◽  
Vol 14 (66) ◽  
pp. 80 ◽  
Author(s):  
RG Fawcett ◽  
OG Carter
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Budget ◽  
Plant Density ◽  
Budget Model ◽  
North West ◽  
The North ◽  
South Wales ◽  
Profile Changes

A study was made of the effects of plant density, time-of-sowing and level of fallow water on profile changes in soil water content and potential during the growing season of spring wheat. The pattern of soil moisture extraction was affected by all treatments although water depletion occurred chiefly in the 0-90 cm zone. The results are discussed in relation to limitations of a simple soil water budget model and to wheat cropping on the north-west slopes and plains of New South Wales.

Utility of a simple soil water budget model in agronomic research. 3. Estimation of the potential evapotranspiration function

1974 ◽  
Vol 14 (70) ◽  
pp. 684
Author(s):  
RG Fawcett ◽  
OG Carter
Keyword(s):  
Soil Water ◽  
Water Budget ◽  
Potential Evapotranspiration ◽  
Regression Equation ◽  
Wheat Crop ◽  
Budget Model ◽  
Plant Densities ◽  
Potential Transpiration

It has been shown that a regression equation relating the cumulative potential transpiration function (T/Eo) with the yield of tops, week of sowing and available fallow moisture, together with a simple budget model, can be used to estimate weekly changes in available soil water under a wheat crop. It is concluded from the data that use of the equation and budget model should be most suited to situations where plant densities are about 60 plants per m2 and the available fallow water is about 150 mm or less.

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.

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.

Influence of Water Content of Soil to Strength of Unfired Soil Lime Bricks

2015 ◽  
Vol 719-720 ◽  
pp. 187-192
Author(s):  
Heru Purnomo ◽  
Rahmat N.D. Syah ◽  
Mochammad R. Syaifulloh ◽  
Srikandi W. Arini ◽  
Essy Arijoeni Basoenondo ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Physical Change ◽  
Three Point Bending ◽  
Mass Proportion ◽  
Influence Of Water ◽  
Water Contents

The paper discusses strength-time relation of unfired soil-lime bricks in presence of different water content of soil as one of principal materials for the brick making. Two batches of soil-lime bricks were made with a mixture of lime, soil and water with a mass proportion of 1: 5.7: 1. Water contents of the first and second batch of soil are 30% and 40.581% respectively. Both batches of brick underwent compression and three point bending test. Absorption and physical change of bricks were also evaluated. Experimental investigation reveals that for both batches of bricks, up to 90 days compressive strength decreases a little but modulus of rupture rapidly decreases with time. The study shows that unfired soil-lime bricks with lower soil water content resulted in better strength performances compared to those with higher soil water content.

The Effects of Temperature and Humidity on a Field Population of Bradysia odoriphaga (Diptera: Sciaridae)

2020 ◽  
Vol 113 (4) ◽  
pp. 1927-1932
Author(s):  
Cai-hua Shi ◽  
Jing-rong Hu ◽  
You-jun Zhang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Control Strategies ◽  
Beijing City ◽  
Drought Treatment ◽  
High Soil ◽  
Soil Temperatures ◽  
Water Contents ◽  
Soil Water Contents

Abstract The production of Chinese chives is reduced throughout China due to a root-feeding dipteran pest Bradysia odoriphaga Yang et Zhang (Diptera: Sciaridae), therefore deciphering the conditions influencing its growth and development are important in developing ecological control strategies. A study was conducted from 2014 to 2017 to determine the relationship between the abundance of B. odoriphaga and temperature (atmospheric and soil), soil water content, and atmospheric humidity in a Chinese chive field in Beijing City, China. Numbers of adults peaked in March and October to November and were lowest in July to August and December to next February; numbers of larvae were highest in December to next February and lowest in July to August. From 2014 to 2017, the numbers of adults and larvae were significantly correlated with monthly mean atmospheric temperatures and soil temperatures, but were not significantly correlated with monthly mean atmospheric relative humidity and soil water content. However, for both adults and larvae, numbers were significantly greater with high soil water contents compared with drought treatment. The results of this study suggest that the very low soil water contents, high atmospheric temperatures, and high soil temperatures were critical for regulating field populations of B. odoriphaga.

EFFECT OF SOIL WATER AND TEMPERATURE ON CORN (Zea mays L.) ROOT GROWTH DURING EMERGENCE

1986 ◽  
Vol 66 (1) ◽  
pp. 51-58 ◽  
Author(s):  
H. W. CUTFORTH ◽  
C. F. SHAYKEWICH ◽  
C. M. CHO
Keyword(s):  
Root Growth ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Zea Mays L ◽  
Rate Sensitivity ◽  
Corn Hybrids ◽  
Soil Water Stress ◽  
Soil Temperatures ◽  
Water Contents

Root growth between germination and emergence for the corn hybrids Pioneer 3995, Northrup King 403 and Pride 1108 was studied. Soil temperatures of 15, 19, 25 and 30.5 °C and a range of soil water contents were used. Decreases in soil temperature and water content both decreased root growth rate. Sensitivity to water content decreased with decreasing soil temperature. All three hybrids responded to soil temperature in the same way. By contrast, Pioneer 3995 was less sensitive to soil water stress than was Northrup King 403, while Pride 1108 was the most sensitive. Key words: Soil water, soil temperature, root growth (early), corn

Calculation of soil water contents from gamma ray readings

Soil Research ◽  
1964 ◽  
Vol 2 (1) ◽  
pp. 29 ◽  
Author(s):  
CG Gurr
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Gamma Ray ◽  
Initial Conditions ◽  
Large Numbers ◽  
Field Samples ◽  
Water Contents ◽  
Soil Water Contents

A method is given for calculating water contents of a column of soil from gamma ray data. The method is particularly useful for undisturbed field samples of unknown initial conditions. Values of water content and bulk density determined at the end of an experiment are used for calibration. To aid the calculation of large numbers of results, a nomogram has been constructed.

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