Variability in soil moisture and infiltration on two Riverina soils

1951 ◽  
Vol 2 (2) ◽  
pp. 126 ◽  
Author(s):  
AL Tisdall
Keyword(s):  
Soil Moisture ◽  
Sandy Loam ◽  
Brown Soil ◽  
Soil Group ◽  
Coefficients Of Variation ◽  
Irrigated Soils

Studies of variability in soil moisture and of a method for determining infiltration were conducted on two irrigated soils in the Riverina region, a sandy loam of the red-brown earth group and a clay of the grey and brown soil group respectively. Coefficients of variation were high in all cases. It is concluded that the use of 16 replicates gives adequate precision in the estimate of infiltration (C.V. of 8 and 12 per cent, for the two soils studied). Similarly, the use of 16 gravimetric determinations, each bulked from four sites, would give a satisfactory estimate for soil moisture (C. V. of less than 10 per cent. for the two soils studied). This number of samples is not excessive from practical considerations. Sampling for soil-moisture increment, following the type of irrigation used on these soils, should be carried out to a depth of two feet, but the duplication of gravimetric determinations is not warranted by the small increase in precision obtained.

Long-term tillage effects on spring wheat production on three soil textures in the Brown soil zone

1996 ◽  
Vol 76 (4) ◽  
pp. 747-756 ◽  
Author(s):  
B. G. McConkey ◽  
C. A. Campbell ◽  
R. P. Zentner ◽  
F. B. Dyck ◽  
F. Selles
Keyword(s):  
Soil Moisture ◽  
Spring Wheat ◽  
Sandy Loam ◽  
Silt Loam ◽  
Grain Yields ◽  
Wheat Production ◽  
Brown Soil ◽  
Soil Zone ◽  
Tillage System

The adoption of reduced tillage practices has increased markedly on the Canadian prairies in recent years. Producers in the semiarid Brown Chernozemic soil zone require information on how the intensity of tillage will affect moisture conservation and grain yields in the long term. A 12-yr study was conducted in the Brown soil zone of southwestern Saskatchewan on Swinton silt loam (Orthic Brown), Hatton fine sandy loam (Orthic Brown), and Sceptre heavy clay (Rego Brown) to determine the influence of tillage on the production of hard red spring wheat (Triticum aestivum L.) (on the silt loam and clay) and durum (Triticum turgidum L.) (on the sandy loam). The study was conducted with fallow-wheat (F–W) and continuous wheat (Cont W) rotations. The tillage systems were no-tillage (NT), minimum tillage (MT) and conventional tillage (CT). On the sandy soil with its low water-holding characteristics, tillage system did not affect stored spring soil moisture (SSM), nor grain yields, nor grain N. On the silt loam and clay, there were several instances when NT increased stored moisture in the soil, especially on the clay, but the extra moisture conserved was not always associated with increased grain yields. Generally, when significant increases in stored moisture for F–W were accompanied by below-average growing season precipitation (GSP), an advantage in yield accrued to NT. However, when GSP was above average, CT and MT often had greater yields than NT. We rarely observed yield advantages favouring NT on Cont W on the silt loam or on the clay. Our results suggest that wheat grown under NT on the clay has a higher lower limit of available soil moisture than under CT. Generally, grain N concentration was lower for F–W (NT) on the silt loam and clay. This study has shown that mono-culture wheat production in the Brown soil zone was influenced little by tillage system. Key words: Crop rotations, grain protein, soil water, grain production

Evaluation of Presswheels and Seed Coverers for Direct Seeding of Brassica

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 599E-600
Author(s):  
Regina P. Bracy ◽  
Richard L. Parish
Keyword(s):  
Soil Moisture ◽  
Sandy Loam ◽  
Visual Observation ◽  
Mustard Seed ◽  
High Soil Moisture ◽  
Loam Soil ◽  
Direct Seeded ◽  
Plant Emergence ◽  
Moisture Conditions ◽  
Determine Effect

Improved stand establishment of direct-seeded crops has usually involved seed treatment and/or seed covers. Planters have been evaluated for seed/plant spacing uniformity, singulation, furrow openers, and presswheel design; however, effects of presswheels and seed coverers on plant establishment have not been widely investigated. Five experiments were conducted in a fine sandy loam soil to determine effect of presswheels and seed coverers on emergence of direct-seeded cabbage and mustard. Seed were planted with Stanhay 870 seeder equipped with one of four presswheels and seed coverers. Presswheels included smooth, mesh, concave split, and flat split types. Seed coverers included standard drag, light drag, paired knives, and no coverer. Soil moisture at planting ranged from 8% to 19% in the top 5 cm of bed. Differences in plant counts taken 2 weeks after planting were minimal with any presswheel or seed coverer. Visual observation indicated the seed furrow was more completely closed with the knife coverer in high soil moisture conditions. All tests received at least 14 mm of precipitation within 6 days from planting, which may account for lack of differences in plant emergence.

New Method for Estimation of Contaminant Travel Rate in Unsaturated Zone under Irrigated Soils

1993 ◽  
Vol 27 (7-8) ◽  
pp. 173-178 ◽  
Author(s):  
M. Zilberbrand
Keyword(s):  
Water Content ◽  
Unsaturated Zone ◽  
Sandy Loam ◽  
Chestnut Soil ◽  
Deep Penetration ◽  
Groundwater Recharge Rate ◽  
Capillary Tension ◽  
Travel Rate ◽  
Tracer Experiments ◽  
Irrigated Soils

In a thick unsaturated zone, when quick deep penetration of rain and irrigation water is absent, at the depths below 3-5 m there exists a zone of downwards quasi-steady water flow. Darcy's water velocity in this zone remains constant with depth and equal to the groundwater recharge rate; unit hydraulic head gradient occurs above the capillary fringe. Therefore, contaminant travel rate is equal to the ratio of hydraulic conductivity (K) and effective volumetric water content (θef). Field tracer experiments and laboratory K and θef determinations were carried out for several representative irrigated lots in the South Ukraine. The dependence of θef on capillary tension was studied for the first time. For loess loam with a capillary tension decreasing from 46 kPa to 0, θef nonlinearly increases from 12% to 27-28%. The effective water content portion (β1) of the total water content increases nonlinearly from 0.38 to 0.65-0.7. The β1 values were estimated for different unsaturated sedimentary rocks. For a capillary tension of about 5 kPa β1 values were: 0.88-0.99 for sands, about 0.65 for loess loam and chestnut soil, about 0.6 for sandy loam, about 0.32 for limestone and about 0.07 for clay. Calculated chloride travel rates in loess loams under irrigated soils fit the values of 0.001-0.003 m/day, determined by the results of field tracer experiments.

Soil Persistence of Dinitramine

Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 650-654 ◽  
Author(s):  
J. A. Poku ◽  
R. L. Zimdahl
Keyword(s):  
Mathematical Model ◽  
Soil Moisture ◽  
Field Data ◽  
Soil Moisture Content ◽  
Sandy Loam ◽  
Clay Loam ◽  
First Order ◽  
Soil Persistence ◽  
Herbicide Concentration ◽  
Increasing Temperature

The effects of soil temperature, moisture, and herbicide concentration on the rate of degradation of dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine) were measured in clay loam and sandy loam in the laboratory. In sandy loam, the rate of degradation increased with increasing temperature. In clay loam, the rate of degradation increased from 10 to 30 C and decreased at 40 C. Soil moisture content influenced the rate of degradation in the following order: 22>11>>2.2% (air-dry) for clay loam and 12.0 = 6.0>>0.5% (air-dry) for sandy loam. First-order half-lives ranged from 3.2 at 30 C to 47 weeks at 10 C in clay loam, and 2.3 at 40 C to 31 weeks at 10 C in sandy loam. Applications in 2 yr did not cause buildup of dinitramine in the field. A mathematical model was used in an attempt to correlate laboratory and field data.

scholarly journals Effect of Ploughing Depth, Tractor Forward Speed, and Plough Types on the Fuel Consumption and Tractor Performance

2019 ◽  
Vol 9 (1) ◽  
pp. 43-49
Author(s):  
Kareem Ibrahim kareem ◽  
P. Sven
Keyword(s):  
Soil Moisture ◽  
Fuel Consumption ◽  
Agricultural Production ◽  
Soil Moisture Content ◽  
Sandy Loam ◽  
Forward Speed ◽  
Power Requirement ◽  
Primary Tillage ◽  
Loam Soil ◽  
Ploughing Depth

Cost of fuel has a significant impact on the input costs of agricultural production, especially during primary tillage. It is affected by several parameters including tractor forward speed, depths of ploughing, and plough types. The experiment was performed in a Soil Hall at Harper Adams University, United Kingdom, in April 2015. A Massey Ferguson 8480 4WD tractor was used for investigating objectives of this study. The experiment was performed in a sandy loam soil texture at 11.73% soil moisture content and 1.35 (g/cm3) dry bulk density to study the amount of fuel consumption (l/ha) and the performance of tractor with effect of moldboard and disc ploughs as ploughs type, 15 and 20 cm as ploughing depth and 5 and 7 km/h as tractor forward speeds. The results showed that fuel consumption with a disc plough 5% was higher compared to the moldboard. Fuel consumption decreased approximately 8% when tractor at 7 km/h. Fuel consumption significantly decreased about 34% when ploughing depth increased from 15 to 20 cm. The power requirement to operate moldboard plough was higher by about 14% than a disc. The power requirement at speeds of 7 km/h was higher compared to the speeds of 5 km/h by about 27%. When the depth of ploughing increased from 15 to 20 cm, the power requirement increased by about 1.5%.

scholarly journals Sensitivity of Near-Surface Temperature Forecasts to Soil Properties over a Sparsely Vegetated Dryland Region

2014 ◽  
Vol 53 (8) ◽  
pp. 1976-1995 ◽  
Author(s):  
Jeffrey D. Massey ◽  
W. James Steenburgh ◽  
Sebastian W. Hoch ◽  
Jason C. Knievel
Keyword(s):  
Thermal Conductivity ◽  
Soil Moisture ◽  
Sandy Loam ◽  
Early Morning ◽  
Surface Model ◽  
Silt Loam ◽  
Soil Thermal Conductivity ◽  
Near Surface ◽  
Ground Heat Flux ◽  
Loam Soil

AbstractWeather Research and Forecasting Model forecasts over the Great Salt Lake Desert erroneously underpredict nocturnal cooling over the sparsely vegetated silt loam soil area of Dugway Proving Ground in northern Utah, with a mean positive bias error in temperature at 2 m AGL of 3.4°C in the early morning [1200 UTC (0500 LST)]. Positive early-morning bias errors also exist in nearby sandy loam soil areas. These biases are related to the improper initialization of soil moisture and parameterization of soil thermal conductivity in silt loam and sandy loam soils. Forecasts of 2-m temperature can be improved by initializing with observed soil moisture and by replacing Johansen's 1975 parameterization of soil thermal conductivity in the Noah land surface model with that proposed by McCumber and Pielke in 1981 for silt loam and sandy loam soils. Case studies illustrate that this change can dramatically reduce nighttime warm biases in 2-m temperature over silt loam and sandy loam soils, with the greatest improvement during periods of low soil moisture. Predicted ground heat flux, soil thermal conductivity, near-surface radiative fluxes, and low-level thermal profiles also more closely match observations. Similar results are anticipated in other dryland regions with analogous soil types, sparse vegetation, and low soil moisture.

Phosphorus sorption and nitrogen transformation in two soils treated with piggery wastewater

Soil Research ◽  
2002 ◽  
Vol 40 (2) ◽  
pp. 335 ◽  
Author(s):  
I. R. Phillips
Keyword(s):  
Cation Exchange ◽  
Root Zone ◽  
Sandy Loam ◽  
Sorption Kinetics ◽  
Land Application ◽  
Piggery Wastewater ◽  
Wastewater Disposal ◽  
P Sorption ◽  
High Affinity ◽  
Irrigated Soils

Land application of piggery wastewater has the potential to contaminate receiving water bodies due to the presence of elevated concentrations of nitrogen (N) and phosphorus (P). This paper investigates P sorption and N transformation using soil from 2 wastewater disposal sites in south-east Queensland. Soil from Site 1 was classified as a clay (Vertosol) and soil from Site 2 was classified as a sandy loam (Sodosol). Soil was collected from wastewater disposal (irrigated) and non-disposal (non-irrigated) areas of each site. Nutrient sorption kinetics and transformation were studied by reacting each soil with either wastewater or an inorganic salt solution over a period of 21 days. Solution P concentrations decreased with time for all soils. These changes were greatest during the early stage of the study (<10 days), after which time solution P concentrations remained relatively stable. Concentrations of solution P tended to remain higher in irrigated than non-irrigated soils. This was attributed to a loss of high-affinity sorption sites due to past wastewater additions. Cation exchange (for times <3 days) and nitrification (for times >3 days) were found to be the primary mechanisms responsible for decreases in solution ammonium (NH4-N) over the 21-day period. Phosphorus and NH4-N sorption isotherms were determined using a leaching procedure, and the data were adequately described (r2 >0.95) by the Freundlich equation. Irrigated samples generally sorbed less P than non-irrigated soils. This was attributed to the loss of high-affinity P sorption sites due to previous wastewater additions. Cation exchange and competition between added and resident cations for the exchange sites was found to govern NH4-N sorption by these soils. Results from this study suggest that long-term land application of piggery wastewater may encourage leaching of N and P from the plant root-zone in soils with limited capacity to retain these nutrients. Appropriate management strategies to minimise these losses need to be developed to avoid degradation of the receiving soil and/or water environments. sorption kinetics, nitrification, ammonium, nitrate.

An empirical model for drainage from soil under rain fed conditions

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 205 ◽  
Author(s):  
AR Aston ◽  
FX Dunin
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Empirical Model ◽  
Sandy Loam ◽  
Empirical Relationship ◽  
Field Conditions ◽  
Natural Field ◽  
Moisture Contents ◽  
Weighing Lysimeter

An empirical relationship was derived for drainage from a podzolic sandy loam using a weighing lysimeter at Krawarree, N.S.W. The form of the equation was similar to those used to describe drainage following irrigation. The agreement between computed and measured soil moisture contents over a period of five years was good, and indicated the usefulness of such an approach to characterize drainage of soil water under natural field conditions.

Soil water drying and recharge rates as affected by tillage under continuous barley and barley-canola cropping systems in northwestern Canada

2001 ◽  
Vol 81 (1) ◽  
pp. 45-52 ◽  
Author(s):  
R H Azooz ◽  
M A Arshad
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Sandy Loam ◽  
Time Domain Reflectometry ◽  
Sandy Loam Soil ◽  
Soil Conditions ◽  
Silt Loam ◽  
Silt Loam Soil ◽  
Loam Soil ◽  
The Impact

In areas of the northwestern Canadian Prairies, barley and canola are grown in a short growing season with high rainfall variability. Excessively dry soil in conventional tillage (CT) in dry periods and excessively wet soil in no-tillage (NT) in wet periods could cause a significant decrease in crop production by influencing the availability of soil water. The effects of CT, NT and NT with a 7.5-cm residue-free strip on the planting rows (NTR) on soil water drying (–dW/dt) and recharge (dW/dt) rates were studied in 1992 and 1993 during wet and dry periods to evaluate the impact of NTR, NT and CT systems on soil moisture condition. The soils, Donnelly silt loam and Donnelly sandy loam (both Gray Luvisol) were selected and soil water content by depth was measured by time domain reflectometry. Water retained at 6 matric potentials from –5 to –160 kPa were observed. In the field study, –dW/dt was significantly greater in CT than in NT in the silt loam for the 0- to 30-cm layer during the first 34 d after planting in 1992. The 0- to 30-cm soil layer in CT and NTR dried faster than in NT during a period immediately following heavy rainfall in the silt loam in 1993. The drying coefficient (–Kd ) was significantly greater in CT and NTR than in NT in the silt loam soil in 1993 and in the sandy loam soil in 1992 in the top 30-cm depth. The recharge coefficient (Kr) was significantly greater in NT and NTR than in CT for the silt loam soil. The NTR system increased the –dW/dt by 1.2 × 10-2 to 12.1 × 10-2 cm d-1 in 1992 and 1993 in the silt loam soil and by 10.2 × 10-2 cm d-1 in 1993 in the sandy loam soil as compared with NT. The dW/dt was 8.1 × 10-2 cm d-1 greater in NTR in 1992 and 1993 in the silt loam soil and was 1.9 × 10-2 greater in NTR in 1992 than in CT in the sandy loam soil. The laboratory study indicated that NT soils retained more water than the CT soils. The NTR practice maintained better soil moisture conditions for crop growth than CT in dry periods than NT in wet periods. Compared with NT, the NTR avoided prolonged near-saturated soil conditions with increased soil drying rate under extremely wet soil. Key words: Water drying, water recharge, water depletion, wet and drying periods, hydraulic properties, soil capacity to retain water

The effects of soil compaction, soil moisture and soil type on growth and nodulation of soybean and common bean

1998 ◽  
Vol 78 (4) ◽  
pp. 571-576 ◽  
Author(s):  
B. R. Buttery ◽  
C. S. Tan ◽  
C. F. Drury ◽  
S. J. Park ◽  
R. J. Armstrong ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Adverse Effects ◽  
Plant Growth ◽  
Water Supply ◽  
Common Bean ◽  
Soil Type ◽  
Soil Compaction ◽  
Sandy Loam ◽  
Clay Loam ◽  
Reduced Water

In field tests we have observed year-to-year differences in the severity of the effects of soil compaction on nodulation and growth of common bean; these differences appeared to be related to the amount of rainfall during the growing season. We decided to use better controlled conditions in the greenhouse, and extend the scope of the study to another legume crop and a different soil type, in order to investigate the hypothesis that copious water supply alleviates the adverse effects of soil compaction on nodulation and plant growth.The effects of two levels of soil compaction and of high and low water supply on the growth and nodulation of common bean and soybean were investigated in separate pot tests using a Fox sandy loam and a Brookston clay loam soil.Root growth of both species was severely restricted by dry compacted conditions. Plant growth as a whole was clearly reduced by both increased compaction and by reduced water supply, presumably mediated by the effects on root growth. The effect of reduced water supply was more severe in the highly compacted pots, and more severe in the clay loam than in the sandy loam.In the sandy loam, low moisture reduced nodule numbers and weights in both species, while increased bulk density reduced the numbers of nodules but not the dry weights. In the clay loam, nodule weights and numbers were very low, presumably, owing to high levels of nitrate, which may have resulted from mineralization of soil organic matter during storage.A generous supply of water obviously alleviated some of the adverse effects of soil compaction on plant growth. This is in general agreement with results of earlier field trials, where severity of the effects of soil compaction varied with the quantity of rainfall. Key words: Soybean, common bean, soil compaction, soil moisture, nodulation, bulk density

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