Potential deep drainage under wheat crops in a Mediterranean climate. I. Temporal and spatial variability

2001 ◽  
Vol 52 (1) ◽  
pp. 45 ◽  
Author(s):  
S. Asseng ◽  
I. R. P. Fillery ◽  
F. X. Dunin ◽  
B. A. Keating ◽  
H. Meinke
Keyword(s):  
Soil Water ◽  
Water Loss ◽  
Soil Type ◽  
Mediterranean Climate ◽  
Clay Soil ◽  
Soil Types ◽  
Deep Drainage ◽  
Average Rainfall ◽  
High Degree ◽  
Rainfall Region

High rates of deep drainage (water loss below the root-zone) in Western Australia are contributing to groundwater recharge and secondary salinity. However, quantifying potential drainage through measurements is hampered by the high degree of complexity of these systems as a result of diverse soil types, a range of crops, different rainfall regions, and in particular the inherent season-to-season variability. Simulation models can provide the appropriate means to extrapolate across time and space. The Agricultural Production Systems Simulator (APSIM) was used to analyse deep drainage under wheat crops in the Mediterranean climate of the central Western Australian wheatbelt. In addition to rigorous model testing elsewhere, comparisons between simulated and observed soil water loss, evapotranspiration, and deep drainage for different soil types and seasons confirmed the reasonable performance of the APSIM model. The APSIM model was run with historical weather records (70–90 years) across 2 transects from the coast (high rainfall zone) to the eastern edge of the wheatbelt (low rainfall zone). Soils were classified as 5 major types: deep sand, deep loamy sand, acid loamy sand, shallow duplex (waterlogging), and clay soil (non-waterlogging). Simulations were carried out on these soil types with historical weather records, assuming current crop management and cultivars. Soil water profiles were reset each year to the lower limit of plant-available water, assuming maximum water use in the previous crop. Results stressed the high degree of seasonal variability of deep drainage ranging from 0 to 386 mm at Moora in the high rainfall region (461 mm/year average rainfall), from 0 to 296 mm at Wongan Hills in the medium rainfall region (386 mm/year average rainfall), and from 0 to 234 mm at Merredin in the low rainfall region (310 mm/year average rainfall). The largest amounts of drainage occurred in soils with lowest extractable water-holding capacities. Estimates of annual drainage varied with soil type and location. For example, average (s.d.) annual drainage at Moora, Wongan Hills, and Merredin was 134 (73), 90 (61), and 36 (43) mm on a sand, and 57 (64), 26 (43), and 4 (18) mm on a clay soil, respectively. These values are an order of magnitude higher than drainage reported elsewhere under native vegetation. When not resetting the soil each year, carry-over of water left behind in the soil reduced the water storage capacity in the subsequent year, increasing long-term average deep drainage, depending on soil type and rainfall region. The analyses revealed the extent of the excess water problem that currently threatens the sustainability of the wheat-based farming systems in Western Australia.

scholarly journals Evaluation of cotton stalks destroyers

2013 ◽  
Vol 33 (5) ◽  
pp. 965-975 ◽  
Author(s):  
Aloisio Bianchini ◽  
Pedro H. de M. Borges
Keyword(s):  
Soil Type ◽  
Energy Demand ◽  
Crop Residues ◽  
Clay Soil ◽  
Field Capacity ◽  
Soil Types ◽  
Mechanical Destruction ◽  
Cotton Crop ◽  
Cotton Stalks ◽  
Medium Texture

The destruction of the cotton crop residues (cotton stalks) is a mandatory procedure in Brazil for prophylactic issues, but is a subject unexplored by the research and there are few studies that deal with this issue. However, this is not encouraged in recent decades, studies aimed at developing and evaluating equipment for this purpose. The present study had the objective to evaluate six methods for mechanical destruction of cotton crop residues. Each method was defined based on the principle of operation of the active parts of the equipment, which were tested in medium texture soil and in a clayey one. The variables used to evaluate the efficiency of the equipment were the regrowth rate, the theoretical field capacity and energy demand. The equipment with convergent concave disks (DCC) and flat cutters discs from manufacturer A (CPS-a) showed the best results in cotton stalks destruction in both soil types. The harrow disc (GPD) was efficient only in clay soil. It was concluded that the equipment with convergent concave disks, among those tested, was the most efficient to destroy cotton stalks, regardless of soil type, and that the harrow disc was not included among the best performers.

scholarly journals Water Loss of Nerium oleander Planted in Two Soil types Under Two Irrigation Regimes

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 838E-838
Author(s):  
N.K. Lownds ◽  
W.A. Mackay
Keyword(s):  
Water Loss ◽  
Soil Type ◽  
Soil Types ◽  
Nerium Oleander ◽  
Plant Water ◽  
Clay Loam ◽  
Irrigation Frequency ◽  
Irrigation Rate ◽  
Landscape Plants ◽  
Plant Water Use

Water loss of Nerium oleander growing in two soil types was determined from mid-June through mid-October. Plants (1 year old, 3.8 liter) were obtained from a local nursery and transplanted in May into 18.9-liter Iysimeter pots containing either clay loam or bluepoint sand. Controls were lysimeter pots containing each soil type but without plants. Irrigation was applied at two rates, approximately field (pot) capacity and 50% of that amount. Irrigation frequency was determined by visual inspection of the plants and was held constant for both irrigation rates in a given soil type. Frequency ranged from 2 to 3 days for the sand and 2 to 5 days for the clay loam. Water loss was determined every 24 h. Plant water loss was higher at the higher irrigation rate. Decreasing irrigation rate by 50% resulted in a 20% to 40% reduction in plant water use in clay loam and a 15% to 30% reduction in sand without affecting plant quality. Plant water loss in the sandy soil was ≈50% greater than in clay loam 48 h after irrigation. Implications of these findings in developing an optimum irrigation model for landscape plants will be considered.

Reliability of canola production in different rainfall zones of Western Australia

2007 ◽  
Vol 58 (4) ◽  
pp. 326 ◽  
Author(s):  
Imma Farré ◽  
Michael Robertson ◽  
Senthold Asseng
Keyword(s):  
Soil Water ◽  
Western Australia ◽  
Soil Type ◽  
Oil Content ◽  
Sowing Date ◽  
Soil Types ◽  
Minor Effect ◽  
High Rainfall ◽  
History Of

The area of canola in the wheat-based farming systems of the wheatbelt of Western Australia (WA) expanded rapidly during the 1990s and has subsequently decreased. Due to the short history of canola production in WA, there is little information on yield and oil content expectations in relation to rainfall, location, and soil type. In this paper we: (1) present the recent history of canola production in the context of the long-term climate record; (2) assess the effect of location, rainfall, soil type, and soil water at sowing on yield and oil content; and (3) determine cut-off sowing dates for profitable canola production. Simulations were run using the APSIM-Canola model with long-term climate records for 3 selected locations from the low-, medium-, and high-rainfall zones and different soil types. Analysis of recent trends in canola area showed that poor seasons and price volatility in the last few years have contributed to farmers’ perception of risk and hence the decline in area sown. Long-term simulations showed the importance of location, sowing date, soil type, and stored soil water at sowing on grain yield. Yield was negatively related to sowing date. Light-textured soils had lower yields and larger yield penalties with delayed sowing than heavy-textured soils. Soil water at sowing gave a yield advantage in most years in all locations studied, but especially in low- and medium-rainfall locations. Variation in oil content was most strongly affected by sowing date and location, while soil type and soil water at sowing had a minor effect. Long-term simulation analysis can be used as a tool to establish the latest possible sowing date to achieve profitable canola for different locations and soil types, given different canola prices and growing costs. Given the vulnerability of profitability to seasonal conditions, in the low- and medium-rainfall zone, the decision to grow canola should be tactical depending on stored soil water, sowing opportunities, seasonal climate outlook, prices, and costs. In contrast, in the high-rainfall zone, canola production is relatively low risk, and could become a reliable component of rotations.

Seed production of Trifolium subterraneum subsp. brachycalycinum as influenced by soil type and grazing

1987 ◽  
Vol 27 (4) ◽  
pp. 539 ◽  
Author(s):  
MDA Bolland
Keyword(s):  
Soil Water ◽  
Seed Production ◽  
Seed Yield ◽  
Soil Type ◽  
Trifolium Subterraneum ◽  
Soil Types ◽  
Pasture Legumes ◽  
Annual Medics

Twenty-six strains of Trifolium subterraneum subsp. brachycalycinum were assessed as potential pasture legumes on the 2 major soil types (neutral-slightly acid sandy [sandplain] soils and alkaline mallee soils) near Esperance, W.A. The pH (1 : 5, soil: water, w/v) of the top 10 cm of the sandplain soil was 6.3, and of the mallee soil, 8.2. In ungrazed swards on both soil types, subsp. brachycalycinum buried very few burrs but successfully produced seed in the unburied burrs in the dark, dense canopy of leaves. However, when the swards were grazed up to the start of flowering of the earliest flowering strains, subsp. brachycalycinum produced few burrs and little seed (0-47 kg/ha). By contrast, on the sandplain soils, subsp. subterraneum buried most of its burrs and produced much seed in both ungrazed (390-1050 kg/ha) and grazed (403-987 kg/ha) swards, whereas on the alkaline mallee soils, annual medics (Medicago spp.) produced much seed in unburied burrs in both grazed (506- 1050 kg/ha) and ungrazed (480-730 kg/ha) swards. Grazing may have exposed the developing unburied burrs of subsp. brachycalycinum to light, which is known to inhibit the development of burrs and seed. There was no relationship between seed yield and maturity for strains of subsp. brachycalycinum in ungrazed swards on both soils.

Changes in soil water content under annual- and perennial-based pasture systems in the wheatbelt of southern New South Wales

2006 ◽  
Vol 57 (3) ◽  
pp. 321 ◽  
Author(s):  
G. A. Sandral ◽  
B. S. Dear ◽  
J. M. Virgona ◽  
A. D. Swan ◽  
B. A. Orchard
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Profile ◽  
Subterranean Clover ◽  
Perennial Grasses ◽  
Deep Drainage ◽  
Annual Average ◽  
Eastern Australia ◽  
Average Rainfall

Nine pasture treatments differing in species composition were monitored for changes in soil water content at a depth of 0.10–1.70 m, at 2 sites (Kamarah and Junee), in the wheatbelt of eastern Australia. Treatments containing perennial species, viz. lucerne (Medicago sativa L.), phalaris (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), mixture (lucerne + phalaris + cocksfoot), wallaby grass (Austrodanthonia richardsonii Cashmore.), and lovegrass (Eragrostis curvula (Schrader) Nees.), were sown with subterranean clover (Trifolium subterraneum L.). In addition, 3 treatments based solely on annual species were examined: subterranean clover (sown by itself and kept weed-free with herbicides), annual (sown to subterranean clover but weed invasion not controlled), and serradella (Ornithopus compressus L.). The experiment was conducted from 1994–97 at the Junee site (annual average rainfall 550 mm/year) and from 1995–97 at the Kamarah site (annual average rainfall 450 mm per year). At the higher rainfall site (Junee), there were few differences among pasture types in soil water content to 0.70 m. Below 0.70 m the soil profile was drier under all the perennial swards than under the annual pasture treatments by the end of the 4-year pasture phase. At the drier Kamarah site, where the pasture phase was shorter due to an initial sowing failure, all the perennials, except cocksfoot, dried the profile below 1.05 m. At both sites, lucerne dried the 1.05–1.70 m section of the soil profile more rapidly than the other perennials, which apparently took longer to reach this depth. At the Junee site, the soil water deficit in May (SWD(MAY), defined as field capacity (mm) – stored soil water (mm) at the beginning of May) was largest in the phalaris, mixture, lucerne, and cocksfoot treatments (155–162 mm), whereas as under a pasture of subterranean clover alone, SWD(MAY) was only 89 mm. At the drier Kamarah site, the largest SWD(MAY) was created by the lovegrass (114 mm) and lucerne (107 mm) treatments. The cocksfoot and subterranean clover treatments created the smallest SWD(MAY) at this site, at 79 and 72 mm, respectively. The study showed that currently available C3 and C4 perennial grasses can be as effective as lucerne in drying the soil profile to 1.70 m in the 450–600 mm rainfall areas of the southern NSW wheatbelt, creating a dry soil buffer to reduce the risk of deep drainage during subsequent cropping phases. As the rate at which grasses dried the profile was slower than lucerne, pastures based on perennial grasses may have to be retained longer to achieve the same level of dewatering.

Effect of soil type on burrowing behavior and cocoon formation in the green-striped burrowing frog, Cyclorana alboguttata

2006 ◽  
Vol 84 (6) ◽  
pp. 832-838 ◽  
Author(s):  
D.T. Booth
Keyword(s):  
Water Potential ◽  
Sandy Soil ◽  
Soil Type ◽  
Clay Soil ◽  
Soil Types ◽  
Soil Drying ◽  
Laboratory Conditions ◽  
Water Potentials ◽  
Burrowing Behaviour ◽  
Burrowing Behavior

This study examined the effect of soil type on burrowing behaviour and cocoon formation during aestivation in the green-striped burrowing frog, Cyclorana alboguttata (Günther, 1867). Given a choice, frogs always chose to burrow in wet sand in preference to wet clay. Frogs buried themselves faster and dug deeper burrows in sandy soil. However, under my laboratory conditions, there was little difference in the pattern of soil drying between the two soil types. Frogs in both sand and clay soil experienced hydrating conditions for the first 3 months and dehydrating conditions for the last 3 months of the 6-month aestivation period, and cocoons were not formed until after 3 months of aestivation. After 6 months, there were more layers in the cocoons of frogs aestivating in sand than those aestivating in clay. Frogs were able to absorb water from sandy soil with water potentials greater than –400 kPa, but lost water when placed on sand with a water potential of –1000 kPa.

scholarly journals Longevity of buried ragwort seed in four soils

2000 ◽  
Vol 53 ◽  
pp. 253-257
Author(s):  
T.K. James ◽  
A. Rahman
Keyword(s):  
Sandy Soil ◽  
Soil Type ◽  
Clay Soil ◽  
Soil Types ◽  
Senecio Jacobaea ◽  
Silt Loam ◽  
Viable Seed ◽  
Peat Soils ◽  
Nylon Mesh ◽  
Mesh Bags

The viability of ragwort (Senecio jacobaea L) seed buried for several years at 0 2 4 6 and 19 21 cm depths was evaluated in four different soil types Seed samples in nylon mesh bags were removed after 1 2 3 5 11 and 16 years burial and their viability determined by germination After 16 years no viable seed was found in the clay soil In the silt loam and peat soils 1 3 viable seed remained while in the sandy soil up to 13 remained viable In the surface 0 2 cm layer of soil it took from 109 to 146 years for the percentage of viable seed to fall to 1 of the original viable seed depending on soil type At the 4 6 and 19 21 cm depths the corresponding times were 128 165 years and 130 180 years

North-east Victoria SGS National Experiment site: water and nutrient losses from grazing systems on contrasting soil types and levels of inputs

2003 ◽  
Vol 43 (8) ◽  
pp. 799 ◽  
Author(s):  
A. M. Ridley ◽  
B. P. Christy ◽  
R. E. White ◽  
T. McLean ◽  
R. Green
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Water Loss ◽  
Surface Runoff ◽  
Acid Soil ◽  
Soil Types ◽  
Soil Water Deficit ◽  
Nutrient Losses ◽  
High Input ◽  
North East

Water and nutrient losses, pasture and animal production were measured for a prime lamb enterprise at Maindample (rainfall 750 mm/year) and a wool enterprise at Ruffy (rainfall 671 mm/year) in north-east Victoria from 1998 to 2000. Each site comprised 3 paddock-scale treatments: control, unsown pasture receiving about 5�kg�phosphorus (P)/ha.year; medium input, sown pasture (about 10 kg P/ha.year); and high input, sown pasture (≥22 kg P/ha.year). Sown pastures were based on phalaris (Phalaris aquatica L.) at Maindample and cocksfoot (Dactylis glomerata L.) at Ruffy, and sheep were set stocked. Pastures at Maindample created a larger soil water deficit (commonly about 120 mm) compared with Ruffy (about 70 mm) in summer. Maximum soil water deficit at Maindample occurred under the high input pasture and was about 30 mm greater than the medium or control treatments. Phalaris content ranged between about 200 and 1300 kg DM/ha, between 10 and 70% of total composition (commonly about 20%). In contrast, at Ruffy the control, which had 20–40% native grasses (Austrodanthonia and Microlaena) achieved the greatest soil water deficit, about 25 mm greater than for sown pastures. Cocksfoot persisted poorly at the acid soil at Ruffy. Small differences in green leaf area over summer (about 200 kg DM/ha) between treatments could generate the soil water deficit differences over the summer.The most striking result was the markedly different pathways of water loss between surface losses and deep drainage at the 2 sites, which was of greater consequence than the effect of pasture type. At Maindample, on average, 166 mm of water was lost annually (22% of rainfall) with 110 mm of this as surface runoff. At Ruffy, annual water loss was 128 mm (19% of rainfall) with 110 mm of this total water loss estimated as loss through deep drainage.Phosphorus losses were low in all treatments (≤1 kg P/ha.year), and nitrate-N (NO3-N) losses (7–12 kg N/ha.year) were comparable with previous work. Concentrations of P in water were highest from the high treatments at both sites, averaging 0.91 and 0.83 mg P/L in surface runoff from Maindample high and Ruffy high treatments, respectively. Average soil water NO3-N concentrations ranged from 3 to 26 mg N/L. Both P and N concentrations were higher than acceptable for aquatic health.Environmental risks in terms of water and nutrient losses could be either higher or lower for sown than unsown pastures, depending upon soil type, botanical stability, persistence and the soil water extracting ability of the pasture. Results indicated that better environmental outcomes could be achieved if soil types were targeted for particular land uses. High management skills are needed if grazing enterprises are to be both profitable and have lower off-site impacts.

Influence of soil type and stress state on predicting shear strength of unsaturated soils using the soil-water characteristic curve

2011 ◽  
Vol 48 (12) ◽  
pp. 1886-1900 ◽  
Author(s):  
Wan Soo Kim ◽  
Roy H. Borden
Keyword(s):  
Shear Strength ◽  
Stress State ◽  
Soil Water ◽  
Soil Type ◽  
Unsaturated Soils ◽  
Characteristic Curve ◽  
Soil Types ◽  
Strength Data ◽  
Soil Water Characteristic Curve ◽  
Predicted Values

Comprehensive studies on the prediction of unsaturated shear strength were performed using three commonly used empirical procedures: Fredlund et al. approach (published in 1996), Vanapalli et al. approach (published in 1996), and Khalili and Khabbaz method (published in 1998). Shear strength data published in the literature for 15 soils were examined using these procedures. Comparisons between measured and predicted values of unsaturated shear strength are presented for different soil types. The effect of stress state on the prediction of shear strength is also discussed.

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