Mapping available soil water capacity in New South Wales, Australia using sparse data - An inverse Bayesian approach

2021 ◽  
pp. e00396
Author(s):  
P.D.S.N. Somarathna ◽  
Ross Searle ◽  
Daniel W. Gladish
Keyword(s):  
Soil Water ◽  
Bayesian Approach ◽  
New South ◽  
New South Wales ◽  
Sparse Data ◽  
Water Capacity ◽  
South Wales

Effect of gypsum on vertisols of the Gwydir Valley, New South Wales. 1. Soil properties and wheat growth

1989 ◽  
Vol 29 (1) ◽  
pp. 51 ◽  
Author(s):  
DC McKenzie ◽  
HB So
Keyword(s):  
Soil Properties ◽  
Soil Water ◽  
New South ◽  
New South Wales ◽  
Nitrogen Deficiency ◽  
Crop Productivity ◽  
Plant Response ◽  
Crown Rot ◽  
Soil Water Storage ◽  
South Wales

The effect of gypsum on the properties and crop productivity of 6 contrasting vertisols of the Gwydir Valley, New South Wales was investigated in 1978 and 1979. These soils are often used for dryland wheat production, although crop growth is generally restricted by their structural instability. In 2 of the soils used in our study, the surface aggregates were sodic and dispersive (poor soils), 2 were relatively stable when wetted (good soils), whilst the other 2 soils had surface aggregates that were intermediate in behaviour (intermediate soils). The effects of added gypsum at 4 rates (0, 2.5, 5.0 and 7.5 t ha-1) on soil water profiles, soil properties and the growth of wheat were monitored over a 2 year period. Dryland wheat grain yields were increased by as much as 230% following the application of gypsum. Benefits were most pronounced on clays with sodic topsoils, a high water-holding capacity and adequate nutrition; plant response to gypsum on nearby soils with non-dispersive surfaces was less pronounced. Yield increases were associated with better seedling establishment, greater tiller production, increased grain weight, and lower incidence of 'Crown Rot' disease. Plant response to gypsum was related to improved water penetration into the soil, allowing greater storage of water in the subsoil, rather than loss via evaporation and possibly runoff. Increases as high as 137% in the soil water storage to a depth of 1.2 m were observed. Crop performance was also strongly influenced by rainfall, time of sowing and weed control. Where nitrogen and, to a lesser extent, phosphorus, were deficient in gypsum-treated soil, they had to be added before the extra soil water could be utilised effectively by wheat. On the lighter textured clays, gypsum appeared to aggravate nitrogen deficiency, apparently because of enhanced leaching.

Effects of continuous and seasonal grazing strategies on the herbage mass, persistence, animal productivity and soil water content of a Sirosa phalaris - subterranean clover pasture, North-West Slopes, New South Wales

2003 ◽  
Vol 43 (6) ◽  
pp. 539 ◽  
Author(s):  
G. M. Lodge ◽  
S. R. Murphy ◽  
S. Harden
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Animal Production ◽  
North West ◽  
South Wales ◽  
Continuous Grazing

An experimental site was established in 1997 on the North-West Slopes of New South Wales to further investigate the use of strategic grazing management to improve the persistence of phalaris (Phalaris aquatica cv.�Sirosa) and subsequent effects on animal production and soil water content. The pasture was sown in 1992 to Sirosa phalaris, subterranean clover (Trifolium subterraneum var. subterraneum cv. Seaton Park) and lucerne (Medicago sativa cv. Aurora). Four grazing treatments were applied in a randomised 3-replicate design. Treatments consisted of continuous grazing at 12.3 sheep/ha (C12 or control); continuous grazing at 6 sheep/ha (C6), and 2� spring and autumn strategies of either resting from grazing for 6 weeks in each season (SAR0), or reducing stocking rate from 12.3 to 4.0 sheep/ha (SAR4). Despite annual applications of fertiliser and high clover content, Sirosa phalaris herbage mass in plots continuously grazed at 12.3 sheep/ha declined from a mean of 3300 kg DM/ha in spring 1997 to < 700 kg DM/ha by May 1998. At the end of the study (February 2001), Sirosa mean herbage mass in these plots was 670 kg DM/ha and lower (P < 0.05) than for the other treatments (mean value 5400 kg DM/ha). These marked changes in herbage mass, and the degradation of the Sirosa-based pasture to an annual pasture by continuous grazing at 12.3 sheep/ha, were not generally reflected in either short-term animal production or substantial differences in soil water content. Wool production (kg/head) was not significantly different among treatments each year. Compared with continuous grazing at 12.3 sheep/ha, sheep liveweights were higher (P < 0.05) in plots continuously grazed at 6.1 sheep/ha from November 1997 to February 1999. However, from February 1999 to 2001, sheep liveweights in the 2 treatments with the highest Sirosa phalaris content were lower (P < 0.05) than those continuously grazed at 12.3 sheep/ha. Only the soil water content for the C6 and SAR4 treatments at 0–30�cm was significantly different to the control treatment, but the differences were predicted to be < 2.5 mm/year. In the root zone (0–90 cm), mean soil water content ranged from 159 to 309 mm (mean 220 mm), while plant available water (soil water content – soil water content at –1500 kPa) was a mean of 79 mm, ranging from 11 to 168 mm.

Sustainable grazing systems for the Central Tablelands of New South Wales. 4. Soil water dynamics and runoff events for differently-managed pasture types

2006 ◽  
Vol 46 (4) ◽  
pp. 483 ◽  
Author(s):  
J. D. Hughes ◽  
I. J. Packer ◽  
D. L. Michalk ◽  
P. M. Dowling ◽  
W. McG. King ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Soil Water ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Environmental Data ◽  
Quality Data ◽  
Water Runoff ◽  
South Wales ◽  
Management Factors

Soil water, runoff amount and quality, pasture production and environmental data were measured for a pastoral prime lamb enterprise in the Central Tablelands of New South Wales from 1998 to 2002. There were 4 pasture treatments: fertilised and sown chicory (CH), fertilised and sown introduced pastures (SP), fertilised naturalised pastures (FN) and unfertilised naturalised pastures (UN). Two grazing management regimes, tactically grazed (TG) and continuously grazed (CG) were imposed on the SP, FN and UN treatments. The CH treatment was rotationally grazed. To compare pasture and grazing system water use, maximum soil water deficit values (SWDMax) were calculated from neutron moisture meter data. SWDMax was influenced by both environmental and management factors. Management factors that influenced SWDMax were herbage mass of perennials, degree of perenniality, and the perennial species present. Environmental factors accounted for >50% of the variation in SWDMax. Inclusion of management factors (perennial herbage mass of C3 and C4 species and percentage perennial herbage mass), accounted for an additional 16% of variation. While the influence of pasture management appears to be relatively small, importantly, management is the only avenue available to land managers for influencing SWDMax. The UNTG and all sown treatments, with greater perennial herbage mass or greater C4 herbage mass consistently produced the highest SWDMax. Runoff amount and quality data are presented for ground cover percentages which generally exceeded 80% for the experimental period. Runoff as a proportion of rain received during the experiment was <3%. Environmental factors explained 47% of variation in runoff, while pasture herbage mass and ground cover percentage explained an additional 2% of variation. Water quality was monitored on 3 treatments (SPTG, FNTG and UNCG) for total nitrogen (N), total phosphorus (P) and total suspended solids (TST) over a 6-month period. The mean values for total N and P were below the acceptable contaminant concentration for agricultural irrigation water. An important outcome of this research is the concept of a practical Targeted Water Management Plan (TWMP) which devises a framework for optimum water usage and productivity at a landscape scale.

Effect of gypsum on vertisols of the Gwydir Valley, New South Wales. 2. Ease of tillage

1989 ◽  
Vol 29 (1) ◽  
pp. 63 ◽  
Author(s):  
DC McKenzie ◽  
HB So
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Fuel Consumption ◽  
New South ◽  
New South Wales ◽  
Soil Strength ◽  
South Wales

An experiment was carried out to deter- mine the effect of applied gypsum on the ease of tillage in 3 vertisols of the Gwydir Valley, New South Wales. The soils were classified as 'poor' and 'good' on the basis of past dryland wheat yields and structural of their surface aggregates.Where gypsum had been applied 22 months earlier at a rate of 7.5 t ha-1, tractor fuel consumption per centimetre of soil tilled was reduced by as much as 37% (0.85 v. 0.54 L ha-1 cm-1). The effect was most marked on the more sodic clays. The reduction in fuel consumption due to gypsum was associated with instability creased soil water content (0.127 v. 0.224 kg kg-1) and lower soil strength (330 v. 140 kPa).

Forecasting wheat yields using a water budgeting model

1989 ◽  
Vol 40 (4) ◽  
pp. 715 ◽  
Author(s):  
I Cordery ◽  
AG Graham
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
Meteorological Data ◽  
New South Wales ◽  
Balance Model ◽  
Soil Layers ◽  
South Wales

A model has been developed to forecast soil water variations and wheat crop growth in dry land situations. The forecast of the yield to be expected if sowing occurred today is obtained by running the calibrated model for all years for which meteorological data are available. The soil water content on today's date in each year is fixed at today's observed soil water value. From each year of observed meteorological data, an estimate is made of the yield. These yield data allow construction of a frequency distribution of yield which can be used to make a probabilistic forecast. The model involves two sub-models, a water balance model and acrop development model. The two sub-models interact to provide 5-day estimates of soil water content, actual evaporation and transpiration, runoff and increments to biomass and grain yield. The water balance model takes inputs of daily rainfall and estimated potential evapotranspiration. Available energy is partitioned between evaporation and transpiration depending on leaf area index. There are two soil layers plus a surface interception and depression store. Water removal from the soil layers is dependent on root development and the location of available water. Biomass production is driven by actual transpiration and transpiration efficiency and so biomass and grain development are dependent on the timing and amount of water and energy utilization by the crop. The model was first calibrated in northern New South Wales with 13 years of research station data. With minor recalibration, it provided good estimates of observed district wheat harvests for a continuous period of 75 years. Further recalibration with 30 years of shire data from Queensland, 29 years of single farm data in southern New South Wales and with 31 years of county data from northwestern USA., indicated the model is able to accurately reproduce observed yields and has the potential to provide reliable forecasts of yield, in a range of different climates.

A comparison of irrigated maize growth in southern New South Wales on sites with and without a preceding fallow

1983 ◽  
Vol 23 (120) ◽  
pp. 58
Author(s):  
WK Mason ◽  
WS Meyer ◽  
HD Barrs ◽  
RCG Smith
Keyword(s):  
Soil Water ◽  
Root Length Density ◽  
New South ◽  
New South Wales ◽  
Neutron Probe ◽  
South Wales ◽  
Management Procedures ◽  
Initial Hypothesis ◽  
Soil Water Extraction ◽  
Water Potential Measurements

This experiment was carried out on a grey cracking clay soil near Griffith in southern New South Wales. Maize grown after a two year fallow produced 2.7 t/ha or 45% more grain than maize grown on a continuously cropped site. This difference occurred despite large fertilizer inputs and similar management procedures. The yield differences resulted from increased plant establishment (20%),kernel numbers per cob (26%), and kernel size (11%) in the fallow area. However, experimental results were mostly inconsistent with our initial hypothesis that restricted root growth and soil water uptake were limiting yields on continuously cropped sites. Water use was measured throughout the season with a neutron probe, but no differences in depth or amount of soil water extraction were detected. Root length density and leaf water potential measurements indicated that plant water relations were similar for the two sites and so this did not seem to account for the improved yield from the fallowed site.

Evaluation of strategies for increasing irrigation water productivity of maize in southern New South Wales using the MaizeMan model

2008 ◽  
Vol 48 (3) ◽  
pp. 304 ◽  
Author(s):  
E. Humphreys ◽  
R. J. G. White ◽  
D. J. Smith ◽  
D. C. Godwin
Keyword(s):  
Soil Water ◽  
Real Time ◽  
Irrigation Water ◽  
New South ◽  
Water Productivity ◽  
New South Wales ◽  
Irrigation Scheduling ◽  
Weather Data ◽  
South Wales ◽  
Irrigation Water Productivity

MaizeMan is Windows-based decision support software, derived from CERES Maize and SWAGMAN Destiny, which can be used for real-time irrigation scheduling or strategic analysis. Evaluation of MaizeMan for sprinkler and furrow-irrigated maize (Pioneer 3153) showed good predictive ability for yield, biomass, runoff and soil water depletion between sowing and harvest. MaizeMan simulations using 43 years of weather data from Griffith, New South Wales, suggested that the biggest influence on yield, irrigation requirement and irrigation water productivity is seasonal weather conditions. For example, yield of October-sown 3153 irrigated frequently to avoid soil water deficit varied from about 8 to 16 t/ha, while net irrigation and net irrigation water productivity varied from 7 to 11 ML/ha and 0.8 to 1.6 t/ML, respectively. The optimum sowing window for maximising yield and irrigation water productivity is wide, from late September to mid November. Delaying sowing beyond this may result in higher yield and irrigation water productivity; however, delayed maturity would lead to problems for grain drying and harvesting in winter and increased insect pressure. The simplest management strategy for maximising yield and irrigation water productivity is irrigation scheduling tailored to soil type. Irrigation scheduling can be assisted by real-time scheduling using MaizeMan, provided soil hydraulic properties are accurately characterised. One to two irrigations can also be saved by growing shorter duration hybrids, but the tradeoff is lower yield, while irrigation water productivity is maintained. Simulated sprinkler irrigation increased yield and net irrigation water productivity by small amounts (averages of 0.5 t/ha and 0.2 t/ML, respectively) relative to well-scheduled flood irrigation, through improved soil water and aeration status and reduced deep drainage loss.

Agricultural drought analyses for temperate Australia using a biophysical pasture model. 1. Identifying and characterising drought periods

2008 ◽  
Vol 59 (11) ◽  
pp. 1049 ◽  
Author(s):  
G. M. Lodge ◽  
I. R. Johnson
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
New South Wales ◽  
Agricultural Drought ◽  
Wagga Wagga ◽  
Winter Rainfall ◽  
Seasonal Drought ◽  
South Wales

The SGS Pasture Model was used to estimate daily total soil water content (mm) for the period 1998–2001 (using experimental data) and from July 1905 to June 2005 (using a 100-year daily climate file). For both model simulations, the correlation coefficient for actual and predicted data was >0.86. Four sites were examined, three in the winter-rainfall zone (Albany, Western Australia; Hamilton, Victoria; and Wagga Wagga, New South Wales) and one in the predominantly summer-rainfall zone (Barraba, New South Wales) of temperate Australia. Trends were detected in long-term rainfall data for lower mean annual rainfall at the Albany site since the mid 1950s and at the Hamilton site since the mid 1970s. Analyses of days in which herbage accumulation was likely to be limited only by water allowed a minimum soil water content to be defined; below this value, soil water was in deficit. A drought period was defined as occurring after >50 consecutive days of predicted soil water deficit. For the four sites, six categories of drought duration were described, ranging from >50–120 days (seasonal drought) to >364 days (exceptional drought). Numbers of predicted droughts were 90, 90, 65, and 60, respectively, at Albany, Hamilton, Wagga Wagga, and Barraba sites. At the three winter-rainfall sites, most predicted droughts occurred in a regular pattern and were an extension of a seasonal drought, but at the Barraba site they were of a longer duration and irregular in occurrence.

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