Effects of grazing and management on herbage mass, persistence, animal production and soil water content of native pastures. 1. A redgrass - wallaby grass pasture, Barraba, North West Slopes, New South Wales

2003 ◽  
Vol 43 (8) ◽  
pp. 875 ◽  
Author(s):  
G. M. Lodge ◽  
S. R. Murphy ◽  
S. Harden
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
Linear Trend ◽  
Subterranean Clover ◽  
Ground Cover ◽  
Basal Cover ◽  
South Wales ◽  
Continuous Grazing

A study was conducted on a native pasture (dominated by redgrass, Bothriochloa macra) in the Barraba district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. Plots were grazed with Merino wethers and data were collected from spring 1997 to spring 2001 and analysed to determine the effects of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 4 and 6 sheep/ha (C4 and C6), continuous grazing at 8 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C8+sub), and, rotational grazing at an annual stocking rate of 4 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12).Total herbage mass declined in the C4 (control) treatment throughout the experiment and, compared with this treatment, the C6 treatment had less (P<0.007) linear trend over time, while the R4/12 treatment had a greater (P<0.001) linear trend. Stocking rates could not be maintained in the C4 and C6 treatments and sheep were supplementary fed or removed from these treatments for a total of 133 and 263 days, respectively. For ground cover, the linear trend was greater (P<0.05) in the C8+sub, R4/4, and R4/12 treatments compared with the continuously grazed C4 and C6 treatments and for litter mass this trend was also greater (P<0.05) for the R4/12 treatment than the C4 treatment. Basal cover of wiregrass (Aristida ramosa), wallaby grass (Austrodanthonia spp.) and windmill grass (Chloris truncata) was not affected by grazing treatment but for redgrass the linear trend was greater (P<0.05) in the C8+sub, R4/4, and R4/12 treatments compared with the C4 and C6 treatments. Sheep liveweight (kg/head) was greater (P<0.001) in the C8+sub treatment compared with the C4 treatment. Annual wool production (kg/head) was also higher (P<0.05) in the C8+sub treatment compared with all other treatments. Compared with the C4�treatment, significant differences in soil water content occurred in the R4/12 and C8+sub treatments, but these were predicted to be only 2.9 mm per year for the R4/12 treatment (0–30 cm depth) and 5.7 mm per year for the C8+sub treatment (30–170 cm). Use of a biophysical model indicated that evapotranspiration was the largest output term in the soil water balance and that both drainage and surface runoff of water were episodic events. A sustainability index derived from economic (equivalent annual net return ($/ha) for a 10-year period), animal production, pasture, soil health and soil water data indicated that the C4 and C6 treatments had the lowest scores for each of these parameters and the lowest overall indices. These scores were highly correlated with subjective assessments of the impact of the treatments (r�=�0.93). Overall, these data indicated substantial benefits of either rotationally grazing or the addition of fertiliser and subterranean clover to the production and sustainability of the native pasture studied.

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.

Effects of grazing and management on herbage mass, persistence, animal production and soil water content of native pastures. 2. A mixed native pasture, Manilla, North West Slopes, New South Wales

2003 ◽  
Vol 43 (8) ◽  
pp. 891 ◽  
Author(s):  
G. M. Lodge ◽  
S. R. Murphy ◽  
S. Harden
Keyword(s):  
Soil Water ◽  
New South ◽  
Ground Cover ◽  
Perennial Grasses ◽  
Litter Mass ◽  
Wool Production ◽  
Basal Cover ◽  
South Wales ◽  
Continuous Grazing ◽  
Over Time

As part of the Sustainable Grazing Systems (SGS) National Experiment a study was conducted on a native pasture in the Manilla district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. The pasture was a mixture of native perennial grasses, with redgrass (Bothriochloa macra) and wiregrass (Aristida ramosa) dominant on a red Chromosol soil type and bluegrass (Dichanthium sericeum) on a brown Vertosol. Wallaby grasses (Austrodanthonia richardsonii and A. bipartita) were common on both soils. Plots were grazed with Merino wethers and data collected from spring 1997 to spring 2001 were analysed to determine the effect of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 3.1 and 6.2�sheep/ha (C3 and C6), continuous grazing at 9.2 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C9+sub) and rotational grazing at an annual stocking rate of 3.1 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12). Over time, treatments had no significant effect on either total pasture herbage mass (compared with the C3�control) or the basal cover of the major perennial grasses. Treatments had inconsistent significant effects on ground cover, litter mass, sheep liveweight and wool production (kg/head) over time. Compared with all other treatments ground cover was less (P<0.05) in the C6 treatment in only May and September 2000 and litter mass less (P<0.05) in only December 1998 and March 1999. Treatment sheep liveweights were not significantly different from the C3 treatment from September 1997 to 1999. However, from October 1999 to October 2001 sheep liveweight in the C6 treatment was significantly less than in the C3 treatment, while in the C9+sub and R4/12 treatments it was significantly greater than the control. In 1999, wool production per head was higher (P<0.05) in the C9+sub and R4/12 treatments compared with all other treatments but treatment differences were not significant in all other years. Significant differences in SWC only occurred at the 0–30 cm depth between the C3 and the C6 and R4/12 treatments, but were predicted to be <1.5 mm/year. A sustainability index derived from economic [equivalent annual net return ($/ha) for a 10-year period], animal production, pasture, soil health and soil water data indicated that the overall indices were lowest for the C3, C6 and C9+sub treatments and highest for the R4/4 and R4/12 treatments.

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.

Root depth of native and sown perennial grass-based pastures, North-West Slopes, New South Wales. 2. Estimates from changes in soil water content

2006 ◽  
Vol 46 (3) ◽  
pp. 347 ◽  
Author(s):  
S. R. Murphy ◽  
G. M. Lodge
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
Perennial Grass ◽  
Maximum Depth ◽  
Root Depth ◽  
North West ◽  
South Wales ◽  
Native Pasture

Root depth of pasture is an important hydrological parameter that has substantial implications for the use of rainfall by plants and in estimating deep drainage using biophysical modelling. Studies were undertaken for native and sown perennial grass-based pastures on the North-West Slopes of New South Wales to investigate 4 approaches that may identify the depth of plant roots based on objective assessments of change in soil water content (SWC). The 4 approaches were to examine traces of SWC measured with a neutron moisture meter (NMM) at about 4-week intervals (0–210 cm profile at 20-cm increments) for defined periods with root depth interpreted as, (i) the maximum depth at which there was a distinct decrease in SWC, (ii) the maximum depth at which there was a >0.01 m3/m3 decrease in SWC, (iii) the uppermost depth at which the change in SWC was significant using t0.05, and (iv) the uppermost depth at which the daily rate of change in SWC was significant using t0.05. For each of these approaches, 4 preliminary criteria were applied as filters to the SWC data before they were used in these analyses, (i) the depth of NMM tubes and maximum depth of measurement of SWC was greater than the anticipated pasture root depth, (ii) the depth of initial profile wetting was greater than the anticipated pasture root depth, (iii) there was a drying period of >3 months duration in the major pasture growth phase to allow pastures to extract soil water to the maximum extent, and (iv) the SWC was measured at a sufficient frequency to determine extraction of soil water by roots. SWC data were available from spring 1997 to spring 2001 for Barraba (45 access tubes, native pasture), Manilla (45 tubes, native pasture) and Nundle (36 tubes, sown pasture). Analyses of monthly rainfall compared with mean values identified 3 times where substantial rainfall was followed by an extended drying period. These periods occurred in 1998, 1999 and 2000. SWC data for the 1998 drying period best met all the preliminary filters, particularly criteria (ii) and (iii). Root depth values estimated from these data using the 4 approaches were not significantly different for Barraba (188 ± 4 to 190 ± 3 cm, n = 45), Nundle (142 ± 5 to 143 ± 7 cm, n = 13) and Manilla Red Chromosol (164 ± 7 to 176 ± 7 cm, n = 14), but were significantly different for Manilla Brown Vertosol (98 ± 7 to 121 ± 7 cm, n = 23). It was concluded that reliable estimates of root depth may be readily obtained for a range of soils and environments by firstly applying the 4 simple criteria used in these studies to the SWC data and by determining the depth of significant drying using t0.05. The depth of significant drying approach was the most objective, providing consistent results among sites and accounting for variance among NMM counts and tubes in these studies.

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.

Surface soil water dynamics in pastures in northern New South Wales. 2. Surface runoff

2004 ◽  
Vol 44 (3) ◽  
pp. 283 ◽  
Author(s):  
S. R. Murphy ◽  
G. M. Lodge ◽  
S. Harden
Keyword(s):  
Soil Water ◽  
Surface Runoff ◽  
New South ◽  
Ground Cover ◽  
Simulation Modelling ◽  
Runoff Generation ◽  
Grazed Pastures ◽  
South Wales ◽  
Runoff Events

Surface runoff can represent a significant part of the hydrological balance of grazed pastures on the north-west slopes of New South Wales, and is influenced by a range of rainfall characteristic, soil property, and pasture conditions. Runoff plots were established on grazed pastures at 3 sites as part of the Sustainable Grazing Systems National Experiment (SGS NE). Pastures were either native (redgrass, wallaby grass and wire grass) or sown species (phalaris, subterranean clover and lucerne) and a range of grazing management treatments were imposed to manipulate pasture herbage mass, litter mass and ground cover. Rainfall and runoff events were recorded using automatic data loggers between January 1998 and September 2001. Stored soil water in the surface layer (0–22.5 cm) was monitored continuously using electrical resistance sensors and automatic loggers. Pasture herbage mass, litter mass and ground cover were estimated regularly to provide information useful in interpreting runoff generation processes.Total runoff ranged from 6.6 mm at Manilla (0.3% of rainfall) to 185 mm at Nundle (5.7% of rainfall) for different grazing treatments, with the largest runoff event being recorded at Nundle (46.7 mm). Combined site linear regression analyses showed that soil depth, rainfall depth and rainfall duration explained up to 30.3% of the variation in runoff depth. For individual sites, these same variables were also important, accounting for 13.3–33.6% of the variation in runoff depth. Continuous monitoring of stored soil water in relation to these runoff events indicated that the majority of these events were generated by saturation excess, with major events in winter contributing substantially to regional flooding. Long-term simulation modelling (1957–2001) using the SGS Pasture Model indicated that most runoff events were generated in summer, which concurred with the number of flood events recorded at Gunnedah, NSW, downstream of the SGS sites. However, floods also occurred frequently in winter, but the simulations generated few runoff events at that time of the year. These results have important implications for sustainability of grazed pastures and long-term simulation modelling of the hydrological balance of such systems, since runoff generation processes are likely to vary both spatially and temporally for different rainfall events.

Surface soil water dynamics in pastures in northern New South Wales. 1. Use of electrical resistance sensors

2004 ◽  
Vol 44 (3) ◽  
pp. 273 ◽  
Author(s):  
S. R. Murphy ◽  
G. M. Lodge
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Real Time ◽  
Surface Runoff ◽  
Electrical Resistance ◽  
New South ◽  
Water Dynamics ◽  
Continuous Data ◽  
Soil Water Dynamics ◽  
South Wales

Stored soil water may influence both the generation of surface runoff and the rate of evapotranspiration from pastures, which may be significant in northern New South Wales. Continuous data is essential to fully understand these processes in field studies. Electrical resistance sensors were used to capture continuous data and they were calibrated directly for soil water content (SWC), so as to provide quantitative data in real time. Calibration equations (logarithmic regression) were significantly different for a range of installation depths (2.5–20 cm). To�provide quantitative insight into soil water dynamics in studies of stored soil water, surface runoff, and evapotranspiration, real time data were collected at intervals ranging from 4 min to 24 h. Resistance sensors provided estimates of stored soil water (0–30 cm) that differed by up to 29% compared with estimates obtained from using a neutron moisture metre alone. In surface runoff studies, data collected at 4 min intervals showed that runoff was generated when soil water content was high. In studies of evapotranspiration, daily data were used to quantify different evapotranspiration rates (2.3–4.9 mm/day) and progressive depth of drying for a range of treatments. We concluded that data collected in real time using resistance sensors may be used to make better estimates of SWC and so improve the interpretation of surface runoff generation and evapotranspiration data.

Nitrogen and water flows under pasture - wheat and lupin - wheat rotations in deep sands in Western Australia. 2. Drainage and nitrate leaching

1998 ◽  
Vol 49 (3) ◽  
pp. 345 ◽  
Author(s):  
G. C. Anderson ◽  
I. R. P. Fillery ◽  
F. X. Dunin ◽  
P. J. Dolling ◽  
S. Asseng
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Western Australia ◽  
Root Zone ◽  
N Uptake ◽  
Subterranean Clover ◽  
Lower Amount ◽  
Wheat Crop ◽  
Mineral N

Quantification of nitrate (NO-3) leaching is fundamental to understanding the efficiency with which plants use soil-derived nitrogen (N). A deep sand located in the northern wheatbelt of Western Australia was maintained under a lupin (Lupinus angustifolius)-wheat (Triticum aestivum) and a subterranean clover (Trifolium subterraneum) based annual pasture-wheat rotation from 1994to 1996. Fluxes of water and NO-3 through, and beyond, the root-zone were examined. Drainage was calculated on a daily basis from measurements of rainfall, evapotranspiration, and the change in soil water content to a depth of 1·5 m. Evapotranspiration was estimated from Bowen ratio measurements,and soil water content was determined by time domain reflectrometry. Soil was sampled in layers to1·5 m at the onset of winter rains and analysed for NO-3 . Ceramic suction cups were installed at 0·25, 0·4, 0·6, 0·8, 1·0, 1·2, and 1·4 m to sample soil solution from June to mid August. The NO-3 leached from each layer was computed by multiplying the daily drainage through each layer by the estimated concentration of NO-3 within the layer. The estimated concentration of NO-3 in a layer was calculated by taking into account NO-3 either entering that layer through mineralisation and leachingor leaving the layer through plant uptake. Mineral N was added to the surface 0·2 m in accordance with measured rates of net N mineralisation, and daily N uptake was calculated from the measured above-ground plant N derived from soil N. Root sampling was undertaken to determine root lengthdensity under pastures, lupin, and wheat. Cumulative drainage below 1·5 m was similar under wheat and lupin, and accounted for 214 mmfrom 11 May to 15 August 1995 and 114 mm from 2 July to 15 September 1996. The cumulative evapotranspiration (Ea) over these periods was 169 mm from a wheat crop in 1995, and 178 mm from a lupin crop in 1996. The amount of NO-3 in soil at the start of the growing season was afiected by previous crop, with a lower range following wheat (31-68 kg N/ha) than following legumes (40-106 kgN/ha). These large quantities of NO-3 in the soil at the break of the season contributed substantially to NO-3 leaching. Leaching of NO-3 below 1·5 m in wheat crops accounted for 40-59 kg N/ha where these followed either lupin or pasture. In contrast, less NO-3 was found to leach below 1·5 m in pastures (17-28 kg N/ha). Greater N uptake by capeweed (Arctotheca calendula L.) than by either wheat or lupin was the main reason for the lower amount of NO-3 leached in pastures.

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.

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