scholarly journals Effects of farming systems, tillage, and traffic practices on deep drainage and soil salt loads in the Queensland Murray–Darling and Fitzroy Basins using soil chloride

Soil Research ◽  
2021 ◽  
Author(s):  
D. M. Silburn ◽  
P. E. Tolmie ◽  
A. J. W. Biggs ◽  
M. H. Crawford
Keyword(s):  
Farming Systems ◽  
Deep Drainage ◽  
Soil Salt ◽  
Soil Chloride

Deep drainage and soil salt loads in the Queensland Murray - Darling Basin using soil chloride: comparison of land uses

Soil Research ◽  
2011 ◽  
Vol 49 (5) ◽  
pp. 408 ◽  
Author(s):  
P. E. Tolmie ◽  
D. M. Silburn ◽  
A. J. W. Biggs
Keyword(s):  
Root Zone ◽  
Drainage Water ◽  
Native Vegetation ◽  
Deep Drainage ◽  
Water Capacity ◽  
Available Water ◽  
Murray Darling Basin ◽  
Available Water Capacity ◽  
Secondary Salinity ◽  
Soil Chloride

Increases in deep drainage below the root-zone can lead to secondary salinity. Few data were available for drainage under dryland cropping and pastures in the Queensland Murray–Darling Basin (QMDB) before this study. Modelled estimates were available; however, without measured drainage these could not be validated. Soil chloride (Cl) mass-balance was used to provide an extensive survey of deep drainage. The method is ‘backward-looking’ and can detect low rates of drainage over longer times. Soil Cl and other soil properties were collated for a number of soils, mostly Vertosols and Sodosols, for paired native vegetation, cropped and sometimes pasture sites, from historical data and new soil sampling. Large amounts of salt and Cl had accumulated under native vegetation (Cl mean 25 t/ha, range 6–54, in 2.4 m depth), due to low rates of drainage. Steady-state Cl balances for native vegetation gave average drainage of 1.2 mm/year at wetter, eastern sites and 0.3 mm/year for Sodosols and Grey Vertosols in drier, western areas. Chloride profiles were mostly of a shape indicating matrix/piston flow. One site (Hermitage fallow trial) appeared to be affected by diffusion of Cl to a watertable. The Cl profiles from 14 longer term cropping sites (18–70 years), mainly used for winter cropping/summer fallow, indicate: (i) large losses of Cl since clearing (mean 50%, range 13-85% for 0–1.5 m soil); and (ii) drainage rates from transient Cl balance are a relatively low percentage of rainfall but are considerably higher than under native vegetation. Drainage averaged 8 mm/year and ranged from 2 to 18 mm/year. This variation is partly explained by rainfall (R2 = 0.63) (500–730 mm/year) and soil plant-available water capacity (R2 = 0.77) (80–300 mm). Deep drainage increases with increasing rainfall and with decreasing available water capacity. Drainage under pasture was less than under cropping but greater than under native vegetation. The deep drainage water (leachate) was of poor quality and will increase salinity if added to good quality groundwater. Leachate at nine sites was too saline to be used (undiluted) for irrigation (>2500 mg Cl/L) and was marginal at the remainder of sites (~800 mg Cl/L). Cropping areas in the QMDB have the precursors for secondary salinity development—high salt loads and an increase in drainage after clearing. The Vertosols and Sodosols studied occur in 90% of croplands in the QMDB. Salinisation will depend on the properties of the underlying regolith and groundwater systems.

If long fallow cropping is leaky then shallow groundwaters on the Liverpool Plains should be of recent origin

2004 ◽  
Vol 44 (10) ◽  
pp. 1051 ◽  
Author(s):  
R. R. Young ◽  
A. Broughton ◽  
J. M. Bradd ◽  
J. F. Holland
Keyword(s):  
Cropping Systems ◽  
New South ◽  
Shallow Groundwater ◽  
Agricultural Practices ◽  
Farming Systems ◽  
Deep Drainage ◽  
Site Specific ◽  
South Wales ◽  
Recent Origin ◽  
Unexpected Outcome

Previous groundwater studies have indicated that up to 195 000 ha of the Liverpool Plains catchment, south of Gunnedah, New South Wales, Australia, are at risk from shallow saline watertables. Replacement of hydraulically stable, native perennial grasslands with more ‘leaky’ annual cropping systems since the 1950s, particularly long fallow wheat–sorghum rotations, has been held responsible for an apparent increased frequency of shallow watertables and saline discharge. If so, then it follows that shallow groundwater in the alluvium will be recent (less than about 30 years old) and the solution to the problem is a straightforward reduction in deep drainage under farming systems via increased evapotranspiration. However, in this study, we have found levels of bomb pulse tritium in shallow groundwaters that indicate that about half of the shallow groundwaters in the Mooki subcatchment pre-date current agricultural practices. A hypothesis for this unexpected outcome suggests that the problem is complex and that solutions need to be site-specific.

Modelling shows that the high rates of deep drainage in parts of the Goondoola Basin in semi-arid Queensland can be reduced with changes to the farming systems

Soil Research ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 58 ◽  
Author(s):  
J. B. Robinson ◽  
D. M. Silburn ◽  
D. Rattray ◽  
D. M. Freebairn ◽  
A. Biggs ◽  
...  
Keyword(s):  
Water Balance ◽  
Good Condition ◽  
Shallow Groundwater ◽  
Farming Systems ◽  
Field Measurements ◽  
Simulation Modelling ◽  
Soil Types ◽  
Native Vegetation ◽  
Deep Drainage ◽  
Deep Roots

Clearing native vegetation and introducing crops and pastures may increase deep drainage and result in dryland salinity. In south-west Queensland, native vegetation of the Goondoola Basin has been substantially cleared for cropping and pastoral activities, resulting in shallow groundwater and localised salinity. Simulation modelling was used to estimate the water balance of a range of vegetation and soil types. Six soils were studied, with plant-available water capacity (PAWC) of 71 mm (a Kandosol) to 198 mm (a Vertosol) for 1200 mm depth. Vegetation types were annual wheat, opportunity cropping, and perennial pastures in poor and good condition, and high quality perennial pasture with deep roots growing on deep (2400 mm) variants of the 6 soil types. Opportunity cropping did not reduce deep drainage. Substantial differences were found in long-term average deep drainage (mm/year) between wheat crops and pastures for all soil types. The differences in deep drainage between wheat cropping and pasture in good condition were greatest for the 2 Kandosols, which had the lowest PAWC (34 and 21 mm/year less deep drainage, reductions of 53% and 62%, respectively), and a Vertosol with intermediate PAWC (23 mm/year less deep drainage). A Chromosol and a Dermosol with intermediate PAWC had smaller reductions in deep drainage (14 and 11 mm/year, respectively). In the case of a Vertosol with high PAWC (198 mm), deep drainage was negligible with all pastures. Due to increased infiltration and reduced soil evaporation, more deep drainage was simulated with pasture in good condition than pastures in poor condition, especially for 2 Kandosols. Pasture with deep roots (2400 mm) growing on deep variants (2400 mm) of the 6 soils had lower rates of deep drainage than the other pastures. Simulated deep drainage and other components of the water balance were in good agreement with field measurements and expectations. These results indicate that large reductions in deep drainage can be achieved in the Goondoola Basin by replacing cropping with pastoral activities. Kandosol soils used for wheat cropping should be the primary target for land use change.

Productivity, sustainability, and rainfall-use efficiency in Australian rainfed Mediterranean agricultural systems

2005 ◽  
Vol 56 (11) ◽  
pp. 1123 ◽  
Author(s):  
Neil C. Turner ◽  
Senthold Asseng
Keyword(s):  
Weed Control ◽  
Nitrogen Availability ◽  
New Technologies ◽  
Disease Risk ◽  
Farming Systems ◽  
Agricultural Systems ◽  
Deep Drainage ◽  
Deep Roots ◽  
Environmentally Sustainable ◽  
Perennial Vegetation

Mediterranean environments are characterised by hot, dry summers and cool, wet winters. The native vegetation in Mediterranean-climatic regions is predominantly perennial shrubs and trees intermixed with annual forbs. In south-western Australia, the spread of agriculture has seen the well adapted perennial vegetation replaced by rainfed annual crops and pastures. This has increased waterlogging and secondary salinity, thereby causing loss of productivity in ~10% of the cleared land area. To reduce deep drainage and make the agricultural systems environmentally sustainable requires the re-introduction of perennial vegetation in the form of belts of trees or shrubs, and phase-farming systems with perennials such as lucerne replacing annual pastures between the cropping years. To be economically viable, agricultural productivity needs to increase by at least 3% per annum. Yields of dryland wheat, the predominant crop in the Mediterranean agricultural regions of Australia, have increased at ~1%/year for the century preceding the 1980s and since then by nearly 4%/year. Increases have arisen from both genotypic and agronomic improvements. Genotypic increases have arisen from selection for earliness, early vigour, deep roots, osmotic adjustment, increased transpiration efficiency, improved disease resistance, and an improved harvest index from high ear weight (grain number) at flowering and high assimilate storage and remobilisation. Agronomic increases have arisen from early sowing that has been enabled by minimum tillage, increased fertiliser use, especially nitrogen, weed control, and rotations to improve weed control, minimise disease risk, and increase nitrogen availability. Evidence is presented suggesting that the rapid increase in yield of wheat in the last two decades has likely arisen from the rapid adoption of new technologies. For productivity to be maintained in the face of the increasing requirement to be environmentally sustainable will be a challenge and will require better integration of breeding and agronomy.

Deep drainage and land use systems. Model verification and systems comparison

2005 ◽  
Vol 56 (9) ◽  
pp. 995 ◽  
Author(s):  
Zahra Paydar ◽  
Neil Huth ◽  
Anthony Ringrose-Voase ◽  
Rick Young ◽  
Tony Bernardi ◽  
...  
Keyword(s):  
Land Use ◽  
Production Systems ◽  
Farming Systems ◽  
Model Verification ◽  
Experimental Results ◽  
Moist Soil ◽  
Deep Drainage ◽  
Systems Model ◽  
Drainage Rate ◽  
South Wales

Deep drainage or drainage below the bottom of the profile usually occurs when rain infiltrates moist soil with insufficient capacity to store the additional water. This drainage is believed to be contributing to watertable rise and salinity in some parts of the Liverpool Plains catchment in northern New South Wales. The effect of land use on deep drainage was investigated by comparing the traditional long fallow system with more intense ‘opportunity cropping’. Long fallowing (2 crops in 3 years) is used to store rainfall in the soil profile but risks substantial deep drainage. Opportunity cropping seeks to lessen this risk by sowing whenever there is sufficient soil moisture. Elements of the water balance and productivity were measured under various farming systems in a field experiment for 4 years in the southern part of the catchment. The experimental results were used to verify APSIM (Agricultural Production Systems Simulator) by comparing them with predictions of production, water storage, and runoff. The verification procedure also involved local farmers and agronomists who assessed the credibility of the predictions and suggested modifications. APSIM provided a realistic simulation of common farming systems in the region and could capture the main hydrological and biological processes. APSIM was then used for long-term (41 years) simulations to predict deep drainage under different systems and extrapolate experimental results. The results showed large differences between agricultural systems mostly because differences in evapotranspiration contributed to differences in profile moisture when it rained. The model predicted that traditional long fallow farming systems (2 crops in 3 years) are quite ‘leaky’, with average annual deep drainage of 34 mm. However, by planting crops in response to the depth of moist soil (opportunity or response cropping), APSIM predicted a much smaller annual drainage rate of 6 mm. Opportunity cropping resulted in overall greater water use and increased production compared with long fallowing. Furthermore, modelling indicated that average annual deep drainage under continuous sorghum (3 mm) is much less than under either long fallow cropping or continuous wheat (39 mm), demonstrating the importance of including summer cropping, as well as increasing cropping frequency, to reducing deep drainage.

Nitrogen fertilizer value of cattle manure applied on soils originating from organic and conventional farming systems

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 789-800 ◽  
Author(s):  
Monika Langmeier ◽  
Emmanuel Frossard ◽  
Michael Kreuzer ◽  
Paul Mäder ◽  
David Dubois ◽  
...  
Keyword(s):  
Nitrogen Fertilizer ◽  
Farming Systems ◽  
Cattle Manure ◽  
Conventional Farming ◽  
Fertilizer Value ◽  
Organic And Conventional Farming

Farmers' needs for management, research and extension, and policy - findings of a farmers' workshop and their implications

1992 ◽  
pp. 7-10
Author(s):  
A.F. Mcrae
Keyword(s):  
Technology Transfer ◽  
Farming Systems ◽  
Management Research ◽  
Business Objectives ◽  
Research Technology ◽  
Systems Research ◽  
Farming Systems Research

Farmers' objectives, their circumstances and the constraints they face are central to any consideration of ways and means of improving farming systems. The management, research and extension, and policy needs of the farmers attending this workshop were diverse. This appeared to be linked with the (unexpected) degree of diversity in the business objectives and management structures on these farms. More formal research on these issues across the spectrum of farmers is required to ensure that research and technology transfer meet the industry's needs. Keywords farming systems, research, technology transfer, objectives

A REVIEW OF 10 YEARS' RESEARCH WITH RED CLOVERS UNDER GRAZING IN SOUTHLAND

1989 ◽  
pp. 181-187
Author(s):  
R.J.M. Hay ◽  
D.L. Ryan
Keyword(s):  
Tall Fescue ◽  
Red Clover ◽  
Farming Systems ◽  
Seasonal Growth ◽  
Sheep Grazing ◽  
High Quality ◽  
Late Flowering ◽  
Heavy Weight ◽  
Widespread Acceptance ◽  
Summer Growth

In a series of trials at Grasslands Gore, over 10 years, the late-flowering tetraploid red clover 'Grassland Pawera' was more productive and persistent than other red clover cultivars. The strong summer growth of Pawera meets the need for heavy-weight lamb feed and high quality forage for conservation in intensive sheep farming systems in Southland. Lenient. infrequent defoliation is necessary to maximise DM production and persistence of Pawera. The most compatible of the grasses evaluated was 'Grasslands Roa' tall fescue. However, 'Grasslands Nui' ryegrass will still be the major grass sown with Pawera owing to its widespread acceptance. In ryegrass mixtures, sowing rates of 5-7 kg/ha of red clover were needed to optimise establishment and subsequent yield. Evidence of oestrogenic activity of Pewera to sheep prompted Grasslands Division to select within Pawera for a low formononetin cultivar. Keywords: red clover, Pawera. Hamua, Turoa. G21. G22, G27. oestrogenic activity, Nui ryegrass, Roa tall fescue, Maru phalaris. Southland, sheep grazing, frequency, intensity, quality. seasonal growth

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