Production risks and water use benefits of summer crop production on the south coast of Western Australia

2005 ◽  
Vol 56 (6) ◽  
pp. 597 ◽  
Author(s):  
M. J. Robertson ◽  
D. Gaydon ◽  
D. J. M. Hall ◽  
A. Hills ◽  
S. Penny
Keyword(s):  
Water Use ◽  
Grain Sorghum ◽  
Rooting Depth ◽  
Annual Rainfall ◽  
Grain Production ◽  
Deep Drainage ◽  
Winter Crop ◽  
Sorghum Grain ◽  
Summer Crop

Summer crops grown during the summer fallow in a Mediterranean-type climate have the potential to produce out-of-season biomass and grain, increase water use, and reduce deep drainage. The potential effects of growing grain sorghum on components of the water balance, sorghum biomass and grain production, and yield of subsequent wheat crops were investigated by simulation using APSIM and long-term climate data from the Esperance district. Sorghum was simulated as part of 3 systems: (1) as an opportunity crop following wheat harvest, (2) as a fallow replacement after pasture removal and before entering a cropping phase, or (3) as a fallow replacement after a failed or waterlogged winter crop. Simulations were conducted for the period 1957–2003 at Myrup (mean annual rainfall 576 mm), Scaddan (408 mm), and Salmon Gums (346 mm). Sorghum was assumed to have a similar rooting depth to wheat. In order to gain confidence in using APSIM for these investigations, tests were initially conducted against field data involving summer and winter crops in sequence and measurements of soil water dynamics. Data sets also varied in summer rainfall, species (forage sorghum, grain sorghum, Japanese millet), and soil type (deep sand, and medium and shallow duplex). Overall, the simulations showed that incorporation of a sorghum crop increased transpiration by 10–30 mm/year, made the soil profile drier by a similar amount at wheat sowing, and consequently reduced deep drainage by 3–25 mm/year, depending upon cropping system and location. Long-term average drainage results were dominated by large episodes in wet years. The increased transpiration from the summer crop, although reducing drainage in wet years, could not eliminate drainage. Following wheat yields were reduced by an average of 200–400 kg/ha, corresponding to a reduction of 10% at wetter and 30% at drier locations. In the 2 fallow replacement systems, sorghum biomass was produced in nearly every simulated season. However, averaged over all seasons, sorghum grain production was much less reliable comprising only 10–20% of biomass. In the opportunity system, sorghum produced biomass in only 1 in 3 seasons at Salmon Gums and Scaddan and 1 in 2 at Myrup. Grain was produced in 1 in 5 seasons at all 3 locations, underlining the riskiness of this opportunity niche for summer crops in the Esperance district. Although summer cropping was shown to result in modest reductions in deep drainage, it also comes at a cost to wheat production. The largest effects on drainage and most reliable biomass production were seen in the systems where the summer crop was grown following pasture removal or a failed (waterlogged) winter crop. This research has also shown that recent farmer and researcher experiences of summer cropping are likely to be more favourably biased towards prospects for summer cropping than indicated by long-term simulations because of their longer-term perspective.

SGS Water Theme: influence of soil, pasture type and management on water use in grazing systems across the high rainfall zone of southern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 907 ◽  
Author(s):  
R. E. White ◽  
B. P. Christy ◽  
A. M. Ridley ◽  
A. E. Okom ◽  
S. R. Murphy ◽  
...  
Keyword(s):  
Water Use ◽  
Western Australia ◽  
Weather Data ◽  
Rooting Depth ◽  
Marginal Effect ◽  
Deep Drainage ◽  
High Rainfall ◽  
Daily Weather Data ◽  
Grazing Systems

Eleven experimental sites in the Sustainable Grazing Systems (SGS) national experiment were established in the high rainfall zone (HRZ, >600 mm/year) of Western Australia, Victoria and New South Wales to measure components of the water balance, and pathways of water movement, for a range of pastures from 1997 to 2001. The effect of widely spaced river red gums (Eucalyptus camaldulensis) in pasture, and of belts of plantation blue gums (E. globulus), was studied at 2 of the sites. The soil types tested ranged from Kurosols, Chromosols and Sodosols, with different subsoil permeabilities, to Hydrosols and Tenosols. The pasture types tested were kikuyu (Pennisetum clandestinum), phalaris (Phalaris aquatica), redgrass (Bothriochloa macra) and annual ryegrass (Lolium rigidum), with subterranean clover (Trifolium subterraneum) included. Management variables were set stocking v. rotational grazing, adjustable stocking rates, and level of fertiliser input. Soil, pasture and animal measurements were used to set parameters for the biophysical SGS pasture model, which simulated the long-term effects of soil, pasture type, grazing method and management on water use and movement, using as inputs daily weather data for 31 years from selected sites representing a range of climates. Measurements of mean maximum soil water deficit Sm were used to estimate the probability of surplus water occurring in winter, and the average amount of this surplus, which was highest (97–201 mm/year) for pastures in the cooler, winter-rainfall dominant regions of north-east and western Victoria and lowest (3–11 mm/year) in the warmer, lower rainfall regions of the eastern Riverina and Esperance, Western Australia. Kikuyu in Western Australia achieved the largest increase in Sm compared with annual pasture (55–71 mm), while increases due to phalaris were 18–45 mm, and those of native perennials were small and variable. Long-term model simulations suggested rooting depth was crucial in decreasing deep drainage, to about 50 mm/year for kikuyu rooting to 2.5 m, compared with 70–200 mm/year for annuals rooting to only 0.8 m. Plantation blue gums dried the soil profile to 5.25 m by an average of 400 mm more than kikuyu pasture, reducing the probability of winter surplus water to zero, and eliminating drainage below the root zone. Widely spaced river red gums had a much smaller effect on water use, and would need to number at least 14 trees per hectare to achieve extra soil drying of about 50 mm over a catchment. Soil type affected water use primarily through controlling the rooting depth of the vegetation, but it also changed the partitioning of surplus water between runoff and deep drainage. Strongly duplex soils such as Sodosols shed 50% or more surplus water as runoff, which is important for flushing streams, provided the water is of good quality. Grazing method and pasture management had only a marginal effect in increasing water use, but could have a positive effect on farm profitability through increased livestock production per hectare and improved persistence of perennial species.

Water use efficiency and water use of Mediterranean annual pastures in southern Australia

1999 ◽  
Vol 50 (6) ◽  
pp. 1035 ◽  
Author(s):  
T. P. Bolger ◽  
N. C. Turner
Keyword(s):  
Water Use Efficiency ◽  
Linear Relationship ◽  
Water Use ◽  
Management Practices ◽  
Root Zone ◽  
Annual Rainfall ◽  
High Input ◽  
Deep Drainage ◽  
Pasture Production ◽  
Use Efficiency

There is a perception in the farming and research communities that annual pastures have low produc- tivity and water use, and contribute disproportionately to problems of rising watertables and dryland salinity. Our aim was to determine potential pasture production in relation to water use and the influence of management factors on this relationship. Experiments were initiated at 4 locations along a gradient of 300–1100 mm annual rainfall across the Western Australian agricultural zone. At each site a high input treatment was compared with a low input control. There was a strong linear relationship between water use and pasture production up to 440 mm of growing- season water use. After 30 mm of water use the potential pasture production was 30 kg/ha.mm. An upper limit to pasture production may be reached at about 12 000 kg/ha in this environment due to rainfall distribution patterns and soil water holding capacity in the root-zone. Although pasture production was increased by as much as 3500 kg/ha, water use was generally similar or only slightly more for high input compared with control plots. The marginally higher water use by the high input pastures resulted in an extra 18 mm of water extracted from the subsoil at one location by the end of the third season. A drier subsoil may provide a buffer for storing excess rainfall and reduce deep drainage. Estimated drainage was small at low rainfall sites so even marginal increases in water use by highly productive annual pastures could play a significant role in reducing water loss to deep drainage and mitigating water-table rise and secondary salinisation in low rainfall regions. Management practices aimed at promoting early growth and adequate leaf area should maximise water use, water use efficiency, and yield. The linear relationship defining potential pasture production provides a useful benchmark to farmers.

Impact of rain-fed cropping on the hydrology and fertility of alluvial clays in the more arid areas of the upper Darling Basin, eastern Australia

Soil Research ◽  
2014 ◽  
Vol 52 (4) ◽  
pp. 388 ◽  
Author(s):  
Rick Young ◽  
Neil Huth ◽  
Steven Harden ◽  
Ross McLeod
Keyword(s):  
Water Use ◽  
Nutrient Deficiency ◽  
Annual Rainfall ◽  
Continuous Cropping ◽  
Zero Tillage ◽  
Crop Water ◽  
Deep Drainage ◽  
Crop Water Use ◽  
Average Annual Rainfall ◽  
Chloride Concentrations

The impact of cropping on the hydrology and fertility of Vertosols in the northern Darling Basin (average annual rainfall >550 mm) has received much attention, together with the constraints placed on crop growth by naturally occurring subsoil salt stocks. These factors have not been quantified in the drier (450–550 mm), marginal cropping areas to the west. With widespread adoption of zero tillage technology and the potential for large increases in the capture and storage of rainfall in good seasons, mobilisation of salt could be exacerbated should crop water use be constrained by salt toxicity and/or nutrient deficiency. We investigated the size of salt stocks, historic deep drainage, and nutrient depletion under continuous cropping in the Grey and Brown Vertosols of the Walgett and Coonamble districts of north-western NSW. Soils collected from seven paired sites (cropped v. control native vegetation) showed chloride concentrations >500 mg/kg within 0–1.2 m, high exchangeable sodium percentage (~30%) at depth and deficiency in phosphorus, manganese and zinc. Soil total nitrogen decreased from an average stock of 4.9 t/ha at a rate of 0.008 t/ha.year under cropping within 0–0.1 m and soil carbon stocks decreased from 39 t/ha by 0.20 t/ha.year within 0–0.5 m.. Despite low rainfall, high evaporation and the large water-holding capacity of the cracking clays, there were significant downward shifts in chloride concentrations under cropping. Estimates of deep drainage under continuous cropping using chloride mass balance, chloride-front displacement and crop water-balance modelling with the Agricultural Production Systems Simulator (APSIM) generally agreed (range 0.1–2% of average annual rainfall). Simulations suggested that deep drainage may be increased 5–10-fold under zero-tillage winter cropping due to enhanced capture of rainfall by zero tillage compared with traditional practices. The associated flushing of salt from the root-zone together with correction of nutrient deficiency would enhance crop water use and productivity. Current methods indicate little storage in the subsoil for future deep drainage and that hydraulic conductivity is very low. Hence, the long-term effects of any increase in drainage rates, due to changes in cropping practices and/or climate, on the potential for salinisation of groundwater or transient water logging of the surface, are equivocal.

Water sustainable house: water auditing of 3 case studies in Perth, Western Australia

2019 ◽  
Vol 14 (2) ◽  
pp. 435-443 ◽  
Author(s):  
J. J. Byrne ◽  
M. Anda ◽  
G. E. Ho
Keyword(s):  
Case Studies ◽  
Water Use ◽  
Western Australia ◽  
Sustainability Assessment ◽  
Energy Requirement ◽  
Water Saving ◽  
Annual Rainfall ◽  
Saving Behavior ◽  
Greywater Reuse

Abstract Householders in cities face water-related issues due to the increasing cost and restrictions in water use, especially during drought. They respond in many different ways, ranging from installing water efficient appliances, adopting water-saving behavior and implementing greywater reuse, to being water self reliant (off-mains supply). The latter approach should consider using only rainwater falling on the property boundaries, and if self-supply is from groundwater it should be derived from rainwater falling on the property. Therefore, sustainability depends on the annual rainfall, size of property and availability of storage for water to be used during periods without rainfall. In principle any house can be retrofitted to rely solely on rainwater, because technologies exist to treat subsequent wastewater to any quality desired for reuse. However, the energy requirement and investment needed may negate overall sustainability. Very few studies have assessed water use in households to determine whether relying solely on rainwater is practical or sustainable in the long-term. Three case studies in Perth, Western Australia are reported here, where water auditing has been used for sustainability assessment.

Long-Term Tillage on Yield and Water Use of Grain Sorghum and Winter Wheat

2018 ◽  
Vol 110 (1) ◽  
pp. 269-280 ◽  
Author(s):  
Alan J. Schlegel ◽  
Yared Assefa ◽  
Lucas A. Haag ◽  
Curtis R. Thompson ◽  
Loyd R. Stone
Keyword(s):  
Winter Wheat ◽  
Water Use ◽  
Grain Sorghum

Low input grasses useful in limiting environments (LIGULE)

1999 ◽  
Vol 50 (1) ◽  
pp. 29 ◽  
Author(s):  
W. H. Johnston ◽  
C. A. Clifton ◽  
I. A. Cole ◽  
T. B. Koen ◽  
M. L. Mitchell ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Deep Drainage ◽  
Native Grass ◽  
Eastern Australia ◽  
C3 Species ◽  
Use Pattern ◽  
Water Use Pattern

This paper presents a case for the selection and development of a wider range of perennial grasses for pastoral use in the higher rainfall (annual rainfall >500 mm) zone of southern Australia, especially the southern sector of the Murray–Darling Basin. There is also a need to reconsider the use of ‘high-input’ pastures on hill lands by developing more appropriate recommendations for managing existing native grass pastures productively. Past experiments which compared native grass based pastures with sown pastures promoted the view that indigenous grasses were inferior in most respects to exotic improved species. Even though many of the findings were confounded with fertiliser, stocking rate, and other treatment effects, they reinforced the general direction of cultivar development programs which in the temperate zone have been based mainly on the 4 exotic C3 species Phalaris aquatica L., Dactylis glomerata L., Lolium L. spp., and Festuca elatior var. arundinacea (Schreb.) Hackel (syn. Festuca arundinacea Schreb). This has led to an imbalance in the adaptability and range of species available to be sown in pastures, particularly for sowing on less productive landscapes where stony, shallow, infertile, acid soils limit the persistence of current cultivars. The pre-European vegetation of temperate Australia comprised species with a capacity for active growth and transpiration during summer. The water use pattern resulted in soil moisture being near capacity in late winter and spring, and exhausted by summer’s end. Replacement of this vegetation with annual-growing and summer-dormant C3 species has changed the water use pattern so that soils are drier in spring and wetter in autumn. This has reduced the pre-winter soil moisture deficit, which in turn has increased rates of deep drainage in winter. Land degradation in southern Australia is a consequence of this changed water use pattern. Deep drainage of water beyond the reach of plant roots has mobilised salts stored in the landscape and caused watertables to rise, which has led to large areas becoming saline. Lack of growth in summer in pastures consisting of senescent annual-growing species and dormant C3 perennial grasses limits utilisation of the products of nitrogen mineralisation, which allows nitrate nitrogen to accumulate in summer and be readily leached by rainfall in autumn. This increases rates of soil acidification. Although there may be scope to reduce deep drainage by increasing pasture growth in spring in areas where there is little likelihood of summer rainfall, this is not the case in south-eastern Australia where significant falls of rain occur during summer and autumn.

Lucerne in crop rotations on the Riverine Plains. 1. The soil water balance

2001 ◽  
Vol 52 (2) ◽  
pp. 263 ◽  
Author(s):  
A. M. Ridley ◽  
B. Christy ◽  
F. X. Dunin ◽  
P. J. Haines ◽  
K. F. Wilson ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Use ◽  
Water Storage ◽  
Soil Water Storage ◽  
Rooting Depth ◽  
Annual Rainfall ◽  
Winter Period ◽  
Annual Species ◽  
Annual Crops

Dryland salinity, caused largely by insufficient water use of annual crops and pastures, is increasing in southern Australia. A field experiment in north-eastern Victoria (average annual rainfall 600 mm) assessed the potential for lucerne grown in rotation with crops to reduce the losses of deep drainage compared with annual crops and pasture. Soil under lucerne could store 228 mm of water to 1.8 m depth. This compared with 84 mm under continuous crop (to 1.8 m depth), except in 1997–98 where crop dried soil by 162 mm. Between 1.8 and 3.25 m depth lucerne was able to create a soil water deficit of 78 mm. The extra water storage capacity was due to both the increased rooting depth and increased drying abiliy of lucerne within the root-zone of the annual species. Large drainage losses occurred under annuals in 1996 and small losses were calculated in 1997 and 1999, with no loss in 1998. Averaged over 1996–1999, drainage under annual crops was 49 mm/year (maximum 143 mm) and under annual pastures 35 mm/year (maximum 108 mm). When the extra soil water storage under lucerne was accounted for, no drainage was measured under this treatment in any year. Following 2 years of lucerne, drainage under subsequent crops could occur in the second crop. However, with 3 or 4 years of lucerne, 3–4 crops were grown before drainage loss was likely. Our calculations suggest that in this environment drainage losses are likely to occur under annual species in 55% of years compared with 6% of years under lucerne. In wet years water use of lucerne was higher than for crops due to lucerne’s ability to use summer rainfall and dry soil over the summer–autumn period. During the autumn–winter period crop water use was generally higher than under lucerne. The major period of increased soil water extraction under lucerne was from late spring to midsummer, with additional drying from deeper layers until autumn. Under both lucerne and crops, soil dried progressively from upper to lower soil layers. Short rotations of crops and lucerne currently offer the most practical promise for farmers in cropping areas in southern Australia to restore the water balance to a level which reduces the risk of secondary salinity.

Analiza ekonomiczna uprawy sorgo ziarnowego w zależności od technologii zbioru

2015 ◽  
pp. 191-203
Author(s):  
Józef Sowiński ◽  
Łukasz Kuta
Keyword(s):  
Statistical Analysis ◽  
Economic Analysis ◽  
Direct Costs ◽  
Grain Sorghum ◽  
Grain Production ◽  
Correct Interpretation ◽  
Sorghum Grain ◽  
The Cost ◽  
On Farm ◽  
Financial Result

Economic analysis of harvest methods of grain sorghum (grain variety 251) was the main purpose of this study. For this analysis, the total direct costs per 1 ha of sorghum crops with the conjunction of the yield obtained in Polish conditions and calculation of the profitability of sorghum grain production were estimated. Statistical analysis taking into account the cost of sorghum harvesting methods including drying costs indicated fertilization as one of the main costs. An economic analysis showed that sorghum is competitive to corn. Correct interpretation of the financial result will affect the process of planning of cultivation sorghum on farm level.

Potential deep drainage under wheat crops in a Mediterranean climate. II. Management opportunities to control drainage

2001 ◽  
Vol 52 (1) ◽  
pp. 57 ◽  
Author(s):  
S. Asseng ◽  
F. X. Dunin ◽  
I. R. P. Fillery ◽  
D. Tennant ◽  
B. A. Keating
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Management Practices ◽  
Cropping Systems ◽  
Deep Drainage ◽  
Secondary Salinity ◽  
Carry Over ◽  
Water Holding

High rates of deep drainage in Western Australia are contributing to groundwater recharge and secondary salinity. Strategies are being sought to increase water use in cropping systems and to reduce deep drainage. 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, and in particular the inherent seasonal variability. Simulation models can provide the appropriate means to extrapolate across time and space. The Agricultural Production Systems Simulator (APSIM) was used to explore the effect of alternative agronomic practices on wheat production and deep drainage for representative soils and rainfall regions of the central wheatbelt of Western Australia. Soil water profiles were reset each year to the lower limit of plant-available water, assuming maximum water use in the previous crop. The long-term simulation studies showed that management practices with N fertiliser directed at yield increase were most effective in achieving these aims in the medium to high rainfall regions. The corresponding effect for drainage reduction was marginal. The small effect on drainage control associated with production increase can be traced to the effect of rainfall distribution with major occurrences of both rainfall and drainage during winter (June–August) coinciding with the lowest potential atmospheric demand for evapotranspiration, in combination with low water-holding capacity soils. Nitrogen-induced increases in crop transpiration were in conjunction with reduced soil evaporation, which increased water use efficiency and occurred mostly after the main drainage period, but had little effect on deep drainage within the season. Similar outcomes of enhanced productivity with minor impact on deep drainage were noted with crops sown at different times and with a hypothetical wheat crop having a deeper rooting system. Simulations without resetting soil water each year enabled the quantification of potential carryover effects on long-term average deep drainage. The carry-over of soil water left behind at crop harvest reduced the water storage capacity of the soil in a subsequent year and could increase long-term deep drainage substantially, depending on soil type. Improved management increased late water use in the high rainfall region, in particular on better water-holding soils, and could largely reduce this carry-over effect. The current wheat-based cropping systems, even with alternative management practices, continue to be a major threat to sustainability on the low water-holding soils in the wheatbelt of Western Australia, as a main cause of secondary salinity.

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