Trends in grain production and yield gaps in the high-rainfall zone of southern Australia

2016 ◽  
Vol 67 (9) ◽  
pp. 921 ◽  
Author(s):  
Michael Robertson ◽  
John Kirkegaard ◽  
Allan Peake ◽  
Zoe Creelman ◽  
Lindsay Bell ◽  
...  
Keyword(s):  
Western Australia ◽  
Crop Production ◽  
Crop Yields ◽  
Growing Season ◽  
Yield Potential ◽  
Annual Rainfall ◽  
Potential Yield ◽  
High Rainfall ◽  
Eastern Australia

The high-rainfall zone (HRZ) of southern Australia is the arable areas where annual rainfall is between 450 and 800 mm in Western Australia and between 500 and 900 mm in south-eastern Australia, resulting in a growing-season length of 7–10 months. In the last decade, there has been a growing recognition of the potential to increase crop production in the HRZ. We combined (1) a survey of 15 agricultural consultants, each of whom have ~40–50 farmer clients across the HRZ, (2) 28 farm records of crop yields and area for 2000–2010, (3) 86 wheat and 54 canola yield observations from well managed experiments, and (4) long-term simulated crop yields at 13 HRZ locations, to investigate recent trends in crop production, quantify the gap between potential and actual crop yields, and consider the factors thought to limit on-farm crop yields in the HRZ. We found in the past 10 years a trend towards more cropping, particularly in WA, an increased use of canola, and advances in the adaptation of germplasm to HRZ environments using winter and longer-season spring types. Consultants and the farm survey data confirmed that the rate of future expansion of cropping in the HRZ will slow, especially when compared with the rapid changes seen in the 1990s. In Victoria, New South Wales and South Australia the long-term water-limited potential yield in HRZ areas, as measured by experimental yields, consultant estimates and simulations for slow developing spring cultivars of wheat and canola was 5–6 and 2–3 t/ha for a decile 5 season. For Western Australia it was 4–5 and 2–3 t/ha, where yields were less responsive to good seasons than in the other states. The top performing farmers were achieving close to the water-limited potential yield. There are yield advantages of ~2 t/ha for ‘winter’ over ‘spring’ types of both wheat and canola, and there is scope for better adapted germplasm to further raise potential yield in the HRZ. Consultants stated that there is scope for large gains in yield and productivity by encouraging the below-average cropping farmers to adopt the practices and behaviours of the above-average farmers. The scope for improvement between the below- and above-average farmers was 1–3 t/ha for wheat and 0.5–1.5 t/ha for canola in a decile 5 season. They also stated that a lack of up-to-date infrastructure (e.g. farm grain storage) and services is constraining the industry’s ability to adopt new technology. Priorities for future research, development and extension among consultants included: overcoming yield constraints where growing-season rainfall exceeds 350 mm; adaptation of winter and long-season spring types of cereals and canola and management of inputs required to express their superior yield potential; and overcoming barriers to improved planning and timeliness for crop operations and adoption of technology.

Crop production in the high rainfall zones of southern Australia — potential, constraints and opportunities

2006 ◽  
Vol 46 (8) ◽  
pp. 1035 ◽  
Author(s):  
H. Zhang ◽  
N. C. Turner ◽  
M. L. Poole ◽  
N. Simpson
Keyword(s):  
Crop Production ◽  
Crop Yields ◽  
Growing Season ◽  
Yield Potential ◽  
High Yield ◽  
Seeding Rate ◽  
Potential Yield ◽  
Genetic Constraints ◽  
High Rainfall ◽  
Large Yield

Annual cropping has been expanding in the high rainfall zone of southern Australia. The higher rainfall and longer growing season compared with the traditional wheatbelt contribute to a much higher yield potential for major crops. Potential yields range from 5 to 8 t/ha for wheat and 3 to 5 t/ha for canola, although current crop yields are only about 50% of those potentials. The large yield gap between current and potential yields suggests that there is an opportunity to lift current yields. Both genetic constraints and subsoil constraints such as waterlogging, soil acidity, sodicity, and high soil strength contribute to the low yields. Waterlogging is a widespread hidden constraint to crop production in the region. Controlling waterlogging using a combination of raised beds and surface or subsurface drains is the first step to raise the productivity of the land. Increasing root growth into the subsoil remains a key to accessing more water and nutrients for high yield through early planting, deep ripping, liming and use of primer crops to ameliorate the subsoil. In order to realise the high yield potential, it is essential to achieve higher optimum dry matter at anthesis and high ear number through agronomic management, including early sowing with appropriate cultivars, a high seeding rate and application of adequate nitrogen along with other nutrients. Current cultivars of spring wheat may not fully utilise the available growing season and may have genetic limitations in sink capacity that constrain potential yield. Breeding or identification of long-season milling wheat cultivars that can fully utilise the longer growing season and with the ability to tolerate waterlogging and subsoil acidity, and with disease resistance, will give additional benefits. It is concluded that improving crop production in the high rainfall zone of southern Australia will require attention to overcoming soil constraints, particularly waterlogging, and the development of longer-season cultivars.

Crop responses to lime in long-term pasture-crop rotations in a high rainfall area in south-eastern Australia

2001 ◽  
Vol 52 (3) ◽  
pp. 329 ◽  
Author(s):  
G. D. Li ◽  
K. R. Helyar ◽  
M. K. Conyers ◽  
B. R. Cullis ◽  
P. D. Cregan ◽  
...  
Keyword(s):  
Crop Production ◽  
Acid Soils ◽  
Crop Rotations ◽  
Severe Drought ◽  
High Rainfall ◽  
South Eastern ◽  
Permanent Pasture ◽  
Eastern Australia ◽  
South Eastern Australia

A long-term trial, known as ‘managing acid soils through efficient rotations’ (MASTER), commenced in 1992 to develop and demonstrate a cropping system that is economically viable on the highly acid soils of the traditional permanent pasture region in south-eastern Australia, so that their fertility is sustained or improved. There were 2 permanent pasture systems and 2 pasture–crop rotations, each with and without lime. This paper reports the effect of lime on crop production over the first cycle (6 years). On annual pasture–crop rotations, lime significantly increased the dry matter production at anthesis and grain yields of wheat (cv. Dollarbird) compared with the unlimed treatments. Averaged across years from 1992 to 1997 (excluding the severe drought year 1994), wheat crops produced 1.6 t/ha more grain on the limed treatments than on the unlimed treatments (3.6 v. 2.0 t/ha). On perennial pasture–crop rotations, the lime effects varied with crops grown at each phase and year. For example, despite being tolerant of acidity, oats (cv. Yarran) responded to lime in 1996. Likewise, triticale (cv. Abacus) responded to lime in 1997. Wheat (cv. Dollarbird) that is moderately tolerant to acidity responded to lime in phase 6 from 1992 to 1997 excluding 1994 (3.5 v. 1.7 t/ha). Acid-tolerant wheat varieties, triticale, and narrow-leaf lupins are considered the most viable crops for the soil and climatic conditions encountered in this high rainfall (5000—800 mm per annum) area of south-eastern Australia.

Electromagnetic induction sensing of soil identifies constraints to the crop yields of north-eastern Australia

Soil Research ◽  
2011 ◽  
Vol 49 (7) ◽  
pp. 559 ◽  
Author(s):  
Y. P. Dang ◽  
R. C. Dalal ◽  
M. J. Pringle ◽  
A. J. W. Biggs ◽  
S. Darr ◽  
...  
Keyword(s):  
Grain Yield ◽  
Electromagnetic Induction ◽  
Crop Production ◽  
Crop Yields ◽  
Yield Potential ◽  
Management Options ◽  
Soil Constraints ◽  
Eastern Australia ◽  
North Eastern ◽  
On Farm

Salinity, sodicity, acidity, and phytotoxic concentrations of chloride (Cl–) in soil are major constraints to crop production in many soils of north-eastern Australia. Soil constraints vary both spatially across the landscape and vertically within the soil profile. Identification of the spatial variability of these constraints will allow farmers to tune management to the potential of the land, which will, in turn, bring economic benefit. For three cropping fields in Australia’s northern grains region, we used electromagnetic induction with an EM38, which measures apparent electrical conductivity of the soil (ECa) and soil sampling to identify potential management classes. Soil Cl– and soluble Na+ concentrations, EC of the saturated extract (ECse), and soil moisture were the principal determinants of the variation of ECa, measured both at the drained upper limit of moisture (UL) and at the lower limit (LL) of moisture extracted by the crop. Grain yield showed a strong negative relation with ECa at both UL and LL, although it was stronger for the latter. We arrive at a framework to estimate the monetary value of site-specific management options, through: (i) identification of potential management classes formed from ECa at LL; (ii) measurement of soil attributes generally associated with soil constraints in the region; (iii) grain yield monitoring; and (iv) simple on-farm experiments. Simple on-farm experiments suggested that, for constrained areas, matching fertiliser application to realistic yield potential, coupled to gypsum amelioration, could potentially benefit growers by AU$14–46/ha.year (fertiliser) and $207/ha.3 years (gypsum).

High ear number is key to achieving high wheat yields in the high-rainfall zone of south-western Australia

2007 ◽  
Vol 58 (1) ◽  
pp. 21 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole ◽  
Senthold Asseng
Keyword(s):  
Western Australia ◽  
Spring Wheat ◽  
Harvest Index ◽  
Dry Matter ◽  
Growing Season ◽  
Growth And Yield ◽  
Yield Potential ◽  
Dry Matter Accumulation ◽  
High Rainfall ◽  
Sink Capacity

The growth and yield of spring wheat (Triticum aestivum L.) were examined to determine the actual and potential yields of wheat at a site in the high rainfall zone (HRZ) of south-western Australia. Spring wheat achieved yields of 5.5−5.9 t/ha in 2001 and 2003 when subsurface waterlogging was absent or minimal. These yields were close to the estimated potential, indicating that a high yield potential is achievable. In 2002 when subsurface waterlogging occurred early in the growing season, the yield of spring wheat was 40% lower than the estimated potential. The yield of wheat was significantly correlated with the number of ears per m2 (r2 = 0.81) and dry matter at anthesis (r2 = 0.73). To achieve 5–6 t/ha of yield of wheat in the HRZ, 450–550 ears per m2 and 10–11 t/ha dry matter at anthesis should be targetted. Attaining such a level of dry matter at anthesis did not have a negative effect on dry-matter accumulation during the post-anthesis period. The harvest index (0.36−0.38) of spring wheat was comparable with that in drier parts of south-western Australia, but relatively low given the high rainfall and the long growing season. This relatively low harvest index indicates that the selected cultivar bred for the low- and medium-rainfall zone in this study, when grown in the HRZ, may have genetic limitations in sink capacity arising from the low grain number per ear. We suggest that the yield of wheat in the HRZ may be increased further by increasing the sink capacity by increasing the number of grains per ear.

Claying and deep ripping can increase crop yields and profits on water repellent sands with marginal fertility in southern Western Australia

Soil Research ◽  
2010 ◽  
Vol 48 (2) ◽  
pp. 178 ◽  
Author(s):  
D. J. M. Hall ◽  
H. R. Jones ◽  
W. L. Crabtree ◽  
T. L. Daniels
Keyword(s):  
Organic Carbon ◽  
Western Australia ◽  
Crop Production ◽  
Crop Yields ◽  
Nutrient Retention ◽  
Soil Strength ◽  
Yield Potential ◽  
Control Treatment ◽  
Water Repellent ◽  
Water Repellence

Sandplain soils on the south coast of Western Australia have multiple limitations to crop production that include water repellence, low water and nutrient retention, subsoil acidity, and high soil strength. Crops on sandplain soils achieve, on average, almost 85% of their rainfall-limited yield potential; however, where there are multiple limitations the corresponding value is often <50% in any given year. Previous research has shown the value of applying clay-rich subsoil (‘claying’) to ameliorate water repellent soils and improve nutrient retention. Other studies have shown that deep ripping is effective in reducing compaction in sandplain soils. This paper quantifies the effects of 5 subsoil clay rates (0, 50, 100, 200, and 300 t/ha), with and without deep ripping to 0.5m, on soil properties, crop growth, and profitability in a replicated field experiment. Crop yields were increased by 0.3–0.6 t/ha as result of added clay. The clay content of the surface soil required to alleviate water repellence and achieve the highest yield increases was 3–6% in soils with ~1% organic carbon. Longer term effects of claying included increased soil organic carbon by 0.2%, pH by 0.6 units, potassium by 47 mg/kg, soil strength by 250 kPa, and cation exchange capacity by 1.3 cmolc/kg to a depth of 0.1 m. However, changes in plant-available water (mm/m) were inconsistent between the clay treatments. Deep ripping to 0.5 m increased crop yields by 0.1–0.5 t/ha. These crop yield responses were still evident 3 years after the ripping treatment had been applied. Soil strength measurements indicate that re-compaction of the ripped treatments had occurred to a depth of 0.2 m in the second year following ripping. Crop responses to claying and deep ripping were additive. Claying and deep ripping, while almost doubling yields, achieved only 50–70% of the rainfall-limited yield potential on these marginally fertile soils. The highest clay rates (>3–6%) had cumulative discounted cash returns $AU100–200/ha higher than the unclayed ‘control’ treatment and $300/ha higher than the lowest clay rates. For most of the clay treatments, deep ripping increased discounted returns between 2005 and 2007 by $80–120/ha.

Can increased nutrition raise cereal yields to the rainfall-limited potential in the high rainfall cropping zone of south Western Australia?

2007 ◽  
Vol 47 (1) ◽  
pp. 39 ◽  
Author(s):  
N. L. Simpson (née Hill) ◽  
R. McTaggart ◽  
W. K. Anderson ◽  
L. Anderton
Keyword(s):  
Western Australia ◽  
Management Practices ◽  
Growing Season ◽  
Triticum Aestivum L ◽  
Seasonal Rainfall ◽  
Hordeum Vulgare L ◽  
Potential Yield ◽  
Water Losses ◽  
Grain Yields ◽  
High Rainfall

Average yield of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) in the high rainfall cropping zone (>750 mm) of south Western Australia from 1996 to 2001 was 2.5 t/ha. This is far below the water-limited potential yield (water losses of 110 mm, transpiration efficiency of 20 kg/ha.mm) of 6–8 t/ha. Nutrition of the cereal crops has been regarded as one constraint to reaching the potential yield, although grain yield increases (responses) under conventional management practices (a series of full cultivation operations) have been inconsistent. Three experiments, with a total of five trial sites conducted over two seasons, were carried out to test the response of wheat and barley to fertiliser applications of nitrogen (N), phosphorus (P), potassium (K), sulfur (S) and trace elements (TE). Various combinations of nutrients were applied. These ranged from no fertiliser (nil), to farmer practice (N at rates at 34–82 kg/ha, P at 3–17 kg/ha, K at 0–50 kg/ha and S at 4–11 kg/ha), to nutrients calculated to supply the needs of a 6–8 t/ha cereal crop (N, P, K, S, TE). The aim was to determine whether the supply of non-limiting levels of crop nutrients could raise yields to the potential yield as determined by seasonal rainfall. In the drier seasons experienced in 2001 and 2002 at Arthur River and Cranbrook, with growing season rainfall (May–November) up to about 350 mm, it was possible to raise grain yields to levels at or above the calculated rainfall-limited potential with increased nutrition (4.2 t/ha for barley and 4.5 t/ha for wheat). However, in the wetter environment of Boyup Brook in 2002, where seasonal rainfall was greater than 500 mm, extra nutrition by itself was not sufficient to reach the water-limited potential, even where the yields were increased from 3.5 to 5.2 t/ha for wheat and from 3.9 to 4.5 t/ha for barley. Further experimentation is required to clarify the factors limiting responses to nutrition when the growing season rainfall is greater than 500 mm and thus allow greater confidence in extrapolating these results in the high rainfall cropping zone of Western Australia. In wheat, the highest profits were obtained from the complete fertiliser strategy (N, P, K, S, TE). However, for barley, the greatest profits were not obtained with the highest grain yields and fertiliser strategies due to decreased grain quality.

scholarly journals Modelling the effects of row configuration on sorghum yield reliability in north-eastern Australia

2005 ◽  
Vol 56 (1) ◽  
pp. 11 ◽  
Author(s):  
Jeremy Whish ◽  
Giles Butler ◽  
Michael Castor ◽  
Shayne Cawthray ◽  
Ian Broad ◽  
...  
Keyword(s):  
Light Interception ◽  
Yield Potential ◽  
Annual Rainfall ◽  
Average Yield ◽  
Crop Failure ◽  
Production Risk ◽  
Eastern Australia ◽  
The Difference ◽  
Sorghum Production

In recent years, many sorghum producers in the more marginal (<600 mm annual rainfall) cropping areas of Queensland and northern New South Wales have used skip row configurations in an attempt to improve yield reliability and reduce sorghum production risk. This paper describes modifications made to the APSIM sorghum module to account for the difference in water usage and light interception between alternative crop planting configurations, and then demonstrates how this new model can be used to quantify the long-term benefits of skip sorghum production. Detailed measurements of light interception and water extraction from sorghum crops grown in solid, single and double skip row configurations were collected from on-farm experiments in southern Qld and northern NSW. These measurements underpinned changes to the APSIM-Sorghum model so that it accounted for the elliptical water uptake pattern below the crop row and the reduced total light interception associated with skip row configurations. Long-term simulation runs using long-term weather files for locations near the experimental sites were used to determine the value of skip row sorghum production as a means of maintaining yield reliability. These simulations showed a trade-off between long-term average production (profitability) and annual yield reliability (risk of failure this year). Over the long term, the production of sorghum in a solid configuration produced a higher average yield compared with sorghum produced in a skip configuration. This difference in average yield is a result of the solid configuration having a higher yield potential compared with the skip configurations. Skip configurations limit the yield potential as a safeguard against crop failure. To achieve the higher average yield in the solid configuration the producer suffers some total failures. Skip configurations reduce the chance of total failure by capping the yield potential, which in turn reduces the long-term average yield. The decision on what row configuration to use should be made tactically and requires consideration of the starting soil water, the soil’s plant-available water capacity (PAWC), and the farm family’s current attitude to risk.

An approach to crop yield improvement through diagnostic systems research in a winter-dominant rainfall environment

2014 ◽  
Vol 65 (9) ◽  
pp. 922 ◽  
Author(s):  
W. K. Anderson ◽  
R. M. McTaggart ◽  
N. C. McQuade ◽  
D. Carter ◽  
T. Overheu ◽  
...  
Keyword(s):  
Crop Production ◽  
Crop Yields ◽  
Farming System ◽  
Limiting Factors ◽  
Annual Rainfall ◽  
Diagnostic Systems ◽  
Potential Yield ◽  
Pasture Production ◽  
Systems Research ◽  
Yield Responses

Crop production in the high-rainfall zone of Western Australia (>450 mm average annual rainfall) is an increasing proportion of the state’s total farming system since the 1990s, when the profitability of animal production based on improved pastures was threatened. However, the yields of the dominant crops barley, canola and oats have often been insufficient to maintain whole-farm productivity in the changed system. The aim of this study was to test the diagnostic approach to agronomic research as a means of increasing crop yields. Experiments were conducted at two farm sites over 5 years with treatments applied according to an initial diagnosis of the factors that may have been limiting production. The diagnosis of limiting factors was based on soil physical and chemical tests, plant tissue analyses and the observations of the farmers. The diagnostic tests were assessed against agreed standards. The highest yields in each year were compared with an estimate of the rainfall-limited potential yields. In both experiments, more than one factor was considered likely to be limiting crop and pasture production; therefore, factorial combinations of treatments were used, including deep-placed lime, deep-placed potassium and claying at one site, and deep ripping, raised beds and gypsum at the other. Split doses of nitrogen were applied to half of the plots after waterlogging events in some years. The yield responses to the treatments changed each year but the highest yields were close to the calculated potential yield after taking account of estimated losses of water. Interactions between the factors were not often significant. That is, the responses were additive and independent, so they can be applied sequentially. No single factor could be identified as the most limiting at either site over the 5 years. However, the results suggested a hierarchy of measures that could be taken according to the least cost or the most profit principle, or according to farmer preference and convenience.

scholarly journals Diagnosing the Climatic and Agronomic Dimensions of Rain-Fed Oat Yield Gaps and Their Restrictions in North and Northeast China

2019 ◽  
Vol 11 (7) ◽  
pp. 2104 ◽  
Author(s):  
Chong Wang ◽  
Jiangang Liu ◽  
Shuo Li ◽  
Ting Zhang ◽  
Xiaoyu Shi ◽  
...  
Keyword(s):  
Northeast China ◽  
Crop Production ◽  
Crop Yields ◽  
Climatic Conditions ◽  
Planting Density ◽  
Limiting Factors ◽  
High Yield ◽  
Yield Gap ◽  
Potential Yield ◽  
Yield Gaps

Confronted with the great challenges of globally growing populations and food shortages, society must achieve future food security by increasing grain output and narrowing the gap between potential yields and farmers’ actual yields. This study attempts to diagnose the climatic and agronomic dimensions of oat yield gaps and further to explore their restrictions. A conceptual framework was put forward to analyze the different dimensions of yield gaps and their limiting factors. We quantified the potential yield (Yp), attainable yield (Yt), experimental yield (Ye), and farmers’ actual yield (Ya) of oat, and evaluated three levels of yield gaps in a rain-fed cropping system in North and Northeast China (NC and NEC, respectively). The results showed that there were great differences in the spatial distributions of the four kinds of yields and three yield gaps. The average yield gap between Yt and Ye (YG-II) was greater than the yield gap between Yp and Yt (YG-I). The yield gap between Ye and Ya (YG-III) was the largest among the three yield gaps at most sites, which indicated that farmers have great potential to increase their crop yields. Due to non-controllable climatic conditions (e.g., light and temperature) for obtaining Yp, reducing YG-I is extremely difficult. Although YG-II could be narrowed through enriching soil nutrients, it is not easy to improve soil quality in the short term. In contrast, narrowing YG-III is the most feasible for farmers by means of introducing high-yield crop varieties and optimizing agronomic managements (e.g., properly adjusting sowing dates and planting density). This study figured out various dimensions of yield gaps and investigated their limiting factors, which should be helpful to increase farmers’ yields and regional crop production, as long as these restrictions are well addressed.

The Brigalow Catchment Study: III. Productivity changes on brigalow land cleared for long-term cropping and for grazing

Soil Research ◽  
2007 ◽  
Vol 45 (7) ◽  
pp. 512 ◽  
Author(s):  
B. J. Radford ◽  
C. M. Thornton ◽  
B. A. Cowie ◽  
M. L. Stephens
Keyword(s):  
Crop Production ◽  
Clay Soil ◽  
Soil Nutrient ◽  
Grain Protein Content ◽  
Annual Rainfall ◽  
Soil N ◽  
Stocking Rate ◽  
Beef Production ◽  
Eastern Australia ◽  
Productivity Decline

Productivity of grain crops and grazed pastures inevitably declines without soil nutrient replacement and may eventually make these enterprises unprofitable. We monitored these declines in north-eastern Australia during 23 years after clearing 2 of 3 adjacent brigalow catchments, in order to define the productivity levels of developed brigalow land over time. One catchment (11.7 ha) was used for grain production and another (12.7 ha) for beef production from a sown buffel grass pasture. There was no upward or downward trend in annual rainfall amounts throughout the study period. In the cropped catchment, grain yield from 14 winter crops without added nutrients declined significantly in 20 years from 2.9 to 1.1 t/ha.year on the upper-slope clay soil (92 kg/ha.year) and from 2.4 to 0.6 t/ha.year on the Sodosol (88 kg/ha.year). Crop production per year declined by 20% between 2 successive 10-year periods. Wheat grain protein content also declined with time, falling below the critical value for adequate soil N supply (11.5%) 12 years after clearing on the Sodosol and 16 years after clearing on the clay soil. Such declines in grain quantity and quality without applied fertiliser reduce profitability. The initial pasture dry matter on offer of 8 t/ha had halved 3 years after clearing, and a decline in cattle liveweight gain of 4 kg/ha.year was observed over an 8-year period with constant stocking of 0.59 head/ha. Due to fluctuating stocking rate levels of 0.3–0.7 head/ha over the trial period, liveweight productivity trends are attributed to the multiple effects of stocking rate changes and fertility decline. The amount of nitrogen exported from the cleared catchments was 36.1 kg/ha.year in grain but only 1.6 kg/ha.year in cattle (as liveweight gain). Total soil N at 0–0.3 m declined by 84 kg/ha.year under cropping but there was no significant decline under grazing. The soil nutrients removed during grain and beef production need to be replaced in order to avert productivity decline post-clearing.

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