A review of trends in wheat yield responses to conservation cropping in Australia

1995 ◽  
Vol 35 (7) ◽  
pp. 835 ◽  
Author(s):  
JA Kirkegaard
Keyword(s):  
Wheat Yield ◽  
Farming Systems ◽  
Yield Response ◽  
Soil Conditions ◽  
Stubble Retention ◽  
Conservation Farming ◽  
Rhizoctonia Root Rot ◽  
Using Data ◽  
Yield Responses

Trends in wheat yield responses to conservation cropping in Australia were analysed using data from 33 medium-term (3-5 year) and long-term (>5 year) agronomic experiments. The overall effect of tillage (direct drilled v. cultivated) was small in all regions (-0.18 to +0.06 t/ha), while stubble retention (stubble retained v. stubble burnt) reduced yield in all regions (-0.31 to -0.02 t/ha). There was large year-to-year variation in the yield response to both tillage and stubble retention at all sites, but no consistent relationship between yield variation and amount or pattern of seasonal rainfall based on monthly totals. There was also little evidence that the yield of direct-drilled and stubble-retained treatments increased relative to cultivated or stubble-burnt treatments with the duration of the experiments, despite the improvement in soil conditions reported at many sites. The factors thought responsible for the year-toyear variation in yield response varied within and between regions, although some consistent effects emerged. Reduced early seedling growth of directdrilled crops was considered a major factor underlying the yield response at most sites, and this was rarely associated with the availability of water or nitrogen. High soil strength and increased severity of rhizoctonia root rot were responsible for these effects at some sites, but at others the cause remains unclear. Stubble retention influenced yield in many ways but the significance of the allelopathic effects of stubble, suspected by many authors to influence crop growth, is poorly understood. Adoption of direct drilling and stubble retention is likely to remain low in areas where no long-term yield benefit can be demonstrated and where greater management flexibility is offered by systems of reduced cultivation and late stubble burning-incorporation. Further research should identify and develop strategies to overcome the constraints to yield in conservation farming systems, particularly stubble retention, and assess the sustainability of recent innovations incorporating minimum disturbance and partial stubble retention. The more rapid adoption of such intermediate strategies will hasten the move of the grains industry toward sustainable production.

Soil measurements and wheat yield response to superphosphate in Victoria

1975 ◽  
Vol 15 (72) ◽  
pp. 93
Author(s):  
B Palmer ◽  
VF McClelland ◽  
R Jardine
Keyword(s):  
Wheat Yield ◽  
Geographic Location ◽  
Yield Response ◽  
Soil Test ◽  
Soil Tests ◽  
Yield Data ◽  
Chemical Measurements ◽  
Soil Measurements ◽  
Yield Responses ◽  
Available Phosphate

The relationships between soil tests for 'plant available' phosphate and wheat yield response to applied superphosphate were examined and the extent to which these relationships were modified by other soil measurements was determined. Soil samples and wheat yield data were obtained from experiments conducted in the Victorian wheat belt. The sites were grouped into four relatively uniform classes using soil pH measurement and geographic location. The soil test values differed widely and were accountable for by the soil characteristics measured. However, the overall and within group yield responses to applied superphosphate could not be accounted for in terms of either the soil test value or the associated chemical measurements. By inference, yield response was clearly dependent on factors other than those determining the results of soil tests.

Cropping practices in the Victorian Mallee. 1. Effect of direct drilling and stubble retention on the water economy and yield of wheat

1993 ◽  
Vol 33 (7) ◽  
pp. 877 ◽  
Author(s):  
M Incerti ◽  
PWG Sale ◽  
GJ O'Leary
Keyword(s):  
Crop Yield ◽  
Wheat Yield ◽  
Production Costs ◽  
Research Station ◽  
Stubble Retention ◽  
Conservation Farming ◽  
Direct Drilling ◽  
Chemical Fallow ◽  
The Impact ◽  
Lower Production

Two experiments were conducted at the Mallee Research Station, Walpeup, between 1985 and 1989 to evaluate the impact of conservation farming practices on wheat yields. The first experiment compared wheat crops established by direct drilling into a chemical fallow with those conventionally sown into a cultivated fallow. Over the 5 years, yields ranged from 1.31 to 3.24 t/ha, and there was no reduction in crop yield associated with chemical fallowing and direct drilling compared with the cultivated fallow. There was also no significant effect of the chemical fallow on the amount of water conserved in the soil at sowing, at depth 0-100 cm; the range was 206-274 mm water. The second experiment from 1987 to 1989 examined the effect of maintaining 4 rates of stubble (0, 0.5, 1.0, 2.0 t/ha) on the surface of a conventionally cultivated long fallow. Stubble maintained at 2 t/ha increased the amount of water stored in the soil at sowing, at depth 0-140 cm, by 16 mm in 1 year of 3. This increase in soil water availability was not reflected in increased crop yield. These findings indicate that erosion control and potentially lower production costs associated with direct drilling and stubble retention can be achieved without loss of wheat yield in the Victorian Mallee.

Comparative soil water, pasture production, and crop yields in phase farming systems with lucerne and annual pasture in Western Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 295 ◽  
Author(s):  
R. A. Latta ◽  
L. J. Blacklow ◽  
P. S. Cocks
Keyword(s):  
Soil Water ◽  
Western Australia ◽  
Oil Content ◽  
Field Experiments ◽  
Crop Yields ◽  
Wheat Yield ◽  
Farming Systems ◽  
Yield Response ◽  
Grain Protein ◽  
Pasture Production

Two field experiments in the Great Southern region of Western Australia compared the soil water content under lucerne (Medicago sativa) with subterranean clover (Trifolium subterranean) and annual medic (Medicago polymorpha) over a 2-year period. Lucerne depleted soil water (10–150 cm) between 40 and 100 mm at Borden and 20 and 60 mm at Pingrup compared with annual pasture. There was also less stored soil water after wheat (Triticum aestivum) and canola (Brassica napus) phases which followed the lucerne and annual pasture treatments, 30 and 48 mm after wheat, 49 and 29 mm after canola at Borden and Pingrup, respectively. Lucerne plant densities declined over 2 seasons from 35 to 25 plants/m2 (Borden) and from 56 to 42 plants/m2 (Pingrup), although it produced herbage quantities similar to or greater than clover/medic pastures. The lucerne pasture also had a reduced weed component. Wheat yield at Borden was higher after lucerne (4.7 t/ha) than after annual pasture (4.0 t/ha), whereas at Pingrup yields were similar (2 t/ha) but grain protein was higher (13.7% compared with 12.6%) . There was no yield response to applied nitrogen after lucerne or annual pasture at either site, but it increased grain protein at both sites. There was no pasture treatment effect on canola yield or oil content at Borden (2 t/ha, 46% oil). However, at Pingrup yield was higher (1.5 t/ha compared to 1.3 t/ha) and oil content was similar (41%) following lucerne–wheat. The results show that lucerne provides an opportunity to develop farming systems with greater water-use in the wheatbelt of Western Australia, and that at least 2 crops can be grown after 3 years of lucerne before soil water returns to the level found after annual pasture.

scholarly journals Pasture yield responses to irrigation in Canterbury

1994 ◽  
pp. 165-168 ◽  
Author(s):  
S.D. Mcbride
Keyword(s):  
Soil Moisture ◽  
Drop Out ◽  
Yield Response ◽  
Research Station ◽  
Response Curves ◽  
Response Data ◽  
Term Trial ◽  
Water Restrictions ◽  
Yield Responses

Major findings from 13 pasture irrigation experiments conducted in Canterbury are discussed. Yields and response curves on 8 of the experimental sites were very similar to those of the long-term trial (34 years) site at the Winchmore Research Station. Irrigating when soil moisture dried to 50% asm (available soil moisture), increased annual pasture DM yields by an average of 5.2 t/ha DM (80% increase over the non-irrigated yield). Response per irrigation and yield variation between years decreased as the number of irrigations increased. During water restrictions, irrigators often choose to either keep watering their whole farm with a longer irrigation return period, or drop out paddocks and fully irrigate the remainder. The irrigation response data are used to discuss these and other possible strategies. Keywords: irrigation, pasture yields, response curves, water restrictions

Superphosphate on wheat: The cumulative effect of repeated applications on yield response

1968 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
VF McClelland
Keyword(s):  
Wheat Yield ◽  
Cumulative Effect ◽  
Cumulative Effects ◽  
Residual Effects ◽  
Yield Response ◽  
Experimental Site ◽  
Growing Period ◽  
Rotation System ◽  
Repeated Applications ◽  
Yield Responses

The cumulative effects of repeated applications of superphosphate on wheat yield responses, over a period of 26 years (10 cycles of a rotation system), were examined. Since cumulative effects are the sum of current and residual effects and current effects diminish with repeated applications of superphosphate, this approach enabled residual effects to be inferred. Residual effects were apparent at all rates of application (30, 60, 90, and 120 lb/acre), being greater at the three higher levels. The influence of rainfall in the growing period (April to October) on cumulative effects was also examined. April rainfall increased yield at all levels of application, whereas September rainfall increased yield only at 90 and 120 lb/acre of superphosphate. The results indicate that, for this particular experimental site, residual phosphorus has become more important in determining yield responses than currently applied phosphorus.

An evaluation of several soil tests for predicting wheat yield response to superphosphate in Victoria

1968 ◽  
Vol 8 (30) ◽  
pp. 52
Author(s):  
JV Mullaly ◽  
JKM Skene ◽  
R Jardine
Keyword(s):  
Field Experiments ◽  
Wheat Yield ◽  
Response Variability ◽  
The Other ◽  
Yield Response ◽  
Available Phosphorus ◽  
Soil Test ◽  
Soil Tests ◽  
Using Data ◽  
Soil Groups

The predictability of three different measures of wheat yield response to superphosphate from each of four soil test measures of available phosphorus (0-6 inches) was examined, using data from field experiments over the period 1951 to 1965. The associations were studied separately within the three great soil groups that are dominant over the wheatgrowing areas of Victoria. Whichever measure of yield response was considered, soil bicarbonate P test measurement gave the best basis for prediction. However, at most, only 26 per cent of the yield response variability was predictable, and the other three tests were substantially less successful. Under the general conditions considered, where yield response is subject to a variety of uncorrected environmental deficiencies, it is concluded that the soil tests for P investigated in this paper are of doubtful practical value.

Effects of annual pasture composition on subsequent wheat yields in the Waite Permanent Rotation Trial, South Australia

1998 ◽  
Vol 38 (1) ◽  
pp. 55 ◽  
Author(s):  
A. D. Moore ◽  
P. R. Grace
Keyword(s):  
Yield Loss ◽  
Wheat Yield ◽  
South Australia ◽  
Farming Systems ◽  
Published Data ◽  
Pasture Grass ◽  
Permanent Rotation ◽  
Cereal Yields ◽  
Pasture Legume

Summary. Legume-based annual pastures are commonplace in southern Australian dryland farming systems. By using the long-term wheat and pasture yield records from the Waite Permanent Rotation Trial (established in 1925), we have quantified how changes in the production and composition of a ley pasture will affect subsequent cereal yields and profitability. An analysis of the 1965–89 record reveals that 43% of the variance in wheat yield can be accounted for by the equation: WY = 3.42 + 0.0165AOR – 0.0000165AOR2 + 0.12PL – 2.64PG + 0.39PG2 – 0.019PG3 where WY is wheat yield (t/ha), AOR is April –October rainfall in the wheat year (mm), PL is pasture legume yield in the preceding year (t/ha) and PG is pasture grass yield in the preceding year (t/ha). By comparison with other published data, our results support the claim that nitrogen from legume sources is economically more efficient than fertiliser nitrogen, but the largest effect of increasing legume content comes from avoiding yield loss associated with grassy pastures.

Wheat yield response to rainfall in a long-term multi-rotation experiment in the Victorian Wimmera

1995 ◽  
Vol 35 (7) ◽  
pp. 951 ◽  
Author(s):  
MC Hannah ◽  
GJ O'Leary
Keyword(s):  
Wheat Yield ◽  
Field Pea ◽  
Yield Response ◽  
Yield Data ◽  
Long Term Trends ◽  
Quadratic Response ◽  
Wheat Stubble ◽  
High Yields ◽  
Crop Sequence

Seventy-six years of wheat yield data from a long-term rotation experiment at Dooen in the Victorian Wimmera were analysed to describe the response of wheat yield to seasonal rainfall, crop sequence, and time. Wheat yields from 7 different 1- to 4-course rotations involving wheat, barley, oat, field pea, grass pasture and fallow were compared as a function of growing-season (May-November) rainfall. The field layout had no within-year replication, but each phase of each rotation was represented once in each year. An approximate quadratic response of wheat yield to both current year and previous year May-November rainfall was observed for each rotation. Previous year May-November rainfall boosted wheat yields grown on fallow, but decreased the yield of wheat grown on field pea or wheat stubble. Highest wheat yields followed fallow preceded by pasture, high yields followed fallow preceded by a cereal, moderate yields followed field pea, and low yields occurred for continuous wheat. Long-term trends in wheat yields adjusted for rainfall depended on crop sequence and fluctuated more in the non-fallow, 3-course rotations. Over the 76 years, average yield declined in all rotations except the continuous wheat, which was always low, but there was evidence that yield of all continuous cropped rotations had increased during the last 2 decades.

scholarly journals Strategic tillage of a long-term, no-till soil has little impact on soil characteristics or crop growth over five years

2020 ◽  
Vol 71 (12) ◽  
pp. 945
Author(s):  
John Kirkegaard ◽  
Clive Kirkby ◽  
Albert Oates ◽  
Vince van der Rijt ◽  
Graeme Poile ◽  
...  
Keyword(s):  
Fine Fraction ◽  
Crop Growth ◽  
Total Carbon ◽  
Growth And Yield ◽  
Soil Conditions ◽  
Stubble Retention ◽  
No Till ◽  
C Stocks ◽  
The Impact

Strategic tillage describes the occasional use of tillage in an otherwise no-till system. The practice can provide a pragmatic solution to emerging agronomic issues in no-till systems but raises concerns about prolonged or irreversible soil damage. We investigated the impact of a single tillage event at a long-term no-till experiment under treatments with retained or annually autumn-burned crop residues. One half of each residue-treatment plot received a single pass of a rotary hoe (ST) 4 weeks before sowing in 2011, the first year of the experiment; the other half of each plot remained unchanged (NT). Soil physical, chemical and biological fertility in the surface layers (0–20 cm), as well as crop growth and yield were monitored for 5 years (2011–15). Following the ST treatment, soil bulk density and strength were initially reduced to the depth of cultivation (~15 cm) irrespective of residue treatment. Water-stable macroaggregates in the surface 0–5 cm were also reduced but recovered to pre-tillage levels within 1–2 years after ST treatment. Soil pH, total carbon (C), total nitrogen (N), and fine-fraction C and N were all initially stratified in the surface layer (0–5 cm) of the NT treatment but were redistributed more evenly throughout the 0–10 cm layer of the ST treatment and remained so throughout the 5-year period. With ST, there was an initial loss in total C stocks in the 0–10 cm layer of 2.2 t/ha, which recovered within 2 years; however, total C stocks remained lower in plots with stubble retained than with stubble burnt after 5 years. Soil Colwell P levels were not stratified and not influenced by tillage treatment, presumably because of the annual additions in the starter fertiliser at sowing. ST had no impact on crop establishment or grain yield in any year but increased the early biomass of wheat at Z30 compared with NT in the first 2 years. Annual stubble retention reduced the early growth of crops in all years, and yield of wheat in the first 3 years, consistent with long-term effects of retained stubble at the site, but there was no interaction between stubble retention and tillage treatments on soil conditions or crop growth. Crop yields of long-term, annually cultivated treatments were also similar to those of ST and NT treatments during the 5 years of the experiment. Overall, the minor short-term negative impacts on soil physical conditions, the persistent and arguably beneficial effects on soil chemistry and biology, and absence of impacts on crop production suggest that strategic tillage can be a valuable agronomic tool in sustainable production in this region.

Advances in precision agriculture in south-eastern Australia. V. Effect of seasonal conditions on wheat and barley yield response to applied nitrogen across management zones

2009 ◽  
Vol 60 (9) ◽  
pp. 901 ◽  
Author(s):  
M. R. Anwar ◽  
G. J. O'Leary ◽  
M. A. Rab ◽  
P. D. Fisher ◽  
R. D. Armstrong
Keyword(s):  
Grain Yield ◽  
Precision Agriculture ◽  
Wheat Yield ◽  
Barley Grain ◽  
Yield Response ◽  
Management Zones ◽  
Yield Zone ◽  
Crop Models ◽  
Eastern Australia

Spatial variability in grain yield across a paddock often indicates spatial variation in soil properties, especially in regions like the Victorian Mallee. We combined 2 years of field data and 119 years of simulation experiments (APSIM-Wheat and APSIM-Barley crop models) to simulate crop yield at various levels of N application in 4 different management zones to explore the robustness of the zones previously determined for an experimental site at Birchip. The crop models explained 96% and 67% of the observed variability in wheat and barley grain yields, with a root mean square error (RMSE) of 310 kg/ha and 230 kg/ha, respectively. The model produced consistent responses to the observed data from the field experiment in 2004 and 2005 where a high and stable yielding zone produced the highest dry matter as well as grain yield, while a low and variable zone recorded the lowest grain yield. However, from the long-term (119 years) simulation, the highest median wheat yield value was obtained on the low variable zone (2911 kg/ha) with high N fertiliser application, while the lowest was obtained on the high variable zone (851 kg/ha). Similarly, the highest barley yields (1880–3350 kg/ha) occurred on the low variable zone using the long-term simulation. In 10–20% of years the highest yield occurred in the high-yielding zones, with the variable and stable zones changing rank with interactive behaviour only under early-sown conditions. Our analyses highlight the problem of using a limited range of seasons of different weather conditions in agronomy to make strategic conclusions as the long-term simulation did not confirm the original yield zone determination. The challenge ahead is to predict in advance the seasons where application of N fertiliser will be beneficial.

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