Increasing the depth of soil disturbance increases yields of direct drilled wheat on the sandplain soils of Western Australia

1994 ◽  
Vol 34 (6) ◽  
pp. 777 ◽  
Author(s):  
CP Schmidt ◽  
RK Belford

We evaluated on sandplain soils in the northern wheatbelt of Western Australia in 1990 and 1991 the effect on wheat yields (Triticum aestivum) of increasing the depth of soil disturbance (4-40 cm) while direct drilling. These sandplain soils are easily compacted and eroded by wind, but yields after direct drilling with tined implements are frequently poorer than yields after cultivation. Direct drilling with a tined seeder was compared with: (i) direct drilling with a modified seeder on which the front 3 rows of cultivating tines could be lowered relative to the rear 3 rows of seeding tines; and (ii) with direct drilling followed immediately by deep ripping. Progressively increasing the depth of disturbance reduced soil strength and generally increased grain yields of wheat. Effects on yield were more pronounced in the wetter year of 1991 on an experimental site that had not been previously ripped; responses of 32 kg/ha for each centimetre increase in depth of disturbance were recorded. The highest yields followed deep ripping (3429 kg/ha), and the lowest yields followed minimal soil disturbance using narrow (5 cm) seeding tines working to seeding depth only (2144 kg/ha). These results confirmed that it is possible to use a modified direct drilling technique (thus retaining the advantages of timely sowing after rainfall and lowered risk of wind erosion) and raise yields above those normally expected from direct drilling on these soils.

1994 ◽  
Vol 45 (3) ◽  
pp. 547 ◽  
Author(s):  
CP Schmidt ◽  
RK Belford ◽  
D Tennant

Experiments were conducted to compare different direct drilling and conventional sowing techniques, and describe the effects of these techniques on soil strength, root growth and grain yield of wheat on sandplain soils in the northern wheat-belt of Western Australia. Soil strength was identified as a critical factor affecting root growth; increasing the depth of soil loosening beneath seeding depth with a modified direct drill reduced soil strength relative to that found in the traditional direct drill treatments, and increased rooting density beyond the 10 cm soil depth. As loosening depth increased, there were increases in both shoot growth and grain yields, and water use efficiency also improved. Maximizing the depth of soil disturbance by deep ripping after sowing resulted in the highest grain yields, but the time and cost penalties associated with this tillage operation are substantial and likely to deter its routine use. Modifying a direct drill to loosen soil beneath sowing depth therefore combined the advantages of conventional direct drilling (timeliness, moisture conservation and lower risk of erosion), with those obtained by sowing after cultivation (improved root growth and yield) without the yield penalties associated either with direct drilling or delayed sowing on these soils.


1993 ◽  
Vol 33 (7) ◽  
pp. 895 ◽  
Author(s):  
CP Schmidt ◽  
RK Belford

The effects of tillage-seeding method and 2 times of sowing on yields of wheat (Triticum aestivum) were examined on the sandplain soils in the northern wheatbelt of Western Australia. Four methods were compared: sowing after cultivation, sowing followed by deep ripping, direct drilling (i.e. single-pass seeding with a tined drill), sowing with a new cultivation depth modified drill (CDM) modified to cultivate up to 14 cm deep while sowing at 4 cm. Crops direct-drilled with the CDM produced more grain than crops established with conventional direct drilling or 'crops sown later using the cultivate-sow method and had similar yields to late-sown deep-ripped crops, where appropriate cultivars were used. Early sowing followed by deep ripping produced the highest grain yield. However, increasing the depth of soil disturbance while sowing early with the CDM in a 1-pass system resulted in a progressive increase in grain yield. When the cost of the extra ripping or cultivation operation is taken into account, early direct drilling with the CDM drill is likely to be more profitable than either conventional direct drilling or sowing with deep ripping or cultivation.


1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.


2014 ◽  
Vol 36 (2) ◽  
pp. 146 ◽  
Author(s):  
T. L. Moore ◽  
M. D. Craig ◽  
L. E. Valentine ◽  
G. E. St J. Hardy ◽  
P. A. Fleming

Soil disturbance by terrestrial vertebrates when foraging for food and shelter is not only a sign of activity but an ecosystem function required for soil health. Many forests and woodlands worldwide are currently showing signs of a decline in condition due to various causes. Eucalyptus wandoo, endemic to south-west Western Australia, has undergone a decline in condition over the last decade. This paper explores the influence of E. wandoo condition (e.g. loss of canopy) and the associated changes in the habitat (e.g. changes in leaf litter and bare ground cover) on the foraging activities and soil disturbance by vertebrates. The number of diggings and scats, a representation of the foraging effort by some vertebrates, were recorded in Dryandra Woodland and Wandoo Conservation Park, Western Australia. Mixed-model ANOVAs were used to explore the relationships between the number of scats and diggings with tree and habitat characteristics. More vertebrate diggings and scats were recorded beneath healthier E. wandoo trees. Diggings and scats were also correlated with time since last fire and seasonal differences, with more time since last fire and wetter months related to more diggings and scats. Changes in foraging effort, or turnover of soil by vertebrates, could be a result modification of the level of soil turnover and alter many ecosystem services such as tree recruitment and nutrient cycling, in turn altering the habitat quality and even tree condition itself.


1992 ◽  
Vol 32 (7) ◽  
pp. 857 ◽  
Author(s):  
DJ McFarlane ◽  
JW Cox

Excess water in duplex soils can be removed by drains. In soils in which drainage is impractical, some success has been obtained by deep ripping and by gypsum amendment. These practices can increase profile storage or drainage. Interceptor drains are suitable for duplex soils with slopes of more than about 1.5%. On more gentle slopes, relief drains are used to remove excess water. Subsurface tube and mole drains have been used successfully to drain cereal crops in Victoria, but in Western Australia open drains are preferred because they can carry storm runoff as well as seepage waters. The greatest cost of open drains is the land removed from production. Over 35% of the rain falling during the growing season has been removed by drains in Victoria and Western Australia in wet years. Drainage was almost entirely downslope of monitored interceptor drains in Western Australia, which is not predicted from the theory. Simulation of water levels between drains and of drain flows using the DRAINMOD model indicated significant, preferred pathways for water flow to drains. The pathways explain the predominantly downslope effect of interceptor drains and the wide drain spacings which can be used. Deep ripping and the incorporation of gypsum can reduce waterlogging in some soils, but has had no effect in several others. The effect of deep ripping on recharge is unclear. Drains may decrease groundwater recharge, water and wind erosion, and soil structure decline. Their effect on phosphate export from catchments is unclear.


1997 ◽  
Vol 11 (1) ◽  
pp. 30-34
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper

Seven field experiments were conducted in Oklahoma to compare efficacy and wheat response to currently registered cheat suppression or control herbicide treatments. Chlorsulfuron + metsulfuron premix (5:1 w/w) at 26 g ai/ha applied PRE controlled cheat 20 to 61%, increased wheat grain yields at two of seven locations, and decreased dockage due to cheat at five of seven locations. Chlorsulfuron + metsulfuron at 21 g/ha tank-mixed with metribuzin at 210 g/ha, applied early fall POST, controlled cheat 36 to 98% and increased wheat yield at four of seven locations. Metribuzin applied POST in the fall at 420 g/ha controlled cheat 56 to 98% and increased wheat yields at five of seven locations. Both POST treatments decreased dockage at all locations.


2007 ◽  
Vol 47 (11) ◽  
pp. 1368 ◽  
Author(s):  
D. M. Bakker ◽  
G. J. Hamilton ◽  
D. J. Houlbrooke ◽  
C. Spann ◽  
A. Van Burgel

Waterlogging of duplex soils in Western Australia has long been recognised as a major constraint to the production of agricultural crops and pastures. The work described in this paper examines the application of raised beds to arable land that is frequently waterlogged for the production of crops such as wheat, barley, field peas, lupins and canola. Raised beds are 138 cm wide, seed beds separated by 45 cm wide furrows 183 cm apart. These beds were made with a commercial bed former. Seven sites were selected across the south-eastern wheat belt of Western Australia with the experimental areas varying in size from 10 to 57 ha. These large sites were used to accommodate commercial farm machinery. Each site had raised beds formed with a commercial bedformer. The production from the bedded areas was compared with crops grown conventionally on flat ground under minimum tillage as the control. The experiments were established in 1997 and 1998 and the sites were monitored for a maximum of 5 years. In 11 of the 28 site-years of the experiments, grain yields on the raised beds were statistically significantly higher than the yield from crops grown on the control, with an average yield increase of 0.48 t/ha. Across the whole dataset, growing crops on raised beds did not produce significantly lower yields. Below average rainfall was received for much of the experimental period at several sites. Growing season rainfall had a large effect on grain yield and high rainfall over a period of 40 days after seeding significantly increased the grain yield difference between the raised bed and the control. These data indicate that the use of raised beds lead to higher grain yields when seasonal conditions are appropriate.


1990 ◽  
Vol 30 (5) ◽  
pp. 687 ◽  
Author(s):  
RF Brennan

The effectiveness of copper oxychloride (CU2Cl(OH)3, 52% Cu) and chelated Cu (Cu-EDTA, 15% Cu) were compared with the effectiveness of copper sulphate (CuSO4, 25% Cu) as foliar sprays for alleviating Cu deficiency and obtaining maximum grain yields of wheat (1.93-2.5 t/ha). The experiments were conducted over 4 years at 4 sites in the Lake Grace and Newdegate districts, about 300-350 km south-east of Perth, Western Australia. Each source was sprayed at 6 or 7 rates of Cu to define the relationship between grain yield and the amount of foliar Cu applied for wheat grown on soils where Cu had not been previously applied. The levels of Cu sprayed in experiment 1 were 0, 21, 63, 125, 250, and 375 g/ha, and for experiments 2,3 and 4, the levels of Cu were 0, 25, 50, 100, 200, 400 and 800 g/ha. The relative effectiveness of foliar-applied chelated Cu and CU2Cl(OH)3, compared with CuSO4, was 1.72-2.24 and 0.47-0.63, respectively. Although the relative effectiveness of each product was different, similar quantities of each were required to achieve maximum wheat grain yield because of the difference in the Cu contents of each source of Cu. The amounts of Cu product sprayed for maximum grain yields of wheat varied within the ranges 0.9-1.8 kg/ha, 0.8-1.2 kg/ha and 0.8-1.8 kg/ha for CuSO4, chelated Cu and CU2Cl(OH)3, respectively.


1996 ◽  
Vol 36 (2) ◽  
pp. 209 ◽  
Author(s):  
KHM Siddique ◽  
SP Loss ◽  
SP Herwig ◽  
JM Wilson

The growth, phenology, grain yield and neurotoxin (ODAP) content of Lathyrus sativus, L. cicera and L. ochrus were compared with a locally adapted field pea (Pisum sativum L.) to examine their potential as grain legumes in Western Australian farming systems. About 17 lines of each species were obtained from ICARDA, Syria, and grown at 3 agro-climatically different sites. In general, the 3 species were later flowering than field pea, especially L. cicera and L. ochrus; however, L. sativus was the last species to mature. The best Lathyrus lines produced biomass near flowering similar to field pea. At the most favourable site, grain yields were up to 1.6, 2.6 and 1.7 t/ha for L. sativus, L. cicera and L. ochrus respectively, compared with a field pea grain yield of 3.1 t/ha. There was considerable genotype and environmental variation in ODAP concentration in the seed. On average, the ODAP concentration of L. ochrus (6.58 mg/g) was about twice that of L. sativus, and L. cicera had the lowest ODAP concentration (1.31 mg/g). Given that Lathyrus spp. have not had the same breeding effort as field pea and other grain legumes in Australia, these results encourage further selection or breeding. In the shor-tseasoned, mediterranean-type environment of Western Australia, harvest indices and grain yields could be improved with early flowering. Low ODAP concentration should also be sought.


1997 ◽  
Vol 11 (3) ◽  
pp. 591-597 ◽  
Author(s):  
Eric Spandl ◽  
Beverly R. Durgan ◽  
Douglas W. Miller

Rates and application timings of postemergence herbicides for wild oat control in spring wheat and barley were evaluated at Crookston, MN, from 1994 to 1996. Diclofop, imazamethabenz, and fenoxaprop plus MCPA plus thifensulfuron plus tribenuron were applied to one- to three-leaf wild oat; and difenzoquat, imazamethabenz, fenoxaprop plus MCPA plus thifensulfuron plus tribenuron, and fenoxaprop plus 2,4-D plus MCPA were applied to four- to five-leaf wild oat at 1/2 ×, 3/4 ×, and 1 × rates. Wild oat response to herbicide rate and timing was similar in wheat and barley. Wild oat control with 1/2 × rates generally was less than that with 3/4 × rates, which was lower than or similar to that with 1 × rates. Wild oat biomass was often reduced less with 1/2 × rates than 1 × rates. However, reducing herbicide rates generally did not influence grain yields or net economic return. Grain yields and net economic return were generally greater in herbicide-treated plots than in the nontreated control.


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