•  Bill Crabtree harvesting 2009 crop

  • Iguazu falls, South America 2016

  • Cotton, Rondonopolis, Brazil, South America 2016

  • On the Amazon, South America 2016

  • 13 t/ha wheat crop in England on 2015 Europe Ag Tour

  • Finding ANZAC relations’ graves in Ypres, Belgium, 2015 Europe Ag Tour

  • China Tour 2013

     China-Vietnam Study Tour 2013

  •  China-Vietnam Study Tour 2013

  •  China-Vietnam Study Tour 2013

  •  North America Study Tour 2010

  •  North America Study Tour 2010

  • James Crabtree

     The late James Crabtree (92) enjoying the fruits of our labour

  •  The 2011 crop year – our best so far

  •  The 2011 crop year – our best so far

  •  The 2011 crop year – our best so far

  •  The 2011 crop year – our best so far

  •  The 2011 crop year – our best so far

WAN3 - Scientific Officer Project or 'No-till Systems Scientific Officer' for: 'The development and extension of no-till farming systems in WA'

October 2002

The project was undertaken by Bill Crabtree [B.Ag. Sci., M.Sc.]
Supervised by WANTFA from 24th April 1997 to 31st Sept 2002 – By Geoffrey Marshall (Hyden farmer) for 4 years and Neil Young (Kojonup farmer) for 1.5 years

Contents

Summary
Project overview
Adoption of No-Tillage
Developments of no-till in WA
Some problems with no-tillage
Where to now with no-tillage?
Appendix (Refer to pdf)
References (Refer to pdf)

Summary

The project has been extremely successful. Perhaps one of the most successful Projects that GRDC has funded. This Project has helped to take no-tillage adoption from 25% to about 75% through the 5.5 years of the Project. The Project in partnership with WANTFA has had an enormous positive impact on the agricultural economy of Western Australia, particularly in the last three dry years (2000–2002).

This report estimates that no-tillage adoption has resulted in an extra 12 mt of grain being produced in the last three dry years. This is estimated to be worth $2.4 billion to the rural economy of Western Australia.

The spectacular success of this Project can be attributed to the effectiveness of the WANTFA network and a no-till idea whose time was right for WA. The Project had a spectacular contact of 20,000 farmer through group meetings. There were also thousands of one to one farmer contacts, a well respected quarterly WANTFA Farming Systems magazine, large WANTFA Annual Conferences, dynamic local field days, the large WANTFA Meckering R&D site and a well used WANTFA website.

This report gives an overview of the WAN3 Project and discusses the adoption, development and problems with no-tillage in Western Australia. The report also discusses some future requirements for no-till and its economic impact.

For completeness, this report will also contain some background on no-till developments for the six preceding years to the Project – which began in April 1996. References in the text to page numbers and dates refers to the WANTFA Farming Systems magazine which is published on the WANTFA website [www.wantfa.com.au].

Project overview

Background to Project
In the early 1990’s there was enormous farmer enthusiasm for the adoption of no-tillage, particularly on the wind erosion prone sandy soils of the south coast. Some senior staff from the Western Australian Department of Agriculture (WADA) were not positive about this farmer enthusiasm and their rapid adoption of no-tillage. Farmers were frustrated by what they believed to be, a lack of objective WADA data that reflected their positive whole-farm benefits from their adoption of no-tillage.

Wisdom did prevail and the Department of Agriculture worked with WANTFA in writing a joint submission to GRDC for the 5-year WAN3 Project (worth $540,000) for the extension of no-tillage information. The Department contributed $100,000, over five years to the Project, to enable it to be administered external to the Department. The ‘not for profit’ WANTFA group was at this time 5-years old and through their committee they managed the Project through to completion.

General extension overview
There has been a large amount of work conducted through the Project. There have been approximately 20,000 contacts made with farmers and scientists in groups throughout WA, Australia and the world during the project (see summary table below and attached appendix for specific detail). Most contacts were initiated by the Project yet about 9,000 were initiated by others where the Scientific Officer was invited to contribute.
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Over the five years, WANTFA has held Conferences and Seminars that have attracted 6,580 people, and field days that have attracted 3,710. The Scientific Officer has conducted at least 68 radio interviews and has spoken at other non-WANTFA events to a further 9,110. This totals 19,920 day-group contacts. Individual contacts have not been documented. WANTFA membership has grown from 600 to 1,370 as of September 2002. During this time relations with WADA staff have strengthened, with WADA now generally adopting no-tillage as the most sensible form of crop establishment.

The Project has enabled thousands of individual contacts to be made (not monitored). Peak group activity occurred in the middle two years when demand for information was at its greatest. In the last 20 months of the Project there was an increase in research activity mostly through the GRDC funded Meckering Project (WAN6) to help answer many of the questions raised during the project. Most of this research has been conducted by private researchers and supervised by the Scientific Officer.
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Peak group activities occurred during autumn and spring. Autumn group contacts were generally in a Conference or Seminar setting, while spring contacts were usually as field days, with some Seminars.

Through years of farmer ‘trial and error’ and sharing of these experiences through WANTFA forums (conferences, magazine, field days and via the ABC radio) farmers have become very confident in the no-tillage system for establishing crops in marginal moisture conditions. The WAN3 Project has been a highly effective catalyst for this adoption.

Other significant Project activities and impact
  • Nurtured the three-fold adoption of no-tillage in WA, from 25 to 75% of cropping land;
  • Through no-tillage, farmer water use efficacy has generally doubled in the last 10 years;
  • No-till adoption, with improved water use efficacy, has probably increased crop grain production by 12 mt grain during this time, and the benefits will continue to be felt for many years;
  • This extra farm production has injected money and life into rural towns and communities;
  • The Project oversaw the doubling of WANTFA membership from 600 to 1,370;
  • WANTFA conducted two international Study Tours, being; 53 people to North America in August 1998 and 35 people to South America in August 2001;
  • The Scientific Officer was a catalyst for the birth of South Australia (SANTFA), Pacific North West (PNWDSA) and South African, Western Cape no-till farmers associations;
  • The Scientific Officer co-edited the WA produced "No-Tillage Essentials" in conjunction with the Western Australian Department of Agriculture and other contributing groups;
  • The Scientific Officer helped to edit three sections of the ‘Min-Till Drill’ and co-edited a chapter on "Rotations for no-tillage in Australia" for the Kondinin Groups publication;
  • Young farmers are particularly drawn to the leading edge information that WANTFA provides;
  • The Scientific Officer edited the quarterly WANTFA Farming Systems magazine for the 5 years. This magazine has improved in quality with each edition, becoming colour in July 1998;
  • Set up and managed the $180,000/year Meckering R&D site (30% funded by GRDC, WAN6);
  • The Scientific Officer has designed, supervised and written up more than 70 trials over four years, mostly through the Meckering site;
  • Worked hard at cementing good relations with the Department of Agriculture, joint Projects are now being undertaken;
  • Organised the speaking program for five WANTFA Annual Conferences;
  • Supervised and managed the large and highly used WANTFA website;
  • The Scientific Officer has had 5 invitations to talk to large farmer groups on no-tillage in other countries (Oregon USA, Ohio USA, Argentina, Spain and South Africa) and three other Australian states;
  • WANTFA has become a source of information on sustainable agriculture and innovation;
  • The key to the success of this Project has been the dynamic link it has created between researchers and farmers and the intensity of activity of the Scientific Officer.

Adoption of No-Tillage

What is no-till?
No-tillage is sowing without prior cultivation and with little soil disturbance at seeding. These terms have evolved through the 1980’s in WA (page 122 of Nov 1997), but have remained constant within WANTFA since then. The main useful tillage terms WANTFA promotes are:

  1. multiple tillage - two or more tillages before seeding, it replaces the term conventional tillage;
  2. reduced tillage - one pass prior to seeding with a full cut-out;
  3. direct drilling - one pass seeding with a full-cut;
  4. no-tillage - knife point seeding with less than full cut-out (with less than 20% topsoil disturbance);
  5. zero-tillage - disc seeding without soil throw.

From an agronomic point of view all these systems have different implications for water harvesting, herbicide efficacy, soil drying, stubble handling and fertiliser placement. Other compounding factors like wider row spacings and harrows also change the amount of soil disturbance. Sowing pulse crops, with knife points on wide rows, may even throw less soil than a zero-tillage operation. Heavy harrows can move significant amounts of topsoil and fill-in the furrows. There is, even now, reluctance by some WA agriculturalists to adopt the WANTFA evolved tillage terminology.

There is also the term minimum tillage – which is often used. However, this term is confusing! The term has traditionally meant one working before seeding. This was the common use of the term during the 1980’s when I was employed as an extension officer promoting ‘minimum tillage for wind erodable south coast sandplain soils of WA’ in 1985. Nowadays minimum tillage can mean any of the terms 2-5 above. WANTFA supports the idea that terms 2–5 above are minimum tillage systems, but not that any one of these is min-till.

In soils that respond to deep cultivation, some farmers deep rip on wide rows without topsoil inversion. Perhaps it is not valid to call this no-tillage. However, at least two seeders, the DBS and Primary’s Nichols tine, have evolved that can cultivate deep while seeding. The amount of topsoil disturbance in these situations would still be less than 20% and therefore arguably could still be considered as no-tillage. The DBS and Nichols tines can cultivate to 20 and 30 cm depth respectively while sowing.

The incentive to adopt no-till in WA
In the 1980’s many farmers were experimenting with direct drilling, particularly with wheat into lupin stubbles. A subsequent increase in crop yield, with higher stubble levels, coincided with a desire to grow more crops and have less pasture. Farmers were forced to either burn or otherwise remove stubble, or to seed crops using openers capable of getting through the stubble.

Conventional advice that farmers could burn was rejected by many, especially those farmers on the south coast where soils were sandy surfaced and wind erodable. These farmers were also told that they would incur a 10% yield penalty by adopting no-tillage (with knife-points or discs). However, these farmers were desperate for more sustainable cropping systems. Similarly, farmers in the high rainfall areas, usually in southern regions, would often experience water erosion and bogging from tillage based cropping systems.

Despite advice that discouraged the adoption of no-till the farmers still did. Farmers discovered that the yield losses predicted usually did not eventuate. There are many examples, from 1990, when no-tillage produced 2 t/ha crops at Jerramungup when conventionally sown crops could not be established. These experiences were regularly recounted to others and helped to catapult many other farmers into no-till.

The successful establishment of no-tilled crops in dry conditions created a farmer desire to share this information with others. Hence the Western Australian No-Tillage Farmers Association was incorporated in September 1992. The growing awareness of the numerous soil conservation benefits that no-till gave helped to further encourage its adoption.

In 1994 farmer strips and research plots showed that trifluralin worked exceptionally well, and with good crop safety in no-tillage systems (page 60 of May 1995). It performed significantly better than in full tillage systems. At this time farmers were desperate for herbicides that would control ryegrass, other than group A and B – to which resistance was becoming common. This provided a strong continued momentum for further farmer adoption of no-tillage.

No-till adoption patterns in WA
Farmer adoption of no-tillage, including zero-tillage, now covers 75% of WA’s cropland. As the graph below shows, adoption has been rapid (page 308 of Jan 2000). Most adoption occurred in the mid-1990’s. Many farmers now have more than 10 years of no-till experience.
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There are different adoption patterns observed throughout the state. The below table is an estimate based on my farmer contacts. Areas of the State where the soils are very sandy and have persistent strong winds are where adoption has been most rapid - in particular on the south coast and northern sandplain.
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In the early 1990’s the zero-till disc seeders were readily embraced on the south coast. Only a few farmers purchased disc seeders in the northern and central agricultural regions and it remains the same now. Currently, on the south coast, the no-tillage approach is about 30% zero-tillage and 70% knife-point no-tillage.

The availability, cost and suitability of seeders also influenced farmer no-till adoption. In the early 1990’s the Great Plains disc and John Deere’s Biomax (later the Germinator) seeders were popular, particularly on the south coast. However, the lowering Australian dollar, against the US dollar, and the Great Plains’s slow reaction to adapt the drills to be more friendly to Australian conditions resulted in new zero-till farmers tending to purchase other seeders. These included the WA built Walkers discs and the Canadian built K-Hart disc seeders. The disc seeders are not effective in the alkaline sandy soils of WA – these soil types are confined to a small area just north of Esperance.

No-till uptake in other States
My understanding of the adoption of no-tillage in other States, through the Australian network of no-till groups, is that it is less than in WA. Queensland now has perhaps 70% of their land sown with no-tillage. NSW is next with perhaps 35%, then South Australia with perhaps 20% and Victoria with perhaps 15%. I have no idea for Tasmania.

The Kondinin Group conducted a National Survey in 1998 on no-till adoption. However, I doubt the accuracy of their data. Their results suggested that Victoria has 33% of land sown with no-till, when I know that nearly no-one no-tills in the Victorian mallee and perhaps only 5% of the Wimmera is no-tilled (A. Postlethwaite pers comm). These two regions constitute approximately half of the Victorian dryland agriculture and make me conclude that Victorian no-till adoption might be 15%.

The benefits of no-till are extensive in WA’s strong Mediterranean climate with mostly acidic soils, and in the sub-tropical northern regions. However, in South Eastern Australia, in light winter rainfall areas and alkaline soils, it seems that farmers struggle to make no-till work reliably - with high levels of nematodes and frequent summer rains that encourage summer weed growth – which they say are too costly to control with herbicides. However, given that there are good farmers making no-tillage work in the dry SA mallee, I suspect that farmers could find a way to manage these problems with no-tillage.

Developments of no-till in WA

Knife points take no-till adoptions forward
At the same time, in the early 1990’s, farmers were rapidly embracing the new hard-wearing knife point openers. The technology of attaching tungsten carbide to the front of spring steel or cast iron points was refined. As a result kinfe-opener life was increased 10-20 fold. Local Western Australian knife-point manufacturing companies grew strongly during the 1990’s, in particular Agmasters Harrington knife point and Primary Sales Super Seeder points. Similarly, new WA seeders were designed and have become popular - in particular the Ausplow DBS seeder.

During the last 10 years the adoption of disc openers has been static. However, because of their ability to disturb less soil with fewer weeds germinating, particularly observed on the south coast, it is likely that they will become more popular in future years.

No-till has made ryegrass control more achievable
Most weeds can be more effectively controlled with herbicides when used in conjunction with no-tillage. This fact has induced most farmers into no-tillage – even those who were reluctant to adopt no-till. The discs were observed to disturb less weeds - with fewer weeds resulting in crop (page 259 of July 1999). After 4-5 years of zero-till many south coast farmers say that ryegrass has fallen out of their paddocks. This is often, but not always, associated with less sheep grazing also.

In a similar dramatic fashion, farmers and researchers have found that the herbicide trifluralin works best with no-tillage. The knife points have been shown to incorporate high rates of trifluralin without crop damage while being highly effective on ryegrass (Lolium rigidum) control (page 245 of April 1999).

Trifluralin does not work as well in thick stubbles as on bare ground. Therefore WANTFA has conducted several trials (page 277 of Nov 1999) where trifluralin granules are employed, as no-till farmers do in Canada. This formulation allows the granules to fall through the thick straw and come in closer proximity to the weed seed, whereas a liquid spray would bind to the straw.

Improved ryegrass control with no-till gave a solid thrust to its adoption. Such improved control was perfect timing as ryegrass weed populations were rapidly becoming resistant to Group A and B herbicides in the mid-1990’s. WAN3 Project readily extended this finding.

It is ironic that farmers have long been cultivating to promote and control extra ryegrass germinations. Farmers have noted that up to 14 cultivations at Wongan Hills in the mid-1970’s was still encouraging new germinations of ryegrass and the subsequent crop was still over-run with ryegrass. Interestingly, cultivation is still being promoted by WADA and WAHRI and it appears that the researchers acknowledging are not adjusting their models to these no-till benefits (page 245 of April 1999).

Press wheels become popular
When no-till was first adopted farmers observed the benefits of precise seed placement. Most disc seeders also employed press wheels. With knife openers farmers began trialling press wheels in gangs or alone, in some cases press wheels came with the seeder. In dry seasons the benefits were obvious and they have become increasingly popular.

In most cases press wheels are an advantage. However, their use is not helpful when sowing into wet soil and where their pressure is too high. Their pressure needs to be adjustable such that they can be either removed completely or made to press less than 2 kg/cm width of press wheel – especially in loamy sands with pulse crop emergence.

No-tillage is powerful in dry conditions
No-tillage has always meant sowing in the bottom of furrows. During the life of this Project two exciting moisture observations were made by no-till farmers and were extended to others. Both observations show the power of no-tillage for seeding into marginal moisture. In one case the moisture moves up from the subsoil and in the other it moves down via the furrows in preference to the inter-row, even when the inter-row is wettable.

Farmers, particularly in the northern regions, have regularly observed soil moisture coming up and into the seeding row from below when using no-till, when subsoil moisture is present. This occurred despite them thinking they had dry sown - placing the seeds well above the wet subsoil layer.

A possible physical explanation for this (Paul Blackwell pers comm) is that in April-May there is more heat in the subsoil than at the surface. The subsequent knife-point fracture of the topsoil provides a path of least resistance for the heat to escape through, and the heat escapes through moisture movement (page 220 of February 1999).

Similarly, a typical no-till sowing soil profile creates furrows about 100 mm wide every 250-300 mm. These furrows seem to harvest water, even when the soil is wettable (page 521 of July 2002) and small rainfall events of 2-4 mm occur. Perhaps 65% of this rainfall ends up in the furrow, enabling the wetting front to penetrate perhaps 100 mm deep in the furrows - where seeds and fertiliser are located. Thus crops are able survive on small rainfall events, especially when the crops are small and when cool conditions prevail in the middle of winter.

In both moisture situations the young crops in the furrow have a profound advantage over the weeds. The no-till precision of seeds being placed in the furrows, with the fertiliser, in the moisture, and every time the rain falls, is vital for enhancing crop competition against weeds. These types of real and powerful benefits need to be considered by agriculturalist when they suggest tillage as an integrated weed management tool.

More earthworms with no-till
Usually after 2–3 years of spraying weeds with knockdowns and no-tilling, farmers observe strong earthworm activity that they did not notice with multiple tillage systems. This activity has been reported in all regions of the State, though it is more pronounced in southern, cooler regions. Dr Margaret Roper (CSIRO Perth) has reported to WANTFA members that earthworms are a good indicator of microbial activity. Improved microbial activity has been reflected in better soil water infiltration and soil structure.

These consistent earthworm observations have made farmers realise that soil life plays an important role in nutrient re-cycling and soil health. These greater numbers of earthworms, and also increased ant activity, with no-till, help us to understand why soil water infiltration is higher under no-till and why the soil is more trafficable and soil aeration is also improved. It has also helped farmers realise that stubble has soil conditioning properties that need to be better understood.

Some problems with no-tillage

Mind-set issues
These days most agronomists have accepted that no-till is an important and valuable crop establishment technique. Some agronomists still promote tillage as a tool that should be used about every 5 years as a matter of course. Such a mind-set needs to be checked with experimentation in the environment that it is promoted, as sometimes going back to tillage has not been positive (page 525 of July 2002). However, it is a healthy rule to ‘never say never’. This Project, in conjunction with the WAN6 Project, has shown that lime does not require tillage to move it to depth (page 430 of July 2001).

Water repellent sands need tillage and clay
Soils with less than 3% clay in the topsoil have a propensity to become non-wetting or water repellent. It often takes 20-30 years for this to occur. One solution has been to seed in the bottom of the furrow with press wheels (no-till) and this has been effective. However, these furrows will most probably become wet in the following year and it is difficult to reliably seed in these old furrows.

The most effective and permanent way to solve this problem is to apply clay to the sand and mix it in thoroughly with several deep cultivations. WANTFA has led the extension of this claying technique with many articles written, several seminars and 5 long-term claying trials.

Water-logging
In high rainfall areas no-tillage retains more soil moisture. In these environments farmers need to either adopt higher water using crop types in the rotation, like sorghum, or adopt raised beds. WANTFA, through the WAN3 Project has promoted both of these techniques, with some success.

Changing weed populations
While there have been strong weed control improvements with no-tillage there are also some weeds that have benefited from no-till. Marshmallow, couch, windmill grass and trees have become common no-till weeds. In some cases no-till farmers have had to resort to cultivation to help manage them and in other cases new herbicides and herbicide mixes have become available that are effective. Data on these issues have been presented throughout the Project, in particular by David Minkey, Gordon Cummings and Dr Doug Derksen.

Slug in wet and thick stubbles
In high stubble levels, on the south coast, slugs are causing significant concern to no-tillers. The slugs thrive in the thick mat of residue, particularly in emerging canola sown into cereal stubble. Changing crop rotation is likely to be the most effective method of control.

WANTFA has attempted to address this by inviting Brazillian entomologist Dirceu Gassen to speak on ‘ways of managing insects in no-tillage’. This and other similar issues are discussed in a recent WANTFA article (page 510 of April 2002).

Nematode in alkaline sands
Root lesion nematodes are a significant problem in alkaline sands, which in WA are mostly found only north of Esperance. Nematodes are less of a problem on acid sands but they have become more of a concern recently. Nematodes make it more difficult to ensure no-tilling is successful and require more careful attention to diverse rotations and good nutrition. Other than extending interstate information on nematodes (page 304 of Jan 2000) we have not conducted any trials due to the relatively small area of the state with alkaline sands.

Herbicide resistance
Since no-tillage relies greatly on herbicides to control weeds it is important that farmers use herbicides from a wide range of groups. Usually resistance occurs when a farmer relies on one or two herbicide groups. No-till farmers who rotate crop types and herbicides seem to develop resistance at the same rate as more tillage based farmers.

The most concerning resistance threat to no-tillage is perhaps glyphosate resistant ryegrass. WANTFA has been promoting the double knock approach of SpraySeed after glyphosate for nearly ten years. This should keep the problem in check, but assumes that every farmer will practice it – which is too much to expect.

Leaving the weed seeds on the surface for ants to eat and the environment to degrade is also a useful tool. No-tillage can employ this well. Collection and killing of weed seeds, in conjunction with swathing, is also a useful weed control tool.

Where to now with no-tillage?

The stubble retention challenge
In any single year farmers may find stubble burning attractive, as burning often gives small benefits with slightly improved disease and weed control. This is especially true where wheat is sown into wheat stubble. However, the stability of the farming system is challenged when stubble is burnt (page 522 of July 2002). This is particularly true where either sheep are used to graze the stubble before burning, topsoils contain less than 3% clay, or in regions where erosive winds are common.

Retaining stubble without any yield penalties is important to WANTFA (page 482 of Jan 2002). WANTFA has requested, and received, GRDC funding for three years to develop and extend "successful crop establishment into high residues" (WAN00003 Project).

Sowing pulse crops on wider rows has helped farmers to sow through thick wheat stubbles without blockages - even after 5 t/ha crops. Recent WANTFA research, through WAN3 and WAN6, has shown that lupins can return good crop yields when grown on 1 m wide rows (page 477 of Jan 2002). Other data by Fosbery and Roe confirms this (page 534 of July 2002).

This Project has also been advocating the adoption of effective residue managers (page 198 of Nov 1998) and has conducted trials that simulate their benefit (page 508 of April 2002). Sowing canola into thick wheat stubble has caused canola emergence problems. Effective residue managers would help overcome this problem (page 523 of July 2002).

The WAN3 Project has encouraged WADA research that has shown tall wheat stubble to suppress the spread of pulse diseases. This project has also initiated researched into in-furrow fungicides for leaf disease suppression in high stubble levels through the WAN6 Meckering Project.

Rural communities despair of wind erosion
When whole communities expose their soil to erosion the whole community suffers. Houses fill with sand, clothes get dirty on the line, dams fill with sand, roads need sand graded from them, weed seeds become mobile, driving on the road is dangerous and valuable topsoil and moisture are lost. This is not to mention the mental despair that lingers, knowing that such soil loss is permanent.

Perhaps every year there are paddocks in WA that blow or wash (page 263 of July 1999, page 320 of May 2000, page 402 and 405 in June 2002). The wind erosion events are always associated with poor soil cover and strong winds - both can be blamed on bad seasonal conditions. Although, in perhaps every erosion event there are no-till neighbours who maintained stubble cover and have no erosion.

Improved crop productions with no-tillage
No-till farmers regularly report (through the WANTFA Farming Systems and the rural press) that their water use efficiency has nearly doubled after 10 years of no-tillage (page 271 of July 1999, page 538 of July 2002). No-tillage enables early time of sowing into minimal soil moisture. No-till also reduces the risk of the new crop droughting due to the limited rain being harvested into the furrows. No-tilled crops also grow with less vigour and therefore use less water at the early stage of development (page 59 of Jan 1996, page 452 of Nov 2001).

The ability of no-tillage seeders to establish crops on minimal moisture into retained stubble has created a revolution in crop establishment in dry and marginal soil moisture regions. Studies have shown that farmers who have purchased new no-till seeders in WA are more profitable than those that have not. This is due to the knife-points being able to penetrate dry soil and place the seed in a precise soil band in a furrow and with press wheels which has ensured reliable crop emergence.

This earlier time of sowing has profoundly improved crop yields. Sometimes the difference has been establishing an early May sown crop that yields 1.2 t/ha with no-till compared to a worked up paddock that never gets sown and yields almost nothing. Full tillage seeders are not able to penetrate dry and undisturbed soil. In drought years the crop prices are usually buoyant and this has a large impact on long-term farm profitability.

Other agronomic factors have also contributed to these improved grain yields. These include extra nitrogen fertiliser, some new herbicides, greater crop rotational diversity and some slight improvements in crop varieties. However, studies in South Australia (with Federation wheat trials) have shown that wheat grain yields gained from improved genetics is small, perhaps only 30% over 60 years. Yet earlier time of sowing in dry conditions, with improved weed control that no-till affords, has often given 50% yield improvements in the last 10 years.

Many WA trials show that wheat grain yields are penalised by 1% per day, when sowing is delayed beyond the first week in May. Waiting for optimal soil moisture before the soil can be cultivated for soil softening or weed germination may be a long wait, and the cultivation dries the soil by 15-20 mm. During the years 2000-2002 in WA substantial rain events rarely came in May but occasionally did in late June and July. This often meant a 6-10 week delay in sowing – if tillage was required. This is a 42-70 day sowing delay, which converts to 42–70% grain yield penalty.

Applying good crop agronomy in marginal moisture environments without no-tillage still amounts to a poor result. Often good crop agronomy is just not possible without no-tillage. Perhaps the two most profound examples are good ryegrass control with high rates of trifluralin and early time of sowing into marginal soil moisture. Also, when nitrogen is topdressed onto no-tilled paddocks, about 80% of this urea ends up in the furrows that gain water for the benefit of the young crop and away from the young weeds. Such precise N placement is not possible with full tillage systems.

The whole system benefit that WA has experienced with no-tillage in recent years deserves greater public acknowledgement. No-till gains eclipse any other recent agricultural gain, and perhaps eclipse any other gain from any other period of Western Australian agriculture. Researchers who are keen to promote tillage and burning for short-term weed, disease and insect control should carefully consult those who have a broad appreciation for the system benefits that no-till has afforded WA.

Data collected for a land use audit by Stephens (2002) shows that WA has lifted wheat production more than any other Australian State. With State average wheat yields climbing from 1.45 to 1.90 t/ha over the last 10 years – during rapid farmer adoption of no-tillage, grain delivered to CBH over the last 10 years also show a steady increase.
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Economic implications
Politicians and experienced agriculturalists have publicly stated, without rebuttal, that no-tillage increased WA crop production in the year 2000 by at least 3 mt. This was repeated again in 2001, with perhaps an extra 5 mt from no-till and in 2002 it might be 4 mt more grain from no-tillage adoption in WA.

It is therefore highly likely that an extra 12 mt of grain has been grown in WA in the last three dry years of 2000-2002, and there have also been smaller, but positive, gains from the wetter years 1997-1999. Much of the farmer adoption of no-till should be accredited to WANTFA and this WAN3 Project where the Scientific Officer vigorously and publicly, without fear or favour, encouraged farmer adoption of no-tillage. Therefore an extra 12 mt of grain produced as a result of no-tillage at an average value of $200/t equates to $2,400,000,000. This $2.4 billion dollars has had an enormous impact on rural WA communities as well as a significant positive impact on the whole of Australia.

No-till has provided both short and long-term economic gains. The soil health and fertility has improved with no-till and a lot of soil has been saved from erosion that would otherwise be lost with tillage-based agriculture. Better soil health has ensured improved soil-water infiltration and increased organic matter that is able to effectively store and release to plants available water and nutrients.

No-till has also taught farmers to be better managers. Management mistakes are more obvious with no-tillage and agronomic decisions have a greater impact than in previous tillage based systems.

It is my hope that the progress we have made in recent years with improved sustainable cropping systems will continue and will bring increased economic prosperity to rural Australia.
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