WHAT THE EQUIPMENT RESEARCH HAS SHOWN

Research at Massey University from 1969 - 1990 showed that there are four key aspects of no-tillage equipment design.

1. The shape of the seed slot (seed micro-environment). Soils that are undisturbed have very different characteristics to those that have been disturbed by cultivation. Cultivated soils have little ability to trap soil moisture vapour and consequently, planting into tilled soils relies heavily on the presence of liquid moisture. This has a number of implications with regard seeding depth and timing.

Un-tilled soils on the other hand have the potential to trap nearly 100% moisture vapour. Consequently, harvesting this moisture vapour can be valuable in achieving reliable germination and emergence in a range of soil moisture conditions. The ability of no-tillage drill openers to exploit this moisture vapour can be measured and affects both germination and emergence markedly. Openers that make seed slots that return the surface residues over the slot essentially undisturbed (inverted T-shaped slots) trap more moisture vapour than those that create slots that are open at the top and difficult to cover (V- or U-shaped slots).

2. Control of seeding depth. Seed drills designed for seeding into cultivated seedbeds require much less sophisticated depth control mechanisms than those designed for no-tillage because tilled seedbeds generally provide a level surface and consistent texture. Conversely, no-tillage equipment must cope with dramatic changes in soil "hardness" and a relatively uneven surface, all within a single field. This places considerable demands on the ability of the machine to faithfully follow the soil surface, ignore changes in soil type and thus seed at a constant depth.

3. Residue handling and micro-management. The key to successful no-tillage is residue management. Very few arable farmers in New Zealand are practising "true" no-tillage where residues are retained on the surface to provide moisture retention, erosion control, weed suppression, soil organic matter, nutrients and a habitat that will encourage earthworm numbers and activity. Yet effective residue management is vital to a sustainable arable system. No-tillage equipment must not only "handle" residues, it must "micro-manage" them to ensure they are placed back over the seed zone to provide maximum benefit. Drill openers must not place the seed in direct contact with the residues above or below the soil surface.

4. Fertiliser placement. There is considerable debate, and conflicting research data, on the issue of fertiliser placement versus broadcasting under conventional tillage systems. With no-tillage there is no debate. The scientific evidence shows very clearly that separate fertiliser placement beside and/or below the seed is significantly superior to broadcasting fertiliser or mixing it with the seed under no-tillage systems. A recent survey of US no-tillage farmers rated separate fertiliser placement as the top priority for no-tillage seed drill/planter design.

What do the above four factors have in common? Firstly, their importance is biological. This shows that the design of no-tillage equipment should be driven predominantly by biological parameters (factors that influence plant establishment and growth) rather than purely mechanical considerations. Secondly, the effects of these parameters can all be measured scientifically (and have been). This means that various designs of opener and machine can be compared on a scientific and objective basis. Thirdly, all of the above factors are controllable and equipment can be designed to accommodate these requirements. Equipment designed to specific biological parameters is generally regarded as "high-tech".


THE PRODUCT

The Cross SlotTM no-tillage opener was the product of the research that defined the above biological parameters. Its central disc and winged side blades create an inverted T-shaped slot that places seed to one side of the vertical disc cut and fertiliser to the other side. Following press/gauge wheels fold the soil and residue back over the seed zone in their same relative positions as they were prior to drilling, thus creating the ideal micro-environment. The depth wheels control seeding depth very close to the point of seed release and when coupled with a nitrogen-cushioned hydraulic system allow each opener to follow vertical ground surface changes of as much as 0.5m with minimal change in down-force.

Baker No-Tillage Limited from Feilding have recently released a range of no-tillage air drills featuring Cross SlotTM openers and Kverneland Accord air seed and fertiliser metering. The drills have some unique features such as being able to increase or decrease the number of rows depending on available tractor power. Most importantly however, the machines have been designed specifically for no-tillage.

THE ROLE OF MANAGEMENT

Sophisticated drill technology will not perform to its potential unless it is accompanied by an equally effective no-tillage management programme and, of course, vice versa. To this end, a fourteen-step management plan is suggested to ensure that management inputs are as effective as the drill technology. After all, the strength and effectiveness of the system will only be as good as the effectiveness of the individual inputs (e.g. the system will fail at the "weakest link in the chain"). The steps are:

1. INFORMATION !
Good decisions rely on good information. Risk can be reduced by ensuring that the information used in the decision making process is accurate, objective, up-to-date and complete, not opinions derived from tillage or even some low-tech no-tillage experience.

2. CONFIDENCE !
A no-tillage programme based on good information should allow the system to be applied with confidence that the inputs are such that risks are minimised. Start with the best paddock, not the worst.

3. COMMITMENT !
To want the system to be effective is not sufficient on its own but it is an integral part of the overall programme. A long-term commitment to profitability and preservation of soil resources is essential - a part of creating a sustainable arable system.

4. PLANNING !
Planning starts before the previous crop is harvested and continues well past planting date. Since residue management is a key component of a true no-tillage programme, the residues from the previous crop must be managed at harvest to ensure effective utilisation during the next season.

5. EQUIPMENT SELECTION!
Recognise that not all no-tillage drills perform equally. Choose the best technology available but be sure to recognise any limitations of the particular technology being used. The features listed earlier in this paper provide a guideline for the selection of no-tillage equipment and an objective means by which to compare no-tillage drills.

6. RESIDUE MANAGEMENT !
Utilise residues! This can start with a change in vocabulary. Drop the word "trash" and replace it with "residue". Trash is a waste product left at the gate by city dwellers for the garbage collectors. Residue is a valuable resource containing many dollars worth of nutrients and possessing all of the attributes listed previously.

7. WEED CONTROL !
Herbicides replace all of the tillage processes under conventional tillage. Therefore, application of the correct chemical, at the correct time, at the correct rate and under the correct conditions is essential.

8. PEST CONTROL !
The environment into which a crop is drilled with no-tillage is totally different to that under tillage. Not surprisingly the requirements for weed control, machinery, management and pests differ greatly also. Once again, good information will lead to good pest management decisions. It is not that more pests appear under no-tillage. It is just that the same old pests behave differently!

9. FERTILITY MANAGEMENT !
The importance of separate fertiliser placement with no-tillage has already been stressed. But other aspects of fertility management also differ from tillage. These include the types and rates of fertiliser that can be effectively utilised and the nature of release of nutrients from previous crop residues.

10. SEED QUALITY CONTROL !
Like many of the 14 factors listed here, using good quality seed is as important with no-tillage as it is with conventional tillage systems. Seed vigour is one factor that assumes greater importance under no-tillage systems but the most important factor is control. Control of the quality of the seed being used will ensure accurate determination of the appropriate seeding rate and confidence in the resulting establishment.

11. DISEASE CONTROL !
The key factor in controlling disease is the use of appropriate crop rotations. While these rotations may differ from those traditionally used with tillage, they must take account of potential disease build-up. So far, the problems expected to arise from continuous no-tillage and it's associated residue retention have not been evident.

12. PATIENCE !!
The no-tillage farmer requires patience on two levels. Long-term patience is required to fully reap the benefits to soil physical and biological characteristics from eliminating tillage. Short-term patience is required to understand and utilise the reduced time pressure that is historically associated with conventional tillage.

13. VIGILANCE !!
Regular crop monitoring will provide evidence of the success of the system and early warning of pest, disease and nutrient problems. Since less time has been spent on the system required to establish the crop, more time is available to monitor its progress. It is not hard to see that the return on investment of time is going to be greatly increased when time is invested in the latter activity.

14. PLANNING !
PLANNING !!
PLANNING !!!
More time can also be used to plan for the utilisation and harvest of the crop thus enhancing returns. Future programmes, rotations, fertiliser requirements and crop management are all issues that should be considered while the current crop is still growing. The importance of the planning function cannot be over-emphasised.

A no-tillage management manual is soon to be released to provide more information on the above topics.

WHAT HAPPENS IN PRACTICE

In 1995, a Manawatu mixed livestock and arable farmer decided that his system of farming was not sustainable and could not realise his goals. He wanted to increase the arable proportion of his enterprise but under conventional tillage this was not possible on his heavy soils. He spent considerable time gathering information and finally decided to convert his entire operation to no-tillage. This allowed him to increase his amount of cash and forage cropping from 84 ha in 1994 to 120 ha in 1998. His total investment in arable equipment (including a new 13-run Cross SlotTM no-tillage drill) was reduced from $226,500 to $193,000. Labour input and tractor hours have dropped from 4 hours per hectare using two people for conventional tillage to less than 1 hour per hectare using only one person for his no-tillage system. Fuel consumption per hectare is now 30% of what it used to be. Earthworm numbers have doubled on monitor paddocks.

And what about yields? Average cereal yields for the last six years under tillage on this farm have been compared with those of the first three years of no-tillage. The results were different by 0.1 t/ha.

Another example comes from Mid-Canterbury:

"In the early 1980's we tried both minimum- and no-tillage with triple disc and hoe points on a Duncan 734 drill. With extremely varied results and glyphosate three times the price it is now, we did not stick at it for too long! I liked the concept of no-tillage but decided to sit out for a while. We did however continue to try and get the crop residue back into the system and improve soil structure. We have only burnt one paddock in the last twelve years.

In 1996 we bought a 17-run Cross SlotTM drill, as this new technology was achieving the results we were looking for. It was New Zealand made, robust and came with excellent back-up from Baker No-Tillage Ltd. I have never regretted that decision and as our planning and management of no-tillage improves, so do the results. Our yields over the first two years were just as good, if not better, than I would have expected from conventional tillage. With better soil structure and much improved moisture retention we can now set up our crops to produce higher yields than in the past. Our yields in the 1998/99 drought were testament to the benefits of no-tillage on this farm when we equalled our best ever average barley yield. In 1999/2000 we surpassed last years yield by and average 1.6 T/ha.

We now farm 268 hectares and aim to grow 75% of this in cereal crop each year. We put 75% of the crop ground into greenfeed and grass to finish lambs or take in grazers. That's 350 hectares per year of drilling; one man, one tractor, one drill and only two hundred hours of tractor work. All crop residues are retained in the field."

Both farmers list the following reasons for converting from conventional tillage to no-tillage:
- Improve and protect the soil structure.
- Encourage earthworms.
- Continuous crop without soil damage.
- Improve soil organic matter by retaining crop residues.
- Significantly reduce tractor hours per hectare.
- Halve labour input.
- Increase flexibility.
- Reduce turnaround time between grain harvest and drilling autumn forage crops.
- Maintain yield.

Most of these objectives have been achieved already.

SUMMARY

No-tillage works! There are an increasing number of farmers who have successfully adopted the system and are reaping increasing short- and long-term benefits. Others have tried the technique in the past but were plagued with inconsistent results. The common factor amongst all those who have succeeded is that they have had a positive attitude, adequate information and appropriate technology.