Zero tillage improves the short and long term economics of farming and protects the soil and water on which we all depend. This is as true in Australia, Africa or South America, as it is in our northern plains. The idea behind zero tillage is to increase net returns through higher yields and lower costs. In nearly all conditions this is possible provided other issues like tradition and management abilities do not upset the decision making process. This component will show that once zero tillage is adopted management is as important as technology in making it pay.

WHY ZERO TILLAGE?

Zero tillage is now economical due to less expensive glyphosate and increasing costs for fuel, labour and interest relative to the value of grain. As well, improved seeding equipment and good agronomic practices give the opportunity for higher and more consistent yields. Whether the incentive to adopt zero tillage is yield or lower cost of production depends largely on farm location. In wetter areas of the northern plains, lower costs have been a great incentive. In the more arid regions, farmers have adopted zero tillage to save moisture and increase their yields.

Farmers everywhere are using zero tillage to manage risk and diversify their income. This is the first step toward achieving long term environmental, economic and social sustainability.

IMPROVED SOIL MOISTURE

Zero tillage can supply about 50 mm (2") more soil water at seeding time (Figure 1).1 Up to 100 mm (4") of extra soil moisture has been measured in zero till fields. These water savings can protect crops from drought and translate into higher yield (Table 1).2

Higher average yields make zero tillage less risky than conventional tillage systems. Moisture savings translate into an increased net return in a zero till system (Figure 2).3 In this Manitoba example, less evaporative loss, increased snow trap and better infiltration of rain and snow with zero tillage gave higher yields and profits.

Typically, catching 250-300 mm (10-12") of snow returns 25 mm (1") of water. Broadleaf crops especially respond to this extra water because they are more sensitive to drought stress. Diversifying farms by growing broadleaf crops is a good economical strategy made less risky through zero tillage.

Even in the wetter, heavy clays of the Red River Valley, zero till systems can improve permeability of the soil, while protecting the crop from midsummer drought stress. Farmer yield comparisons in the wet Red River Valley show that zero tillage works comparatively well, particularly in dry years (Table 2).4

In the majority of soils farmed by the members of the Manitoba - North Dakota Zero Tillage Farmers Association, the use of zero till has eliminated the need for fallow. The expense of having land idle is avoided.

More uniform soil moisture in zero tilled fields allows crops to ripen evenly. Crops can then often be straight harvested to reduce losses from predators and bad weather.

COSTS ARE LOWER

Everyone appreciates increased yields, but at what price? A recent survey of 300 farmers in Manitoba showed the cost savings with zero tillage.5 Net savings of $5.62 per acre combined with about $14.00 extra per acre of grain, resulted in $19.60 per acre more returns for zero tillage over conventional tillage.

Savings for the zero tillers on a per acre basis included N ($1.01); P ($0.81); fuel and lubricants ($1.54); repairs ($2.17); machinery depreciation ($2.53); and crop labour ($0.98). There were increased costs for herbicides ($2.08), S fertilizer ($0.55), and seed ($0.79). These last two costs are most likely not due to a change in tillage systems, but perhaps reflect no-tillers general awareness of better agronomic practices.

With lower costs, zero tillage is more profitable even in years when there is no yield advantage over conventional tillage. Other work confirms this result.6

DIVERSE ROTATIONS PAY!

In general, returns from growing broadleaf crops outweigh the risks of growing them in the northern plains. Returns have been high enough to encourage farmers to solve their associated agronomic and engineering obstacles.

More diverse rotations are probably necessary to maximize profits in zero till. A Manitoba study showed that when both zero till and diverse rotations were used farm profits were greater than any other combination of rotation and tillage (Table 3).1 The better profits came from higher yields and lower machinery costs. In contrast, diversifying into broadleaf crops with conventional tillage was less profitable than staying with continuous wheat.

This is an important point! It is common for no-till wheat-fallow or continuous wheat rotations to fail due to diseases, weeds and poor seedbeds. These rotations are less risky as part of a tillage-based system. However, with non-cereal crops, the risk is greater with tillage than no-till because of moisture limitations. No-till and non-cereal crops further complement each other as the added diversity minimizes concerns about pests and improves the relationship between risk and return for the farm.

A strategy which can provide better net returns would combine less herbicides in wheat, variable seeding dates, and a crop rotation that includes cereals, oilseeds and annual legumes.8 This allows a more timely and cost effective use of herbicides, boosting returns in no-till more than in conventional systems, making no-till the more profitable system.

Using fixed labour and capital efficiently is important. Diverse cropping schemes spread costs over more acres by keeping labour and machinery busy for longer.9 Net returns, in suitable areas, are higher when at least 50% of the rotation is corn, soybean, millet and sorghum. Traditional wheat-based systems may not cover variable and land costs in a no-till system. Clearly, crop rotations are more important with zero tillage than with tillage-based systems. No-till farmers in the northern plains have learned that no more than 50-75% cereals in the rotation is optimal. Zero till has been good for their soil and their family's income. However, some are wary of an over-reliance on herbicides as the lone replacement for tillage. By rethinking their system from the bottom up, they have recognized that crop rotation can play a larger role in their operations.

OTHER BENEFITS

Surveys and research give an important snapshot of improvements from zero tillage. But they rarely cover the human side. For example, farmers report that by zero tilling they spend less time in the tractor cab and more time planning their cropping system and capturing important market information. And then there's the time that always seems to be in short supply - family time. Families report an improvement here too!

OTHER ECONOMIC FACTORS

Increasing net returns requires identifying the factors most limiting farm profit. Water is less limiting in zero tillage. But, as Figure 3 shows, there is little sense in filling the barrel with water only to have it cascade out because of a weakness elsewhere in the system.7

Gaining an economic advantage is a lot like setting a combine. A new and improved combine provides the potential to harvest and save more, but if it is not properly adjusted, economics could be worse than staying with the old one.

Zero till is the thoroughbred of tillage systems. Decision making is intensified and information needs are great. To win the race, farmers must develop a timely, cost effective system which capitalizes on economic opportunities. The question many are asking today is not "Will zero till work?" but "How do I make it work better"? or, perhaps more importantly, "Am I ready to rethink my zero till system?" For this, a little imagination goes a long way.

The future viability of zero tillage is not guaranteed. Potential problems like herbicide resistance, disease outbreaks and unusually wet seedbeds need to be resolved. Part of the challenge is to identify the problem, its causes and possible remedies. A trouble shooting guide is provided (Table 4) to give insight into reasons why a farmer may not see economic advantages to zero till or, alternatively, why previous economic advantages are declining.

The other challenge is to develop ways to manage problems in a cost effective manner. Technology will provide some solutions. However, as zero tillage evolves, farmers need to do more than replace tillage with herbicides. They need to balance their reliance on technology with the use of cultural practices.

Figure 3: An illustration of the principle of limiting factors. The level of water in the barrels represents the level of crop production. (Left) In conventional tillage, water is shown as the most limiting factor. Even though other elements are present in more adequate amounts, crop production can be no higher than that allowed by the water. When water is added (right) under zero tillage, crop production is raised until it is controlled by the next most limiting factor, in this case crop rotation.7

Prepared from information provided by:

David Rourke, Ag-Quest Inc.

Box 144, Minto, Manitoba, R0K 1M0

Telephone (204) 776-2087 Fax (204) 776-2250

Email agquest@agquest.com

References:

1. Rourke D and Hargrave (1995). Rpt Cons. Till. Prod. Ctr, Minto, MB
2. Lafond GP and Derksen (1996). Can. J. Plant Path. 18:151
3. Rourke D and Hargrave (1993). Rpt Cons. Till. Prod. Ctr, Minto, MB
4. McCutcheon J (1989). Proc. MB-ND Zero Till Farmers Wrkshp
5. Driver HC and Josephson (1992). U of Manitoba, Winnipeg, Paper #92
6. Dunn R et al (1996). Alberta Agric. Agdex 519-8
7. Brady NC (1974). The Nature and Properties of Soils. MacMillan Co. Ltd. NY
8. Zentner RP et al (1996). PARI Factsheet

Beck D and Doerr (1996). South Dakota State U (unpublished)