Report card on soil conservation
February 27, 2007:
Canadian farmers get good marks for progress, but there's still tough work ahead to make the grade.
Tom Goddard has advocated soil conservation for more than 25 years. It's not just his job, it's his passion. Today, he looks at the Canadian agriculture industry like a teacher watching students leave school – knowing some will excel, some will simply keep up and others will need to stay after class.
Goddard is head of Soils and Climate Change for Alberta Agriculture, Food and Rural Development (AAFRD) and is also the Canadian representative for the World Association of Soil and Water Conservation. Speaking candidly from many years on the front line of soil conservation, he delivers a balanced report card on how far the industry has come.
Better farming practices have reduced the risk of wind erosion, water erosion and soil degradation. Innovative research has helped mould a smarter farming community. But short-term economic thinking has undermined solid soil conservation decisions for both farming practices and research. "Overall, the risk of soil erosion and degradation has decreased because of improved farming practices, but it hasn't decreased to zero," says Goddard. "We still see it. It happens every year."
The industry can improve a lot by simply taking more time to think about soil conservation and putting a bit of work in to implement better conservation practices. "Conservation practices need to be economical, and practiced consistently over the long-term," says Goddard. "Sometimes they are only economical for one type of farming operation or one commodity or one system. It may take a farmer some time to discover the appropriate and most economical conservation practices for the whole operation."
To help farmers begin the thought process toward improvements, Goddard offers his thoughts on five key questions surrounding the status of soil conservation progress in Canada.
What are farmers doing right?
Farmers have come a long way with soil conservation, says Goddard. In the past, wind erosion alone depleted millions of tonnes of topsoil over the years. Tillage also contributed to a major decline in soil organic matter and overall soil quality. But farmers have helped the soil rebound in recent years by implementing better conservation practices.
Machinery developments allow the farmer to customize and refine their system or diversify their cropping opportunities and still stay within direct seeding systems. "It used to be that the equipment would do a good job on only one crop but now we have equipment that is easily adjustable and will do a good job on a number of crops with different needs," says Goddard. "Direct seeding systems are not a hurdle anymore."
Producer knowledge is also a key factor, he says. "Farmers are becoming more conscious of the nutrient cycle and how the nutrients in their soil are managed, a trend that may be fueled by the high cost of fertilizer." More farmers are growing green manure crops or crops that will increase the nitrogen in their soil. Legislation around nutrients, and manure in particular, has farmers thinking again about how they manage their soil nutrients.
Farmers are also learning the value of residue, planting high residue crops after low residue crops in an effort to keep mulch on the field. "This supports a continuum of decomposition of organic matter," says Goddard. "We don't want just one type of organic matter in our soils; we want the whole suite of decomposition."
They are also gaining an appreciation of landscapes on the farm – how fertility and nutrient requirements, risk, and crop yields can vary by landscape. "Farmers are becoming more aware and concerned, which is good for the bottom line as well."
Where are farmers failing?
Despite the progress, some poor practices persist, says Goddard. For example, there are still farmers who burn stubble to manage excess residue. This could be due to a certain mind set of "We've always burnt stubble so therefore we have to." This could also be because burning is seen as being the easiest and cheapest way out of a management problem.
"Stubble burning might seem economical in the short term but it costs the nutrient cycling adjustments and the soil biology makeup in the long term," says Goddard. The immediate economics of the practice are considered without considering the long term effects.
Expansion of irrigation farming and increased acres in row crops, like potatoes, can leave portions of the field at risk for erosion, especially wind erosion. "These crops don't have a lot of residue and the cultivation practice for that kind of crop is conventional tillage," says Goddard. "It's a good formula for topsoil loss."
What is some of the most promising research?
Research is key to improving conservation practices, and there are many examples of valuable work underway, says Goddard.
Scientists in Alberta are running with some of the new predictive models of erosion developed by the United States Department of Agriculture's Agricultural Research Service. "The model is very detailed and can handle all possible farming scenarios," says Goddard. "This work indicates a leap in technology because before this, we were working with model technology from the 1950s and 1960s." Researchers are looking forward to making this product user-friendly and accessible to farmers.
Globally, one of the most exciting areas of research is digital soil information. Canada, Australia and the United Kingdom are the only three countries that are looking at automatically characterizing landscapes from elevation models. "One can pair digital topographic information with specific computer software and the farm will be split up into management zones or risk zones," says Goddard.
The management zones help the farmer optimally manage discrete soil landscapes on the farm. The risk zones identify which landscapes are at most risk of soil loss or degradation. These could be areas that are drowned out, where nutrients are lost or tied-up, or areas of high erosion risk. Once these areas are identified, they can be managed appropriately.
"We are learning a lot from the landscape research and deriving numbers to drive complex erosion models," says Goddard. "It will allow us to look at issues such as pesticide leaching risk."
In what areas have research efforts lacked?
Despite this progress, there are areas where research efforts need improvement, says Goddard.
Most of the research done in Canada is plot research done on the best soils and not on different landscapes. "Farmers farm on whole landscapes so there is a disconnect between the research and the real world application," says Goddard.
"As well, most research is being done in a conventional tillage situation. In the case of a plant breeder developing a variety and using a conventional tillage system, are we inadvertently selecting for traits better expressed under conventional tillage?" asks Goddard. "Are we missing opportunities we might discover if we were using direct seeding in our research plots?"
Another concern is nutrient management, he says. "We know direct seeding changes the rates and dynamics of nutrient cycling. How does this relate to the recommendations that have come out of research conducted on a conventional tillage platform? We have very few people researching that and are missing an opportunity there."
"Accepted principles and rules of agronomy developed under earlier tillage systems and crops may need to be re-examined as is the case in South American countries where the adoption rate of direct seeding systems has surpassed us. They are asking the question of whether the principles we've been taught still apply as we adopt direct seeding," says Goddard.
"For example, when liming acid soils, the recommendations have been to apply the lime and incorporate it, therefore making the practice not suitable for direct seeded fields. Agronomists in South America are now finding that a pH correction can be achieved without incorporation," says Goddard. "We have more to learn about how soil biology and chemistry is affected by the different cropping systems, tillage systems and landscapes."
Who can we learn from?
In the area of soil conservation, Canadian farmers can learn from what other countries are doing right - using South America as an example as they re-examine their knowledge. On the other side of the coin, we can also learn from emerging conservation issues in other countries.
For example, European countries are realizing the consequences of their cheap nitrogen policy. "They have polluted groundwater and high nutrient soils so they are legislating that at a very high cost to the farmer. This is a double-edged sword though; we can look at how they overcome their problems and learn from that," says Goddard. "We thought farming was simple but it's becoming more complex."