Lessons learned from the last crop

It pays to do some ‘regressive analysis’ to see if some practice or treatment helped a crop excel even under adverse conditions

Rapeseed field and sun

Yield results aren’t necessarily the end of the story, says a longtime western Canadian agrologist who recommends farmers get more scientific about how they use those yield numbers as a reference point for examining the past season, and for planning the next year.

Increasingly, data analysis will drive crop production, says Rob Saik, who founded Agri-Trend Agrology of Red Deer, Alta. some 17 years ago.

In mid-November, Trimble bought Agri-Trend, which operates a network of independent ag consultants and “coaches” across North America.

Farmers keep production records from the year, and many also collect yield data at harvest. Now, says Saik, it pays to do some “regressive analysis” of that information to see if some practice or treatment helped the crop excel even under adverse conditions.

“Whether it was surprising or disappointing or what was expected, have a look at the production practices and the growing conditions of the past season to see what actually contributed to that yield,” says Saik. “In a lot of cases in 2015, yields were better than many had expected — look back and find out what made the difference.”

Soil test foundation

Heading toward the new crop year, Saik emphasizes the importance of basing plans on a proper soil test analysis. The western Canadian network of Agri-Trend agrologists routinely collects soil samples from zero to six inches, six to 12 inches and 12 to 24 inches in depth. “The multiple depth analysis is particularly important when you are tracking mobile nutrients such as nitrogen,” says Saik. “It is important to know what nutrient levels are in the soil and where they are.”

Saik says he recently spoke to one farmer who was planning to seed peas on one field until he looked at the soil test analysis. “That field had such high levels of residual N, that farmer felt he would be crazy to put a nitrogen-fixing crop on that field,” says Saik. “So he put another crop on that field, and reduced the amount of added nitrogen that year. The peas could be planted elsewhere, where they would have more benefit.”

It’s knowing that kind of information and making those decisions that can save farmers hundreds and thousands of dollars. It all stems from soil tests.

Other indicators

Another vital piece of information Agri-Trend is now extracting from soil test samples is a measure of available soil moisture for next year’s crop. Saik says soil samples are collected in the fall and immediately sampled for moisture along with nutrient and organic matter levels. “Fall rains and snowfall can make some change in soil moisture levels over winter,” he says. “But getting that reading when the sample is taken can help farmers in their crop planning for the coming year.”

For most crops you need a minimum of four to five inches of soil moisture to build the crop on, he says. With a moisture analysis you get a good idea of what potential the crop will start with at seeding, and then you can plan accordingly.

Saik also says a plant tissue analysis taken in season is another useful tool for not only determining the nutrient status of the growing crop, but in evaluating the overall fertility program. “The tissue sample will tell you where the nutrient levels of the crop are at the moment,” says Saik. “And depending on the reading, some corrective action may be taken.”

However, the bigger benefit may come next year. Knowing if the fertility program you followed is meeting the crop’s needs this year will also tell you how you can change the fertility program to better meet the needs of the crop the following season.

Saik says some exciting evaluation tools being developed will expand the range of precision agriculture. So rather than precision agriculture just helping direct variable-rate applications of crop inputs, Saik says the technology also has potential to measure the efficacy of products and treatments over field zones as well.

Lee Hart is a field editor for Grainews in Calgary, and an occasional contributor to Country Guide magazine.

About the author


Lee Hart is a long-time agricultural writer based in Calgary and a contributor to Country Guide.

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