GrainsWest Fall 2020

Fall 2020 grainswest.com 27 n the past growing season Mike Ammeter encountered “sort of a mystery” on his farm near Sylvan Lake. He seeded malt barley into wheat, canola and pea stubble and lightly harrowed it. “It seemed to emerge OK,” said Ammeter. But by the end of June the crop was quite uneven. Though he’s not certain, he has a guess as to the cause. “It might have been something to do with two-and-a-half inches of rain right after seeding, along with fairly heavy crop residue on the ground.” One hundred-bushel wheat was unheard of 15 years ago, but today’s higher yielding cereal varieties can come with increased plant size. Heavy crop residue, or trash, in combination with excess moisture has implications for direct seeding and conservation farming practices. In certain parts of Alberta, excessive crop residue is a complicating agronomic factor and it has become a topic of discussion among farmers. If the timing works out and conditions warrant, Ammeter usually follows combining with a light harrow to distribute residue. Spring is the next best option, he said. Given the unevenness of his crop in June, he may adjust the straw chopper on the combine. “I have it set pretty fine so it’s almost like a powder on the soil surface," he said. “That doesn’t move very much when I harrow. Perhaps the setting should be coarser so the harrows can actually move the residue.” Near Rycroft in the Peace Region, Warren Sekulic said excess moisture probably contributed to one of the poorest crops he’s had in 10 years, although he appreciates that other areas of the province had it much worse. Once Sekulic’s crop began growing through heavy crop residue it was hit with 13 centimetres of rain over a couple of days, followed by hail in places. This set it back substantially. “I’m a firm believer in zero-till farming, although I’m not a zealot either,” he said. “We plan to direct-seed everything, but I will apply some tillage if needed.” Cropping about 4,300 acres, Sekulic grows peas, wheat, oats and canola in rotation. His major crop residue management practice, particularly in cereal crops, is to cut stubble as tall as possible. He also keeps the combine’s chopper knives sharp and replaces them every couple years. Tall stubble that is anchored to the soil allows his disk drill to better work through residue at seeding. Dave Davidson farms near Joffre, 30 kilometres northeast of Red Deer. To better manage heavy crop residue, he uses the combine to chop and spread chaff over a wide area. Ideally, on cereal and pea stubble fields, he follows harvest with a heavy harrow. He leaves canola stubble as tall as possible at harvest and will heavy harrow the crop in the spring to distribute residue and expose a bit of soil to warm the seedbed. “On the cereal and pea fields I prefer to harrow in the fall,” said Davidson. “But due to late harvest last year, that didn’t get done. To heavy harrow in the spring ahead of seeding helps, but it’s not as good. There is better breakdown of crop residue if I can get it done in the fall.” He seeds the crop in one pass with a Bourgault drill equipped with mid-row banders for fertilizer placement. Jay Bruggencate, who farms near Lacombe, believes in zero-till farming, but has incorporated tillage to help manage excess moisture and heavy crop residue. “For many years I was passionate about direct seeding and zero-till,” said Bruggencate. “But in the past three or four growing seasons we’ve had high moisture and big crops with high residue. And wet conditions during a late harvest doesn’t help. The straw is tough and it doesn’t chop as well, and there can be a lot of starting and stopping so the residue isn’t spread as even as it should be.” Bruggencate said he has had to “pivot on his strategy” to manage residue. He grows high-yielding crop varieties but also looks for those with shorter stature or semi-dwarf characteristics. If circumstances are right, he’ll bale at least some crop residue to remove straw from the field. And he’s also considering fall banding of fertilizer to take some pressure off at seeding time and to help with residue management. He has heavy harrowed fields in the fall, but in recent years he has worked fields with a high-speed disc. “Mainly it is to manage that heavy residue, work it into the soil and prepare a good seed bed for quick crop emergence,” said Bruggencate. “We grow malt barley often seeded into canola stubble, so getting that soil exposed and warmed up is important to get a quick and even emergence on the crop.” Bruggencate said while tillage produces benefits there are trade-offs. With tillage, he can better manage heavy residue and expose some black soil. This improves crop germination and gets the crop up and growing with emergence “about a week to 10 days earlier than if it had to work its way through undisturbed crop residue,” he said. On the flip side, he said disc tillage along with straw removal by baling takes its toll on soil organic matter and reduces the soil’s water holding capacity. Disturbing the soil will also affect development of soil biology. Bruggencate has also seen “I think it has to be looked at as intelligent tillage. As an occasional treatment it can help make soils more productive.” —Elston Solberg I