Medium Disturbance System Works on Clay Soils - Leigh Christensen, Standard, AB

Medium Disturbance System Works on Clay Soils - Leigh Christensen, Standard, AB
Author: Helen McMenamin
Date Created: March 12, 2002
Last Reviewed: March 12, 2002
“You can’t be too idealistic about a seeding system when you farm heavy clay soils,” says Leigh Christensen. About 70 percent of the land he and his brother, Barry, farm at Standard, 60 miles east of Calgary, is heavy clay. “Our soils are quite challenging,” he says. “If it’s wet, they’re sticky and difficult. If it’s dry, they’re cloddy and difficult. We also have problems with cold soils in spring.” “Some of our neighbours still continue to use the old one-ways. Diskers work beautifully on these soils, but harrowpacking afterwards breaks down the soil structure and leaves the soil prone to erosion.” The heavy soil intensifies the challenges of seeding 4300 acres in spring with one 40 foot drill. “You have to pay attention to details in clay,” says Christensen. “But, because we have a lot of land to cover in a short time with one drill, we have to keep moving even when conditions aren’t ideal. We decided our main need was for a system that’s not an abject failure in adverse conditions.” Christensen has tried a few systems since he started one-pass seeding with an airseeder in the early ‘80’s. The air-seeder left the land too rough and erodible. With a low disturbance knife he had glazing of the seed channel that sealed small seeds from moisture and cut emergence and, with any amount of rain the packer wheels skidded and sealed the seed row. Two years ago, Christensen settled on a Concord drill with 12 inch spacing and 7 inch shank-mounted sweeps. He thinks this time he’s got a seeding system he’ll be able to live with for a while, even though it bothers him that he couldn’t increase his footage. “I didn’t want to go to a higher disturbance system,” he says. “But, it seems to be what works on clay. I use Bourgault 200 series with sweeps. They scour and get a shine and the ground doesn’t hyperpack and capillary action can keep the seedbed moist.” Leigh Christensen with modified openers This year, Christensen plans to raise the crown of his shovels with a forged V from Gen that will work like a carbide cutting edge and increase shovel life four times. He’s also hoping the higher crown will lead to less plugging of the seed boots. The high seedbed utilization is a big benefit for Christensen. “In heavy soils, the best yields are with higher SBU,” he says. “Once clay bakes tight, secondary root development is poor, but if you spread the seed further, you get better root development. “At 50 percent seedbed utilization, we have a lot of flexibility. The system is actually made for corn but it fits our cold soils. If things get really ugly, and for some reason we have to go to full tillage, we have that option. “The disturbance warms the soil, it lets me put on all my N as urea without risk of toxicity and I can use just one split tank for seed and fertilizer. That makes for less compaction than you get with a train behind the tractor, even if each unit is lighter.” The high SBU is also a benefit if Christensen has to swath, something he’s forced into about two years out of five. With a low disturbance system, he figures 10 inches is the widest spacing that will support a swath, even if he swaths on the diagonal. To minimize compaction, Christensen uses radial tires on his packer wheels to maximize the surface area. He’s found radials are the best at shedding mud and they work well in dry conditions too. Opener width matches radial width to minimize compaction “Most people pack too much, especially on clay,” he says. “I think we need the lowest packing pressure possible.” Christensen put disk levellers on all four ranks. Each one possibly deflects soil back onto the seed row and prevents stepping problems that could leave the rear furrows uncovered. Close up of levellers “We have consistent seed depth, the seed is covered and packed and all the furrowing is contained,” he says. “The system works well for us, even going through very heavy straw. It also allows us to seed a 5 mph. “Idealists like to seed at 3.5 or 4 mph. You can do a better job at that speed, but we can’t afford the 20 percent reduction in our speed. We can’t slow down if we’re going to seed everything with just 40 feet of drill. “This system isn’t perfect, but it’s user friendly at all moisture levels. We need that in clay soils.” Fertilizer application is another important part of the picture. His Bourgault 5440 air tank, split so 67 percent of its capacity is for fertilizer is ideal for urea blends, according to Christensen. He put on the biggest rice tires available to minimize compaction. “One well-floated tank is much better than a train of smaller tanks,” he says. He switched to dry products for several reasons, but mainly for the assurance the product is there when he needs it. “It’s a real push to get things done in spring,” he says. “Any problems in the delivery system and we’re hooped. We’re 45 miles from the closest dealership that delivers anhydrous, and even though he has nine trucks, you’re going to be waiting if one breaks down. We could coulter it in after harvest, but conditions aren’t always right for that. “Cost is a big factor too, liquid costs more and either we had to run to town or store the fertilizer on the farm. If you pre-pay for fertilizer, you run the risk of the company, even a big one, going down. But if you take delivery, there’s some risk of leakage that’s an environmental hazard as well as a financial risk. We can store dry fertilizer on the farm without too much cost or hassle.” With a dry fertilizer blend, all going on with the seed, Christensen has a two truck seeding system. “We have the trucks, but every move is time consuming and now we have one less vehicle to move,” he says. “Using just one truck for fertilizer, we can use two for seed and we don’t lose time when we switch to a different crop. And we still have the option of changing to knife openers and fall banding. With the well-floated outfit we have now, I’m not afraid to do that.” Last year, Christensen was part of a comparison of seeding systems. A few weeks after seeding, he worked with Alberta Agriculture specialists to compare the performance of eight seeding systems. His Concord system rated second for germination. “The Bourgault drill with 10 inch spacing and midrow banding worked best, but it’s a three truck outfit,” he says. The plots were also rated for roughness. Most of the systems scored around 8 out of 10, or fairly rough. Christensen’s Concord scored 3 and the Dutch knife scored 2 out of 10. “We were quite happy with our system’s overall performance,” says Christensen. “Roughness matters. For some reason, you’re always going to have to work against the furrows at least some of the time. And, on a rougher field, some seeds take longer to emerge and they’re going to be green at harvest time.” Christensen recognizes his system is a compromise, but he believes each aspect of a seeding system has to fit into the rest of the farm operation. “What’s technically number one may not fit your system or give you the most profit,” he says. “I envy people who can use a low disturbance system. It’s the way to go, but I can’t make it work on our soils with the acreage we have to cover.”