b'This aerial viewshows the difference in crop growth caused by field traffic and soil compaction in a corn crop. The diagonal wheel tracks as well as those going straight across the field are clearly visible. These field operations show up in crops for the entire growing season. PHOTO: JODIDEJONG-HUGHES alfalfa, with rotation decisions not generally ad- a number of growers that routinely do ripping [deepripper following planting with shanks penetrating dressing compaction concerns, but rather economictillage] in the summer months in the year beforebeneath the seed. return, says Sawatzky. Rye, canola and alfalfapotato planting to break up compaction layers. How-tend to leave the soils a little looser than other rowever, its important that this be done under relativelyLOOKING FORWARD crop rotations, he notes. Mustard is used more fordry conditions, as ripping in wet conditions canFor the best results, DeJong-Hughes says all Verticillium control. Provincial soil extension work hascause smearing and make the problem worse.preventative practices need to be put in place to the been carried out over the past few years with daikonA number of P.E.I. potato growers, he adds, havegreatest extent possible. She says most compaction, radishes to determine their effect on compaction.replaced moldboard plowing with vertical tillage80 per cent, happens on the first pass. She also Radish, and to a lesser extent clover/mustard, hasequipment (such as the Lemken Karat or Pottingerwarns as much as is possible, do not till as tilling less effect on structural compaction, but has beenSynkro) associated with improved soil structure. destroys soil structure. Build your soil structure. shown to open up better water infiltration channelsSawatzky says in Manitoba, vertical and min- Its your most important defence against future soil within the soil.imum till are extensively practiced, with attentioncompaction.also given to protecting overall soil health andIn Sawatzkys mind, much remains to be learned RIPPING AND TILLAGE PRACTICES replenishing organic matter. In addition, cover crop- about the effects of soil compaction on potato While the crop management practices that preventping is practiced on lighter soils prone to erosion,production in Manitoba. A lot of compaction studies compaction mentioned above are most critical, farm- and some producers will incorporate deep ripping ashave dealt with other crops which have different root ers who wish to reverse damage already done canpart of their normal routine, he says.development patterns and may not relate directly to do some ripping up of compaction layers. However,Like Barrett, he warns mechanical tilling or deeppotato research, he says. We also see a range of the appropriate equipment is necessary. Barrett saysripping methods rely on the right soil moisture con- penetrometer readings within the field, but we dont deep tillage with straight shanks that reach two toditions to achieve the most effectiveness, and if notknow at what level of compaction potato yield is af-three inches below the compaction layer in relativelyused correctly can result in establishing a hardpanfected. With the thin margins of the potato industry, dry soil conditions can help fracture the layers. deeper in the soil profile. the cost-benefit of any change in cropping practice Last spring, after verifying the depth of com- Sawatsky adds that many Manitoba growersneeds to be proven. paction in various farmers fields, Barrett and hiswill use a Dammer-Diker tool after planting to both colleagues ran a ripper two to three inches belowloosen soil to a deeper depth and create pockets the identified compaction layer ahead of the potatofor moisture retention. Some do this as a standard planter. This was the first year of this trial and wepractice each spring, ripping between rows and plan to repeat it in 2020, he says. There are alsowhere hills will eventually be as well. Others use a WINTER 2020 SPUDSMART.COM 27'