sizes in our HeavyDuty lineup, there's a Frontier Soil Pulverizer just right for your needs. The 20 Series StandardDuty Soil Pulverizers are compatible with tractors of 30 to 50 horsepower. They're perfect for landscaping professionals and homeowners. For tractors of 40 to 90 horsepower, the 22 Series HeavyDuty Soil Pulverizers work well