Crop rotation plays a major role in effective disease control in barley, whether direct seeding or conventional tillage is used. Growing barley in a three- to four-year rotation will eliminate or effectively control most soil-borne diseases, including major diseases such as scald, net blotch and root rot.
Producers continuously growing barley or using short rotations will need to pay special attention to soil fertility, resistant barley varieties and fungicidal disease control. Growing barley continuously generally results in significantly reduced yields and lower quality grain, especially in wetter, higher yielding areas of Alberta. Since many root, foliar and head diseases are involved, yield losses in the order of 20 to 30 percent are not uncommon.
Crop residue effects:
The crop residue cover on direct seeded fields conserves soil moisture and traps snow. Thus, seeding depth can be shallower in direct seeded fields. Shallow seeding may result in earlier emergence, leaving more energy for healthier seedlings better able to withstand disease.
Direct seeding avoids the marked temporary nitrogen deficiency in conventional tillage fields caused by incorporating large amounts of straw into the soil immediately before seeding. Thus, direct seeding can give barley seedlings a better start for a healthier stand.
A crop residue cover may result in cooler spring soil temperatures. Thus, in cool, wet springs, direct seeding may result in a greater delay in crop emergence.
