Montana Small Grain Guide Pages 42-48

Crop Rotation: Sidney Research Center Results b Highest annual yields were obtained with continuous cropping b Residue Management for snow trapping was very important b Adequate fertility & weed control needed b Rotating spring & winter grains good for breaking disease & weed cycles b Residue from winter wheat can cause seedbed problems

Crop Rotation: Sidney Research Center Results b Spring wheat stubble was the best for recropping; fewer volunteer plants b Wild oats, cheatgrass, pigeon grass & volunteer grain were serious problems with continuous cropping b Cephalosporium stripe when winter wheat grown in monoculture

Crop Rotation b Three year rotations worked best b Spring wheat after oats or barley lowered wheat quality b Feed grains after wheat wasn’t a factor b Forage crops (corn, oats, barley) can replace a spring grain stubble is insufficient for trapping snowstubble is insufficient for trapping snow

Crop Rotation b Sunflower or Safflower can replace spring grains can utilize Nitrogen that has leached below the root zone of spring grainscan utilize Nitrogen that has leached below the root zone of spring grains

Tillage & Residue Management b Can reduce wind & water erosion b Conserve moisture b Trap snow b Tillage implements determine degree of residue incorporation

Conservation Tillage b Stubble mulch: minimum tillage while maintaining a protective residue cover b Ecofallow: uses chemicals and tillage together to control weeds & conserve soil moisture b No-till: seed directly into residue of previous crop

How much residue remains after tillage? b Multiply bushels/acre you harvested by 100 b Multiply by the percentage from chart Moldboard Plow5%Moldboard Plow5% Chisel Plow75%Chisel Plow75% Harrow80%Harrow80% Disk50-60%Disk50-60% Rodweeder85-90%Rodweeder85-90% b Multiply by factors for each subsequent pass

How much residue remains after tillage? b 20 bu. Per acre crop b 20 X 100 = 2,000 lbs. b Summerfallow using a chisel plow b 2,000 X.75 = 1,500 lbs. b 1,500 X.75 = 1,125 lbs. b 1,125 X.75 = 843 lbs

How much residue should be on the soil surface? b 1, ,000 lbs per acre b No tillage would be necessary from a 20 bu/acre crop b With no-till drills and adapting drills, tillage to incorporate residue is NOT needed

Affect of tillage on the soil b Loosens soil in the plow layer b Increases soil aeration b Increases water infiltration b Long-term results: less aggregated, more compacted

Soil Compaction b 90% of soil surface is traversed by wheels during seeding b 25% at harvest b 60% when straw is baled and hauled off

Deep Tillage b Subsoiling: breaks or shatters compacted soil layers (Hardpan) b Done at 16” - 36” soil depth b Should be done in fall when soil is fairly dry b Need for subsoiling can be avoided where management practices prevent compaction reducing secondary tillage operationsreducing secondary tillage operations adding organic matteradding organic matter