Increasing Crop Diversity and Production Chris Benedict WSU Whatcom County Extension
Outline Crop Rotation Cover Cropping Emerging Research Principles/Theoretical Practice
Crop Rotation A planned sequence of crops grown in succession on the same field over time Commonly consists of crops with different temporal, spatial, and cultural needs (Power and Follet 1987; Liebman and Dyck 1993) Crop Rotation Principles
Crop Rotation Rotation Planning vs. Crop Sequencing Crop Rotation Principles
Effective Rotations: Crop Rotation Maintain or improve profitability Increase crop (plant) diversity Consist of crops with diverse nutrient req. Maintain healthy soil Utilize/create temporally or spatially diverse niches Reduce off-farm inputs Crop Rotation Principles
A well-functioning rotation for a dairy farm should: Meet the feed needs of the operation Grow crops adapted to the soils and climate Effectively use nutrients from manure Match the labor availability of the operation Minimize pesticide use through IPM practices Minimize soil erosion Crop Rotation Principles
Flexibility Estimate Feed Requirements Essential Components Estimate Production Credit for Rotations Rotation Match Crops to Soils Adjust Ration to rotation Crop Rotation Principles
Pest Pressures Feed Shortages Rotations as Tool to Address Production Issues Forage Quality Inconsistent Corn Performance Efficient N Use Crop Rotation Principles
Rotation and Nutrients Match soil nutrient pulses with rotational demands Pulses timed for uptake of high-demand crops Crop Rotation Principles
Long-term Systems Experiment established WSU Puyallup 2003 Crop Rotation Practices
Three Cover Crop Treatments Relay planted Legume (RLY) Post-Harvest Cereal & legume (PH) Short-term Grass-legume Pasture (LEY) Crop Rotation Practices
Soil quality measurements include physical, chemical, and biological indicators Bulk Density Infiltration Compaction Particulate OM Enzyme activity Nematodes Collembola Microbial biomass Nitrogen cycling Microbial community structure Nutrients and carbon Crop Rotation Practices
Bulk density is an indicator of porosity and compaction. Crop Rotation Practices
Soils had higher bulk density during short-term pasture cycle. Bulk density, g/ml 1.3 1.2 1.1 1.0 0.9 a b c a Ley Post Harvest Relay a b a Cover crop 2004 2005 2006 2007 2008 2009 2010 a b a b a Cogger, 2013 Crop Rotation Practices
Crop Rotations and Weed Populations Anderson, 2010 Crop Rotation Practices
Fig. 3 Wild oat populations in research plots at Lacombe, Alta. over four years as affected by growing barley for grain (grain-0) compared to cutting barley for silage at the soft dough stage (norm. silage) or just after head emergence (early sil... J.T. Donovan, R.E. Blackshaw, K.N. Harker, G.W. Clayton, J.R. Moyer, L.M. Dosdall, D.C. Maurice, T.K. T..Integrated approaches to managing weeds in spring-sown crops in western Canada. Crop Rotation Practices
Designing Effective Rotations for Weed Management More complex rotations results in lower total weed density and greater weed diversity (Liebman and Dyck 1993) Reduced dominance of a narrow range of species Promote diversity by creating niches for wider range of weeds (Cardina et al. 2002, Dorado et al. 1999; Liebman and Dyck 1993) Crop Rotation Practices
Liebman and Staver 2001 (adapted from Kelner et al 1996, and Derksen 1997)
Influence of Crop Rotation on Weed Biology/Ecology Davis et al. 2005, Swanton et al., 1999 Crop Rotation Practices
Crop Rotation and Plant Disease -Effectiveness is organism-based Soil invader vs. soil inhabitant Source: Davis et al. 1994 Crop Rotation Practices
Crop Rotation & Cover Crops Benefits of Crop Rotation Build soil Reduced pest pressure Reduced dependence on external inputs Decreased crop risk Increased profitability Benefits of Cover Crops Build Soil Reduced pest pressure Reduced dependence on external inputs Reduced nutrient leaching Increased profitability
Cover Crop Choice Goal Problem or Use Identify Place Time Select Cover Crop Integrate Rotation Niche Cover Crop Principles
Cash/Cover Crop Interactions N-Immobilization Grain vs. Legume Residue Management For benefit? Pest bridging/breaking Disease Arthropods Weeds Cover Crop Principles
Interseeding Cover Crops Tetraploid ryegrass Cold tolerance Non-competitive Planted 3-6 leaves (corn) @ 10-15 lbs/a Disease resistance > still host
Winter Cover Crops: Cover Crop Blends Trial Pure rye, pure hairy vetch, and 3 mixtures 30% Rye 40% Rye 50% Rye 2 planting dates Mid Sept and early Oct 2 termination dates Late March and late Apr Cogger et al., 2010
Winter Cover Crops: Cover Crop Blends Trial More vetch and early termination decreases C:N Pure vetch and early termination blends should be net suppliers of N in short run Late termination blends should supply N a little more slowly Pure rye would tie up N in short run Carbon:Nitrogen ratio 28 26 24 22 20 18 16 14 12 10 8 2005-2008 Sept planting late harvest Sept planting early harvest Oct planting late harvest Oct planting early harvest 0 20 40 60 80 100 % Rye Cogger et al., 2008
Nitrogen uptake by cover crops Winter Cover Crops: Cover Crop Blends Trial June soil nitrate following cover crops N uptake, lb N/a 100 90 80 70 60 50 40 2005-2008 Sept planting date Oct planting date Soil nitrogen, NO 3 -N mg/kg 45 40 35 30 25 20 15 2005-2008 Sept planting date Oct planting date 30 0 20 40 60 80 100 Rye % 10 0 20 40 60 80 100 Rye % Cogger et al., 2008
8210HR 8210HR 8210HR 8210R 8210HR 8210HR 8210HR 8210HR 8210HR 8210HR 8210R 8210HR 8210HR 8210HR 8210HR 8210R 8210HR 8210HR Ryegrass 8210HR Aroostook Rye Common Rye Ryegrass Aroostook Rye Common Rye 8210HR 8210HR 8210R 8210HR 8210HR Field 485' E400' N-S REP 4 90 30' REP 3 40 30' REP 2 No CC (Bare) 40 REP 1 STND 150 lbs N/A PSNT-based 75 lbs N/A 30' 40 Cover Crop Practices
Aroostook Rye Common Rye Cover Crop Practices
Cover Crop Practices
Cover Crop Practices
Emerging Research Interseeding Soybeans/Corn Perennial Wheat
Post Sexual Cycle Regrowth, October
Stay Green 6 1/2 feet
November, 2012
What we Know: Tonnage of dry matter per area is 3X wheat or barley. Twelve ton per acre straw alone? Feed quality (green chop) is good. Grain protein higher than comparable cereals. Indeterminate types offer a range of options for growers.
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Chris Benedict Questions 1000 N. Forest St. Bellingham, WA 98225 chrisbenedict@wsu.edu 676-6736 ext. 21 whatcom.wsu.edu/ag