Delta Farmland & Wildlife Trust Coastal Winter Cover Crops Christine Terpsma, Program Coordinator Outline Delta/DF&WT Overview Should I Cover Crop? Winter Cover Crop Varieties Challenges and Opportunities Coastal Cover Crops 1
Tyler Garnham Evan Leeson Coastal Cover Crops 2
The Fraser Estuary is located along the Pacific Flyway Conservation Designations: Canada s Premier Important Bird Area Migratory Bird Sanctuary National Wildlife Area Provincial Wildlife Management Areas Ramsar Site (Wetland of International Significance) Site of the Western Hemisphere Shorebird Reserve Network The mission of the Delta Farmland & Wildlife Trust is to promote the preservation of farmland and associated wildlife habitat in the Fraser Delta through sustainable farming and land stewardship Working with local farmers, DF&WT establishes and maintains over 3,500 acresof wildlife habitat annually on the lower Fraser River delta Grassland Set-asides Winter Cover Crops Should I Cover Crop? DF&WT Winter Cover Crop Program Example Hedgerow & Grass Margin Laser Laser Levelling Leveling Field Liming Markus Merkens David Bradbeer Markus Merkens Coastal Cover Crops 3
Winter Cover Crop Program Provides cost-share to farmers for establishing vegetative cover on their fields during nongrowing season Contract with specific land management practices Must seed at recommended rates for maximum cover Must be seeded by specific deadline for each variety Coastal Cover Crops 4
WCC Program 2014: 3,284 Ac $155,472.50 Functions of Winter Cover Crops: Soil cover and erosion control Nitrogen scavenging/fixation Weed suppression Pollinator habitat Building soil organic matter Habitat for overwintering waterfowl Act as a lure crop, or Alternate Feeding Area to offset damage to perennial forage fields Function of Winter Cover Crops: 1.)Building soil organic matter 2.)Habitat for overwintering waterfowl/ Act as a lure crop, or Alternate Feeding Area Coastal Cover Crops 5
Soils of the Lower Fraser Moderately fine textured Silty-clays -> Silt/clay loams Moderate to high nutrient holding capacity Fluctuating seasonal water table Poorly drained Prone to compaction Soil in this area is subject to intensive tillage Tillage reduces aggregate size, increasing risk of compaction Tillage speeds the breakdown of organic matter Markus Merkens What does well aggregated soil look like? Pores for water to drain through Space for roots to grow Holds nutrients Habitat for soil micro-organisms Results of Mechanical Cultivation over time: Aggregate size reduced Compaction Poor crop production Challenge Number Two: Field Visitors 1.4 million to be exact Butler, R.W. & Campbell, R.W. (1987). The birds of the Fraser River delta: populations, ecology and international significance. Canadian Wildlife Service Occasional Paper, pp. 71. Canadian Wildlife Service, Pacific and Yukon Region. Coastal Cover Crops 6
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Variety Trials Find Cover Crops that are well adapted to local weather/soil conditions: 1991 1996 cover crop screening trials conducted by the UBC Soil and Water Conservation Group in partnership with Delta Farmers Varieties Timing of seeding (early vs late) Waterfowl grazing capacity SCREENING TRIALS: 16 VARIETIES TESTED Fall Rye (3 cultivars) Spring Wheat Winter Wheat (2 cultivars) Forage Rape Annual Rye Grass Forage Kale Winter Triticale (2 cultivars) Crimson Clover Winter Barley Alsike Clover Spring Barley (3 cultivars) Red Clover Spring Oats Sudan Grass Austrian Winter Peas Buckwheat Temple, W.D., Bomke, A.A., L., P., A., P. & Smith, R. (2001). Farmland stewardship in Delta: final report. Delta Farmland and Wildlife Trust, Delta, unpublished report Cover Crops that didn t make the cut*: Sudan Grass Buckwheat Austrian Winter Peas Winter Triticale Red Clover* Crimson Clover* Alsike Clover* Winter Barley Cautionary Note on Brassica: Avoid the Green Bridge Forage Rape Forage Kale *Take results with a grain of salt! Approved Varieties Frost-sensitive Spring Cereals Spring Barley Spring Oats ***Also Annual Ryegrass Frost-tolerant Winter Cereals Winter Wheat Fall Rye Spring Wheat Spring Cereals (Barley & Oats) Frost sensitive Cheap seed Establish rapidly; chokes out chickweed Generally planted August Mid September Coastal Cover Crops 8
Spring Cereal Planting Recommendations Plant EARLY Early plantings accumulate biomass, frost kill and produce a good mulch If planted LATE, they may not die back; may become diseased; weak cover Spring barley over oats? Good spring weed control (due to allelopathic effects) Oats: 18 acres planted September 14, 2013 Winter Cereals Winter Wheat, Fall Rye, Spring Wheat More expensive seed Frost tolerant Rapid establishment; choke out weeds Biomass accumulation takes place in spring regardless of planting date (usually planted mid-sept) Can be harvested the following year Field Notes on Fall Rye Hardy and disease resistant High biomass yields and cover in trials Historical cover crop in Delta Can delay field work in spring Annual Ryegrass Relay-cropped with silage corn Can be cut for hay following spring Excellent cover Recommended for late planting dates Coastal Cover Crops 9
Residual Soil Nitrate Conservation PLANT EARLY N-uptake often exceeded 75kg/ha for WCC planted in August Delaying until late September reduces uptake of residual soil N Late-seeded WCC took up less than 60kg/ha total N prior to winter Continued Spring barley and wheat take up substantial residual N if planted well before first frost If planting late-sept, spring wheat is more capable of capturing/retaining residual N than spring barley Winter wheat, annual ryegrass and spring wheat were most effective at retaining soil N Fall rye contained LEAST N at spring plow down Further Notes WCC cannot prevent nitrate leaching if N additions to previous crop are in excess of crop needs, or if growth potential prior to winter is LOW Using cereal cover crops can prevent leaching losses of 500 750kg N/ha over a decade. What about clover? Long-term Goal: higher mineralizable soil N and reduced fertilizer requirements Coastal Cover Crops 10
Crimson Clover: Wasn t a consistent performer in trials Doesn t Like Wet Feet Rapid growth when conditions are favourable White Clover Slower establishment Not fond of wet soils Works best underseeded with grain Red Clover: Most popular clover in Delta rotations Deep taproot good for drainage Can Survive Water-logged Soils Clover & Cereal Markus Merkens Coastal Cover Crops 11
Winter Cover Crop Program 2014 Cover Crop Type Acres Planted Spring Barley 1925.5 Spring Barley/grass 29 Red Clover 17 Cover Crop Mix 162 Fall Rye 23 Fall Rye/clover 19.8 Forage Grass 16 Forage Radish 404 Oats 336 Spring Wheat 189 Winter Wheat 63 Coastal Cover Crops 12
Cover Crop Mix Sudan grass, Radish, Sunflower, Sugar Beet, Lentil and Chick Pea mix Forage Radish Challenges of Cover Crops Difficult to Incorporate Immobilize Soil N Soil Water Retention Cover Crop becomes a Weed (fall rye) Fungal Disease Pests (e.g., wireworm) Not enough vegetation in spring Cover Crop Opportunities Hairy Vetch? Black Medic? Seeding rate calculator: https://greencoverseed.com/legacy/s martmix/index.htm Black Oat? www.deltafarmland.ca Coastal Cover Crops 13
Approximately 70,779 acres of Winter Cover Crops have been established in the lower Fraser River delta since 1990 Coastal Cover Crops 14