200 likes | 287 Views
Soil Amendments: How to Find and Apply. Rupert Jannasch and Roxanne Beavers. Considerations for Organic Growers . The basis of your fertility regime needs to be from on-farm sources Crop rotation, cover crops Livestock
E N D
Soil Amendments: How to Find and Apply Rupert Jannasch and Roxanne Beavers
Considerations for Organic Growers • The basis of your fertility regime needs to be from on-farm sources • Crop rotation, cover crops • Livestock • Supplementing can be done with products allowed by the Permitted Substances List • Natural source, minimally processed products
Amending your Soil • How do I know how much fertility is needed? • Soil test, type of crop, contribution of green manure and organic matter • Nutrient availability from most organic amendments is a gradual process driven by microbes
Sources of N: Manure • Source of nitrogen and organic matter • Composted is preferable, and if not organic, composting may be required • Non-composted manure must be applied far before harvest (90-120 days) • Nutrient levels depend on animal source, moisture content, bedding • Raw manure should be incorporated to minimize N losses
Composts • Why use compost instead of raw manure? • Composting kills weed seeds, pathogens, stabilizes nutrients • Provides macro and micro nutrients • Adds organic matter to soil which makes it better able to hold nutrients • Increases microbial activity which makes nutrients more available
Composts • Made on your farm? • Temperature must reach 55C for 2 days • Keep records of temp and turning • Off-farm compost? • Meet CCME Category A levels for trace contaminants and criteria for acceptable pathogen levels • Both – must use only allowed feedstocks
Other sources of N • Alfalfa Meal • Soybean Meal (must be non-GMO) • Crab Meal • Feather Meal • Blood Meal • Pelletized Manures
More amendments • Phosphorus - Rock P, bonemeal • Potassium – Greensand, wood ash • Calcium – calcitic lime, calphos, crabmeal/lobster meal/shells, ash, dolomitic lime too • Magnesium – dolomitic lime, Epsom salts / magnesium sulphate • Sulphur – elemental S, gypsum, Sul-Po-Mag, K-Mag
Micronutrients • Required in small amounts for plant metabolism; high amounts may be toxic • Boron, Copper, Iron, Manganese, Molybdenum, Zinc • Standard requires a soil test or plant tissue test showing low levels before using specific amendments
Micronutrients • Amendments might address one deficiency (Solubor) or multiple deficiencies • Kelp • Seaweed extracts • Basalt rock powder • Fish emulsions • Blended organic fertilizers
Is it Allowed? • Check the label/MSDS for ingredients • Ask your Certifier • If in doubt, contact the manufacturer • Get your answer in writing! • Does the product come from the US? • Must ensure that it doesn’t contain Chilean Nitrate (will be phased out by 2013) • Is the Nitrogen analysis >3? Be cautious
How to Apply • Composts may be tilled in or used to topdress • Manures must be incorporated, applied to warm soil, avoid runoff • Rock powders – apply early in season, or add to composts • Liquid products – can be used as a foliar feed or a soil drench • Need to determine your application rate
Application Rates • Joe has a 1 ac (0.4 ha) market garden • He gets a truckload of 20 yards of compost delivered – how much N will this provide? • Assume 800 lbs/yard bulk density • 7.2 tonnes of compost was delivered • This corresponds to a rate of 18 t/ha compost
Application Rates • Compost analysis is 1.5 -1- 1 • 20% of the N is available in the first year (1.5)(20%) = 0.3% • If 18 t/ha compost is applied • then 54 kg N /ha is added • If Joe is growing heavy-feeding crops or has low background soil N, he will need to add more N
Application Rates • Soil test for boron comes back low: 0.32 ppm Want to add 1 kg/ha boron: • Borax – 11% B • 1 / 0.11 = 9 kg/ha or 0.9 g/m2 • This product can be applied directly to soil
Solubor – 20% B • 1/0.20 = 5 kg/ha or 50 g/100m2 • To apply with a sprayer, use spray rate (e.g. 200 L/ha) to determine the area covered by one tank • 10 L tank would cover 0.05 Ha or 500m2 • Multiply this area by your application rate to figure out what amount to mix in the backpack - 250g/10L
Where to Source Products? • Farm supply stores • Consider delivery in bulk • Regional representatives for different companies • ACORN Database • Talk to other farmers • Trade publications – Rural Delivery, Small Farm, Canadian Organic Grower
Other Considerations • OMRI & Certifier Input Approvals • Before you source, read the Permitted Substances List to look for restrictions • Questions?