Nutrient Management in Organic Systems Chris Reberg-Horton, Greg Hoyt, Julie Grossman, John Spargo.

Nutrient Management in Organic Systems

Chris Reberg-Horton, Greg Hoyt, Julie Grossman, John Spargo

What are the rules?

• “Select and implement tillage and cultivation practices that maintain or improve the physical, chemical, and biological condition of soil and minimize soil erosion.”

• “The producer must manage crop nutrients and soil fertility through rotations, cover crops, and the application of plant and animal materials”

• “The producer must manage plant and animal materials to maintain or improve soil organic matter content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances. “

ManuresRaw animal manure, must be composted unless it is:

• (i) Applied to land used for a crop not intended for human consumption;

• (ii) Incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles; or

• (iii) Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have direct contact with the soil surface or soil particles;

Manures

• Does not need to be organic for the U.S. market

• Does not need to be organic for the E.U. any longer

The “National List of Allowed and Prohibited Substances helps understand acceptable commercial

products

• List of exceptions to the general requirement that natural materials are allowed and synthetic materials are prohibited. (NOP §205.602)

• Rule of Thumb #1: all natural products are allowed, unless they listed as prohibited

• Rule of Thumb #2: All synthetic products (fertilizers, amendments, pesticides, growth regulators, etc.) are are prohibited unless specifically allowed

Certified Organic Compost from Manures

• Compost must have an initial Carbon:Nitrogen ratio of between 25:1 and 40:1.

• Producers using a windrow system must maintain the composting materials at a temperature between 131 deg. F and 170 deg. F for 15 days, during which time, the materials must be turned a minimum of five times.

• Prove it! • Uncomposted manures and non-manure

compost much more common.

So is organic agriculture reliant on manure?

• Yes and no• Yes -current practices on most farms• No – some outliers who are not

Bob and Leda Muth Family Farm, Williamstown, NJ use municipal leaves as the ONLY fertility source

Outliers

Most organic farmers

• Manures obtained locally supply P, K, and micronutrients

• Cover crops supply additional N• Possible purchasing of processed

manures/animal by products

A lot of nutrients in litterN P K S

---------- lbs acre-1 ----------

Turkey broiler litter4 tons acre-1

supplies

116 107 160 48

What are the purchasing options?source price per ton % N %P %K price/lb N price/lb p price/lb k

organic gem liquid fish 3.09/gal 0.255 0.255 0.3 12.12 12.12 10.30

chilean nitrate 16-0-0

1000 16 0 0 3.13 - -

Nutrimax 12-1-0 625 12 1 0 2.60 31.25 -

13-0-0 Nature Safe 625 13 0 2.40 - -

feathermeal 395 6.35 0.3 0.11 3.11 65.83 179.55

Allganic Potassium Sulfate

1050 0 0 50 1.05

Rose Acres litter compost

60 1.55 1.3 1.875 1.94 2.31 1.60

Peruvian Bat Guano 650 12 12 6.5 2.71 2.71 5.00

Perdue pellets 210 4 2 3 2.63 5.25 3.50

Phosphorous

• Rock phosphate – very low solubility• Bone meal – more soluble

Potassium

• Muriate of potash (KCl)A mined substance of high solubility. [Prohibited] unless derived from a mined source and applied in a manner that minimizes chloride accumulation in the soil.

• Farmers mostly reliant on animal sources here, other regions use more KSO4

• Potassium sulfate and sulfate of potash cannot be treated with anti-dust agents

Micro-Nutrients

• Micronutrients may be used only in cases where soil/plant nutrient deficiency is documented by soil or tissue testing.

• Sulfate formulations mostly• A few borons allowed, but not the one with

the ammonium

A lot of nutrients in litterN P K S

---------- lbs acre-1 ----------

Turkey broiler litter4 tons acre-1

supplies

116 107 160 48

Just manures would be a problemN P Cu Zn

---------- lbs acre-1 ----------

Corn150 Bushels acre-1 removes

112 53 0.06 0.15

Broiler litter4 tons acre-1

supplies

116 107 2.1 2.6

High Residue Problems

• Planting• Soil drying - roll first - plant later• Lodging of the cover crop and cash crop

Planting problems in High Residue Systems

Hair Pinning = Poor stands Residue accumulation

Weed control can be excellent

Soybean Yield

< 7,000 7-9,000 >9,000Rye Biomass (kg ha-1)

NO-TILL CORN YIELDS

50

75

100

125

150

175

0 33 67 100 133 167 200

NITROGEN FERTILIZER RATE, lbs/acre

CO

RN

GR

AIN

YIE

LD

bu/a

cre

HAIRY VETCH

BARE SOIL

RYE

COVER CROP P K lbs /acre

SMALL GRAIN 20 170CRIMSON CLOVER 18 164HAIRY VETCH 18 180

BARE SOIL 0 0

NUTRIENTS IN COVER CROP RESIDUE

Webster, USDA-ARS, Tifton, GA

Pigweed as a Row Crop

Drainage issue for some soils and crops

Rolling/crimping Crimson cloverU.S. patent # 7,562,517 B1

2-row, 3 furrows roller/crimper 1-row, 2 furrows roller/crimper

Our website

• Quarterly newsletter• Extension bulletins• Organic Grain Production Manual• http://www.organicgrains.ncsu.edu/