The Martens' Farm
Location: about 60 miles southeast
of Rochester, NY, on the western shore of Seneca
Important people: Klaas and Mary-Howell
Martens, Peter, Elizabeth, and
Daniel. Plus Robert Hall (employee/asst farm manager)
Years farming: We've farmed this
farm together since 1991. Klaas has farmed all
Total acreage: 1500
Tillable acres: 1300
Soil type: Honeoye Lima silt
Crops: corn, soybeans, spelt,
wheat, barley, oats, triticale, red kidney beans,
sweet corn, snap beans, cabbage, edamame soybeans
Livestock: sheep, pigs, chickens
for our own use
Regenerative farm practices:
diverse long term crop rotations that incorporate
legumes and small grains, under seeding all small
grains with red clover, actively increasing soil
Marketing: corn & small grains
are sold to Lakeview Organic Grain LLC, our organic
feed business. Soybeans, red kidney beans, and
spelt sold to brokers and processors. Some spelt
is sold as kosher organic spelt. Sweet corn, snap
beans and edamame are sold to processors who freeze
them under brand name labels. Cabbage is made
into sauerkraut and packed under the Cascadian
Farms label. Some of the oats, wheat and barley
are being grown from Foundation Seed to produce
Certified Organic Certified Seed.
note: A version of this column originally ran in
the March 2004 edition of Tails and Tassels, a newsletter
by and for members of New York Certified Organic, Inc.
Posted August 3, 2004: You diligently took
soil tests this winter and now they’ve come back indicating
that potassium or phosphorus is low on some fields, here and
there you have a zinc deficiency, and you know that you will
probably need some additional nitrogen. But you’re organic!
No synthetic fertilizer for you! What do you do?
NOW HEAR THIS: Amending your soil is no substitute for good
agronomic management. Fine-tuning your fertility if the agronomics
are not sound is like tweaking the carburetor adjustments
when there is a blown piston. Take care of the big stuff first!
Adjusting soil fertility is certainly an important part of
good management, but you won’t see any return from the
adjustments unless your crop rotations, choice of adapted
varieties, legume cover crops included frequently in the rotation,
tillage, weed control, and other such factors are in line.
But, if still there are deficiencies and imbalances, there
are approved products you can use (but be sure to check with
your certifier before purchasing any new inputs).
Manure and Compost Based Products
manures supply different amounts of nutrients depending on
the animal species, feed, bedding and manure storage practices.
The amounts of nutrients that become available to the plants
depend on the time of year the manure is applied and how quickly
it is worked into the soil. Existing soil conditions also
affect how quickly the nutrients in the manure are available.
On average, cow manure contains approximately 10 to 15 pounds
of N, 5 to 10 pounds of phosphorous, and 10 to 12 pounds of
potassium per ton. Poultry manure has a higher percentage
of all three elements. The National Organic Program (NOP)
is very specific about the use of manure. Composted manure
is definitely preferred, but if raw manure is applied, then
the timing of application is critical. Where raw manure is
used on land growing crops for human consumption, it must
not be applied within 120 days of harvest for a crop where
the edible portion touches the soil, or 90 days of harvest
where the edible portion does not touch the soil.
a product to technically qualify as compost under the NOP,
it must start with a carbon to nitrogen ratio between 25:1
and 40:1 and be maintained at a temperature of between 131°F
and 170°F for 15 days, during which time the materials
must be turned a minimum of five times. If compost is made
in this manner, then it can be applied to plants with no restrictions
of timing. If you use composted manure or compost made with
some manure and want to apply it less than 90 days before
harvest on food-grade crops, you will need full documentation
on how the compost was made to prove it complies with the
NOP requirements. However, if compost is not made in this
way and contains manure and/or animal products, then it must
be applied according to the timing restrictions for raw manure.
If the compost contains only plant material, then it is considered
plant waste and carries no timing restrictions.
- long favored by organic gardeners and biodynamic farmers,
compost tea is coming under criticism by the NOP because improperly
made compost tea may have the potential for spreading food-borne
pathogens onto plant parts destined to be eaten raw by people.
It continues to be a major topic of discussion among federal
regulators. In April, the National Organic Standards Board
(NOSB) made its recommendations
to the NOP concerning the use of compost tea. Basically,
if you are very careful to use only compost that meets all
of the NOP compost requirements, can document that and are
not using compost tea additives, that compost tea should be
acceptable. If you aren’t sure whether your compost
has meet all the requirements, especially if you are using
purchased compost, then the timing restrictions of raw manure
will probably apply. If additives are used, according to NOSB
recommendations, the tea and brewing process must undergo
a rigid series of tests to make sure no harmful pathogens
are being produced or the 90-120 day timing restrictions apply.
Check with your certifier!
Plant and seaweed products
Alfalfa meal or pellets
contain around 3 percent nitrogen and are commonly used as
an animal feed. This is an excellent fertilizer material in
high-value horticultural crops but would probably be too expensive
for field crops. It is thought to contain unknown growth factors
which make its mineral content more effective as plant nutrients.
Leaf and plant-waste compost
is increasingly available, or you can make it yourself. In
many cases, the compost is a good product, but it is sometimes
ridden with “impurities” such as car waste, pesticides
and garbage. Soybean meal is about 6 - 1.4 - 4 NPK; it can
be useful, but is extremely expensive. Organic farmers should
be careful about not using conventional GMO soybean meal although
it is not specifically prohibited under the NOP.
Most seaweed fertilizers
come from kelp that has been harvested, dried, and ground.
Kelp meal can be applied directly to the soil or in starter
fertilizer. It flows well and is easily applied with most
fertilizer applicators. It can be mixed with other dry fertilizers
and amendments. Soil application rates for kelp meal commonly
range from 150 to 250 pounds per acre for pastures, forages
and small grains. About 200 to 400 pounds per acre are recommended
for corn, horticultural crops, and gardens. Since it is expensive,
kelp meal is most commonly used only on high-value crops.
Dried raw seaweed
tends to contain about 1 percent nitrogen, a trace of phosphorus,
and 2 percent potash, along with magnesium, sulfur, and numerous
trace elements. Raw seaweeds are prepared by various methods
and sold under a number of brand names.
Blood meal and blood meal
are dried slaughterhouse waste and are both allowed under
the NOP, even from non-organic animals. Blood meal contains
about 12 to 13 percent nitrogen and unless used carefully,
it can burn plants with ammonia, lose much of its nitrogen
through volatilization and encourage fungal growth. It is
also very expensive.
is a common by-product of the poultry slaughter industry and
is allowed under the NOP. Although total nitrogen levels are
fairly high (7 to 10 percent), the nature of feathers is such
that they break down and release their nitrogen much more
slowly than many products of similar price.
Fish meal and fish emulsion
are, like most animal by-products, rich in nitrogen. Fishmeal
contains about 10 percent nitrogen along with about 6 percent
phosphate. It is most frequently used as a feed additive but
can be used as a fertilizer. Fish emulsion usually has an
analysis around 4-4-1. Fish emulsion may be fortified with
chemical fertilizer, so organic farmers should be suspicious
of any product with a phosphorus content in excess of 4 percent.
Fish products may also contain synthetic preservatives, stabilizers
and other products prohibited under the NOP.
Other Nitrogen Sources
Most organic farmers try to supply their nitrogen needs with
legumes in the crop rotation
or with manures and composts. Sodium
nitrate or Chilean nitrate were added to the
NOP National list after much discussion. The NOP stipulates
that the nitrogen obtained from sodium nitrate must account
for no more than 20 percent of the crop’s total nitrogen
requirement. This mined product is about 16 to 20 percent
nitrogen and highly reactive. Even though it is ‘natural’,
it acts more like a synthetic fertilizer and can cause sodium
buildup in the soil. This can be used cautiously when rapidly
available nitrogen is needed. Sodium nitrate is prohibited
by the Farm Verified Organic (FVO) and Organic Crop Improvement
Association-International Federation of the Organic Agriculture
Movements (OCIA-IFOAM)-accredited levels of certification.
There are 3 main types of mineral phosphate:
• Colloidal phosphate
• Soft rock phosphate
mostly from ancient sea deposits, and
• Hard rock phosphate
from volcanic deposits.
Clay-based phosphates tend to be more readily available than
the rock phosphates, and soft rock phosphate is more available
than hard rock phosphate. Synthetic phosphorus fertilizers
(prohibited in organic production) are made by reacting rock
phosphate with acids and other chemicals to convert the phosphorus
into a water soluble form. Bone meal typically contains about
27 percent total phosphate, and nearly all of that is readily
The analysis numbers tend to be quite low for rock phosphates
because little of the phosphorus present is water soluble.
Rock phosphate is generally made up not only of phosphorus,
but also of calcium, carbon and lots of trace elements, most
of which are valuable plant food. Unfortunately, some sources
of naturally mined phosphate can also be high in heavy metals.
Organic phosphate materials are most effectively when applied
to a growing cover crop a year or more before the crops will
need the nutrients. This will give the soil microbes the opportunity
to convert the insoluble phosphate into more available and
stable forms. Legumes, like clover, are very efficient at
breaking down rock phosphate into more available forms.
Another efficient way to use rock phosphate is to add it
directly to livestock manure in the barn where the manure
acids dissolve much of the total phosphate and the phosphate
stabilizes the nitrogen in the manure. Many of the same advantages
can be had by adding 20 to 50 pounds of colloidal or rock
phosphate to one ton (two cubic yards) of manure when composting.
and potassium magnesium sulfate
(langbeinite), are allowed under the NOP if you can clearly
document that you are using a mined source that has not been
treated with acid or any other chemical reaction to make the
potassium more available. Potassium sulfate is the better
choice for high Mg soils, but it is fairly reactive and must
be used carefully. There are synthetic forms of potassium
sulfate, so make sure you are getting the mined product. Sulpomag
and K-Mag are two brand names for langbeinite. Amazingly enough,
potassium chloride (muriate of potash) is allowed on the NOP
National List if it can be documented that it is from a mined
source and “applied in a manner that minimizes chloride
accumulation in the soil.” This product is extremely
soluble and is a popular conventional fertilizer. It is the
opinion of some organic farmers that it should not be allowed
in organic production because it is so harsh on soil life
and soil structure and can cause chlorine buildup in the soil.
Potassium chloride is prohibited by the FVO and OCIA-IFOAM-accredited
levels of certification.
is often sold as a “slowly available” potash source
for organic production. Granite dust typically contains from
1 to 5 percent potash depending on overall mineral composition
of the rock, but granite is mostly feldspar, a highly insoluble
mineral, so little of that potassium is easily available.
Another source of slowly available potash is the clay-type
mineral glauconite, commonly
sold as greensand. Total potash content of
greensand is around 7 percent, all of which is deeply locked
into the mineral and only slowly available. The high price
of greensand, however, limits its use solely to high-value
horticultural applications or to small amounts of banded starter
fertilizer. Certain micas, particularly biotite (black mica),
contain potash, which because of mica's physical structure,
is more available than most rock-type materials in microbially
Lime and gypsum
are valuable products to moderate the soil pH and deliver
essential calcium. Here in New York, few soils need more magnesium!
Our glacial heritage has left us with soils high in Mg, with
the tendency to become hard, compacted, and crusty. This soil
condition favors certain tough species of weeds. Therefore,
when raising soil pH and adding calcium, we might want to
avoid hi-Mag or dolomitic lime. Hi-calcium lime or gypsum,
which is calcium sulfate,
are better choices for us. (Talking to other organic farmers
and soil testing will help you determine your own baseline
conditions.) Gypsum is also a
valuable source of sulfur, which is critical for healthy plants,
and for healthy animals that eat the plants. Make sure that
the lime and gypsum are naturally mined, not industrial waste
products. Burned lime is not allowed.
Secondary and minor nutrients from rock
Micronutrients can be supplied in small quantities in a variety
of rock dusts. Certain types of synthetic micronutrients may
be allowed in tiny quantities in a mixed organic fertilizer
if it can be shown (with a soil test) that they are correcting
a documented deficiency. Basalt
dust, if available at a reasonable cost, can
provide a wide range of trace minerals to agricultural systems
over a period of several years. As with most rock powders,
transportation costs are a major factor in determining cost-effectiveness.
Most of the rich volcanic soils of the world are derived from
basalt. Even when too expensive for land application, basalt
dust can be beneficial when mixed with manure in the composting