Question
Hello, I'm interested in starting an organic garden or farm, to be certified organic, and I have some questions about the soil.  I want to make all conditions optimal. What are organic (non-chemical) fertilizers and options that can be used on produce that will be certified organic?

Also, how do you make sure the pH is evenly distibuted throughout the soil.  So it's not different pH levels in different areas.  How do you find the optimal pH for different kinds of plants?

Thanks

Answer
Organic fertilizers are typically fertilizers which is recycled, e.g. it used to consist of plant or animal parts, or animal and human waste.

examples are: bone meal and blood meal from slaughter house industry. cotton seed meal (byproduct of cotton production). The latter makes the soil rather acidic if this is what you are trying. You can also look into alfalfa pellets and cracked corn (foodstuffs for horses and cows). Generally the higher protein rating on the horse feed the higher nitrogen contents does the products have.

You can also look into using composted manures, or byproducts from water treatment plants (e.g. human waste). Some of these may not qualify for organic certification, though. especially water treatment plants can sometime inject high levels of heavy metals such as merkury.

As with any fertilizer, you need to get a good balance of N-P-K depending on your product. If you grow vegetables and roots, then fertilizers with 1-2-2 ratio are preferred, such as 5-10-10, 10-20-20, etc. If you instead grow grains then more nitrogen (first number) may be required.

With organic fertilizers you need to find out what the N-P-K ratio of the various products are and then applying a mixing of various products to achieve the desired NPK ratio.

My recommendation is to make a list of the products you plan to grow. Research the nutritional requirement (e.g. the fertilizers (chemical) usually applied) and then search out organic alternatives. You can either buy organic fertilizers in raw bulk or in prepackaged pelleted versions, such as those offered by Espoma for example (more expensive then raw bulk).

One example is blood meal. This product is 10-0-0 or 12-0-0 which means good high level of nitrogen, but not high in either phosphorus of potassium. Bone meal is 5-10-0 e.g. good source of phosphorus. If you buy bone meal then you may need to add potassium seperately, such as through use of wood ash (makes soil very alakaline) or by buying sulfate of potassium. while latter is not "organic" as such (contain no carbon and is mined, not recycled) it is typically allowed as ingredience in organic farming. e.g. it is not a factory produced ("chemical") fertilizer (byproduct of oil industry).

If you apply your fertilizers evently and till them into the soil, the optimal pH should be evenly distributed. I recommend having soil test done which should be a random sample over a larger area (not just one small area). The average of this area is then used as guideline. I understand your question as to even distribution, but seldom are we concerned with very localized pH swings. However, I recommend contacting your local county extension office in your state/county and ask about their soil tests (check bluepages in the phone book).

Finally, most plants prefer slightly acidic conditions (pH 6.0-6.8) but as usual there are exceptions. therefore, before you start you should probably have an idea which types of products you plan on growing, and then research the pH requirements of each.

The easiest way is to type the product name + pH into GOOGLE and do research accordingly.