Organic fertilizer

Asked February 9, 2017, 10:58 AM EST

In looking through the Grow It Eat It vegetable growing guides, many times a complete 10-10-10 fertilizer is recommended. If I wanted to make the equivalent of 20 lbs of 10-10-10 using organic products, what organic sources and at what levels should I use.

Howard County Maryland fertilizer vegetable organic fertilizers

2 Responses

Of N,P,K (nitrogen, phosphorus and potassium), Nitrogen is the most limiting factor. That is, given most soils, N is most important element.
To figure this out, you would need to know the percentage of N in each organic amendment choice.
Please take a look at our page on Soils and Fertilizers: http://www.extension.umd.edu/sites/extension.umd.edu/files/_images/programs/hgic/Publications/HG42_S...
N,P,K, are figured as a percentage of content per bag, so in a 20-pound bag of 10-10-10 means that the bag contains 10% by volume, or 2 pounds total of each element, with the rest being inert filler.
If you choose to use the organic N source Cottonseed meal, (noting that it's N=6) you figure 20 x 1.6 (10% divided by 6%), which is roughly 33, so 33 pounds of cottonseed meal would be equivalent for your needs.

Here is a Georgia Extension publication which explains more http://extension.uga.edu/publications/detail.cfm?number=C853
and we are hoping to update our pages to make this easier in the future.

cm

Thank you. I guess I was hoping it would be a little simpler but I can work with this. Thanks for directing me to the University of Georgia publication, as it has more detail.