Fertilizing tips
Last fall, the MCG paid for soil testing of five random samples drawn by our Board of Directors. Four out of five of the samples came back with very similar results. One sample had slightly lower requirements for fertilizer supplementation.
ALL tests came back high on P (Phosphorus) which is a pollutant of our lakes and streams. Please do not add any fertilizers containing P until next year and the results of future soil test results. All tests also came back with normal Ca (Calcium) and Mg (Magnesium) levels, so you don’t need to supplement these minerals. The pH (acidity) is within normal limits, so no lime is necessary at this time. But sulfur is recommended if you are growing any berries.
Our soils consist of 73% sand, 18% silt, and 9% clay. So the addition of compost is highly recommended to increase the health and yield of your plants. If you use animal waste fertilizers, please be aware that they often contain seeds of weeds or grasses that might populate your plot.
Since virtually all plots came back with a deficiency in N (Nitrogen) and K (Potassium), the MCG will be purchasing 10 lbs of urea (concentrated N) for all of us to share. If you have access to hardwood ash for K, please feel free to use your own.
Urea is a concentrated form of N that all mammals excrete in their urine. Hardwood ash or potash which contains K comes from various natural sources. Hardwood ash also contains beneficial trace minerals.
Based on our nutrient levels the following fertilizers are recommended by the UW Soil Sciences Lab:
N deficiency:
Add .3lbs /100 ft2
This equals 3/4 cup of urea for an 8’ plot or 1 cup of urea for a 12’ plot.
K deficiency:
Add .2lbs /100 ft2
This equals 1 lb of hardwood ash for an 8’ plot or 1.5 lbs for a 12’ plot
-OR- .2 lbs of Muriate of Potash for an 8’ plot or 0.3 lbs for a 12’ plot
To make fertilization a bit easier for you this year, the MCG fund has purchased these fertilizers (in the equipment shed) for all of us to share! I will purchase a measuring cup and leave a printed copy of the directions in the equipment shed.
The UW Soil Science labs recommend we work both fertilizers into the top 6” of soil 1 week before planting. The fertilizers are NOT toxic but can irritate the eyes and sensitive tissues. Therefore, it is recommended that we handle the fertilizers with gloves and avoid inhaling the fine dust particles.
Additional N can be added during the growing season but it is recommended that you do not apply directly to the leaves of plants. It is recommended that you add supplemental N after planting in rows at least 3” from the plants.
Additional K in concentrated form should not be required for two years but you can add hardwood ash powdered on top of your plot as needed.
Here is a link from the UW to provide guidance on fertilizers: https://uwlab.soils.wisc.edu/wp-content/uploads/sites/17/2016/02/grades.pdf
