proportions of variious chemicals you recommended for my lawn
I did a soil sample test and have the results but dopnt know exactly what amounts I put in my brodcast spreaded. Please help.
Ramsey County Minnesota
Your soil test results should indicate the fertilizer analysis recommended based on your test results for P (phosphate) and K (potash). N (nitrogen) is always recommended because it is a mobile nutrient and moves through soil, making replenishing necessary. MN soils are typically high in P and it's likely your middle number (P) is 0.
You'll want to purchase a fertilizer that matches or comes close to the recommended NPK on your test results. Because N is mobile, it takes priority of the P and K, and you'll want to buy a fertilizer that matches your recommended N as closely as possible. For example, if the test results indicate you need 20-0-8 (20% N, 0% P and 8% K) and your local store has a choice of 10-0-8 or 15-0-10, it would be better to buy the 15-0-10 because it more closely matches the recommend 20-0-8.
If you go to the Soil Test Lab website, you'll find a good explanation:
Here are a couple resources including how to calibrate your spreader.
Calibrating your fertilizer spreader from U of New Hampshire
Fertilizing Lawns https://extension.umn.edu/lawn-care/fertilizing-lawns
Some more lawn care resources:
Essential tips to a healthy lawn Part 1
Essential tips to a healthy lawn Part II
If you have follow up questions, you are welcome to reply to this response.
Results were as follows: Phosphorus = 6, Potassium= 99, Ph= 7.8, Organic matter=5.4. I have purchased a 12 lb. bag of Scott's 21-22-4, a 12lb bag of Scotts 32-0-4 and a 4lb bag of Muriate of Potash 0-0-60. I believe this should cover all my needs. I'm covering about 5,000 sq/ft. Id like to make a single pass in my broadcast spreader with all three ingrediencies in the hopper. If I use say, a 12 oz measuring cup, to add the ingrediences. what proportions should I use to make my batch?
What was the recommended fertilizer analysis from the soil test lab?
Lime -0, Nitrogen- 2 lbs per 1,000 sq/ft, Phos - 1 LBS/1000 sq/ft, Potash 2Lbs/1000 sq/ft, and proportions of the nutrients 20-10-20
I am surprised you need any P - most MN soils are naturally high in P.
If you are using a Scott's spreader, the bag should give you guidelines on the correct settings for your equipment.
Of the 3 products you purchased, the Scott's 21-22-4 is the best match to the recommended NPK analysis of 20-10-20. Of your 12 lb bag of 21-22-4, you'll need 10 lbs to cover 5000 sq ft (2 lbs N / 1000 sq ft = 10 lbs N / 5000 sq ft). As I mentioned before, you want to get as close to the recommendations for N first as it is a mobile nutrient and thus needs to be replenished.
You'll need to supplement with some of the muriate of potash as your Scott's product is only 4% potash and the recommendation is 20%. You'll want to add about 1 lb of your 4 lb bag to the 10 lbs of 21-22-4. This will bring you up to 20% potash (4lbs / 60 % = 1.07 lbs / 16; 16% is the remaining amount needed to bring your potash up to the recommended 20%)
As for the other Scott's product, I would see if you could exchange it for more of the 21-22-4. With each application, use 10 lbs of the 21-22-4 + 1 lb of the potash. Your potash will last the season, but you'll need more of the 21-22-4.
Thank you for your help.
I do need to make a correction though. The Scotts bag weighs 21 lbs. I made a mistake in my typing. Will this effect my ratios.
Bag states—- 21 lbs will cover 5000 square feet . Sorry for the mistake
Based on the soil test recommendations though, I believe 10 lbs would be sufficient to cover 5000 sq ft at 2 lbs N / 1000 sq ft. Without looking at the bag, I'm not sure. You could mix batches of 10 lbs of 21-22-04 + the 1 lb of K, set your calibration on your spreader and apply. You can always add another batch and apply (you likely will have to anyway due to how much your spreader holds).