RE: Permaculture - Mineral fertilizers (Lesson 8 + contest)
Hello @papi.mati, great lecture you have here, I've learnt something from it, here's my answer to the questions;
You have 100m2 of heavy soil, 5,2 pH and you are going to plant veggies there, but the soil lack calcium. You want to use Marl 50% calcium oxide. How much of it you will use (write down the maximum recommended dose), when is the best time to do it, and how often you will repeat fertilization?
From the lecture above, the maximum amount of calcium needed for a heavy soil, with a pH of 5.2 is 1.0 kg per 10m2 (1kg/10m2).
For our soil sample, we have 100m2 so that means we'll have to add 10kg of the Marl sp as to boost the soil's calcium levels.
I.e 1kg = 10m2
xkg = 100m2
When we cross multiply, we have
xkg = 100/10
X= 10kg.
The recommended dosage of the Marl is 10kg/100m2.
The best time to apply this fertilizer is about 3-4 weeks before the actual planting of the crops with a soil depth of 20cm and it should be repeated every 2-3 years.
You miss something in your count :) I didn't receive the correct answer yet so I am leaving the contest open
Yeah, thanks for bringing this to my notice,
For a 100m2 piece of land you need 10kg of calcium, that should be 100%.
But from our question, Marl has only 50% calcium, so to make that up to the required dosage, simply multiply the average recommended dosage of calcium for a 100m2 land by 2
(I.e 10kg X 2) this will give 20kg of Marl. This is so as to make up to the requirements of 100%calcium.
Therefore, the required dosage of Marl is 20kg for a 100m2 piece of Land.
Thanks.
That's correct! You've got the reward, congrats.
Thanks a lot, you're the best. 🙏👏😊