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How much phosphorus should i put in my outdoor soil ?

Gizmo

Member
Hello guys, i hope you are well, its outdoor time and i must say better late than never, and im a little late on my outdoor grow and i need a little help please.

I found a nice forest of brambles/thorns 6-8 foot high near a river and i cleared a small nice patch facing south with a manual hedge trimmer, a gardening handsaw and some special gloves for thorns. it was fun and i prune a nice tunnel in the brambles. now i would like to prepare my soil with a few nutrients before planting end of june. i know its late to prepare the soil but as i said better late than never.

My plan is to check the pH of the soil and adjust with dolomite lime if necessary, add a nice organic fertilizer 7-6-12+4Mgo i bought and add some more phosphorus, here is my problem :

i follow a soil recipe where they add the organic fertilizer 7-6-12+4Mgo and some guano kalong 1-10-1+15Ca. i want to replace the guano kalong with a phosphorus organic fertilizer, its a 29% total phosphoric anhydride (P2O5) with 79% soluble in formic acid.

How much of my phosphorus nutrients should i add to replace the guano kalong 1-10-1 ? my phosphorus nutrients is almost three times stronger in P than the guano kalong so should i put three times less ?

does the two nutrients souces have the same availability of phosphorus ?

The manufacturer advise very low dosage compared to my calculation.

they advise 60 g / m² for the preparation of the soil
50 g / m² for planting flowers and vegetables
150 g / m² for planting fruits trees or ornemental trees

i calculated more than 400g / m² to replace the guano.

please advise me as i dont want to burn the plants and have some nutrient lockout.
thank you very much

Gizmo

Edit, i always posted the soil recipe in another thread but here it is, its Soma soil recipe :

50L worm castings
3 x 50L black peat
50L Organic potting soil
3 x 50L bags of Bio Bizz Light-mix
2KG Guano Kalong
2kg DCM organic fertilizer 7-6-12+4Mgo
1/3 of a 30L bag of perlite (10L)
2KGs Maerl (sea chalk for PH)
 

trichrider

Kiss My Ring
Veteran
err on the side of caution.
too much phosphorus can lock out other nutrients...and vice versa.
 

Gizmo

Member
thank you guys, i have no access to laboratory test soil here and i cant order a soil test i have not the time and im not sure it will help me so much, it will complicate but more importantly i have not the time to order, im a bit hurry to prepare my soil. what im really trying to know is the equivalence between the guano kalong 1-10-1 and the 29% phosphorus nutrient. the manufacturer only advise 50g per square meter for planting vegetables, i always assumed Cannabis nutrients need was close to tomatoes, i dont know.
 
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