Best method of application of inorganic fertilizers

[Farhan Ahmed]

I tested my soil, thanks to Syed Adnan for a gift of Soil test kit. My soil is alkaline, sandy and has least possible nutrients. I have only added cow manure uptill now and want to experiment with inorganic fertilizers. Kindly suggest methods of application of various fertilizers keeping in mind efficiency of fertilizer for soil as well as application effort and more importantly damage to plant thereby meaning "even application avoiding contact with seedlings".

Urea, DP and NPK(granule form)
Which one is better
1) Soil dressing with generous watering
2) Foilar spray
3) Water solution fed to ground
4) Any other

Any precautions etc

Thanks....

[M Farooq]

I tested my soil, thanks to Syed Adnan for a gift of Soil test kit. My soil is alkaline, sandy and has least possible nutrients. I have only added cow manure uptill now and want to experiment with inorganic fertilizers. Kindly suggest methods of application of various fertilizers keeping in mind efficiency of fertilizer for soil as well as application effort and more importantly damage to plant thereby meaning "even application avoiding contact with seedlings".

Urea, DP and NPK(granule form)
Which one is better
1) Soil dressing with generous watering
2) Foilar spray
3) Water solution fed to ground
4) Any other

Any precautions etc
Thanks....

The biggest precaution: Don't try self made foliar sprays :-). Urea has been used in foliar sprays BUT leaf burn is possible, especially small plants because urea eventually converts into ammonia and ammonia is as alkaline as a lime solution (so yo are in effect spraying choona on plants- which is of course harmful).

The safer and convenient way is even soil dressing with generous watering as you listed above.

One would also avoid fertilizing seedlings after they have sprouted with any of the above fertlizers. Let them grow and stabilize. You could have pre-treated the soil if had wished.

With your comment on alkaline and nutrient deficient soil - the next question is, are your plant healthy & doing well? I would disregard the testing kit's results if the plants healthy and fluorishing. Happy gardening.

Regards,
Farooq

[Farhan Ahmed]

@Farooq....i tested the soil where i have not added cow manure. Performance of the plants is not bad at all but you know .....sometime you want to give little extra....

What about weak fertilizer solution, fed to ground.
I want to avoid dressing method as water requirement is more, secondly chances of damage still persist, lastly in winters its not a good idea water sitting in the ground.

[M Farooq]

@Farooq....i tested the soil where i have not added cow manure. Performance of the plants is not bad at all but you know :-).....sometime you want to give little extra.... :lol:

What about weak fertilizer solution, fed to ground.
I want to avoid dressing method as water requirement is more, secondly chances of damage still persist, lastly in winters its not a good idea water sitting in the ground.

Okay...I don't think making a dilute solution vs. granule spreading followed by water sprinkling will make a difference. Or better wait for a warmer season. Urea is extremely water soluble and so are majority of phosphates. Too much of plant growth invited unwanted visitors- the aphids and another pest to attack over healthy plants :-(

A more specific chart is available here:
http://fieldcrop.msu.edu/uploads/documents/e0896.pdf


"The most common phosphate fertilizers are triple superphosphate (0–46–0), monoammonium phosphate (11–52–0), diammonium phosphate (18–46–0), and ammonium polyphosphate (10–34–0) liquid (Table 1.2-11). All of these materials are highly water soluble. The ammonium phosphates also are excellent nitrogen sources. Monoammonium phosphate and ammonium polyphosphate, either alone or with some added potassium, make excellent starter fertilizers because of their high P-to-N ratios, high water solubility, and low free ammonia. Diammonium phosphate (DAP) is not recommended as a starter material because it produces free ammonia, which can harm the seed. Many starter fertilizers, however, contain DAP; thus it is critical that the starter is accurately placed a safe distance (about 2 inches) from the seed, and that high rates are avoided."

Regards.
Farooq

[Farhan Ahmed]

I agree on pest attack due too much growth, but One benefit of winter/frost is minimal pest activity. And hopefully harmful insects will not be seen for another 10-15 days. This period i think should be used for maximum advantage.

Previously i tested weak urea solution on a test bed. One full table spoon of urea in 10 liters of water. Highly soluble i applied it through shower(both foliage and ground) and the seedlings are doing very well. There are no burn marks or any other harmful effect.

Can NPK be applied similarly. Would there be any loss of nutrients(is there any part of NPK might which is not soluble)?

[rabia]

According to my experience NPK 20:20:20 solution 1gm per litre is the safest.You can use it on all plants without fear of leaf burns.Its safe for the seedlings as well .Regarding chemical fertilizer lesser is always better and safe.

[Farhan Ahmed]

@rabia....did you find it completely soluble? 1 gm sound less to me....that would be 2-3 granules?

[Munir]

I have recently used NPK 20+20+20+few other minor contents eg. Boron etc -the product labelled as "Grow More- Plant Food". The dose mentioned on the label is 2 tablespoons in 10 lit water. I gm in a lit thus seems much less.

[Farhan Ahmed]

i have doubts that NPK(granule form)/Grow More is completely soluble in water(residuals are visible)....if that's true the question remains...
1)What part of NPK is not soluble?
2)Insoluble part either would be wasted(accumulated at the base) or applied at concentration at one specific site?

[Tahir Khan]

i have doubts that NPK(granule form)/Grow More is completely soluble in water(residuals are visible)....if that's true the question remains...
1)What part of NPK is not soluble?
2)Insoluble part either would be wasted(accumulated at the base) or applied at concentration at one specific site?

Farhan bhai, the Grow More 20-20-20 formulation is completely soluble in cold water and i use it as a half strength.. the recommended dosage on the bottle is 2 heaped tablespoon per 10 liters, but i use 1 heaped table spoon per 10 liters for foliar spray and 1 heaped tablespoon in 7 liters for direct application to the soil it gives amazing results.. Highly recommended
whereas the large granulated NPK is not recommended as a soluble fertlizer it is best to sprinkle it over the ground around the plant sparingly.