From

Location

Message

Date Posted

The North Coast

I got my second soil test back from Western Labs and for the most part it says that I am in good shape. In the recommendations it said that I need a bit of nitrogen, a tad bit of phosphorus, and an extremely small amount of potassium. My K numbers are high right now at 435 ppm and it is throwing off a couple of my ratios just a bit. My question is with the demand for K that a pumpkin has, would you still spoon feed it any K during the year? Or would that further throw out my ratios and hinder absorption. Thanks very much.

5/31/2012 12:21:53 PM

Colorado

John Taberna(western labs) gave a talk about this subject in vegas this spring.He said that pumpkin crops are heavy feeders of potassium.He suggested feeding k to the plant during the whole season.435ppm is high but not a problem

5/31/2012 1:42:00 PM

Germany

Pumpkins (and this should also hold true for Atlantic Giants) contain about 3 g K per kg pumpkin, which means 1200 g K in a 400 kg pumpkin. To maintain a decent K level, at least the same amount of K should go onto the patch area during the season (the above 400 kg pumpkin was just an example). Perhaps more, because some additional K is needed for plant growth, and further K might be washed out by rain water.

5/31/2012 2:33:38 PM

Glosta

trying to understand the math here, 3 g K per 1 kg, so if that is the case ppm is equal to 1mg/kg which means in order for a pumpkin to take up 3 g of K there needs to be a minimum of 3000 ppm of K in the soil just to supply the pumpkin, not including leaching and plant use. There is something missing here.

We need to look at crop uptake and application per year so we can understand what these plants truly need. alot of us add amendments and then spray foliarly, extremely difficult to track exactly what is applied.

Like cojoe said balance is important, one nutrient helps or locks up the availability of another. some effect multiple nutrients. start with Western labs, John Taberna is a smart man and will talk with you for hours on this subject.

10/12/2012 1:30:02 PM

Www.extremepumpkinstore.com

I don't think you can say that a level is high just by seeing one particular level, you need to see the soil test results as a whole in order to be able top balance your soil. I never really look at PPM, I look at the cation saturation percentages.
I get a bunch of email asking me what are the perfect numbers for each nutrients, remember, since there are so many dependencies between the nutrients, you have to look at the test results as a whole.
I agree with Bry 100%

10/13/2012 7:19:35 PM

Torrance, Ca.

With that said Tom, whats the perfect soil and where can I order it???

;)

10/13/2012 7:57:35 PM

Www.extremepumpkinstore.com

Ron Wallace, RI.
Lmfao!~

10/14/2012 1:05:49 AM

Torrance, Ca.

Thanks for that this morning Tom LOL!!!


How many yards would he allow me to take out of his patch and when a good time????????????????


I'm not picky, I'll take soil out of paps side,,,,,, if Ron says no ;)

10/14/2012 10:44:38 AM

Germany

3 g K in 1 kg of a pumpkin means 1200 g K in a 400 kg pumpkin, and this potassium (1200 g) comes from the soil the pumpkin plant is grown in, lets say from a 50 square metres patch, 0.3 metres soil depth...which amounts to a soil volume of 15 cubic metres...and let´s assume the soil has a density of 1.2 tons (metric tons) per cubic metre, this would mean the pumpkin has taken up 1200 g of K from 18 metric tons of soil (18000 kg), which is 67 ppm. Thus, starting with 250 ppm (and without any K washed out by rain...which would be a dream) the fruit would have lowered the K-content to 183 ppm...and the plant (because the leaves and vines also contain some potassium) would have caused an even lower K content in the soil by some additional ppm. I have no idea how you came to the conclusion that a pumpkin can take up 3 g of K only if there are 3000 ppm of K in the soil.

10/22/2012 1:19:59 PM

Germany

To express it in different words, the 1200 g of potassium in a 400 kg pumpkin are a significant part of the crop uptake from the area of the pumpkin plant.

10/22/2012 1:23:55 PM

Germany

1200 g of potassium equals about 6 lbs potassium sulphate, which probably sounds like the right order of magnitude of K fertilizer for a large AG plant, to account for the crop uptake by this medium size pumpkin, maybe some more K to account for other effects (crop uptake by the other plant material, some loss of K which got washed out etc.), but the other ammendments (compost, manure etc.) also contain loads of K, which enhance the K-level in the soil, and therefore 6 lbs of K2SO4 could already be too much, depending on what else went into the soil.

10/22/2012 1:31:21 PM

Germany

Just to check the effect of 6 lbs of potassium sulphate, I have entered 6 lbs of SOP 0/0/50 for a 538 sqft patch (which is the 50 square metres area mentioned above) into Bry´s soil amendment estimator, and it came up with +92.9 ppm for the K-level. That sounds very similar to the 67 ppm of my above example (where I used the soil depth and density as mentioned above...I don´t know which soil density and which soil depth are considered in Bry´s calculator, his estimator probably gives better results, I don´t doubt them).

10/22/2012 1:45:04 PM