"I started using the MLSN guidelines and was amazed with the huge impact this made"
What do wetting agents really do?

"Could you tell me?"

Ha Darklight wrote from Hanoi with this question:

Could you tell me, in late autumm, how to apply fertilizer for seashore paspalum grass to prepare for early winter?

In general, for northern Vietnam, I would expect seashore paspalum to use N and K in approximately the amounts shown in this chart.

10349156_10152783361016804_926118444458800617_n

The expected amounts in the chart are based on the growth potential (GP) for warm-season grass in Hanoi temperatures, with a maximum N for seashore paspalum set at 3 g N/m2/month when the GP is 1, and recognizing that seashore paspalum uses nitrogen and potassium in a 1:1 ratio.

Our conversation continued:

If I take up high levels of K, ex rates of 3

Whether he means 3 g K/m2/month or 3 times more K than N, I don't see how that would be helpful. My exact reply was "Seashore paspalum uses the same amount of K as it does N. You can add more K if you want to, but it won't provide a benefit to the grass."

Then came another good question from Ha:

How does K affects to diseases?

My answer: "Not much effect. If you are severely deficient in K, or apply way too much K, you may increase disease susceptibility. Application of N and K in a 1:1 ratio to paspalum ensures the grass has enough. Also, you should do a soil test to be sure."

Why should one do a soil test? Because if the soil contains a high amount of K, the grass can use that K, using the soil like a nutrient bank, and the amount of K applied as fertilizer can be reduced. Without a soil test, one doesn't know if all the K the grass will use must be applied as fertilizer, or if some portion of the K used by grass will be supplied by the soil.

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