The N-only pot looked pretty good when I showed roots after 184 days.

But that same grass grew a lot more, and produced a lot more underground roots and rhizomes, when P and K were added.

sequence of photos showing greens-type manilagrass fertilized with N, P, and K

You’ll notice in the image sequence above that the manilagrass supplied with N, P, and K almost had full cover of the pot by January 9. At 100 days after planting, the grass with N-P-K had about the same ground coverage as the N-only grass did at 184 days.

There’s a lot more undergound plant material too, when the grass is not deficient in N, P, or K.

greens-type manilagrass Greens-type manilagrass grown from a 3 cm diameter plug and fertilized N, P, and K for 6 months.

I arranged the images side-by-side for comparison.

side by side pots of grass, roots from N only, and roots from N, P, and K

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