The Bat Guano suggested by Bub would work well, as would a Seabird Guano that's high in N &/or P. Guanos and most solid organic ferts are time-release fertilizers that get mixed into the soil unless they are made into a tea before using. Once made into teas, solid slow-release ferts become instant-release solutions. Other than the Guanos, Blood Meal and Fish Emulsion are also good sources of Nitrogen. Bone Meal is another good source of P. Kelp and Seaweed ferts are mild sources of K, which should be included in your fertilizations even though there isn't an obvious deficiency in it. If you just fed them N & P then next time they'd probably be K deficient.
