Ammonium nitrate and urea are excellent and relatively inexpensive sources of nitrogen for lawn and garden use. Phosphorus Content Phosphorus is essential for flower, fruit, and seed production. It also facilitates seed germination. The supply of phosphorus determines, in part, the rate that the plants reach sexual maturity. It is usually difficult to have too much phosphorus because the supplies in soil are typically so limited.
Plants lacking sufficient phosphorus usually have purplish leaves, petioles, and stems.
The yield of crops like corn, beans, peas, squash, cucumber, etc. will be very low under phosphorus deficiency. A. Rinse out your microcentrifuge tube completely. D. Close the cap of the tube and, holding the cap in place with your finger, shake the tube gently for 30 seconds. E. Place the tube in the centrifuge and spin for 1 minute. F. Remove the microcentrifuge tube from the centrifuge and decant the supernatant liquid into a clean 10 x 75 mm test tube.