Using the thumb and index finger to press organic fertilizer, if you feel hurt hand, there are sand or other impurities, it is likely to be poor fertilizer.
Do tests
Take a potted flower, spreading organic fertilizer directly in the flower’s rhizome, then watering, If it’s good organic fertilizer, it will gradually grow white mycelium, promote plant growth, poor quality organic fertilizer smoked seedlings, plants gradually dispirited, until death. You can also be applied in the field, leaving a part for application of the organic fertilizer, then observe the performance of the plant, good organic fertilizer in the growing, capacity, quality will have a significant effect.