At first glance:

Organic fertilizers that have been dried purely by physical methods still maintain the color of the original feces, with only a decrease in moisture. However, through composting technology, especially after fermentation and maturation with organic fertilizer fermenting agents, the finished product color changes to brown or black brown without any other impurities.

Two touches:

The finished organic fertilizer has a consistent hand feel when held by hand. It is soft and elastic when wet, brittle when dry, and prone to breakage. Poor quality organic fertilizers can be touched by hand with impurities such as sand, and can also be judged by soaking them in water. After soaking qualified and low-quality fertilizers in water for a few minutes, it can be seen that the qualified fertilizers are evenly distributed in the water, while the bottom of the low-quality container will sink a lot of sand or soil, making the difference obvious.

Three experiments:

Whether it is organic fertilizer made from straw compost or chicken manure compost, take out 500 grams, seal it in a bag, and let it sit for three days. If the bag expands and the air inside increases, it indicates that the organic fertilizer has not fully decomposed. If the bag does not expand, it can be basically confirmed that it has matured. Because gas is generated during the maturation process of straw manure, this method is also suitable for detecting whether the seedling substrate is fully matured.