How to judge organic fertilizer is completely decomposed?
Whether it's straw compost or chicken manure, take out 500g and put it in a sealed bag for three days. If the bag swells up and there is more air in it, it is not fully decomposed. If the bag doesn't swell up, it's basically done. Straw and excrement will produce gas in the process of compost.
But those who use municipal sludge to produce organic fertilizer, this method is not tested out. However, this method can be used to detect whether our seedling substrate is fully mature.
time is longer, the better it will be. If it has been stacked for 3 years, it will be completely decomposed, but it also will be mineralized and the nutrients will be poor. Moreover, in the process of innocuous disposal, its organic matter is also being consumed. Too long time will lead to too much nutrient loss, the short time harmless degree is not enough.
So, as long as we stack when the temperature reaches 65 degrees, maintain the high temperature for 5-7 days, the compost process is finished.