Characteristics of various animal manures and precautions when fermenting organic fertilizers(Part 2)

The fermentation and maturation of organic fertilizers is a complex process. To achieve an excellent composting effect, some primary influencing factors need to be controlled:

1. Carbon to nitrogen ratio

Suitable for 25:1:

The C/N of the aerobic compost raw material is (25-35):1, the fermentation process is the fastest, if the C/N is too low (20:1), the reproduction of microorganisms will be inhibited due to insufficient energy. As a result, the decomposition is slow and incomplete, and when the C/N of the crop straw is too large (usually (6080): 1), nitrogen-containing substances such as human and animal manure should be added, and the carbon-nitrogen ratio adjusted to 30: 1 is beneficial to microorganisms. Activities that promote the decomposition of organic matter in compost and shorten fermentation time.

 

2. Moisture content

50%~60%:

Moisture is an important parameter in the composting process. Microbial life activities require constant filling of the surrounding environment to absorb water to maintain normal metabolism. Microorganisms can only absorb soluble nutrients, and the compost material can easily become soft after absorbing water. When the water content is above 80%, water molecules fill the interior of the particles and overflow into the inter-particle gaps, reducing the porosity of the stack and increasing the resistance to gas and gas mass transfer, resulting in a locally anaerobic stack that inhibits The activity of aerobic microorganisms is not conducive to high-temperature aerobic fermentation with material moisture content below 40%, which will increase the pore space of the heap and increase the loss of water molecules, resulting in the accumulation of water shortage in the water, which is not conducive to the activity of microorganisms and affects fermentation. In fertilizers, more water can be added to crop straw, sawdust, and fungus bran.

 

 

3. Oxygen content

8%~18%:

The oxygen demand in compost is related to the amount of organic matter in the compost. The more organic matter, the greater the oxygen consumption. In general, the oxygen demand during composting depends on the amount of carbon dioxide. It is the decomposition activity of aerobic microorganisms and requires good ventilation. If ventilation is poor, aerobic microorganisms are inhibited and the compost matures slowly. If the ventilation is too high, not only will the water and nutrients in the compost be lost too much, but also the organic matter will be strongly decomposed, which is not conducive to the accumulation of humus.

 

4. Temperature

50-65°C:

In the initial stage of composting, the temperature of the heap is usually close to the ambient temperature. The temperature of the compost is rapidly heated by mesophilic bacteria for 1 to 2 days, and the temperature of the heap reaches 50 to 65°C, which is usually maintained for 5 to 6 days. In order to kill pathogenic bacteria, insect eggs, and grass seeds, achieve harmless indicators, and exert a dehydration effect, the temperature is finally lowered to promote the transformation of nutrients and the formation of humus. Too low a temperature will prolong the maturation time of the compost, while too high a temperature (> 70°C) will inhibit the growth of microorganisms in the compost and lead to excessive consumption of organic matter and a large amount of ammonia volatilization, which affects the quality. compost.

 

5. pH

pH6-9:

PH is one of the important factors affecting the growth of microorganisms. Generally, microorganisms are suitable when the pH is neutral or slightly alkaline. Too high or too low pH value will affect the smooth progress of composting. It is rich in cellulose and protein. The optimum pH value of the livestock and poultry manure was between 7.5 and 8.0, and the substrate degradation rate was almost 0 when the pH value was less than or equal to 5.0. When pH≥9.0, the degradation rate of the substrate decreased and the loss of ammonia nitrogen was serious. The pH value has an important influence on microbial activity and nitrogen content. Generally, the pH value of the raw material is required to be 6.5. A large amount of ammonia nitrogen is generated in aerobic fermentation, which increases the pH value. The entire fermentation process is in an alkaline environment with high pH. The pH value increases nitrogen loss, and the pH value should be paid attention to in the factory’s rapid fermentation.

 

Click to read Part 1.


Post time: Apr-07-2022