Common production process problems and solutions of organic fertilizers

The production and treatment process of commercial organic fertilizers varies greatly, and there are many problems that are prone to occur, mainly involving fermentation, drying, molding and other links:

1.One-sided pursuit of aeration and aerobic fermentation

Aerobic aeration fermentation can speed up the fermentation process and shorten the composting time. However, the biggest problem of this process is that during the fermentation process, the malodorous gas is discharged with the ventilation airflow, causing a large loss of nutrients, especially N. In order to reduce the harm of direct emissions, it is necessary to increase the investment in equipment and pollution control.

Improvement measures: Change the structure of the fermentation material, introduce excellent microbial flora, make the aerobic fermentation into facultative fermentation, and achieve the purpose of reducing the number of ventilation or no ventilation.

2.Co-fermentation with fermenting bacteria and functional bacteria

In order to simplify the process, some manufacturers co-ferment fermenting bacteria and functional bacteria. Each microorganism has its own suitable temperature range. Functional bacteria have the functions of dissolving phosphorus, releasing potassium, fixing nitrogen, promoting growth and preventing diseases, but most of them are difficult to reproduce and grow normally at high temperatures above 60 °C, and most microorganisms will die or form spores.

Improvement measures: first ferment the raw materials, add functional bacteria in the decomposing period or before packaging, and mix well.

3.Blindly follow the viable count indicator

Some people only pay attention to the number of viable bacteria when choosing a starter, and they unilaterally believe that the higher the index, the better, while ignoring other parameters. In fact, the selection of microbial species, inoculation ratio, and inoculation conditions are affected by many factors. Generally, a single microorganism is not effective, even if its viable count is as high as billions of Cfu/g. On the contrary, although the content of viable bacteria is low and there may be contamination by miscellaneous bacteria, the fermentation effect of the compound strain is better. The general inoculation amount is 0.05%-1%. In addition, laboratory strains cannot be selected because they have not undergone the industrialization process and have not been registered with the agricultural management department.

4.Relying on mechanical energy consumption for drying

During the fermentation process of organic fertilizers, a certain moisture content must be maintained, but at the end of the fermentation, the moisture content is still high, and the commercial standard of organic fertilizers requires that the moisture content be less than 30%. Therefore, some enterprises use drying equipment to perform forced high-temperature rapid drying to solve the problem of high water content. However, drying will bring serious air pollution, nutrient loss and fertilizer efficiency decline, high energy consumption, large equipment investment and other problems.

Improvement measures: The drying process can be combined with heat drying, sunlight drying, air drying and other means produced by fermentation, and fully utilize biomass, sunlight and wind energy to achieve the purpose of greatly reducing the moisture content. Minimize or use no mechanical energy-consuming drying. It can also be dried in different combinations in different seasons. In addition, select appropriate ingredients for fermentation; adjust the initial water content of fermentation according to the season; make fermentation reach a certain high temperature, which can effectively reduce or avoid mechanical energy-consuming drying.

5.Improper granulation

The production of commercial organic fertilizer granulation can reduce the transportation volume and facilitate the fertilization requirements. However, organic fertilizer molding also has major disadvantages: organic fertilizer itself is a slow-acting and long-acting fertilizer. If it is re-granulated, it is prone to poor fertilizer efficiency.

Improvement measures: The biological bacteria and the fermented organic fertilizer are packaged in separate bags and mixed before use, which is conducive to maintaining the activity of the biological bacteria.