As the number of livestock and poultry has increased, so has the amount of livestock and poultry manure produced. In order to make rational use of these resources, livestock and poultry manure can be converted into organic fertiliser through fermentation treatment. During the fermentation process, microorganisms break down organic matter and produce beneficial metabolites while destroying pathogenic bacteria and insect eggs, ultimately producing a harmless, stable and nutrient-rich fertiliser.
Classification of compost
Compost can be divided into high-temperature compost and normal compost, depending on the raw materials and fermentation methods used.
High-temperature compost: with plant straw as the main raw material, through aerobic fermentation, the internal temperature of compost can reach 50-60 ℃, fast maturing speed, high nutrient content. High temperature can effectively kill germs, insect eggs and weed seeds.
Ordinary compost: more mixed with soil, fermented at lower temperatures, slower maturing. Ordinary compost is suitable for large-scale use, but the nutrient conversion process is slow and the maturing time is longer.
Composting methods
1. High temperature composting: In a windy and sunny place near water sources, straw, dung, urine and other materials are piled up proportionally, while dung containing high-temperature decomposing bacteria (e.g. mule and horse dung) is added. The composting temperature must be maintained at around 60°C for half a month. This process can effectively kill pathogenic bacteria and parasite eggs.
2. Ordinary composting: carried out under anaerobic conditions, often using half-pit composting, where straw, manure and other materials are stacked in layers, sealed tightly and fermented for 1-4 months. During the composting process, the pile must be turned regularly to ensure that the materials are cooked evenly.
Conditions for composting
1. Moisture: The moisture content of compost materials should be controlled at 60-75%. Proper moisture helps microorganisms to multiply and speeds up the decomposition of organic matter.
2. Aeration: Aerobic fermentation requires sufficient air, especially in the high temperature composting process, and stacking should be moderately loose and tight to ensure air circulation.
3. Carbon to nitrogen ratio: The ideal carbon to nitrogen ratio for microbial decomposition of organic matter is 25:1. Different composting materials have different carbon and nitrogen ratios, and the ratio of materials can be adjusted according to the needs in the composting process, for example, by adding chicken manure, pig manure, etc. to reduce the carbon and nitrogen ratio.
Composition of compost materials
Compost materials are mainly composed of main materials, auxiliary materials and other additives:
Main material: such as cattle, sheep, pig, rabbit and other manure, accounting for 80%.
Auxiliary materials: such as straw, dead leaves, sawdust, etc., accounting for 20%.
Fermenter: Special fermenters can be added to speed up the fermentation process if possible.
Composting site and composting time
Site selection: Composting should take place in a sunny, well-drained and easily accessible place to ensure that the compost is not soaked by rain.
Composting period: Spring, summer and autumn are the best times for composting, when the temperature is above 20℃ and the fermentation process is smooth.
Composting method and operation
1. Mixing and moisture control: Mix the main material with the auxiliary material according to the proportion, and keep the moisture at about 60%.
2. Heap construction and sealing: The compost heap is approximately 2 metres wide, 1 metre high and unlimited in length. Make aeration holes every 1-2 metres in the pile, or add small handfuls of straw to increase aeration. Finally, cover the compost pile with a plastic sheet to keep it moist.
3. Turning the heap: When the temperature inside the heap reaches 60°C, it is necessary to turn the heap and add water to maintain the uniformity of the compost.
Checking the degree of maturity
The following criteria can be used to assess whether or not the compost is mature:
1. the temperature of the pile is reduced to below 40℃ and stabilised.
2. the humidity of the compost is less than 35%, with no bad odour and a slight smell of ammonia.
3. the colour of the compost is dark brown and the liquid is light brown or colourless.
4. White mycelium appears in the pile, indicating active micro-organisms.
Cautions
Cautions
1. Use water-soluble fertiliser with organic fertiliser: organic fertiliser decomposes slowly, so it is recommended to use it in combination with water-soluble fertiliser to achieve the best effect.
2. Ensure that the organic fertiliser is fully ripe: unripe organic fertiliser may contain germs, insect eggs and weed seeds that can cause plant diseases if applied directly. In addition, unripe organic fertiliser releases harmful gases as it decomposes, which can easily cause problems such as seedling burns. It is therefore important to ensure that organic fertilisers are fully decomposed before application.
Through proper fermentation, livestock and poultry manure can not only effectively reduce environmental pollution, but also be converted into nutrient-rich organic fertiliser to increase crop yields and improve soil structure.
