How to make compost from weeds

Weeds or wild grass are a very tenacious existence in the natural ecosystem. We generally get rid of weeds as much as possible during agricultural production or gardening. But the grass that is removed is not simply thrown away but can make good compost if properly composted. The use of weeds in fertilizer is composting, which is an organic fertilizer made of crop straw, grass, leaves, garbage, etc., which are composted with human manure, livestock manure, etc. Its characteristics are that the method is simple, the quality is good, the fertilizer efficiency is high, and it can kill germs and eggs.


Features of weed compost:

● The fertilizer effect is slower than that of animal manure composting;

● Stable microbial diversity, not easy to be destroyed, reduce the risk of diseases and continuous cropping obstacles caused by element imbalance, in this respect, its effect is better than manure composting;

● reduce the risk of germination failure of crops;

● Wild grassland has a tenacious root system, and after deep penetration, it absorbs mineral elements and returns to the ground;

● Appropriate carbon-nitrogen ratio and smooth decomposition;


1. Materials for making compost

The materials for making compost are roughly divided into three types according to their properties:

The Basic material

Substances that are not easily decomposed, such as various crop straws, weeds, fallen leaves, vines, peat, garbage, etc.

The Substances that promote decomposition

Generally, it is a substance rich in high-temperature fiber-decomposing bacteria that contains more nitrogen, such as human excrement, sewage, silkworm sand, horse manure, sheep manure, old compost, plant ash, lime, etc.

The Absorbent substance

Adding a small amount of peat, fine sand and a small amount of superphosphate or phosphate rock powder during the accumulation process can prevent or reduce the volatilization of nitrogen and improve the fertilizer efficiency of the compost.


2. Treatment of different materials before making compost

To accelerate the decay and decomposition of each material, different materials should be treated before composting.

lGarbage should be sorted to pick out broken glass, stones, tiles, plastics, and other debris, especially to prevent the mixing of heavy metals and toxic and harmful substances.

lIn principle, all kinds of accumulation materials are better be crushed, and increasing the contact area is conducive to decomposition, but it consumes a lot of manpower and material resources. Generally, weeds are cut into 5-10 cm long.

lFor hard and waxy materials, such as corn and sorghum, which have low water absorption, it is best to soak them with sewage or 2% lime water after crushing to destroy the waxy surface of the straw, which is conducive to water absorption and promotes decay and decomposition.

lAquatic weeds, due to excessive water content, should be dried slightly before piling up.


 3. The choice of stacking location

The place for composting fertilizer should choose a place with high terrain, leeward and sunny, close to the water source, and convenient for transportation and use. For the convenience of transportation and use, the accumulation sites can be appropriately dispersed. After the stacking site is selected, the ground will be leveled.


 4. The ratio of each material in the compost

Generally, the proportion of stacking materials is about 500 kilograms of various crop straws, weeds, fallen leaves, etc., adding 100-150 kilograms of manure and urine, and 50-100 kilograms of water. The amount of water added depends on the dryness and wetness of the raw materials. kg, or phosphate rock powder 25–30 kg, superphosphate 5–8 kg, nitrogen fertilizer 4–5 kg.

To accelerate the decomposing, an appropriate amount of mule manure or old compost, deep underdrain mud, and fertile soil can be added to promote decomposing. But the soil should not be too much, so as not to affect the maturity and compost quality. Therefore, an agricultural proverb says, “Grass without mud will not be rotten, and without mud, grass will not be fertile”. This fully shows that adding an appropriate amount of fertile soil not only has the effect of absorbing and retaining fertilizer, but also has the effect of promoting the decomposition of organic matter.


 5. Production of compost

Spread a layer of sludge with a thickness of about 20 cm on the ventilation ditch of the accumulation yard, fine soil, or turf soil as a floor mat to absorb the infiltrated fertilizer, and then stack the fully mixed and treated materials layer by layer to be sure. And sprinkle manure and water on each layer, and then evenly sprinkle a small amount of lime, phosphate rock powder, or other phosphate fertilizers. Or inoculate with high fiber decomposing bacteria. Weeds in each layer and urea or soil fertilizer and wheat bran to adjust the carbon-nitrogen ratio should be added according to the required amount to ensure the quality of compost.


This is stacked layer by layer until it reaches a height of 130–200 cm. The thickness of each layer is generally 30-70 cm. The upper layer should be thin, and the middle and lower layers should be slightly thicker. The amount of manure and water added to each layer should be more in the upper layer and less in the lower layer so that it can flow downstream and distribute up and down. evenly. The stack width and stack length depend on the amount of material and the ease of operation. The pile shape can be made into a steamed bun shape or other shapes. After the pile is finished, it is sealed with 6-7 cm thick thin mud, fine soil, and old plastic film, which is beneficial to heat preservation, water retention, and fertilizer retention.


 6. Management of compost

Generally 3-5 days after the heap, the organic matter begins to be decomposed by microorganisms to release heat, and the temperature in the heap rises slowly. After 7-8 days, the temperature in the heap rises significantly, reaching 60-70 °C. The activity is weakened and the decomposition of raw materials is incomplete. Therefore, during the stacking period, the moisture and temperature changes in the upper, middle, and lower parts of the stack should be checked frequently.

We can use a compost thermometer to detect the internal temperature of the compost. If you don’t have a compost thermometer, you can also insert a long iron rod into the pile and leave it for 5 minutes! After pulling it out, try it with your hand. It feels warm at 30℃, feels hot at about 40-50℃, and feels hot at about 60℃. To check the moisture, you can observe the dry and wet conditions of the surface of the inserted part of the iron bar. If it is in a wet state, it means that the amount of water is appropriate; if it is in a dry state, it means that the water is too low, and you can make a hole in the top of the pile and add water. If the moisture in the pile is adapted to the ventilation, the temperature will gradually rise in the first few days after the pile, and it can reach the highest in about a week. The high-temperature stage should not be less than 3 days, and the temperature will slowly decrease after 10 days. In this case, turn the pile once every 20-25 days, turn the outer layer to the middle, turn the middle to the outside, and add an appropriate amount of urine as needed to re-stack to promote decomposing. After re-piling, after another 20-30 days, the raw materials are close to the degree of black, rotten, and smelly, indicating that they are decomposed, and they can be used, or the cover soil can be compressed and stored for later use.


 7. Compost turning

From the start of composting, the turning frequency should be:

7 days after the first time; 14 days after the second time; 21 days after the third time; 1 month after the fourth time; once a month after that. Note: Water should be properly added to adjust the moisture to 50-60% each time the pile is turned.


8. How to judge the maturity of compost

Please see the following articles:

Post time: Aug-11-2022