MalaysiaA focus on the restoration of organic matter in the soil, specifically the use of compost in the cultivation of crops should be standard practice. However, depending on the quality of the input materials, the effect can be very minimal and in numerous cases, even adverse results have been reported. Instead of quantity, the issue on the quality of organic input should also be addressed.

The Shimamoto farm in Japan has been doing research on quality organic inputs for more than 50 years, and has published numerous reports on the quality of organic inputs. It’s founder, Mr. Kakuya Shimamoto stated the definition of compost in his first publication of a series of books, “Modern Microbial Farming Method” as early as 1955.  

There are numerous types of compost. These can be defined into two main categories.

1)Compost for the improvement of soil fertility.
The main aim is to restore soil fertility for sustainable cultivation. The raw materials for this type of compost should consist of high fiber and high lignin content, in order to produce a higher level of humus in the soil when applied. Wood chips, saw dust, tree bulk, empty fruit bunch, rice husk, bamboo grass stock, etc., are tough materials to break down but are most suitable for the purpose. With the help of some powerful fermentative microbes, these can be turned into a superb quality compost for soil fertility restoration.

2) Compost as a source plant nutrient.
Raw materials to make compost for the purpose of nutrients to the plant mainly consist of animal dung, padi straw, green grass, vegetable waste and other soft materials. These are thoroughly fermented and used as a basal as well as an additional fertilizer.

To summarize the above, hard and difficult to decompose raw materials for making compost for the purpose of soil fertility restoration and a long lasting effect. Soft and easy to decompose materials, for the purpose of nutrient input.

Both are important in the field of sustainable agriculture. Fertile soil is the biggest asset of a farm. Without it, the yield would drop and the cost of production would go up in terms of higher input in the form of fertilizers and agro-chemicals. If the soil were well taken care of, the farm would benefit in the form of higher yield, better quality, lower cost of input and a healthier environment in the long run.

There are vast differences between complete and incomplete compost. It’s very wasteful in terms of time and efforts taken into making compost and not being able to make a good quality matured one. Moreover incomplete compost may deteriorate soil condition and bring about pest and disease to the plant.

Incomplete compost means a compost heap that has been left unattended for a long time and is smelly from the rotting process. Anaerobic bacteria have taken over and nitrogen is lost due to denitrification. There will also be a loss of phosphate and potassium through leaching. The most important element in soil fertility is humus and it may be decomposed and lost. If incomplete compost is applied into the soil, the anaerobic bacteria in it will discharge organic acids, which will increase the acidity of the soil and will also do harm to the plant in the form of root rot and root burn. If this is applied in padi field, root damaging marsh gas and hydrogen sulphide will be produced. Incomplete compost will decompose into acidic humus. This acidic humus does not hold onto any of the major as well as trace elements. It also inhibits rooting.

Adverse effects of incomplete compost

  1. The loss of organic matters, which are the major components of soil building humus through the rotting of the compost.
  2. Large amount of organic acids, which are harmful to the soil as well as to the plant are produced by the anaerobic bacteria.
  3. Inhibit rooting as well as the intake of phosphate and potassium. Taproot will not be able to reach deep enough for trace elements deep in the soil. The lack of silicate,phosphate and potassium will result in more diseases to the plant.
  4. Marsh gas is produced during decomposition.
  5. Organic phosphate and potassium in the compost are rendered ineffective.
  6. Lost of nitrogen through denitrification.
  7. Oxygen is not present.

It is important to note that the plowing in of fermented green manure can be as harmful as using incomplete compost if planting is done immediately after application.

Complete compost
Fermentative aerobic microbes and facultative anaerobes brew complete compost. Harmful organic acids and toxicity (tannin, terpene, resin) in the raw materials are thoroughly removed.

Properties of complete compost

  1. Brownish or blackish in color and is shinny. Slightly warm to touch and emit a
  2. pleasant fermentative smell.
  3. There is no loss of any organic matters during fermentation, the rate of the formation of humus in the soil is high.
  4. Promotes healthy rooting. Increases the effectiveness of phosphate, potassium, silicate and other trace elements and thus enable healthier plant growth.
  5. Prevents the leaching of nitrogen. Promotes the propagation of nitrogen fixing azotobacteria, actinomycetes and other beneficial microbes in the soil.

As can be seen in the above comparison, complete compost is totally different from incomplete compost. It is very much different from the common understanding of compost is just a heap of fermented organic matters.

Greater than 40 years ago, our founder established the importance of compost in soil building and the quality of compost made the difference in the result. Through countless experiments and actual experience, he found that the proportion and combination of microbe’s present in the process of fermentation determine the quality of compost. This principle has a great impact on the definition compost among the agricultural circle. On top of that, he also established the importance of neutral humus and hard organic matters with high fiber and lignin contents produce most humus in the soil. This theory paved the way of using sawdust and wood chips as composting raw materials as far back as the mid-50s. He is the pioneer in this aspect now that saw dust and wood chip compost is commonly used in Japan.

The effects of neutral humus in the soil

  1. It helps to form crumb soil structure to enable ventilation and drainage.
  2. Promotes the activities and multiplication of beneficial soil microbes. These microbes break down insoluble elements such as phosphate, silicate, calcium, magnesium and other minerals and make them available for healthy plant growth.
  3. Creates a favorable soil condition for healthy and sustained root growth.
  4. Enhances moisture and nutrients retention. Water-soluble nutrients such as ammonical nitrogen and potassium are held back for the plant.

The key to soil building is to build up the amount of neutral humus in the soil. Utmost efforts must be made to attain the level of 5~6%. One must also remember the aim of using compost and the initiative in making good quality compost must be maintained.

Formation of Soil Humus

Essay submitted by Steven Leong