MICROBES IN SOILS

Do you know that in a typical teaspoon of native tropical virgin soil would contain between 600- to 800-million individual bacteria that are members of perhaps 10,000 species?. This living things is part of our natural life cycle. There are several miles of fungi and perhaps 5,000 species of fungi per teaspoon of soil taken from not disturbed soils. There are 10,000 individual protozoa split into three main groups, i.e., flagellates, amoebae and ciliates and perhaps 1000 species of protozoa. There are about from 20 to 30 beneficial nematodes, which are members of as many as 100 species. This article I would like to share knowledge the amazing soil living organism based on my study and learning in University many years ago and from few soil science books. There are many types of soil series in Malaysia from lowland, inland, remote area and highland containing various organisms. This article discuss about the importance of microbes in soils and their effects on soil fertility.


Nematodes

The root-feeding nematodes are quite scarce in truly healthy soils. From my study in Johore in low line area such as in Muar District and Batu Pahat District , the rate of nematode multiplication are rapid during wet season especially on crop like guava, chili,selective fruit tree and few others. In some area with proper drainage system seems that they are present but in numbers so low that it is rare to find them. After only one plowing a few species of bacteria and fungi become extinct locally because the food they need is no longer put back in the system. Ploughing is a good agriculture practice applied in Malaysia especially on new replanting program for industrial crop such as oil palm, rubber and coconut. But for the most part, all the suppressive organisms, all the nutrient cyclers, all the decomposers, all the soil organisms that rebuild good soil structure are still present and continue to try to do their jobs.


Pseudomonas bacteria

I wonder if why doesn't the limited food resources bother them more? A good savings account of organic matter has been built up in native grassland and native forest soil. The soil organisms use the organic matter they "put away" all those years when disturbance did not occur. ...But agriculture continues to mine soil organic matter and kill fungi by tilling. The larger predators are crushed, their homes destroyed. The bacteria go through a bloom and blow off huge amounts of that savings account organic-matter. With continued tillage the "policemen" (organisms) that compete with and inhibit disease are lost. The "architects" that build soil aggregates, are lost. So are the engineers, the larger organisms that design and form the larger pores in soil. The predators that keep bacteria, fungi and root-feeding organisms in line are lost. Disease suppression declines, soil structure erodes, and water infiltration decreases because mineral crusts form.

In reality some intensive agricultural area are using a lot of chemicals to the plants and soil especially on vegetable production area. The effect of chemical fertilizer, pesticides, fungicides, weedicides, sticker and many others will dissolve and accumulate in the soil that able to kill most of the microorganism and beneficial predators. I have seen some vegetable growing area very hard to find any flying or crawling insects due to the pesticide application. If you have take soil sample and sent to the lab may be the result of microbial content is worsen. I always advice the farmers to improve soil fertility by various ways that is proven, cheap, applicable, simple and the most important practical.

The decline can take 20 to 30 years to reach the point that most of the natural controls are finally lost and disease runs rampant. The speed with which the "edge" is reached depends on the amount of soil organic matter that was in the soil when it was first plowed, how often the soil was plowed and how much residue was added back. Additionally, how much variety was added back, and the inoculum base for the disease are also important. Certain diseases don't occur in some places because the disease hasn't reached them yet. But the instant the disease does arrive, it goes throughout he fields like a wildfire, because there are few natural competitors to stop it in the soil .

This article I hope give us some idea how important to know the soil fertility sustainability in our Malaysian farms. The record from DOA shown that the use of more organic fertilizer and reducing chemical application in a continuous campaign in Good Agriculture Practices (GAP). A standard certification program called SALM (Skim Amalan Ladang Baik Malaysia) and SOM (Skim Organik Malaysia) introduced for commercial food crop growers to ensure a high quality and safe produce for domestic and export market. Thanks . . .




By,
M Anem
Port Dickson, Negeri Sembilan,
Malaysia
( 3 Zulkaedah 1432H)