Modern agriculture has more emphasis on developing sustainable agricultural systems. This has led to increased interest in farm management practices to promote the biological aspects of soil fertility. To help farmers in this regard, many approaches for testing of soil biology are developed, which can be divided into tests for population analysis, biological activity and surrogate markers. Population tests look at the types and numbers of organisms present in soil. While providing a current picture of the biology of soil, we should remember that soil populations are very dynamic and rapidly evolving. For example, biological populations before planting can be very different from that at the time of harvest. It is advisable to evaluate the test results in terms of seasonal variations and the time from people of many tests trends.There in use or under development. These include analysis of nematodes (an indicator of nutrient cycling and microbial diversity), the analysis of fatty acid methyl ester (which calculates the ratio of bacteria to fungi, higher values are associated with nitrate / ammonia accumulation ), the analysis of the food chain, diversity and the counting of the detritus of a worm. Analysis of biological activity provides an indication of the level of activity of soil organisms. Microbes react quickly to environmental factors like temperature, soil pH, moisture, organic matter, cultivation, and contamination by toxic chemicals and heavy metals. With so many determinants, it is not easy to separate the ground to isolate problems. But compared with information from other fields, the data indicate that must be done to improve the quality of soil organic matter content in particular. The evidence of biological activity including soil respiration rate (to measure amounts of carbon dioxide from the soil released into the atmosphere), the evidence of specific enzymes, and rates of nitrification. Indirect indicators to assess the factors that, when present in sufficient quantities, suggesting a good biological soil fertility. Most tests measure carbon content at various levels "of soil organic carbon, particulate organic carbon, dissolved organic carbon (to determine the amount of organic carbon) and organic carbon in the biomass (or carbon in microbes). Cover low percentage of the total area is also an indirect indicator for soil health. The lack of ground cover suggests that the salt and acid stains, compact or crusty surfaces. We know that thousands of soil organisms provide different contributions to soil health. The role of some microorganisms – organisms have been demonstrated. Others have subtle role, which makes it difficult to assess its value. Most of the biological tests require specialized equipment and technicians. Many farmers are in the following tests is very important for management decisions: total soil respiration. From This measures the amount of carbon produced by the total population and biological respiration (conversion of organic carbon dioxide carbon) the activity of microorganisms, which gives an idea of the percentage of organic matter degradation. nitrogen of microbial biomass. The organic matter is a rich source of nutrients, including nitrogen. This test measures the amount of nitrogen biologically active in the soil. It is better to look at the values in a time series: a consistently high level provides a good indication of secure land. earthworms. Earthworms influence, and also influenced by other soil organisms. It started the first phase of the litter layer, which supplies food to the microorganisms responsible for more destruction. They are very sensitive to changes (both short and long term) in the soil ecosystem. The farmer finds it difficult to predict the number of worms in field (expressed in grams per cubic meter), without special equipment for a reasonable, albeit crude, measure of land acquisition.