A research on nutrient selection in the determination of the most productive vermi̇compost

Vermicompost was first introduced to the world in the late 1940s. Worm humus is the organic fertilizer that has been widely used in order to grow almost all kinds of fruits, vegetables, trees and plants particularly in United States, in Europe and in a lot of countries which are developed in the field of agriculture. After the beginning of its 70 years of history, worm humus has began to spread in Turkey during early 2000s. The transition to the usage of vermicompost has accelerated due to degradation of soil in Turkey in relation with misuse of the fertilizers. With the transition to organic fertilizer, fertilizer content tests and researches have gained importance.During this research, the aim was to determine the variables of fertilizer productivity on vermicompost. In these tests to reach the most efficient data, 6 different nutrients most common in literature are used. These 6 different nutrient substances are cattle manure, egg shell powder, tea pulp, coffee, bagasse and lettuce. Cattle manure is among the main food sources consumed by Red California Worms. Because of this, the other 5 food sources have composed with cattle manure is separately tested. The total of 225.000 worms have been used as sample size. During one year, 5 different food sources that are composed with cattle manure have been transferred to different pools in the environment that has stable ambient temperature and moisture balance. At the end of two months, fertilizer samples of regularly fed worms have been taken and sent for analysis. As a result of these tests, the data is analyzed in respect to 12 main criterias. These criterias are organic substance, total nitrogen, moisture, ph, ec, total phosphorus, total calcium, total magnesium, total iron, total copper, total zinc and total manganese. According to TOPSIS, the vermicompost that is generated by feeding red california worms with composition of cattle manure and egg shell powder was found to be the most efficient composition. Keywords: Vermicompost, Organic Fertilizer, TOPSIS, Productivity.