The Effects Of Different Fertilizer On Microorganism, Enzyme And Tomato Growth In Growing Media

Aiming at the function mechanism of organic fertilizers in eco-organic type soilless culture system, the experiment was carried out to study effects of different organic manure on substrates' microorganism, enzyme activity and tomato plant growth with cultivar 'zhongza105' as trial material and mixture of vermiculite and perlite (v/v=2/1) as culture substrate. Six treatments were set. Treatment 1 was fertilized with chicken manure, treatment 2 was cow manure fertilizer, treatment 3 was fertilized with sheep manure, and treatment 4 was soybean cake, nutrient solution treatment and no-fertilization treatment were employed as controls to compare the difference of microorganism, enzyme activity in substrates and growth of tomato. The effects of different kinds of fertilizer on quantity of microorganism and activity of enzyme in substrates, tomato growth, physiological characteristics, yield and fruit quality were discussed. The main results were showed as follows:1. Microorganism was one of the important indexes to reflect the bio-activity and the nutrient transformation in substrates. The results showed that the quantity of microorganism was significantly influenced by chicken manure, cow manure and sheep manure. The quantities of bacteria, nitrobacteria, ammonifier were the highest in substrate treated with chicken manure, and they were respectively 7.29, 8.2, 5.8 times higher than those in the nutrient solution treatment extremely. The quantity of actinomyces and cellulose decomposing bacteria (CDB) were the highest in substrate treated with cow manure fertilizer, as compared with nutrient solution treatment, they were 9.5 and 8.6 times higher respectively. Effect of sheep manure was also better than control treatments. The activity of fungi was significantly high in substrates with soybean cake treatment, and was 12.7 times more than those in the nutrient solution treatment, but the propagation of bacteria and actinomyces were restrained at the same time, reduced by 15.29%, 6.85% respectively as compared with nutrient solution treatment. Therefore organic manure could promote microorganism's massive multiplication in substrate, and accelerate the decomposition of organic matter and nutrient fixing and enhance the availability and using efficiency of nutrient elements.2. The results of effects of different organic manure on activity of enzyme in the substrates showed that: as compared with the controls with nutrient solution and non-fertilizer, the influence of cow manure was very significant to enhance activities of enzymes, for instance, the activities of alkaline-phosphatase, neutral-phosphatase, saccharase, urease and cellulase were the highest, followed by chicken manure and sheep manure treatment, chicken manure and sheep manure also enhanced the enzyme activity significantly or very significantly in substrates. Soybean cake only influenced the activity of acid-phosphatase significantly. Whereas the activity of acid-phosphatase decreased in nutrition solution treatment as compared with non-fertilizer treatment. The enzymes played an important role in the biochemical mineralization process in the substrates, and closely connected with the release and storage of nutrient elements, the humus formation in the substrates, the structure and physical properties of substrates. Therefore, the activity of substrates and the transformation of nutrition could be improved with organic fertilizers. 3. Owing to the organic acids and ions decomposed from organic manure, the pH value in the treatments of chicken manure, cow manure and sheep manure decreased differently in the early stage of tomato growth, and increased later because of a mass of irrigating water consumption which resulted in accumulation of Ca²⁺ and Mg²⁺ ions in growing media. There were no visibly changes of electrical conductivity in treatments with chicken manure, sheep manure and soybean cake fertilizer. It indicated that the decomposition of organic manure was slow and lasted long. In tomato's growth cycle, electrical conductivity in every treatment was less than 2.5 ms·cm^-1, which met the requirement of tomato plant growth.4. The cow manure affected significantly on the tomato's growth and development, both of plant height and stem diameter were the highest during whole growth period, and flowering and fruit setting were earliest, followed by chicken manure and the sheep manure. The nutrient solution enhanced tomato growth before fruit setting.5. The yield and biomass per plant with cow manure fertilizer was the highest, and fruit quality was the best amongst all treatments, the content of reducing sugar, the soluble solid, vitamin C were 106.70%, 64.5%, 17.14% higher respectively and very significantly, ratio of sugar/acid of fruit was 46.88% significantly higher, but the nitrate content was 26.37% lower than those in nutrient solution treatment.