The Research On Developing Concentrated Bio-slurry Into Formulated Liquid Organic Fertilizer

In recent decades, the animal husbandry industries and biogas projects developed rapidly, resulting in the pollutions generated by bio-slurry increasing dramatically as well. Although the bio-slurry contains rich nutrients, amino acids, humic acids, auxin, hydrolytic enzymes, vitamins and other biological active materials, the processing of bio-slurry still stays in the patterns of direct farm consumption. The bio-slurry has always been the focus of non-point source pollution which remains to be solved, due to the conflicts between the continuous discharge and seasonal demand for fertilization, and the high cost of transportation. At the same time, bio-slurry is in lack of appropriate fertilizer slurry standards and difficult to be commercialized. The development of high-value utilization patterns of slurry is, therefore, essential and urgent.In the study, nutrient-rich bio-slurry was separated, concentrated and developed into amino acid type and humic acid type organic fertilizers. Fertilizer effect experiments were conducted to characterize the effects of various organic fertilizers on the growth of pakchoi and lettuce. The followings are the conclusions.(1) Bio-slurry from pig manure was used for reverse osmosis membrane concentration tests by 1-10 times. The original bio-slurry was found involved with rich elements like nitrogen, phosphorus and potassium, trace elements, organic materials, amino acids, humic acids, etc. Besides, with the increase of concentration, the total nitrogen, total phosphorus, total potassium, organic materials, amino acids, humic acids and some trace elements in the liquid showed an increasing trend with electrical conductivity rising as well and PH around 8.0.(2) The concentrated formulated fertilizer by 10 times from bio-slurry meets the standards of NY 1106-2010, NY1429-2010 of the Ministry of Agriculture. The content of free amino acid in amino acid type formulated fertilizers reaches 121.6g/L, while the content of humic in humic formulated fertilizers reaches 38.52 g/L.(3) Compared fertilizers are selected as amino acid type and humic acid type formulated fertilizers which are dissolved in water, "Aojie-Miaohuan" water-soluble amino acid fertilizer and "Aojie-Wotu" water-soluble humic acid fertilizer. The results showed that the biomass, ascorbic acid and soluble sugar of pakchoi and lettuce were significantly improved by using formulated fertilizers made from concentrated slurry compared with amino acid type and humic acid type formulated fertilizers made by water and water-soluble fertilizers from Aojie Company. After fertilizing, the nitrate contents didn’t accumulated, but the catalase, urease and the nutrients on soil were significantly improved. With the increasing frequency of application, enzyme activity tended to increase as well. Simultaneously using the basal and foliar fertilizers had the best performance. With more formulated fertilizer made from bio-slurry applied into the vegetables, yields and nutrient content of pakchoi and lettuce are basically showing a decreasing trend after the first increase. Application of diluted formulated fertilizers made from bio-slurry by 250 times worked best on the growth of pakchoi while diluted formulated fertilizers made from bio-slurry by 100 times performed best on the growth and nutrient accumulation of lettuce.