Study On Composting Technology Of Eucalyptus-bark Waste And Application For Seedling Propagation

With the utilization of agricultural and forestry waste and the development of modern nursery, agricultural and forestry waste as organic matrix had become the focus of the study. Agricultural and forestry waste was a good raw material for soilless cultivation substrate, but it contained more harmful substances and performance instability, need to maturity treatment before use as nursery substrate, the effect of decomposition directly affect the results of nursery.Matrix was the basis and key of seedling growth,the physical and chemicalproperties of matrix was the most important factor to determine good or bad of seeding growth. Theparticle size and ratio of nursery substrate was very important physical and chemical parameters, directly affect stability of the matrix porosity and chemical properties. Eucalyptus is one of the world's three fast-growing species, produced a great deal of bark waste when the wood was using. Therefore, we study Eucalyptus-bark waste as nursery substrate, to analysis the effects of matrix decomposition and particle size and stability of the physical and chemical properties and nursery effect, had important application value for environmental protection and substrate deployment and quality of industrial production of matrix.This article was based on Eucalyptus-bark as raw material to study the matrix technology of decomposition of Eucalyptus-bark, the change of physical and chemical properties when used different size and ratio of Eucalyptus-bark for nursery, effect of nursery substrate on quality of seedling growth, finally getting results as following:(1)After thermophilic aerobic composting, the temperature of the treatments of urea were slowly rise and low; the treatments of adding chicken manure and pig manure were heating up fast and high temperature. In the composting process, the physical and chemical properties of Eucalyptus-bark matrix got some improvement. After decomposition of Eucalyptus-bark, each treatment had slight increase in bulk density, total porosity and pore size ratio decreased, water holding capacity had been improved; pH value increased, EC value and CEC value decreased, C/N ratio decreased, matrix properties become more stable performance.(2)There was noticeable difference on the maturity effect of Eucalyptus-bark between the different treatments. The treatments of pig manure and VT^-1000 bacteria, pig manure and enzyme bacteria, chicken manure and enzyme bacteria after maturity was close to or achieve the desired substrate requirements. Comprehensive evaluation showed that the treatment of chicken manure and enzyme bacteria was the best for effect of Eucalyptus-bark composting that was the most suitable treatment for decomposition of Eucalyptus-bark. The treatment of urea and VT^-1000 bacteria was the worst effect of decomposition. Comprehensive considerations combined with cost, chicken manure was the most suitable nitrogen source for decomposition of Eucalyptus-bark, enzyme bacteria can be added as appropriate agents.(3) In the breeding process, bulk density with different treatment of Eucalyptus-bark matrix varied in the range from 0.1 g.ml^-1 to 0.3 g.ml^-1, the total porosity on the rise between 65% to 90%, gas-water ratio fluctuated between 0.05 to 0.40, changed in the broader, capacity of aeration and water-holding in the nursery to get some improvement. With the breeding going on, the chemical properties of matrix changed noticeable.EC value and pH value decreased gradually in the nursery, CEC value increases, C/N ratio changed little, nutrients (N, P, K) content and changes can meet the needs of seedling growth.(4)The analysis of the physics and chemistry character of matrix showed that the effect of chemistry character and nutrient components was bigger than effect of physics character on seedlings. EC value, CEC value, pH value, C/N, total P and total K was the main factors influencing the seeding matrix.(5) Particle size of Eucalyptus-bark was less than 0.2cm and between 0.2cm and 0.5cm, or Eucalyptus-bark accounted for 25% and 50%, physical and chemical properties in the nursery changed little, stable performance. The overall of seedlings growth was good quality, nursery effect was ideal. No.3 was the best of matrix for seeding growth, No.4 and No.7 was the worst of matrix for seeding growth.? Based on an overall consideration, the size of Eucalyptus-bark should not be more than 0.5cm and the ratio should not exceed 50%.(6)The analysis of Eucalyptus-bark matrix and the property of seedlings suggested that the EC value, CEC value, total K of matrix was the main influential factor in seeding growth and CEC value was the most influence over seedling index.