Agro-forestry Organic Waste Compost As Growth Media For Ornamental Plants

Currently, agro-forestry organic waste compost as growth media for peat substitution is an effective way to waste recycle and high quality ornamental plants.Through aerobic composting experiment with spent mushroom (SM), wheat straw (WS) and garden waste (GW), physical and chemical properties dynamic changes were added up and maturity were determined by correlation analysis. Subsequently, main physical and chemical parameters were analyzed and limited factors for waste compost as growth media were found. Water absorption of wheat straw were improved by watering amendments and pH value, EC value and copper content were decreased by natural organic acids. In addition, three kinds of compost were used for growing ornamental plants. Finally, the ideal values and determination methods of growth media were put forward as professional standard.The findings are summarized as follows:1. Maturity parameters evaluation for agro-forestry organic waste compostThe temperature began with rise rapidly and then decline quickly. The speed of temperature rise and the maximum temperatures varied widely among different materials. Water was added to wheat straw frequently due to its rapid dehydration. The pH value curve was inconsistent. The EC and ammonium nitrogen values firstly increased and then decreased. The nitrate nitrogen value first increased, then decreased, and then increased. The humus and humic acid contents first decreased and then increased, and fulvic acid content decreased instantly. The germination indexes (GI) reached or exceeded 80 percents. The Gl, temperature and fulvic acid values were regarded as maturity evaluation parameters for agro-forestry organic waste compost.2. Physical and chemical properties of growth mediaThe physical indicators differences between spent mushroom compost (SMC)and garden waste (GWC) were not significant in the ideal range. The porosity ratio (PR) of wheat straw compost (WSC) is 1.71 exceeding to the ideal target range (0.25-0.67) due to the presence of wax.The pH value of GWC was 7.65, EC value was 2.02 ms·cm-1 and copper content was 106.93 mg·kg-1. The above three parameters all exceeded the ideal values.3. Effect of watering amendments on permeability and water absorption of WSCThe permeability and water absorption of WSC were improved by watering amendments with concentration of 2% and 4%. And rooting parameters of Impatiens hawkeri were improved by watering amendments with concentration of 2%.4. Effect of natural organic acids on pH value, EC value and available copper contents of GWCThe pH value was decreased by one to two units with natural organic acids and was 5.00 to 6.50 with concentration of 2% and 4%. And rooting parameters of Impatiens hawkeri were improved by watering amendments with concentration of 2%. By chemical complexation of natural organic acids, the EC value was controlled in the ideal range (0.12-1.20 ms·cm-1). With the increased dose of natural organic acids, the EC values decreased. The available copper contents were lowest in GWC and Impatiens hawkeri with natural organic acids of 2% concentration.5. Effect of SWC, WSC and GWC on growth of Lilium Siberia.Lilium Siberia had high quality and cut flowers in SWC and vermiculite (SWCV), GWC and vermiculite (GWCV), peat (control) and vermiculite (PV). However, the unstable WSC and vermiculite (WSCV) was not suitable for Lilium Siberia. As PV substitution, SWCV and GWCV can be used for lily cultivation; while stable alternative was needed to WSCV for growth Lilium Siberia.