| Vinegar residue substrate is a new horticultural organic substrate made from vinegar production's solid wastes by composting. Now it can be peat substituted medium, which is widely used in the seedling and cultivation, so it is put into commercial production. However, due to vinegar residue substrate is a new substrate, the changes of substrate physical and chemical properties,the correlation between substrate fertility characteristic itself and crops'fertilizer requirement characteristics during long time cultivation and utilization are short of systematic research. So it is difficult to realize precise management of nutrient during vinegar substrate cultivation, which leads to overuse fertilizer and influence the full potential of substrate cultivation on yields. Based on the above problem, the optimization of key technology in the process of vinegar residue composting,the variation characteristics of substrate physical and chemical properties during long time cultivation and the nutrient absorption and distribution characteristics of cucumber cultured by vinegar residue substrate were systematic analyzed and studied. Also, the decision support system of nutrient management in cucumber cultivated by substrate was built. The aim is to provide scientific basis for establishing the technical system of organic substrate cultivation.The main conclusions were as follows:(1) The stable maturity technology and nutrient structure improvement technology were studied. The results showed that two stages fermentation technology of vinegar residue can realize completely maturity of vinegar residue substrate and the GI value of composting was above 100% after fermentation. Though the nitrogen loss was 8% higher in the treatment of adding plant ashes than in the treatment without plant ashes, the treatment of adding plant ashes can improve the pH of vinegar residue substrate, speed up the rising of temperature in early stage of composting, increase nutrient contents of composting, increase the total nutrient contents of N, P, K by 18.5%, and improve nutrient structure thus the ratio of N, P, K was 1.9:0.3:1, which made vinegar residue substrate's physicochemical characters more suitable for cultivation.(2) The variation characteristics of physical and chemical properties in the condition of long-term cultivation were studied. The results showed that fine particles with diameter<0.45mm in substrates had highly significant positive correlation with bulk density,aeration porosity,retention ability and other indexes of substrate; With time going by, the substrates'pH value decreased rapidly at first and then tended to be stable, the EC value decreased continuously and the content of available nitrogen and total potassium decreased gradually. While the total nitrogen, total phosphorus and the relative contents of iron, manganese, cuprum, zinc, calcium and magnesium increased with time going by because of substrate mineralization and microorganisms' enrichment.(3)On the basis of analysis on the nitrogen content and fluorescence parameters of cucumbers'leaves at different nodes with growth stage changes, the correlation between nitrogen content and fluorescence parameters of cucumbers'leaves was established. The results showed that in different growth period, leaf photosynthetic capacity in the vegetative growth phase was higher than that in the reproductive growth period. In the same period, photosynthetic capacity in middle leaves was higher than that in top leaves, while photosynthetic capacity in bottom leaves was lower than that in other leaves. In different growth periods, leaf nitrogen content was obvious different among leaves at different nodes. The leaf nitrogen content had significant positive correlation with fluorescence parameters qP。Y(Ⅱ),ETR, what's more, in the cucumber primary fruit stage and cucumber early fruit periods, the leaf nitrogen content had good linear correlation with fluorescence parameters qP,Y(Ⅱ),ETR.(4)The nutrient absorption characteristic of different crops'cucumber cultivated by vinegar residue organic media was studied. The results showed that the absorption of total nitrogen,P2O5 and K2O of autumn and winter planting was about 20% less than spring and summer planting. By calculation, in spring and summer planting, per 100Kg yields need absorb averagely N 253g, P2O590g, K2O 307 g, while in autumn planting, per 100Kg yields need absorb averagely N294g, P2O598g, K2O 358g.(5) Using'3414'test, N, P, K optimum fertilization dosage of cucumber cultivated by new vinegar residue was studied. The results showed that new vinegar residue can provide 70% quantities of nutrient supply for cucumber growth, of which N and P had high supplying ability, while K had low supplying ability. From the test, the optimum yields of cucumber cultivated by new vinegar residue substrate was 9236kg/mu, when the N, P, K Ratio was 1:0.57:3.87.(6) On the basis of overall analysis of nutrient supply, nitrogen loss and cucumbers' nutrient absorption characteristics in cultivation by vinegar residue organic matrix, nitrogen supply and loss model of vinegar residue substrate and cucumbers'nitrogen absorption model in substrate cultivation was established. Using balance equation of nutrient, nitrogen fertilization management decision support system in vinegar residue organic substrate cultivation was built. The system's output was realized by Excel, users can use Excel's print function to print fertilization decision report, which made the system easy,simple,convenient and suitable for application. |
