The Study Of Material Proportion In Vermicompost Substrates And Its Influence To The Growth Of Romaine Lettuce And Ornamental Tomato

Earthworm is a versatile bio-resource and its products can be used as Chinese medicine, worm cast, fish bait, worm protein and .bioreactor. In the resent 20 years, the study on earthworm was conducted in soil science, genetic engineering,nutriology, chemistry,ecology and others subjects around the world. The development of earthworm bread was very fast. Though the earthworm bread have a bright prospect, but how to deal with the great quantity of worm cast produced in the process was become a new problem. For the purpose of sufficient using the new resource, three raw materials that were vermicompos, corn stalks and mushroom residue were used in the experiment and studied the proportion of material in vermicompost substrates and its influence to the transformation of C, N in fermentation process and the effect on the growth of romaine lettuce and ornamental tomato and on the physical properties of substrates.The main results were:1.The proportion of vermicompost in substrates had significant effect on the growth of lettuce. The return relations of lettuce seedling emergence, plant height and leaf area with the proportion of vermicompos could be expressed by polynomial equation. The test results for R2 show that the correlation between the plant height and worm cast proportion was the most significant, regression equation for germination rate, plant height and leaf area were: y = -0.0101x2 + 0.8533x + 53.04;y = -0.0023x2 + 0.1898x + 5.503;y = -0.0011x2 + 0.0797x + 3.5027。According to the regression equation and the simulation result of lettuce growth indexes when vermicompost proportion was 30%~55%, the best vermicompost proportion for plant was 40%.2. The proportion of straw and mushrooms residue in substrates for all treatments had significant effect on the C / N of fermented substrates. there was a slight reduction of the total nitrogen content in pre-fermentation, and with the time extension of the fermentation, the total nitrogen content was shown an increasing trend. It was increased from average of 0.89% to 1.53% in the fermentation process and an average increasing of 0.64%。On the contrary, the carbon content was decreased from average of 15.4% to 9.7% in the process。Consequently, the C/N was decreased about 50% in average that were all less than 10 for all treatments.3. In the fermentation process, NH3-N, NO3-N and available N all was shownd a downward trend. The average nitrate was reduced more than nearly 97.8% and the content of ammonium only decreased nearly 58%.The available N downward trend in the fermentation process was: the treatment 5and 6 was declined very distinctin early days and become flat in latter. Throughout the fermentation process, the content of available N in treatment 7and 8 was at a steady decline. Organic N was raised in all fermentation process and trentment 6 gotten the highest content of organic N. Results shown that 30% of the straw and 20% -30% of the mushroom residue in the vermicompost substrates should the best proportion for the fermentation.4. Put straw and mushroom residue to the vermicompost substrates had obvious effect on the physical properties of the substrates. Compared to vermicompost , the substrates bulk density was lower ,and the total porosity, water retention poresity and ventilation pore was improved. Compared with straw, the contribution of mushroom residue to bulk density was more obvious. Vermicompost substrates that mixed with straw and mushrooms residue was shown obvious effect in increasing the total porosity and the J20% + M20% was the best treatment.It got a total porosity for 81.0% and the increasing was 35.9% compared with vermicompost. The fuction of mushroom residue on total porosity and water retention porosity was a negative correlation with itsproportion in the vermicompost substrates. The best proportion of straw was J20% for the total porosity and water retention porosity. The ventilation porosity also increased by straw and mushrooms residue, but there was nor obvious regular.5. The plant height, flower number, leaf area, fruit sweetness, the largest fruit weight and sugar/acid ratio was selected as important indicators to define substrate that suit for ornamental tomato growth.. the total N, C / N, and bulk density of substrate was found in this paper that must be in a very strict range for ornamental tomato. The total N was in the range of 1.40%-1.62%, C / N was 8.8-10.5 and bulk density was 0.40 g/cm3-0.47 g/cm3. And requirements for total porosity, water retention porosity and gas / water ratio was not so strict relatively. However, the ratio of gas/water between 7-8 was more suitable for the growth of ornamental tomato. And 4 optimum treatments of J20% + M30%, J20% + M20%, J30% + M30% and J30% + M10% was selected for ornamental tomato.