| Summary: | 碩士 === 國立中興大學 === 園藝學系所 === 106 === In this study, different proportions of rice or tomato biochar were used to replace peat moss as transplant growth substrates for cabbage and tomato, respectively. The growth phenotype, yield and head or fruit quality of cabbage and tomato plants derived from the above-mentioned transplants were investigated at harvesting stage. Furthermore, chopped rice straw was mixed with field soil at different ratios as growth substrates for cultivation of cabbage in containers, cabbage growth phenotype, head phenotype, and head quality were evaluated to determine the potential of utilizing crop wastes as growth substrates.
Results from transplant growth analysis indicated that rice and tomato biochar both may replace 25% peat moss as growth substrate for cabbage transplants and replace 50% peat moss as growth substrate for tomato transplants. The growth and head phenotypes, the contents of glucosinolate, ascorbic acid and total soluble solid of cabbage plants derived from transplants grown in the rice straw biochar mixed substrate showed no significant difference, but zinc and boron concentrations in the leaves of cabbage head were significantly higher compared to those of cabbage plants derived from transplants grown in peat moss. Tomato plants derived from transplants grown in the rice straw biochar mixed substrate had significantly lower average fruit weight, whereas no significant difference was observed in growth phenotype, yield and fruit quality compared to those of tomato plants derived from transplants grown in peat moss. Outer leaf number and iron concentration of cabbage head were higher but potassium concentration of cabbage head was lower in cabbage plants derived from transplants grown in the tomato biochar mixed substrate relative to those of cabbage plants derived from transplants grown in peat moss. No significant difference was observed in growth phenotype, yield and fruit quality of tomato plants derived from transplants grown in tomato biochar mixed substrate compared to those of tomato plants derived from transplants grown in peat moss. These results suggested that rice straw biochar and tomato biochar may partially replace peat moss as growth substrate for cabbage and tomato transplant growth without negative effect on subsequent transplant growth, yield and head or fruit quality.
In another experiment, 5% (5S) and 15% (15S) chopped rice straw were applied to mixed with field soil for cultivation of cabbage. Our results indicated that total porosity, container capacity and air space were higher in 5S and 15S treatment group relative to the control group (0S, 100% field soil) but bulk density was significantly lower relative to the control group. As to the substrates after cultivation, the proportion of coarse particles decreased but the proportions of fine particles increased in the control and 5S treatment group compared to those before cultivation. Comparing to raw field soil, pH values were significantly lower, EC values were significantly higher and CEC was not significantly altered after addition of chopped rice straw in the raw field soil, furthermore, potassium, magnesium and zinc concentrations were all significantly increased in the chopped rice straw mixed substrates. Larger leaf width and better head phenotypes were noticed in field soil grown cabbages relative to those grown in the chopped rice straw mixed substrates. The content of glucosinolate was significantly higher in 5S treatment group compared to the control group. Besides iron concentration in the cabbage head, the concentrations of the rest nutrient elements tested were below the suitable range in some of all groups tested. In addition, results from this study demonstrated that utilization of chopped rice straw mixed substrates for cultivation of cabbage may have yield reduction due to insufficient supply of boron. It is therefore important to change fertilization strategy or allow the chopped rice straw to be degraded in the field soil before cultivation of cabbage to prevent nutrient competition between soil microbes and cabbage that may inhibit cabbage growth.
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