| In this paper, the field plot experiment was conducted to study the effect of six different fertilization models on yield and quality of lettuce and cabbage, soil microbial, soil enzyme activity as well as emission of greenhouse gases from soil. The six fertilization treatments were phosphates and potash, pure chemical fertilizer,20%nitrogen from pig manure and80%from chemical fertilizer,20%nitrogen from ad residues and80%from chemical fertilizer,20%nitrogen from pig manure compost and80%from chemical fertilizer and no fertilizer respectively. The results were as follows:1、In contrast to phosphates and potash treatment and pure chemical fertilizer treatment, application of manure and inorganic fertilizer could significantly increase chlorophyll content of functional leaves in lettuce and cabbage. At three stages of lettuce, the chlorophyll SPAD value with the fifth treatment(20%nitrogen from pig manure compost and80%from chemical fertilizer) reached the highest level, T3was second. In cabbage growth later period, compared to T1treatment, chlorophyll content with T3, T4, T5increased by10.6%,11.2%and12.5%respectively. And with two determination results, T5reached the highest level.2^Combined application of organic manure and chemical fertilizers could improve nitrate reductase(NR) activity in functional leaves of lettuce and cabbage. Among of them, NR activity of T5was the highest. In contrast to CK, T1and T2, the NR activity of T5increased by100.3%,42.8%and50.0%respectively during the peak period of NR activity in lettuce leaf. While compared to CK and T2, the NR activity of T5increased by16.2%and13.5%respectively during the peak period of NR activity in cabbage leaf, and the difference reached the significant level.3、Combined application of manure and inorganic fertilizer could enhance root vitality of vegetables. In the period of relatively high root vitality in lettuce, root vitality with T3, T4and T5were remarkably improved in contrast to CK. While in cabbage, compared to CK treatment, root vitality with T3, T4, T5increased by 31.9%,28.8%and62.8%respectively.4、In contrast to CK treatment, educable bacteria amount with T3, T4, T5increased by77.98%,32.33%,57.56%respectively in later growth stage of lettuce. In later growth stage of cabbage(November6th), the educable bacteria amount with T3, T4, T5could reach the highest level, which increased by154.1%,16.8%,75.7%, respectively. Compared to CK treatment, in the period of lettuce growth peak, the educable bacteria number with T3and T5enhanced by28.24%and37.35%, respectively. While during the period of cabbage growth peak, the educable bacteria number with T3and T5increased by270.62%and249.65%, respectively. From the perspective of two planting crops, educable actinomyce number with T3and T5were obviously higher than other treatments, especially T2. On Octorber16th, the educable actinomyce number with T3and T5reach the highest, which enhanced by68.75%and72.94%, respectively.5、The mixed application of manure and inorganic fertilizer could improve enzyme activity of vegetable soil, especially T3and T5. During the cabbage planting season, soil urease activity obviously enhanced in each treatment of mixed application of manure and inorganic fertilizer. Among of them, compared to CK, T1and T2, soil urease activity with T5, in the highest period, reached the highly significant level and improved by60.8%,48.1%and34.4%, respectively. In later growth stage of lettuce, in contrast to CK and T2, soil phosphatase activity with T5was significantly different and improved by70.4%and66.3%. While in later growth stage of cabbage, soil phosphatase activity with T4and T5were highly significantly higher than three treatments without manure, which enhanced by80.2%and88.8%compared with CK, by52.3%and59.6%compared with T1, by58.4%and65.9%compared with T2, respectively.At three determining growth stages of lettuce, soil catalase activity with T5was significantly or highly sinificantly higher than three treatments without manure. In later growth stage of cabbage, the variance of soil catalase activity with T3and T5reached significant level compared with other treatments. In the period of lettuce growth peak, soil cellulase activity with T3and T5were relatively high, and in contrast to CK, T1and T2, the cellulase activity with T5enhanced by173.3%, 123.6%and205%, respectively. During planting period of cabbage, the relatively high stage of soil cellulase activity, the soil cellulase activity with T4and T5enhanced by92.5%and82%compared with CK treatment, by33.2%and25.9%compared with T1, by38.8%and31.2%compared with T2, respectively.6、Although mixed application of manure and inorganic fertilizer increased carbon dioxide(CO2) emission in vegetable field, returning pig manure compost or ad residues to soil was helpful to reduce carbon dioxide emission in vegetable field. In contrast to T3, when cabbages were transplanted into soil two days later, the CO2emission of T4and T5decreased by41.5%and71.5%respectively, while when the second day after topdressing, the CO2emission of T4and T5decreased by25.1%and9.6%. In addition, mixed application of manure and inorganic fertilizer could decrease CH4emission from soil. When cabbage was topdressed, the CH4emission from soil of T3, T4and T5were lower than other treatments, which were0.1471,0.5212and-0.9285mg· m-2· h-1.7、Combined application of manure and inorganic fertilizer could obviously enhance yield of lettuce and cabbage. Compared to T2, total yield of lettuce with T3, T4and T5increased by7.4%,0.8%and48.3%respectively. And cabbage growth, to some extent, could be improved in T3, T4and T5, especially T5. Combined application of manure and inorganic fertilizer could increase content of ascorbic acid and soluble saccharide in stem and leaf, and decrease nitrate and coarse fibre content, thus improving nutritional quality and taste of vegetables. |
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