茶叶对土壤脲酶的抑制作用

Inhibitory effect of tea leaves on soil urease

【目的】研究茶叶对土壤脲酶的抑制作用,为利用茶叶废弃物生产绿色环保型脲酶抑制剂提供理论依据。【方法】在土壤与尿素配比固定的情况下,利用静态吸收法,考察不同茶叶用量、土壤含水量、培养温度及茶叶的浸泡次数等因素对茶叶抑制土壤脲酶效果的影响。【结果】绿茶用量为0.4 g时,其对土壤脲酶的抑制率已达50%,乌龙茶约需0.7 g才达到同样的抑制效果,而红茶的加入会促进尿素分解。土壤脲酶活性随土壤水含量的增加、培养温度的升高均呈先升高后降低的变化趋势,在水含量为60%、培养温度为40℃时活性最高,加入的茶叶抑制土壤脲酶活性能力为绿茶>乌龙茶>红茶。经多次浸泡,绿茶和乌龙茶对土壤脲酶的抑制能力均有不同程度降低,浸泡3次后绿茶的抑制率较乌龙茶降低明显。【结论】茶叶对土壤脲酶活性和氨挥发有一定的抑制作用,且以茶多酚含量较高的绿茶抑制效果更佳。

[ Objective ]The inhibitory effect of tea leaf on soil urease were studied, in order to provide theoretical basis for recycling tea leaf residue as environmental-friendly urease inhibitor. [Method]The inhibitory effect of tea leaves on soil urease was influenced by some factors, such as tea leaves dosage, soil water content, culture temperature and soaking times. Under fixed ratio of soil and urea, the influences of these factors were studied by static absorption method. [Result] The results showed that, when the dosage of green tea was 0.4 g, the inhibition rate of urease activity was up to 50% ; When the dosage of oolong tea was 0.7 g, the inhibition rate of urease activity was up to 50% ; While black tea leaf lifted soil urease activity. With the increase of soil water content and culture temperature, soil urease activity firstly increased and then decreased, which was the highest at soil water content of 60% and culture temperature of 40 ~C. Furthermore, different kinds of tea leaves was ranked based on inhibitory effect on soil urease activity, as follows： green tea〉oolong tea〉 black tea. And the inhibitory effects of green tea and oolong tea on soil urease activity were decreased to varying degrees after being soaked many times. Moreover, after being soaked 3 times, the inhibitory effect of green tea was decreased more markedly, compared with oolong tea. [Conclusion]Three kinds of tea leaves have a certain inhibitory effect on soil urease activity and ammonia volatilization, especially green tea, which has the highest inhibitory effect resulted from higher tea polyphenol content.