【摘要】：促進(jìn)土壤酶活性是黃土高原生物結(jié)皮改善土壤養(yǎng)分狀況的重要途徑,但目前認(rèn)識(shí)不夠深入。本文以陜北風(fēng)蝕水蝕交錯(cuò)區(qū)黃綿土和風(fēng)沙土上發(fā)育約30年的典型蘚結(jié)皮為對象,通過分層(0—12 cm)取樣,測定并分析了不同土層的水解酶和氧化還原酶活性及其與土壤理化性質(zhì)的關(guān)系,以期進(jìn)一步揭示蘚結(jié)皮對土壤酶活性的影響及其對土壤養(yǎng)分的貢獻(xiàn),研究結(jié)果如下:(1)研究表明,蘚結(jié)皮的發(fā)育能顯著提高土壤酶活性。與無結(jié)皮相比,黃綿土上蘚結(jié)皮的脲酶、堿性磷酸酶、蔗糖酶和蛋白酶活性分別增加了92.4%、110.4%、119.9%和83.0%,而風(fēng)沙土上蘚結(jié)皮的4種水解酶活性分別增加了11.2%、50.5%、199.6%和21.4%;黃綿土上蘚結(jié)皮的過氧化氫酶、過氧化物酶和多酚氧化酶活性分別是無結(jié)皮的2.27、15.13和5.32倍,而風(fēng)沙土上的3種氧化還原酶活性則分別是無結(jié)皮的2.04、18.58和8.68倍。(2)黃綿土和風(fēng)沙土上蘚結(jié)皮的體積含水量分別降低了6.5%和0.8%,溫度分別降低了2.1℃和3.3℃,表明蘚結(jié)皮對土壤水分和溫度的重新分配有重要意義。(3)研究表明,蘚結(jié)皮的發(fā)育能有效提升土壤碳含量。黃綿土上蘚結(jié)皮土壤的有機(jī)質(zhì)、易氧化碳和微生物量碳含量分別提升了1.59、5.79和4.96倍;風(fēng)沙土上則分別提升1.29、3.16和4.69倍,蘚結(jié)皮的發(fā)育在加速土壤碳循環(huán)過程中有重要作用。(4)研究發(fā)現(xiàn),蘚結(jié)皮的發(fā)育能有效提升土壤氮含量。黃綿土上蘚結(jié)皮的全氮、速效氮和微生物量氮分別提升了2.50、2.08和3.04倍;風(fēng)沙土上則分別提升了3.29、2.15和2.29倍,蘚結(jié)皮的發(fā)育有利于促進(jìn)土壤氮積累。(5)研究認(rèn)為,蘚結(jié)皮的發(fā)育能有效提升土壤磷含量。黃綿土上蘚結(jié)皮的全磷和速效磷含量分別提升了2.31和2.87倍;風(fēng)沙土上則分別提升了1.78和5.28倍,蘚結(jié)皮發(fā)育對于提升土壤磷的有效性具有促進(jìn)作用。(6)研究表明,蘚結(jié)皮加強(qiáng)了加強(qiáng)了土壤酶活性與土壤養(yǎng)分的相關(guān)性,土壤酶對土壤養(yǎng)分存在積極意義。研究證實(shí),黃土高原風(fēng)蝕水蝕交錯(cuò)區(qū)兩種土壤上蘚結(jié)皮均能顯著提升土壤酶活性,這可能是蘚結(jié)皮加速土壤養(yǎng)分積累和提升土壤肥力的重要原因;其中,通過改變土壤含水量和溫度等酶促反應(yīng)條件間接影響酶活性,是蘚結(jié)皮促進(jìn)土壤酶活性的重要途徑。
[Abstract]:Promoting soil enzyme activity is an important way to improve soil nutrient status by biological crust in Loess Plateau, but it is not well understood at present. In this paper, the typical mossy crust developed for about 30 years on the loess spongy soil and aeolian sandy soil in the wind-erosion water erosion interlaced area of Northern Shaanxi is taken as the object, and the samples are taken by stratification (0-12 cm). The activities of hydrolases and redox enzymes in different soil layers and their relationship with soil physical and chemical properties were determined and analyzed in order to further reveal the effect of moss crust on soil enzyme activity and its contribution to soil nutrients. The results are as follows: (1) the results showed that The development of moss crust can increase soil enzyme activity significantly. The urease, alkaline phosphatase, and alkaline phosphatase of the moss crust on yellow spongy soil. The activities of sucrase and protease increased by 92.4%, 119.9% and 83.0%, respectively, while the activities of four hydrolases in the crust of moss on the sandy soil increased by 11.2%, 50.5%, 199.6% and 21.4%, respectively. The activities of peroxidase and polyphenol oxidase were 2.27g / 15.13 and 5.32 times higher than those of non-crusts, respectively. However, the activities of three redox enzymes in windy sandy soil were 2.04 ~ 18.58 and 8.68 times as much as those in no crust, respectively. (2) the volume water content of moss crust was decreased by 6.5% and 0.8%, respectively, and the temperature was decreased by 2.1 鈩，

本文編號(hào)：2234943