Soil Biological Activity of Abandoned Saline Fields With Different Restoration Treatments

27 Mar Soil Biological Activity of Abandoned Saline Fields With Different Restoration Treatments

View Original

Abstract

以干旱区新疆玛纳斯河流域冲积扇缘定点定位试验地为研究对象, 研究灌溉处理、人工草地处理和 补植处理对盐渍化弃耕地土壤微生物量、酶活性及土壤呼吸速率的影响。结果表明, 不同恢复方式均明显增 加了土壤微生物数量和土壤微生物量碳、氮及土壤酶活性。不同处理土壤微生物量碳、氮分别比原始弃耕地 高 17.80%、26.38%、5.33%和 7.89%、12.75%、21.93%; 不同处理土壤微生物数量分别是原始弃耕地的 4.72 倍、6.04 倍和 4.56 倍; 不同处理土壤蔗糖酶活性分别比原始弃耕地高 3.4 倍、3.2 倍和 7.7 倍, 多酚氧化酶活 性比原始弃耕地高 1.7 倍、1.2 倍和 1.5 倍, 脲酶活性比原始弃耕地高 11.1%、52.3%和 37.1%; 灌溉处理土壤 过氧化氢酶活性最高, 是原始弃耕地的 1.53 倍, 土壤呼吸速率变化表现为人工草地处理>灌溉处理>补植处理> 原始弃耕地, 其中, 人工草地处理土壤呼吸速率比弃耕地高 52.25%。相关分析表明, 微生物量碳与微生物 C/N 和微生物数量之间均呈显著正相关关系(P<0.05); 土壤呼吸速率与土壤脲酶、微生物数量和微生物量碳的相关 性达到显著水平(P<0.05), 与土壤微生物量氮呈负相关关系, 但相关性不显著; 土壤蔗糖酶与其他 3 种酶以及 微生物量氮呈显著正相关关系, 土壤脲酶与微生物数量呈显著正相关关系, 多酚氧化酶与过氧化氢酶相关性 达到显著水平(P<0.05)。本研究表明干旱区盐渍化弃耕地采用灌溉与人工草地处理有利于土壤养分积累, 可在 一定程度上改善土壤质量。

English Abstract

The characteristics of soil microorganisms are critical in soil restoration and ecosystem health. To a large extent, different
restoration methods of vegetation have different effects on the activity of soil microorganisms. The understanding of the
characteristics of soil microorganisms under different restoration methods of vegetation is critical for exploring the effects of
vegetation restoration on soils and for laying the scientific basis for ecological restoration of abandoned fields. In this study, a field
experiment was conducted in saline soil of the alluvial fans of the Manas River Valley, which is largely an arid region. The four
treatments were set out in the experiment, including original abandoned field (control), water supplement field, artificial grassland
field and plant supplement field. The last three treatments were applied in the original abandoned field. The main aim of the
experiment was to study the effects of different restoration models on soil microbial biomass, enzyme activity and soil respiration
rate of abandoned saline fields. The results indicated that soil enzyme activity, soil microbial population and soil microbial biomass
carbon and nitrogen were significantly enhanced by different vegetation restoration models. Soil microbial biomass carbon and
nitrogen under water supplement field, artificial grassland field and planting supplement field were respectively 17.80%, 26.38%,
5.33%, and 7.89%, 12.75%, 21.93% higher than those under original abandoned field. The numbers of soil microbes under the three
vegetation restoration treatments were respectively 4.72, 6.04 and 4.56 times that of original abandoned field. Also soil sucrase
activity under the three different restoration treatments were respectively 3.4, 3.2 and 7.7 times that of the original abandoned field.Then soil polyphenol oxidase activity under the three different restoration treatments were respectively 1.7, 1.2 and 1.5 times that of
the original abandoned field. Similarly, soil urease activity of three different restoration treatments were respectively 11.1%, 52.3%
and 37.1% higher than that of the original abandoned field. Among the treatments, soil catalase activity of the water supplement field
treatment was highest (1.53 times that of the original abandoned field). The order of changes in soil respiration rate under the three
different restoration models of abandoned saline field was artificial grassland field > water supplement field > planting supplement
field > original abandon farmland field. Soil respiration rate under artificial grassland field was 52.25% higher than that under the
abandoned field. Water supplement and artificial grassland fields of abandoned saline fields in arid regions enhanced the
accumulation of soil nutrient and thereby improved soil quality. Correlation analysis showed that among the indexes of the
characteristics of soil microorganisms, soil microbial biomass carbon, microbial biomass C/N and soil microbial amount were
positive correlated (significant at P < 0.05). Positive correlations were noted between soil respiration rate versus soil urease, microbial population and microbial biomass C (significant at P < 0.05) and negative (but not significant) correlations between soil respiration rate and soil microbial biomass N. Also positive correlations were noted between soil sucrase activity versus the other three soil enzymes (urease, polyphenol oxidase and catalase) and microbial biomass nitrogen (significant at P < 0.05). A positive correlation was noted between soil urease and soil microbial amount (significant at P < 0.05). There was also a positive correlation between soil polyphenol oxidase and soil catalase (significant at P < 0.05). Thus the characteristics of soil microorganisms were interrelated with soil enzymes and soil respiration rate. This suggested that the three factors not only exhibited distinct characteristics but also mutually influenced and interacted during soil conversion. This interaction therefore needed further clarification in further research efforts