宁夏典型草原不同退耕年限草地植物-土壤生态化学计量特征

发布时间：2018-03-20 22:26

本文选题：宁夏典型草原　切入点：退耕草地　出处：《草业学报》2017年04期 　论文类型：期刊论文

【摘要】：为了研究宁夏典型草原不同退耕年限草地优势植物及土壤C、N、P化学计量特征,本研究以宁夏南部典型草原区退耕草地为对象,分别对退耕0、1、3、5、6、8、11、15、20年草地优势植物及土壤碳、氮、磷等生态化学计量特征进行研究。结果表明,各植物全氮含量均表现为地上部分大于地下部分,且猪毛蒿整体全氮含量较其他植物高。全磷含量除赖草外也表现为地上部分大于地下部分。退耕1年狗尾草和退耕3年赖草有机碳含量表现为地下部分大于地上部分,其余各退耕年限地上部分大于地下部分。优势植物C∶N、C∶P、N∶P整体表现为退耕20年长芒草最大。赖草和猪毛蒿最小。退耕6年以上20年以内土壤有机碳含量由表层向深层逐层递减;全氮含量退耕0~6年呈波动式变化,退耕8年后全氮含量由表层向深层逐层递减;全磷含量变化趋势与全氮相同。研究区土壤C∶N变化范围为7.08~19.62,C∶P变化范围为6.60~35.25,N∶P变化范围为0.82~2.17。各层土壤C∶N平均值变化范围为11.18~15.03,C∶P平均值变化范围为14.09~24.55,N∶P平均值变化范围为1.06~1.98;除C∶N接近我国土壤C∶N均值外,研究区土壤C∶P和N∶P均低于我国土壤C∶P和N∶P均值。并且相应地表优势植物C∶N、C∶P、N∶P明显高于表层土壤。本研究中土壤C∶N与土壤有机碳之间相关性不显著,与全N呈负相关,意味着C∶N主要受N控制,而C∶P与有机碳呈显著正相关,与全P相关性不显著。土壤N∶P与土壤全N含量呈显著正相关,与土壤全P含量相关性不显著,说明主要受N控制,而土壤全N含量随退耕年限的增加呈波动式上升趋势。植物与土壤碳、氮、磷相关性显示:植物全N与土壤N之间相关性不显著(P0.05),植物全P与土壤全N、全P呈极显著的相关关系(P0.01),与土壤有机碳和N∶P呈显著的相关关系(P0.05)。
[Abstract]:In order to study the chemometric characteristics of dominant plants and soil C _ (N) N _ (P) in grassland with different returning years in typical grassland of Ningxia Autonomous region, this study took the returning grassland of typical grassland area in southern Ningxia as an example. The dominant plants and soil carbon and nitrogen in 20 years were studied respectively. The results showed that the total nitrogen content of each plant was higher than that of the underground part. The total nitrogen content of Artemisia hyacinth was higher than that of other plants, the total phosphorus content was higher than that of underground part in addition to Leymus chinensis, and the organic carbon content of Leymus spp for 1 year and 3 years was higher than that of aboveground part. The above ground part of the other cultivated years was larger than that of the underground part. The dominant plant C: n: P was the largest for 20 years, and the least for Leymus and Artemisia pigeonii. The soil organic carbon content decreased from the surface layer to the deep layer within more than 20 years after returning to tillage for more than 6 years. The total nitrogen content was fluctuating from 0 to 6 years, and the total nitrogen content decreased from the surface layer to the deep layer after 8 years. The change trend of total phosphorus content is the same as that of total nitrogen. The range of variation of soil C: n is 7.08 ~ 19.62C: P = 6.60 ~ 35.25N: P = 0.82N = 2.17. The range of average value of C _ (1) N is 11.181.03 ~ (th) C _ (%) P is 14.0924.55N = 1.06 ~ 1.98; Except that C: n is close to the average value of C: n in the soil of our country, In the study area, soil C: P and N: P were lower than those in our country, and the relative dominant plant C: n: C: P was significantly higher than that of surface soil. The correlation between soil C: n and soil organic carbon was not significant, but negative correlation with total N. It means that C: n is mainly controlled by N, while C: P is significantly positively correlated with organic carbon, but not significantly correlated with total P. Soil N: P is significantly positively correlated with soil total N content, but not with soil total P content, indicating that it is mainly controlled by N. The total N content of soil increased with the increase of returning years. Phosphorus correlation showed that there was no significant correlation between plant total N and soil N, but there was a very significant correlation between plant total P and soil total N, total P showed a very significant correlation (P 0.01), and there was a significant correlation with soil organic carbon and N: P (P 0.05).
【作者单位】：宁夏大学农学院;西北土地退化与生态恢复省部共建国家重点实验室培育基地;
【基金】：国家自然科学基金(31360582,31460632)资助
【分类号】：S812

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