喀斯特石漠化地区不同退耕年限下桂牧1号杂交象草植物-土壤-微生物生态化学计量特征

发布时间：2018-04-06 20:20

本文选题：生态化学计量学　切入点：喀斯特　出处：《生态学报》2017年03期

【摘要】：耕地农作物种植与退耕地种草养畜是喀斯特主要的农业生产模式。以喀斯特地区农耕玉米地为对照,研究退耕还草1、5、7a(恢复初期、旺盛期、衰退期)3种年限下桂牧1号杂交象草地植物-土壤-微生物C、N、P生态化学计量特征及内在关联。结果表明:1)牧草地植物地上部分N、P含量均为5a牧草1a牧草7a牧草,C含量则刚好相反;3种退耕年限牧草地植物地上部分C∶N、C∶P、N∶P分别为26.50—33.91、631.70—2254.33、23.89—67.21,且均表现为7a牧草1a牧草5a牧草。2)土壤表层(0—10 cm)C、N、P含量均以玉米地最低,3种退耕年限牧草地中则均为5a牧草地最低;土壤C∶N、C∶P、N∶P在玉米及退耕牧草地之间均无显著差异(P0.05),平均值分别为9.20,27.88,3.38。3)玉米及牧草地土壤MB_C、MB_N、MB_P含量存在显著差异(P0.05);玉米地MB_C/SOC、MB_N/TN、MB_P/TP均高于牧草地,3种退耕年限牧草地中,则均为5a牧草地最高。4)MB_C、MB_P与土壤C、P含量分别呈显著线性正相关(P0.05);植物C、C∶N与土壤C、N含量均呈极显著线性负相关(P0.01)。分析表明,退耕还草地中植物与土壤系统C-N-P化学计量比表现出不一致的时间变化特征,且牧草地植物受P限制严重,尤以恢复旺盛期为甚。
[Abstract]:Cultivated land crop planting and returning cultivated land recommend raising livestock is the main agricultural production mode of karst.The ecological stoichiometric characteristics and their internal relationships of plant, soil and microorganism C _ (N) N _ (P) in Guimu No. 1 hybrid elephant meadow were studied under the control of cultivated corn field in karst area under three different years (early recovery period, exuberant period, declining period) and three years (early recovery period, exuberant period and decline period).The results showed that 7a forage, 1a forage, 5a forage grass. 2) the soil surface layer (0-10 cm ~ (-1) cm ~ (-1)) C ~ (+ +) N ~ (+ +) P content was the lowest among the three kinds of forage land with the lowest returning years in maize field, but all were the lowest in 5 years forage land.There was a significant linear correlation between C0. 05 P content and Con P content in soil, and there was a very significant linear negative correlation between C0. 01 N content and C0. 01 N content in soil.The results showed that the C-N-P stoichiometric ratios of plants and soil systems in the returning grassland showed different temporal variation characteristics, and the plants in the forage land were severely restricted by P, especially in the period of recovery and exuberance.
【作者单位】：中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;中国科学院环江喀斯特生态系统观测研究站;中国科学院大学;
【基金】：中国科学院科技服务网络计划(STS计划)资助项目(KFJ-EW-STS-092) 国家自然科学基金资助项目(41471445)
【分类号】：S54;S154.4

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