黄土丘陵区人工草地牧草营养元素累积及土壤有机碳与养分特征  

Characteristics of Accumulation of Nutrient Elements in Grasses and Soil Organic Carbon and Nutrients in Managed Grasslands in the Loess Hilly and Gully Area

作　　者：王百群[1,2] 姜峻[2] 都全胜 曹庆玉[2] 

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨陵712100 [2]西北农林科技大学水土保持研究所,陕西杨陵712100 [3]陕西省富县气象局,陕西富县727500

出　　处：《水土保持研究》2010年第6期127-132,共6页Research of Soil and Water Conservation

基　　金：国家自然科学基金项目(90502007;40301024);中国科学院知识创新项目(KZCX2-XB2-05);国家科技支撑项目(2006BAD09B07)

摘　　要：以黄土丘陵沟壑区安塞川地及山坡地豆科和禾本科的人工草地为对象,研究人工草地的土壤有机碳及土壤养分变化、草地植物营养元素吸收与循环特征,揭示种植不同种类牧草的人工草地对土壤有机碳及养分变化的驱动作用。结果表明:在各种牧草当年生长的茎叶、立枯物、凋落物及根系中所累积的营养元素中,氮素累积量最高,其次为钾,磷的累积量最少;牧草通过凋落物归还到土壤中的氮素最多、其次为钾素,磷的归还量最少;各种牧草的地上部氮、磷、钾3种元素累积量高于根系。苜蓿的地上部和根系中氮、磷、钾的总累积量最高,其次为红豆草、柳枝稷和达乌里胡枝子,沙打旺的地上部与根系中累积的氮、磷、钾总量最少。川地与坡地草地土壤全氮、土壤有机碳与有机碳储量及有机碳固定量均高于裸地。川地草地土壤全氮、土壤有机碳含量与储量高于坡地,川地草地土壤有机碳固定量低于坡地。土壤全氮含量川地以苜蓿最高,山坡地以白羊草最高。建植草地可有效提高土壤氮与钾的有效性。The plot experiments of planted grass were conducted to examine the impact of growing grasses in the lowland and the slope land on the levels of soil organic carbon and the changes in soil major nutrients.The objective of this study was to probe into the driving effects of various planted grasses on soil organic carbon and nutrients.The amount of nutrient elements accumulated in stalk and leaf,dead organs,litter and root of each grass followed the order of nitrogen（N）potassium（K）phosphorus（P）.The amount of N,P and K accumulated in the aboveground mass of each grass is more than that in root.The quantity of nutrient elements returned to soil through the litter followed the order of N KP.The sum of N,P,K accumulated both in above ground mass and root obeyed the order of Medicago sativa L. Panicum virgatum,Onobrychis viciaefolia Scop. Lespedezadavurica Schindl. Astragalus adsurgens Pall.Soil total nitrogen content（TN）,soil organic carbon content（SOC）,soil organic carbon reserves（OCR） and sequestrated organic carbon of each sown grass at lowland and slope land were higher that in bare land.Soil TN,SOC and OCR of lowland pastures were higher than pastures on slope land,while sequestrated organic carbon soil was lower than the latter.Soil TN in alfalfa land of lowland was the highest,whereas soil TN on slope land grown old world bluestem（Bothriochloa ischaemum,L.） was the highest.It can be seen that pasture cultivation can improved soil available nitrogen and potassium.

关 键 词：人工草地 营养元素 土壤有机碳 养分特征 黄土丘陵区 

分 类 号：S812[农业科学—草业科学]