摘要
本文研究不同放牧率对草原植物土灌系统中C、N、P含量的影响。结果表明，对照区地上生物量和0～60m土层的总根量显著大于各放牧处理（P＜0．01），而放牧处理间差异不显著（P＞0．05）。对照区和1．33只羊／hm2处理植物的C含量显著大于4只羊／hm2和6．67只羊／hm2，而后两个处理的N、P含量较高。4只羊／hm2处理的C／N和C／P最小。6．67只羊／hm2处理已使根系和根系中的N素明显向表层聚集。对照区0～10cm土层土壤有机C含量显著大于各放牧处理，而各放牧处理间差异则不显著。土壤有机C，N含量与报系生物量成显著正相关。0～10cm土层中无机N在4只羊／hm2处理中最大。土壤微生物量C、P含量在6．67只羊／hm2处理中显著降低，其它处理间差异不显著。其中4只羊和6．67只羊／hm2处理的微生物N含量较高。
Effects of stocking rates on C, N, P contents and distributions in Plant-soil system in Leymus chinensis steppe, Inner Mongolia. There are four treatments in the control experiment: 1. 33sheep/hm2,4 sheep/hm2,6.67 sheep/hm2 and a ungrazed Plot. The results indicated that plan species,aboveground and underground biomass, chemical composition in Plant and soil have changed greatly after 8grazing years. The aboveground and underground biomass in 0~ 60cm are significantly higher than those in grazing treatments, but not significantly different among the grazing treatments . Plant carbon content was higher under control and 1.33 sheeo/hm2 than those under 4 and 6.67 sheep/hm2, but N, P content, vice versa. C/N and C/P ratio in plant were smallest in 4 sheep/hm2 treatment. It had showed significant surfication of root and nitrogen content in root under 6.67 sheep/hm2 treatment. Soil C in 0 ~10cm depth under control treatment was higher than those of other three grazing treatments. No significantdifference of soil C in 0 ~ 10cm soil layer was observed among three grazing treatments. Soil organic carbon and nitrogen contents were significantly positive to root biomass.Inorganic N in 0 ~ 10cm soil was highest in 4 sheep/hm2. Soil microbial C and P in 0 ~ 10cm depth were significantly reduced only under6. 67 sheep/hm2. Soil microbial biomass N was higher under 4 and 6.67 sheep/hm2.
出处
《草地学报》
CAS
CSCD
1998年第2期90-98,共9页
Acta Agrestia Sinica
基金
国家自然基金!49790020
关键词
放牧率
土壤-植物系统
羊草小禾草草原
Stocking rate
Plan-soil system
C, N, P contents
Leymus chinensis steppe
