关键词: 夏玉米, 播种深度, 幼苗性状, 根系特性, 产量

Abstract: In order to understand the effects of shade tree species on the carbon storage of different treetea agroforestry systems, three plots with a size of 20 m × 25 m were established in each of five different tea gardens, i.e., a monoculture tea garden and four tea gardens with one, two, four, and six shade tree species, respectively in Menghai County, Xishuangbanna. Biomass regression models were constructed by using the DBH of shade trees and the BD (basal diameter) of tea shrubs, soil samples were taken from five layers (0-20, 20-40, 40-60, 60-80, and 80-100 cm) in each plot, and the carbon storage was then estimated, based on the carbon contents in different organs of trees and tea shrubs and in soils. The total carbon storage of monoculture tea garden (223.442 t·hm^-2) was 22.701 and 3.871 t·hm^-2 lower than that of the Cinnamomum pathenoxylumtea and Cinnamomum pathenoxylum+Cunninghamia lanceolatatea gardens, but 10.828 and 5.717 t·hm^-2 higher than that of the tea gardens with four and six shade tree species, respectively. Soil carbon storage accounted for 91.8%-96.0% of the total carbon storage, being the lowest in the tea garden with four shade tree species. The carbon storage of plants only occupied 4.0%-8.2% of the total carbon storage, and increased from the tea gardens with one to four shade tree species but decreased sharply in the tea garden with six shade tree species. Our results suggested that the tree-tea agroforestry systems in Xishuangbanna had a strong capacity of carbon sequestration.  

Key words: summer maize, sowing depth, seedling trait, root characteristics, grain yield.