关键词: 夏玉米, 混播, 产量, 密度, ¹³C同化物

Abstract: Landscape pattern is easily affected by human activities. In order to accurately grasp the influences of landscape pattern on heavy metal pollution of soil and implement more targeted prevention and control measures, GIS and geostatistical analysis method were adopted. Based on a villagelevel small scale, the contents of 8 kinds of heavy metals in surface soil of cultivated land were measured in a town in South Jiangsu. The study objectives were to reveal the pollution characteristics of the 8 kinds of heavy metals and their spatial distribution pattern, to discover the influences of landscape pattern in buffer area, and to analyze the relationships between overall landscape pattern and heavy metal pollution in administrative villages. The results showed that the content of Cd exceeded national soil quality secondary standard of China. The heavy metal pollution levels were all less than 1; 99.36% of the cultivated land were not polluted and 0.64% of the cultivated land were on the alert against heavy metal pollution. In the buffer area, there was a significant correlation between contents of As, Ni, Pb, Hg, Cd and Zn and some landscape pattern indexes (P<0.05), while there was no significant correlation between contents of Cr and Cu and landscape pattern. There was a significant positive correlation between landscape connectivity/aggregation degree and comprehensive pollution index of heavy metals (P<0.05). Therefore, our results well explained the comprehensive pollution degree of heavy metals in cultivated lands in each administrative village.

Key words: summer maize, density, mixed-cropping, grain yield, ¹³C-photosynthate