| [cycling and balance of copper in farmland ecosystem of jianghan plain in hubei province]. | the cycling and balance of copper in 8 cropping systems, i.e., wheat-rice, rice-rice, rape-soybean, rape-peanut, wheat-sesame, wheat-cotton, pepper-cabbage and radish-eggplant in jianghan plain of hubei province were studied. the results showed that the main output of copper was crop harvesting, up to 85.9%-95.1% of total output, and the output of copper by field runoff and soil leaching was low. the main inputs of copper were organic fertilizer, rainfall, falldrop, and natural return. the input ... | 2003 | 12722442 |