| ¡ ID | 124 |
| ¡ Ží—Þ | ˜_•¶ |
| ¡ ƒ^ƒCƒgƒ‹ | Environmental Problems from Tea Cultivation in Japan and a Control Measure Using Calcium Cyanamide |
| ¡ ’˜ŽÒ | @
Kokyo Oh@
é‹ÊŒ§ŠÂ‹«‰ÈŠw‘ÛƒZƒ“ƒ^[ @ Tadashi Kato@ NPO–@lŽ©‘R¶‚̉ï @ Zhongpei Li@ ’†‘‰ÈŠw‰@“ì‹ž“y댤‹†Š @ Fayun Li@ ’†‘—É”J‘åŠw @ @ @ @ @ @ @ @ @ @ @ @ @ @ |
| ¡ o”ÅŒ³ | |
| ¡ o”Å”N | 2006 |
| ¡ Ž–¼EŠªE†E”N | Pedosphere, Vol.16, No.6, 770-777, 2006 |
| ¡ ´˜^E—vŽ| | A field experiment, involving lime N (calcium cyanamide, CaCN2) fertilization as a control measure, was conducted to study environmental problems induced by long-term heavy N application in Japanese tea fields. Long-term tea cultivation caused serious soil acidification. Seventy-seven percent of the 70 tea fields investigated had soil pH values below 4.0, and 9% below 3.0, with the lowest value of 2.7. Moreover, excess N application in tea fields put a threat to plant growth, induced serious nitrate contamination to local water, and caused high nitrous oxide loss. Compared with the conventional high N application treatment (1100 kg N ha-1) without lime N, the low N application (400 kg N ha-1) with CaCN2 effectively stopped soil acidification as well as achieved the same or slightly higher levels in tea yield and in total N and amino acid contents of tea shoots. The application of CaCN2 could be a suitable fertilization for the prevention of environmental problems in tea cultivation. |
| ¡ ƒL[ƒ[ƒh |
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