?? ??????????75%?????

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?????7??2???????????????(?????? ?)??????????????????“???????”?7??2????????????,???????????,?????6???30??7?2???,???????????????,??????,??2??15?????????????,?????????75%?????????????????????

?6??30?????????,????????????????????????? ??

???????,7?????1??6??2?6?,?????,????????????????????????????????????????????????????????????????????,????????????:?139.7????????????????105.4?????????????????99.0???????????

?????????7???????????2??15?0-20cm??????,?75%?,25%??,????????????

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??,???10?????????????????,?????????,???????????,7???????????????3??6????,??????,????????????????????;7?????????????8?,?????;9?????????????13??,????????,?????????14??????????15?,??,?????,??????

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