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

????:???????????:????????

???????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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