????:1?????300??400:??????300??

2????????????

3??????????

4???????

5???????

?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%?,??????????????????

?????,?,??,????????????????????,??,?????????

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

????????,???:??,?,?????????????????,?,??,????????????????????????????????,??????????????????(?????????)

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