- D ai , ▁and ▁associated ▁with ▁the ▁K au hu q iao , ▁Hem ud u , ▁Maj i ab ang , ▁Song ze , ▁Li ang z hu , ▁and ▁Ma quia o ▁cult ures . ▁The ▁second ▁is ▁in ▁the ▁middle ▁Yang t ze ▁River , ▁believed ▁to ▁be ▁the ▁hom el ands ▁of ▁the ▁early ▁H m ong - M ien - spe akers ▁and ▁associated ▁with ▁the ▁P eng t ous han , ▁Nan mu y uan , ▁Li ul in xi , ▁D axi , ▁Qu j ial ing , ▁and ▁Sh ij ia he ▁cult ures . ▁Both ▁of ▁these ▁regions ▁were ▁heavily ▁populated ▁and ▁had ▁regular ▁trade ▁contacts ▁with ▁each ▁other , ▁as ▁well ▁as ▁with ▁early ▁Aust ro asi atic ▁speak ers ▁to ▁the ▁west , ▁and ▁early ▁Kra - D ai ▁speak ers ▁to ▁the ▁south , ▁facil it ating ▁the ▁spread ▁of ▁rice ▁cultiv ation ▁throughout ▁southern ▁China . ▁ ▁The ▁earliest ▁p addy ▁field ▁found ▁dates ▁to ▁ 4 3 3 0 ▁BC , ▁based ▁on ▁carbon ▁d ating ▁of ▁gra ins ▁of ▁rice ▁and ▁soil ▁organ ic ▁matter ▁found ▁at ▁the ▁Cha od un ▁site ▁in ▁Kun sh an ▁County . ▁At ▁Ca ox ies han , ▁a ▁site ▁of ▁the ▁Ne ol ith ic ▁Maj i ab ang ▁culture , ▁arch ae olog ists ▁exc av ated ▁p addy ▁fields . ▁Some ▁arch ae olog ists ▁claim ▁that ▁Ca ox ies han ▁may ▁date ▁to ▁ 4 0 0