I roto i te 1929, Joseph Russell Smith tāpiri i te wā mua rite te hauraro mō te Tree Crops: He Agriculture Tumau, he pukapuka e whakarāpopoto ana i tona wheako roa whakamātautau ki hua me nati rite hua mo te kai tangata, me te kai kararehe. kite Smith te ao rite te katoa pāhono, me te tūtohu pūnaha ranunga o rakau, me te hua i raro. faauruhia tēnei pukapuka maha takitahi hanga hiahia i runga i te ahuwhenua atu tauwhiro, pērā i Toyohiko Kagawa nei pionia ahuwhenua ngahere i roto i Japan i roto i te 1930s. i roto i te Ahitereiria P. A. Yeomans'1964 pukapuka mo te Farm Water, tautoko ia i te whakamāramatanga o te ahuwhenua pūmau, kia rite ki tetahi e taea te mau tonu mutunga. whakaurua Yeomans rua he huarahi mātakitaki-e hāngai ana ki te whakamahi whenua i roto i Ahitereiria i roto i te 1940s me te 1950s.
ngā pūnaha whakaranu o ngā rākau me ngā huawhenua i raro