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 whakaaro pūnaha ranunga o rakau me hua i raro. whakaaweawe tenei pukapuka maha takitahi i runga i te hanga i te whakaaro i runga i te ahuwhenua atu tauwhiro, pērā i Toyohiko Kagawa nei pionia ahuwhenua ngahere i roto i Japan i roto i te 1930. i roto i te pukapuka 1964 Ahitereiria P. A. Yeomans'mo te Farm Water, tautoko ia i te whakamāramatanga o te ahuwhenua pūmau, rite 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 katoa Keyline?
te whakahaere i te tuku wai me te tohatoha wai