Senanayake, N.De Datta, S.K.2020-09-022020-09-021991Tropical Agriculturist, 147:p.99-109https://dl-doa.nsf.gov.lk/handle/1/2670NATURAL RESOURCES AND ENVIRONMENTExternal P requirementLowland riceExternal phosphorus requirement of some Philippine lowland rice soilsArticle