Wapakala, W.W.2015-07-022015-07-021973Wapakala, W. W. (1973). The Effect of Nitrogen, Phosphorus and Copper on Grain Yield of Wheat on a Copper Deficient Soil. East African Agricultural and Forestry Journal, 38(3), 229–240. https://doi.org/10.1080/00128325.1973.116625850012-8325https://kalroerepository.kalro.org/handle/0/1916The effects of nitrogen, phosphate and copper on the grain yields of wheat on a copper deficient soil were studied in both greenhouse and field trials. Using the method of Systematic Variation in the greenhouse studies, it was found that the optimum ratio of phosphorus: copper for wheat production was 2: 1.enhttp://creativecommons.org/licenses/by/3.0/Journal ContributionNitrogenPhosphorusCopperWheatsGrainhttps://doi.org/10.1080/00128325.1973.11662585