A pot experiment without potassium fertilization was conducted in Lam Son sugarcane area, Thanh Hoa province to determine potassium supply capacity of grey soil (Haplic Ferralic Acrisols) in different conditions of irrigation and fertilization. The potassium supply capacity of soil were determined based on the amount of K2O accumulated in all parts of the sugar cane at the time of harvest, the results showed that, the different conditions of irrigation and NP fertilization has a significant influence on growth, biomass, K2O content as well as K2O accumulated in sugarcane. The total of K2O supplied by soil were accouted for 40.6 kg K2O, 64.4 kg K2O, 56 kg K2O and 114.8 kg K2O per hectares at the treatment of non irrigation. Non NP fertilization
Non irrigation. NP fertilization
irrigation - Non NP fertilization and irrigation - NP fertilization, respectively.