Date Received: 07-03-2016 / Date Accepted: 15-07-2016 / Date Published: 13-06-2025
The phosphorus fertilizer use efficiency in acid sulphate soils usually islow because Fe2+and Al3+ions fix phosphate ions under low pH conditions. The objective of this study was to evaluate the influence of phosphorus fertilizer blended with DCAP on growth and yield of sweet potato, cassavaand yam cultivated in acid sulphate soils in Long My- Hau Giang. The on-farm research was conducted in three farmer’s fields. The treatments included (i) nophosphorus application; (ii) 30 kg P2O5ha-1; (iii)DCAP (2‰) combined with30 kg P2O5ha-1; (iv) 60 kg P2O5ha-1; (v)andDCAP (2‰) combined with60 kg P2O5ha-1. Results showed that application of phosphorus blended with DCAP at 30 kg P2O5ha-1increasedthe diameter, number of tubers and yield on sweet potato and cassava, which were comparable with theapplication of 60 kg P2O5ha-1. Thus, this practiceseemed to be effective inreducing phosphorus fertilizerapplication. However, phosphate fertilizer blended with DCAPdid not increase yam yield.It is needed to further testthe efficiency of phosphate fertilizer blended with DCAP on sweet potatoandcassava cultivated onlarger area in acid sulfate soils in the Mekong Delta.
