ISSN: 2593-9173
Tu Trinh Cong
In Vietnam, basaltic soil is rich in total phosphorus (P), but poor in available P, because of fixing. Most of crops on the soil have symptom of P deficiency. Rock phosphate (RP) was a slow release P fertilizer and has a longer residual effect. This is to research on effect of RP’s to corn and groundnut on basaltic soil in Vietnam. Two parallel experiments with 9 treatments of Control, Super Single Phosphate (SSP), Vietnam RP, Morocco PR, Tunisia PR, Jordan PR, Algeria PR, Senegal PR and Togo PR were conducted during 2015-2016. The experiments were designed to Randomized Complete Block (RCB) with 4 replications and the plot area of 100 m2. The backgrounds consisted 180 N-90 K2O for corn and 45 N-60 K2O for groundnut. Except control, phosphorus dose was 90 P2O5. Study results showed that applying 90 kg P2O5 in RP form improved N and P content in corn leaves, increased biomass by 20.6-22.0% and corn productivity by 7.8-15.5%. Output of 1 kg P2O5 in RP form was 5.2-10.4 kg corn grain. Supplying 90 kg P2O5 in RP form increased groundnut biomass by 43.5-48.5%, root nodulation by 109.3- 115.0% and productivity by 15.5-16.8%. Efficiency of 1 kg P2O5 in RP form was 2.1-2.3 kg groundnut bean. The difference of corn and groundnut productivity among SSP and RP treatments was insignificant.