現地圃場試験の開始
現地圃場試験の開始
To test the P-dipping technique (seedling roots dipped in phosphorus added soil slurry) as a potential strategy to increase rice yield in the highlands of Madagascar, multi-field experiments were established in two different locations. Twenty lowland rice fields with different P retention conditions of soils at Behenjy and Antohobe were selected to compare P-dipping treatment with conventional P broadcasting and no P (farmer practice) application. The fields for early and normal planting times were transplanted and for late planting times are under way. The effect of P-dipping was clearly observed after two weeks of transplanting and it promoted early growth of rice compared to conventional P and no P application (farmer practice). Pot experiment was also conducted at laboratory of Radioisotopes (LRI), Antananarivo University, to assess the effect of seedling roots injury (roots pruning) to apply the P-dipping technique. We harvested all the pots after 35 days of transplanting and plant samples were taken for further measurement of shoot and root dry weight, and plant nutrient uptake.