Micro?dose placement of phosphorus induces deep rooting of upland rice

Upland rice production is often constrained by phosphorus deficiency (P) and drought events. Methods are needed to maximize P use efficiency, while promoting deep root development mitigate drought. This study evaluates micro-dose placement as a technique enhance resilience of upland rice, thereby hypothesizing that enhances development, stimulated the local supply in planting hole, compared broadcast P. Two pot experiments were conducted using deficient soil Tanzania (Expt.1) Madagascar (Expt.2), with factorial combinations doses (control two levels), application method (placement versus broadcast), varieties (DJ123 & NERICA4) water regimes (field capacity drying periods). Micro-dose strongly boosted establishment enhanced recovery rates (4- 5-fold) fertilizer efficiency (9- 14-fold) placements significantly fraction roots found at largest depth (> 30 cm, Expt. 1; >15 2) 22- 33 %. Surprisingly, shoot concentrations markedly lower under than equivalent or biomass, indicating Piper-Steenbjerg effect. first showing rooting after basal placement, suggests replication field scale where subsurface moisture may yield stronger benefits pots. The depleted induced vigorous plant may, however, counteract later growth stages need further attention.