Maize yield and grain quality response to foliar-applied phosphorus in a soil testing high in P

Aim of study: To test the effect of foliar and granular P fertilizer application on maize performance planted under permanent beds from 2012 to 2019 in a soil testing high in P. Area of study: This field experiment was located in the eastern region of the trans-Mexican volcanic belt. Material and methods: Three P treatments, foliar and granular (band and broadcast), and a control (0P) plot were allocated in an randomized complete block design in six replications. Main results: Year-P treatment interaction was significant for yield, agronomic efficiency (AE), and recovery efficiency (RE). Contrastingly, grain quality parameters measured as bulk density and thousand grain weight were only affected by year’s main effect. Yield, AE, and RE were generally more responsive to the foliar than the granular P application. These parameters varied in each treatment according to precipitation accumulated in 40 days during the bracketing-silking period (40d PP) and heat units during the grain filling stage [GDD(t-m)]. As 40d PP increased, yield and AE improved, while RE decreased; as GDD(t-m) increased, yield and grain quality improved. Initial soil available P (46 mg/kg) decreased 26% due to foliar P application. Research highlights: Results suggest that replacing the granular P with foliar P fertilization is an option to mine soil to an acceptable P level without adverse effects on maize performance.