Corn Production as Affected by Phosphorus Enhancers, Phosphorus Source and Lime

Prompted by high cost of fertilizer, farmers are investigating ways to enhance the efficiency of phosphorus (P) fertilizers. This study examined the effects of liming application (0 Mg ha-1 and recommended rate), P source [non-treated control and a broadcast application of diammonium phosphate (DAP) or triple superphosphate (TSP)], and the presence or absence of two commercial enhanced efficiency P products (Avail? and P2O5-Max?) on corn (Zea mays L.) production. The study was conducted at Novelty in northeastern Missouri and Portageville in southeastern Missouri. The P enhancers did not affect plant population, silage dry weights, grain moisture, yield, protein, oil, or starch concentrations at either location. At Portageville, P enhancers did not affect plant N, P, K uptake and apparent P recovery efficiency (APRE). At Novelty, neither P enhancer paired with DAP increased P uptake over the non-treated control. TSP treated with Avail? increased P uptake 8.6 kg ha-1 compared to the non-treated control and 7.1 kg ha-1 compared to P2O5-Max?. In 2010 at Novelty, TSP treated with Avail? increased K uptake 150 kg ha-1 compared to the non-treated TSP and 100 kg ha-1 compared to P2O5-Max?. At Novelty, plant population was 4,800 plants ha-1 greater in the non-limed control compared to the recommended rate in 2011, although plant population at Portageville was not affected. At Portageville, the recommended amount of lime increased grain yields 0.77 Mg ha-1, but there was no effect at Novelty. At Novelty, plant P uptake increased 3.4 kg ha-1with the application of lime, but at Portageville there was no effect. Grain yield increased 0.34 Mg ha-1 with TSP compared to the non-treated control.