Utility of Phosphorus Enhancers and Strip-Tillage for Corn Production

Farmers are seeking ways to diminish phosphorus (P) fertilizer rates and increase plant P uptake by means of enhanced efficiency P treatments. The objectives of this study were to determine the effects of tillage/fertilizer placement [no-till-surface broadcast (NT-BC) or strip-till-deep band (ST-DB)], monoammonium phosphate (MAP) rate (0, 56, and 112 kg ha-1), and the presence or absence of enhanced phosphorus efficiency products (Avail® and P2O5-Max®) on corn (Zea mays L.) production. The field study was conducted in 2010 and 2011 at Novelty and Albany, MO. The two P enhancers had no effect on plant population, silage dry weights, grain moisture, yield, grain protein, grain starch, plant nitrogen (N), potassium (K) uptake, or apparent P recovery efficiency (APRE) at either location (P>0.10). In the NT-BC and ST-DB treatments, the addition of Avail® or P2O5-Max® did not increase plant P uptake over the non-treated controls. ST-DB increased plant populations 3,500 to 15,500 plants ha-1 compared to NT-BC. At Novelty, yields increased 1.57 Mg ha-1 with use of ST-DB over NT-BC, but at Albany yields were affected by tillage/fertilizer placement and MAP rate. Corn grain yields with MAP at 0 kg ha-1 were 0.30 to 0.36 Mg ha-1 more than MAP at 56 or 112 kg P2O5 ha-1, which was probably due to the added ammonium nitrate used to balance the N contribution in MAP. Strip-till is a viable option to increase corn populations and yields on poorly drained soils, but P enhancers are not recommended for similar soil types.