OVERVIEW
Phosphorus (P) and potassium (K), along with sulfur (S), zinc (Zn) and boron (B), are essential nutrients needed for a balanced crop nutrition program in onions.
Ensuring K, S, and B availability through bulb development can be difficult on coarse, well-drained sandy soils.
MicroEssentials SZ contains N, P, S, and Zn combined into one nutritionally balanced granule, providing uniform distribution, increased nutrient uptake, and season-long S availability.
Aspire combines potash along with two forms of B (fast and slow release) in every granule for uniform distribution, season-long B availability, and a flexible application window.
TRIAL DETAILS
Crop: Onion (Allium cepa)
Years: 2019-2020
Locations: 4 trials in Idaho and Washington
Data Source: Field studies conducted by independent, third-party researchers.
Experimental Design: Small-plot RCBD with 4 replications.
Cropping Conditions: All trials conformed to local cropping practices.
TREATMENTS:
Treatment (Trmnt) / Rates / Timing:
N Rate: Applied according to local recommendations
P Rate: 100 lbs P₂O₅/ac applied as MAP or MicroEssentials SZ
K Rate: 120 lbs K₂O/ac applied as either MOP or Aspire
Application Timing: Preplant
Application Method: Broadcast Incorporated
RESULTS
SUMMARY
Addition of MOP increased onion yield 6 cwt/ac compared to MAP only.
MicroEssentials SZ + MOP increased yield by 62 cwt/ac over MAP only and 56 cwt/ac over MAP + MOP.
Replacing MOP with Aspire increased yield 88 cwt/ac over MAP + MOP and 32 cwt/ac over MicroEssentials SZ + MOP.
Higher yields achieved using MicroEssentials SZ + Aspire demonstrate the value of combining P, K, S, Zn, and B for a balanced crop nutrition program in onions.
