Wheat can be grown in high NH4+ with little effect on growth and yield
Counter ion had no effect on Ca2+ uptake in these studies
Inoculation with nitrifying microorganisms may help alleviate high NH4+ problems
Bugbee, Bruce, "Long-Term Effects of NH4+/NO3- Ratios on Growth and Nitrification in Hydroponic Culture" (2000). Hydroponics/Soilless Media. Paper 4.