Sorghum plants were given different levels of nitrogen (nitrate or ammonium) to see how it affected their growth and nitrogen metabolism. The plants grew better with higher nitrogen levels. Ammonium made the roots and leaves have more proteins, amino acids, and chlorophyll. Nitrate increased nitrate reductase activity in leaves and roots. Glutamine synthetase 1 and protein levels increased in roots with more nitrate or ammonium, especially in ammonium-treated plants. Glutamine synthetase 2 protein increased in leaves of nitrate-treated plants. Glutamate dehydrogenase activity increased in both organs with more nitrogen, especially with ammonium. Sorghum plants can handle high levels of ammonium by detoxifying it through nitrogen assimilation in roots.