The solution culture and sand culture in controlled condition were conducted in order to investigate the influence of NH4+-N and NO3--N and their different supply ratios on plant growth, amino acid content as well as phosphorus uptake in oat .The obtained results showed that:①When supplied with both N forms ,the oat growth was obviously better than when NH4+-N or NO3--N was the sole nitrogen source ,and 30:70 was the best NH4+/ NO3- ratio for plant growth
;②When served with constant ...