The dynamics of the accumulation of nitrogen, phosphorus and potassium in maize and peas in the first growth phases at constant mineral nutrition

The authors studied the growth intensity, the accumulation and distribution of nitrogen, phosphorus, and potassium in maize and pea plants under conditions of hydroponic culture. They found that RGR dropped by about 50% within 32 days of cultivation. The content (in mg/g dry weight) of nitrogen and potassium in maize, and of nitrogen and phosphorus in peas registered a substantial decrease, while the content of phosphorus in maize and that of potassium in peas exhibited a slight increase and a slight decrease towards the end of the experiments. The relative absorption rates of nitrogen and phosphorus in maize were maximum after 28 days of cultivation, while that of potassium reached a maximum immediately at the beginning; nitrogen and potassium absorption in peas reached maximum values after 28 to 30 days, whereas phosphorus was highest at the beginning. In the course of growth, the ratio of accumulated ions of N:P:K changed; maize accumulated relatively less potassium, and peas more nitrogen and potassium.