Experiments were carried out to compare the effects of anions on the growth and inorganic constituents of several vegetable crops supplied with different forms of nitrogen in sand culture.
In the preliminary experiments with onion supplied with nitrate nitrogen, plants showed inferior growth with sulphur deficiency symptoms at sulphate (SO
4) 0me, slightly inferior growth without deficiency symptoms at SO
4 0.2me, and better growth was observed between 0.5 and 10me. While, there was detected no chlorine deficiency symptoms even at chloride (Cl) 0me, and plants showed normal growth between Cl 0 and 10me. In both sulphate and chloride series, plant growth was lowered at higher concentrations than 25me, and the higher the concentration, the less was the growth.
In the next experiments of cabbage, turnip, and onion supplied with NaNO
3, NH
4NO
3, or (NH
4)
2SO
4 as nitrogen source (8me as N), there was no clear difference of growth between the treatments supplied with cations as sulphate or chloride (11me as SO
4 or Cl except (NH
4)
2SO
4 treatment). No difference of growth was found also between (NH
4)
2SO
4 plants in which ammonium, in addition to other cations, was supplied as sulphate, and NH
4Cl plants supplied as chloride (19me as SO
4 and Cl, respectively). However, growth of plants in both treatments was markedly inferior to that in the treatments supplied with other forms of nitrogen. The sulphur concentration in the leaves was higher in the SO
4 series than in the Cl series, and the chlorine concentration in the leaves was higher in the Cl series than in the SO
4 series, irrespective of the forms of nitrogen and the kinds of vegetables tested.
In the third experiment of onion and turnip supplied with NaNO
3 or (NH
4)
2SO
4, the effects of SO
4 and Cl given as sodium salt on the growth were compared in the higher concentrations of 12-48me. The higher the concentration of SO
4 or Cl, the lower was the growth, however, there was no difference of growth between SO
4 and Cl series regardless of the forms of nitrogen supplied.
Finally, the effects of different concentrations of phosphorus on the growth of cabbage supplied with different forms of nitrogen were investigated. Growth was increased up to P 0.6me, however, further increase was not observed at P 3me both in NaNO
3 and NH
4NO
3 series. In (NH
4)
2SO
4 series growth was not affected by phosphorus concentration, and their growth was markedly inferior to ones in the other forms of nitrogen. Phosphorus concentration in the leaves became higher with increasing concentration of phosphorus supplied, irrespective of the forms of nitrogen, and was the highest in (NH
4)
2SO
4. However, phosphorus deficiency symptoms appeared on the plants both at P 0 and 0.2me, in any nitrogen form.
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