Specific response of Phyllostachys edulis seedling to NH₄⁺

Phyllostachys edulis seedlings were used as experimental materials, under indoor controlled pot conditions, NH₄⁺ nitrogen compounds of(NH₄)₂SO₄, NH₄Cl and NH₄NO₃ with equal nitrogen concentration(8mM) were set up, and K₂SO₄, NaCl , NaNO₃, KNO₃ and blank treatment(CK) were used as controls, to study the effects of different treatments on P. edulis seedling growth index and cultivation matrix pH. The results showwd that: 1) Growth indexes(seedling height, leaf number, tillering), relative chlorophyll content(SPAD value), root configuration indexes(root length, root surface area, root volume, mean root diameter and root tip number), above-ground, below-ground and total biomass of P. edulis seedlings treated with NH₄⁺ compounds((NH₄)₂SO₄, NH₄Cl, NH₄NO₃) were significantly better than that treated with other compounds(K₂SO₄, NaCl, NaNO₃ and KNO₃)(P < 0.05), but there were no significant differences between the NH₄⁺ compounds treated seedlings; 2) The root shoot ratios of bamboo seedlings treated with NH₄⁺ compounds were significantly lower than that of CK and the NaCl treated seedlings; 3) Culture substrate pH values under NH₄⁺ compound teratments were significantly lower than that of CK and the other compound treatments. Therefore, the present results showed that the NH₄⁺ ion within NH₄⁺ compounds had significant promotion effects on the growth of P. edulis seedlings, and its promotion effect might be related to the reduced culture substrate pH value. Therefore, ammonium nitrogen fertilizer sucha as ammonium sulfate or ammonium chloride should be better applied in the cultivation process of P. edulis seedlings.