Abstract:

To study the effect of pH value regulators on peat pH value, available nutrients, and seedling growth of tomato and hot pepper, potassium carbonate and calcium oxide were applied under different levels. The available nutrients of peat under regulator application were analyzed, the correlation between the application rates of pH value regulators and the available nutrients was studied, and the seedling growth indexes of tomato and hot pepper were compared. The results showed that the pH value, available P and available K of peat increased with the level of potassium carbonate, and the exchangeable Ca, Mg, Mn and available Fe of peat decreased with the level of potassium carbonate. The pH value and the exchangeable Ca of peat increased with the level of calcium oxide, the exchangeable Mg of peat increased firstly and then decreased with the level of calcium oxide, and the exchangeable Mn and available Fe decreased with the level of calcium oxide rapidly. The growth indexes of tomato seedlings and hot pepper seedlings both increased firstly and then decreased with the level of potassium carbonate and calcium oxide. Potassium carbonate was better than calcium oxide for improving the seedling growth of tomato and hot pepper. The seedling growth was improved by 2, 4, 6 g/kg of potassium carbonate and 0.8, 1.6 g/kg of calcium oxide significantly. The pH value of them was pH 5.05, 5.93, 6.28, 5.29, and pH 6.08, respectively. Four kinds of models between pH value and CI were built, and the optimal pH value of the models was pH 5.64, 5.84, 5.61, and 5.76, respectively.

Key words: peat, pH value, potassium carbonate, calcium oxide, available nutrients, seedling growth