Effects of magnesium slag-based Si-K fertilizer on salty soil fertility and growth of Brassica campestris L.

Magnesium slag-based Si-K fertilizer is synthesized by magnesium slag with potassium carbonate （K2CO3）at high temperature. It contains a variety of mineral components such as K，Si，Ca，Mg，etc. A pot experiment was set to explore the effects of magnesium slag-based Si-K fertilize on soil fertility and the growth of plant. Results showed that the available K，slow available K and effective Si content increased by 64.80%，33.43% and 18.85% in the salty soil by applying 2 g/kg magnesium slag-based Si-K fertilizer，meanwhile fresh weight and leaf K content of Brassica campestris L. were significantly promoted compared to that of control. Applying magnesium slagbased Si-K fertilizer could promote the growth and K selective absorption of B. campestris L. by improving the available K content and effective Si content in the soil. However，the pH and heavy metal content of soil were influenced significantly by applying excessive magnesium slag-based Si-K fertilizer. Moderate or acidic medium should be selected to mix with magnesium slag slow-release fertilizer in the long-term fertilization，aiming to play an important role in soil amelioration and fertility enhancement.