Nitrogen is extremely volatile in the soil. Some soil tests gained’t even show nitrogen results. Soil tests that do suggest the amount of nitrogen may perhaps only exhibit nitrogen that is immediately available to vegetation.S? d?ng phân NPK ?úng cách và theo li?u l??ng khuy?n ngh? có th? giúp ng??i tr?ng cây ??t ???c k?t qu? t?t h?n trong