Whose discussion question is this, anyway?

One of the courses I teach on a regular basis has a significant discussion component–after a two hour lecture each week, I and a group of about 20 students meet twice a week for 1.5 hours each to discuss the texts and lecture. I have found that I tend to develop a pattern of encouraging discussion on the questions I’m interested in, and somehow am not doing enough to generate discussion on students’ own questions and ideas. I am not doing this on purpose, but this pattern has inevitably developed each time I’ve taught this course (this is my third year doing so).

Each year I ask that students come to class ready with something to contribute to discussion, be it a question or a comment, related to the text or the lecture or earlier discussions or just the topic in general. And each year, by the middle of the year (it’s a year-long course), we have fallen into the pattern of no one having much to say but me. I ask at the beginning of each class if anyone has anything they’d like to ensure we talk about, and usually there is little to nothing. So then we go on to discuss the questions I have already planned.
I think I am discouraging them from taking the initiative in discussions without really recognizing that I am doing so (until I reflect on it, like I am doing now!). By having several things ready to talk about beforehand, and always moving straight into those when no one has anything else to say, I am setting in place a pattern where students can just wait and see what I want to discuss. They don’t have to take the initiative because I always do so. This is understandable, of course: if I don’t have anything ready, then we might just sit there looking at each other in uncomfortable silence. To avoid this, I have lots of discussion questions and topics ready to go. But it sets up a kind of self-fulfilling prophecy: out of concern that others won’t have much to say, I prepare a lot, thereby ensuring that others don’t need to have much to say and thus don’t do so.
Besides not knowing if what I am bringing up for discussion is engaging to them or not, and not encouraging the opportunity for them to come up with things to discuss that are, by guiding discussion in this way I am also setting up the expectation that they don’t need to really contribute that much overall. I am in charge of the topics we discuss, and since I’ve thought about them beforehand, I have the most to say about them. Students who are hearing these topics for the first time may not be as ready to talk about them as if they had thought them up on their own. Further, the atmosphere in the classroom tends to be less student-driven overall as a result: their only role is to respond to questions I bring up, and for many of them, not even that–too many students sit back passively for much of the time rather than taking an active part. And I am encouraging this by taking on the role of the one who is in charge of the discussion. Further, it can sound like I have something in mind that I want them to say in response to the topics I bring up (since I’ve thought about them beforehand), even though I try very hard to avoid these kinds of topics and questions and only ask open-ended ones that I don’t have a clear answer to myself.
How to remedy this situation? Some preliminary ideas:
1. Hold students to the requirement that they come to class with something to talk about, perhaps by calling on them, or asking them to turn in their question/topic/comment/idea in writing. Ideally, it would be good if they could do so before the seminar, so I could take these into account when planning the seminar meeting. I have tried something like this before with having a few students per day responsible for a question/topic for discussion, and requiring that they send this to me via email before our meeting. It worked fairly well, though often students have questions/comments that I myself have little to say about, and that don’t generate much discussion from others either. But at least it’s an attempt. In the previous course I just had each student responsible for one day out of the whole course (b/c there were many students); whereas for this course each one would have to have a question/comment about every 2-3 weeks. That might be doable, but it is still a fair bit of work for me when preparing the seminar if I get the questions beforehand.
2. I have tried in the past to have student presentations in this course, where each student is responsible for speaking for about 5 minutes, giving a question for discussion and some background on their views about it, why they came up with it/found it important, etc. This has only been partially successful. Rarely has it generated much discussion in other students, and instead it tends to be me and the student presenter discussing their question.
3. I might try to do something like the student presentations in #2 in small groups, where other students might be more comfortable responding, and more likely to take the initiative b/c I am not there to fill in the silence.
For the spring term for this course, I think I’ll try #3, and think about #1…