One of the neatest tricks that I have been using for years is houseplant fertilizer spikes. These are inexpensive (I just bought a bunch at the dollar store) and cycads love them. Unlike most dry plant food, which you sprinkle on the surface and then just wash away, these go down into the root area. And not only do they bring in much needed food, they also loosen up the soil a bit to help bring in moisture. And these plant food spikes provide continuous release for two months, which is just perfect for cycads.
When to feed.
Cycads only grow once a year, in growth spurts called *flushes*. That's when the new leaves begin to emerge. That is the time to feed them. Feeding at any other time is just a waste of time and money. So, be prepared to feed them in the spring and early summer.
How to feed.
Grab a handful of these little spikes and push them in around the plant. Don't worry about hurting the roots - you won't. And if the soil is so hard that you can't push them in, push a hole about the same size and then insert the spike. And if the soil is that hard, chances are you haven't fed or watered the plant properly for years.
I also do foliar feeding with Miracle-Gro through a hose-end sprayer at about the same time. Now go feed your cycads!