If you are prepared to continue to add organic matl. to the soil such as frequent applications of compost or mulching after tilling then I don't think it's an issue IMO. Observe the plants you put in after tilling & amending, they will tell you if nitrogen is a problem. This will get you closer to the earth into which you plant & besides learning as you go is part of the kick of all this "gardening" :)

Hello Mesquieteman,welcome to GW . Rather than suggesting till in or reuse , I will explain the issue so that you may choose which is best for you and your garden. You are correct in not equateing the shells to wood chips. It requires about 3 times as long to compost pecan shells as it does for oak,pecan,elm,ash and other common chips. That means nitrogen depletion will not be an issue. Pulled aside and reused,they will easly last another 2 year and depending on enviormential conditions,up to 5 years. I see it as doing what is easiest but I would add leaves,grass clippings or horse/cow manure to speed the process of composting the shells. Since you mentioned concurn over N depletion,keep this simple principl in mind. The faster high carbon material rots,the more N required to support the process. The more surface area exposed,the faster material rots. A dozen 1 Lb chunks of wood buried in the ground will rot slower and have less efect on N than 12 Lbs of wood chips. Saw dust rots faster than chips and effects N more. Good luck on the upcoming growing season.

Paleogardener, thank you for your thoughts!

Klem1, thank you for laying it out like that! I believe I will save them for re-use as it appears, from your information, that they may not provide much benefit to my soil and I might as well save the money and not have to buy more! I now know, though, that I don't need to worry about trying to get them all up. If I am reading it right, I could get up as much as is easy to get, then just till in the rest.

Anyone know of a benefit the pecan shells will have in the soil? My soil is already rich and when tested last year, was too high in most everything. We do have a high PH here and I have read that pecan shells will naturally, over time, help reduce the ph since they are acidic.

NO. While pecan shells may have a nutrient analysis of about 1% N, and much less P and K the Carbon to Nitrogen ratio is so high it would take years for the Soil Food Web to digest them and that might tie up some N that your plants may need while that is happening.
Like any other organic matter pecan shells will have little to no significant affect on soil pH. Most of what I have been able to find about using pecan shells in the soil involves converting them to bio char first.

I live in apecan production area. So pecan mulch is cheap and plentiful. It's very arid here so even shredded bark etc is slow to break down. I've has pine bark in large chunks out front that are 15 years old still fine. Here the main purpose of mulch is to retain moisture. many people dump gravel everywhere and call it a xeriscape but that just makes your house hotter.

Everything you do gardening should be adjusted for your specific climate.

Something to keep in mind regarding pecan hulls, or any product from a pecan tree, is that they produce the highly allelopathic compound juglone , just as other members of that plant family (Juglandaceae) do. Most plants are not affected by juglone, but those that are really won’t like the pecan hulls. It’s your job to match the plants in your garden to potential sensitivity, as easy task with all of the literature readily available online.

Another comment about the tilling. I have a heavy clay native soil. My first year of vegetable growing was the only one where tilling was done. I added a great deal of pine bark fines as well as mixed wood chips dropped off by a tree removal company, tilled it in and planted. In subsequent years, all I have done is apply a three inch layer of wood chips on top of the soil and watch the earthworms do the work of tilling.