I don't see anywhere in this IRS publication 225 that refers to the clearing of trees from farm land as a capital improvement. The sale of those trees are farm income, but I believe land clearing of those trees (stump removal) is a farm expense. Similar to clearing rocks from farm land to gain more acres/yield or taxable income. So for example fuel is expensed, rental equipment is expensed, purchased equipment is depreciated. Let me know if you learn anything different.
Here's a link for you to review this Farmers Tax Guide;
https://www.irs.gov/pub/irs-pdf/p225.pdf
