http://www.section179.org/
1 year deduction for production equipment across all industries. No real property unless a building that is purpose built for production. Irrigation equipment and wells qualify for 179. Machine shed doesn't.
If you applied 179 to land it would be to the detriment of the smaller farmer. It would help the rich who have the income to offset. When ag income is depressed it would further encourage people with high incomes to invest in farmland. | 
If you could section 179 land would you buy or sell?
