Better than burying wood: Make charcoal. Use the waste heat. Put the charcoal back in the soil, so you're not depleting it of phosphates, minerals, or nitrogen

Better than burying wood: Make charcoal. Use the waste heat. Put the charcoal back in the soil, so you're not depleting it of phosphates, minerals, or nitrogen. Repeat. Maybe you can even use the waste heat to run the Haber process.