# Which Farm Crops Are Most Efficient at Reducing Local CO2?

The presence of nearby rainforest is known to measurably deplete the local atmospheric $$\small\mathsf{CO_2}$$ content, but how much would $$\small\mathsf{CO_2}$$-hungry crops reduce local $$\small\mathsf{CO_2}$$ and which crop would deplete it most? My guess is that maize would be among the most $$\small\mathsf{CO_2}$$-hungry crops. Could anything compete with rainforest?

• Dry biomass produced per hectare per year is a first-order approximation to the amount of CO₂ removed from the air. However, woody and non-woody crops with high yield such as poplar, elephant grass (miscanthus), or sugar cane are often grown specifically for the production of renewable energy, thus there is at best a minimal sequestration effect from residual plant matter being plowed into the ground etc. You may want to clarify the question as to whether you are looking for the highest rate of (short-term) CO₂ removal, or are interested in long-term sequestration aspects. – njuffa Nov 15 '19 at 18:54
• Yes, but corn,sugar cane or some other crop can be harvested year after year. Some climates can support 3 or 4 harvests per year. Unfortunately, farm crops make a very poor habitat for wildlife. – Michael Walsby Nov 15 '19 at 18:55
• I'm asking about the short term effects, but if the land is worked for a hundred years, the short term effect becomes a long term effect. I'm certainly not saying it would be a good thing to cut down the rain forest and replace it with agriculture. – Michael Walsby Nov 15 '19 at 19:02
• If you are talking about the rate of photosynthesis, the map here suggests that rainforests win. – Keith McClary Nov 16 '19 at 1:59