PLEASE HELP 6. Fill in the blanks about the nitrogen cycle. Nitrogen from the atmosphere is fixed into a usable form in the soil by or by Sometimes little pockets of bacteria live in on plant roots, helping the plants get the nitrogen they need for their tissues. Once the pitrogen is fixed in the soil, plants will pick it up with their Animals will get their nitrogen by plants or other organisms in the food chain. When plants and animals die, the nitrogen will be returned to the soil by return nitrogen in the soil to the atmosphere by converting to gas.​