Adequate • Application • Atmosphere • Atmospheric • Availability • Back • Based • Chlorophyll • Compaction • Compete • Convert • Converted • Crop • Crops • Cycle • Development • Dioxide • Does • Effect • Factor • Fixing • Groundwater • Growth • How • Levels • Living • Matter • Minerals • Most • Much • Necessary • Nitrogen • One • Organisms • Phase • Plant • Primary • Rate • Relationship • Rely • Role • Root • Source • Terminated • Transpiration • Used • Varies • When • Which • Yields