Author
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Schepers, James |
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Submitted to: Agronomy Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 7/15/2003 Publication Date: 10/1/2003 Citation: Schepers, J.S. 2003. In-season nitrogen management for corn. Agronomy Abstracts. #401758. CDROM Interpretive Summary: Technical Abstract: Many factors need to be considered when making recommendations for in-season N applications to corn. The major challenge is to recisely match available N (soil-supplied and fertilizer N) with crop needs, avoiding crop N stress while minimizing excess inorganic N in the soil system. Spatial variation in soil properties within most agricultural fields and temporal variations in climate, both which affect available soil N, add to this challenge. This makes it difficult in practice for farmers to evaluate these parameters for whole fields in a timely manner. Robust strategies are needed for making in-season fertilizer N recommendations based on the crop's physiological need for N and responsiveness to fertilizer. Use of aircraft imagery or ground-based sensors for assessing crop N status probably offers the best possibilities for timeliness of data acquisition and spatial resolution. Several types of ground-based sensors were compared with imagery to assess differences in N fertilizer recommendations on corn. Considerable research is needed to link fertilizer N recommendations during the growing season to crop vigor and N status. It is apparent that producers will require several options when adopting an in-season approach to N management. |