Farming Systems Approaches to Concomitantly Increase Corn Yield and NUE.

Farming systems approaches to concomitantly increase corn yield and NUE

Azevedo A.J.C.B., Ciampitti I.A.

Improvement of N use efficiency (NUE) is one of the main grand challenges for closing corn yield gaps in the foreseeable future. Optimizing N application and utilization is essential for assisting key-stakeholders increasing crop productivity and environmental sustainability. Increasing NUE is approached via integration of best nutrient and crop production management practices. The overall goal of this study is to quantify corn yield response to fertilizer N application under diverse treatment factor combinations. The farming system approaches involved eight treatment combinations (replicated five times) of: fertilizer particle sizing (urea in “pellets” vs. regular urea fertilizer), rates, and application timing, row spacing (15 vs. 30”), and nitrification inhibitor (with/without). The study was located in two sites, Scandia (North Central Kansas) and Topeka (East Central Kansas), under full irrigation. Physiological traits were measured for early-growth (four-to-five leaf growth stage) conditions: light interception, canopy cover (imagery data), and shoot root mass and nutrient ratio. Further plant traits such as plant mass (fractions), nutrient content, and SPAD chlorophyll index were determined throughout the growing season (eight-leaf stage, flowering, and reproductive stages). In summary, more research information is needed as related to the interactions between fertilizer particle size, timing, N rates, nitrification inhibitor, and crop production practices (e.g. row spacing) for better understand how to improve NUE from a physiological viewpoint.