Crop model- and satellite imagery-based recommendation tool for variable rate N fertilizer application for the US Corn system

Zhenong Jin, Rishi Prasad, John Shriver, Qianlai Zhuang

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

Precision nitrogen (N) management for corn has gained popularity due to both economic and environmental considerations. There is sufficient evidence demonstrating that N fertilizer efficiency can be improved by implementing sidedress and variable rate fertilization. In this paper, a crop model- and satellite imagery-based decision-support tool for recommending variable rate N fertilization at a high resolution of 5 m × 5 m is introduced. The sub-field management zones were delineated by overlapping the soil survey geographic (SSURGO) soil map units with wide dynamic range vegetation index (WDRVI)-derived relative productivity zones. The calibrated Agricultural Production Systems sIMulator (APSIM) was used to simulate a range of soil N processes, corn growth and N uptake by assimilating real-time weather data from the National Climate Data Center (NCDC). Sidedress N rates were estimated based on the target rate, N loss via leaching and denitrification, plant uptake and leftover N in the soil. The tool was tested on a 66 ha corn field in Illinois, USA for the growing season of 2015. Results showed that N-Prescription was able to give reasonable management zone delineation and sidedress N recommendation. The recommended sidedress N ranged from 60 to over 120 kg ha−1. Corn yield was greater in areas with higher sidedress recommendation, but the benefit from sidedress decreased with the increasing rate and plateaued above 110 kg ha−1. Sensitivity analysis suggested that soil hydraulic properties and soil organic matter content were critical to the sidedress accounting. Corn growth, and hence the cumulative N uptake, can be well simulated by calibrating the WDRVI derived leaf area index. This tool could serve as a good foundation for further development in precision N management.

Original languageEnglish (US)
Pages (from-to)779-800
Number of pages22
JournalPrecision Agriculture
Volume18
Issue number5
DOIs
StatePublished - Oct 1 2017
Externally publishedYes

Keywords

  • Agricultural Production Systems sIMulator (APSIM)
  • Corn
  • Precision fertilization
  • SSURGO
  • Sidedress
  • Wide dynamic range vegetation index (WDRVI)

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