Using remote sensing techniques and vegetation indices (Normalized Difference Vegetation Index-NDVI) to assess nitrogen management in durum wheat (Triticum durum L.)

Abstract

Nitrogen (N) is the most abundant crop nutrient used in crop production for almost all crops worldwide. Much research has been done to establish N management methodologies, using simple but reliable tools. Remote sensing has emerged recently as a set of tools, which are becoming very popular in N management This study aims to evaluate differences in crop productivity caused by various Nitrogen (N) fertilization rates by using remote sensing techniques and vegetation indices (Normalized Difference Vegetation Index - NDVI) to assess nitrogen management in durum wheat (Triticum durum L.). A specific objective is to evaluate the use of this tool for evaluating the Nitrogen Use Efficiency (NUE) in a wheat field. A number of N rates were applied in a wheat field and various time period data were recorded with a handheld NDVI sensor (Trimbler Greenseeker). Yield was measured for each N application part of the field. The yield and N rates were used to calculate Nitrogen Use Efficiency (NUE). A mapping software (SURFER®) was used to create NDVI maps, to relate these with Management Zones, in a part of Precision agriculture methodologies used in this study. Also, important soil properties affecting crop growth and productivity such as pH and Electrical Conductivity (EC) were measured across the field. Results have shown that N rates affected yield and NUE and the use of this sensor could be a very valuable tool in the future to further manage N application rates, in order to provide a more sustainable management of wheat and consequently other crops.