Capability of crop canopy sensing to predict crop parameters of cut grass swards aiming at early season variable rate nitrogen top dressings

Abstract

This study aims to evaluate actual biomass and N-uptake estimates with the Yara N-Sensor in intensively managed grass swards across several trial sites in Europe. The dataset was split by location into an independent calibration data (UK and Finland) and a validation data (Germany) for the first two cuts. Yara N-Sensor readings were better correlated with N-uptake (R²=0.71) than actual biomass (R²=0.53) for the 1ˢᵗ cut. At the 2ⁿᵈ cut, the R² values for both parameters were higher (0.80 and 0.56). A cross-validation with a German grass trial indicated the potential for predicting N-uptake (R²>0.8). It can be concluded that the technology has the potential to guide management decisions and variable rate nitrogen application on European grass swards.