Estimation of nitrogen deficiency of sugar beet and wheat using parameters of laser induced and pulse amplitude modulated chlorophyll fluorescence

摘要

A dependable estimation of nitrogen status of field crops is important for an efficient usage of fertilisers. Remote sensing already uses spectral traits of plants to determine biomass and vitality of crops. The parameters of pulse amplitude modulated (PAM) and laser-induced chlorophyll fluorescence (LIF) techniques have been compared for the detection of nitrogen deficiency in leaves of sugar beet (Beta vulgaris L.) and winter wheat (Triticum aestivum L). Both methods were suitable to detect nitrogen deficiency in the tested species two Weeks following induced N-deficiency. At this time nitrogen and chlorophyll content of sugar beet leaves reached only 49 % and 40 % of N+ control plants and in wheat leaves nitrogen and chlorophyll content declined to 39 % and 48 % of the control treatment.