Çim bitkisinin azot ve su içeriği tahmini için Renk ölçer ve NDVI ölçerin karşılaştırılması

Abstract

Aims: Nitrogen content (NC) and water content (WC) of turfgrass is traditionally determined by laboratory analysis which is time-consuming, tiresome, laborious and costly. The aim of this study was to examine the suitability of two hand held optical instruments (GreenSeeker NDVI meter and chromameter) to evaluate NC and WC of turfgrass.Methods and Results: Six turfgrass plots of 1 m x 1 m with a mixture of five different species were used and variable rate nitrogen fertilizer (N0: 0 g N m-2, N1: 2.5 g N m-2, N2: 5 g N m-2) was applied. NDVI measurements were taken at around noon with a GreenSeeker NDVI instrument from the plots. After mowing, the color values of the clippings were measured using a hand-held chromameter. The data were analyzed using correlation and partial least square regression (PLSR). A high correlation was found between leaf NC, WC, NDVI and color values. The leaf NC (%) can be estimated from the NDVI (R2val=0.73, SEP=0.19%) and color values (L*a*b*C*h°) (R2val=0.76; SEP=0.18%). Also, it was found that the WC (%) can be predicted from the NDVI (R2val=0.40, SEP=5.07%) and color values (L*C*h°) (R2val=0.69; SEP=3.67%) with slightly lower accuracy.Conclusions: Turfgrass leaf NC can be estimated with either an NDVI instrument (R2=0.73, SEP=0.19%) or a chromameter (R2=0.76, 0.18%) with reasonable accuracy in a more objective and economical way.Significance and Impact of the Study: Considering the reduction in time and cost required in the NC and WC analysis, we think that results of this study may be useful for turf field managers. Also, nitrogen determination with sensors will be a more eco-friendly way if used by managers.