University of Tehran, College of Aburaihan Water and Irrigation Management 2251-6298 6 1 2016 04 20 Estimating dry biomass by leaf area index Estimating dry biomass by leaf area index 1 13 60878 10.22059/jwim.2016.60878 FA Abbas Sotoude Nia Journal Article 2015 10 19 Estimating dry biomass is one of the important parts of production estimation. Among vegetation indices, leaf area index (LAI) is the most common used index to estimate water demand and yield. In this study, attempts have made to estimate LAI without destroying plant and by using the AccuPAR-LP80 crop scanner device. The case study performed in Magsal Agro-Industrial Company Qazvin, Iran with the aim of introducing relations to estimate the amount of dry biomass via LAI for three plant- maize, sugar beet and alfalfa. LAI values of above mentioned plants measured through nondestructive method by calibrated AccuPAR-LP80 crop scanner. Statistical evaluation showed that the highest correlation was for maize with R² =0.96 and the lowest was for alfalfa with R² =0.87. In addition, measured dry biomass was a linear function of fraction of photosynthesis active radation (fPAR). Statistical evaluation showed that correlation coefficient varies from 0.94 to 0.90 and PMSE from 2.85 to 3.3 kg ha^-1for maize and alfalfa, respectively. Estimating dry biomass is one of the important parts of production estimation. Among vegetation indices, leaf area index (LAI) is the most common used index to estimate water demand and yield. In this study, attempts have made to estimate LAI without destroying plant and by using the AccuPAR-LP80 crop scanner device. The case study performed in Magsal Agro-Industrial Company Qazvin, Iran with the aim of introducing relations to estimate the amount of dry biomass via LAI for three plant- maize, sugar beet and alfalfa. LAI values of above mentioned plants measured through nondestructive method by calibrated AccuPAR-LP80 crop scanner. Statistical evaluation showed that the highest correlation was for maize with R² =0.96 and the lowest was for alfalfa with R² =0.87. In addition, measured dry biomass was a linear function of fraction of photosynthesis active radation (fPAR). Statistical evaluation showed that correlation coefficient varies from 0.94 to 0.90 and PMSE from 2.85 to 3.3 kg ha^-1for maize and alfalfa, respectively. https://jwim.ut.ac.ir/article_60878_07041af43912c3ade24ee395c6fd5e8d.pdf