Leaf Area Index (LAI) portable meter

Leaf Area Index (LAI) meter MIJ-15 LAI/P

Overview

Measurements of Leaf Area Index (LAI) divided into two types direct and estimating measurements. 
Measuring by Reaping or  leaf litter trap is the direct measurement. 
By estimating leaf volume and light decay based on optical estimation by using hemispherical photograph is the estimating measurement.

Disadvantage of major Plant Canopy analyzer 

1.
To see the LAI results, we will need to have two plant Canopy analyzers; this is because LAI result  must need to compare the transmission of light ratio both inside and outside canopy at the same time.  This means, it is depending on the absolute value of inside and outside light; thus the at least two instruments need to set at inside and outside.

2.
There is no stable atmosphere condition so researchers must care solar radiation intensity every single test. In fact, solar radiation intensity is mostly stable at cloudy weather but do you want to choose cloudy weather for field experiments? Even though solar radiation intensity is stable at cloudy weather condition, you still need to care the sun height, to gain the good LAI results. To do so  instruments need to place at same sun height. But can you keep setting at same height?  

3.
Do you know Plant Area Index (PAI) influencing LAI results? 
This is because general LAI sensor involve branch and dead leaves these elements cannot called leaf but major LAI meter ignoring  the fact that these obstacles messing LAI results so it is impossible to correct exact LAI value.

MIJ-15LAI Sensors

MIJ-15LAI/P and MIJ-15LAI Type2/K2 will be able to let researcher to determine quantity of LAI by measuring the spectral ratio of sunlight transmitted through plant canopy.
How?
We used the measurement by spectroscopy.
(Patented NO.JP5410323B22014.2.5)
PAR(400-700nm) and NIR(700-1000nm) will be reflect and absorption occur at chlorophyll inside leaf so the transmitted light ratio is correlated with LAI.
MIJ-15 LAI/P and MIJ-15LAI Type II/K2 gives numerous hopes for the feature research.
You do not need to think about weather condition and LAI and PAR can be measured  just set under the canopy or leaf. Also you only need to have one MIJ-15LAI Type II/P so price will be reasonable compare to other LAI instruments and it is portable so you can measure easily or traditionally set it under canopy; LAI annual change can be measured with data logger .

Features

The world’s only sensor that adopted the relationship that the spectral ratio of PAR and IR correlates with LAI

Regardless of cloudy weather, fine weather, instantaneous LAI measurement on the spot has been completed

Capable of Exact LAI measurement: counting only live leaves

No PAI (Plant Area Index) counting so avoiding influences from dead leaves, branches, trunks remain

Portable

Related Product

MIJ-15 LAI/K2 Stationary type

Specifications

Display 1. LAI, 2. NIR, 3. PAR, 4. Battery voltage 
Regression eq.  LAI=2.80In(NIR/PAR)+0.69
Unit NIR and PAR / uE (μmol∝S-1∝m-2)LAI / Dimensionless
Operating Temperature -25 to 60 Degree 
Data storage 125,000 data 
Battery 4AA
Shape Sensor :126(W), 49(H), 60(D)  (W/O Gun grip) 
Logger80(W), 189(H), 35(D) 
Cable length Around 1.5m
Weight 1250 grams, 3500grams (Full package) 

Reference for MIJ-15LAI series (written in English or Japanese)

A canopy photosynthesis model based on a highly generalizable artificial neural network incorporated with a mechanistic understanding of single-leaf photosynthesis
Relationship between Canopy Structure and Community Structure of the Understory Trees in a Beech Forest in Japan
Usability of time-lapse digital camera images to detect characteristics of tree phenology in a tropical rainforest
Development of a Nocturnal Temperature Inversion in a Small Basin Associated with Leaf Area Ratio Changes on the Mountain Slopes in Central Japan
放棄二次林におけるアズマネザサの刈り取りが草本層植物の生長・着花・結実に及ぼす影響
光合成有効放射と近赤外放射の透過光の比と水稲の生育指標の相関
アズマネザサの刈り取りが放棄二次林の林床植生に与える影響
LED Lighting for Urban Agriculture 2016/11/17 (本にて出版)
名古屋大学 2020 3月 プレスリリース
Evaluation of Spatial Light Environment and Plant Canopy Structure
Distributions of photosynthetic traits, shoot growth, and anti-herbivory defence within a canopy of Quercus serrata in different soil nutrient conditions
Correlation Network Analysis Visually Identifies Interactions of Antioxidant Compounds with Plant Growth, Leaf Photosynthetic Performance, and Agronomic Quality in Strawberry
冷温帯落葉広葉樹林におけるLAI季節変化 Seasonal variation in LAI from a cool-temperate deciduous broadleaved forest
Howdorubber(Heveabrasiliensis)plantationsbehaveunderseasonalwaterstressinnortheasternThailandandcentralCambodia?
The ratio of transmitted near-infrared radiation to photosynthetically active radiation (PAR) increases in proportion to the adsorbed PAR in the canopy
NIR・PAR の連続測定による生育期間を通じたイネ群落 LAI の非破壊計測法の開発
2008年度 九州大学森林生態圏管理学講座(演習林) 研究発表会 プログラム
Novel technique for non-destructive LAI estimation by continuous  measurement of NIR and PAR in rice canopy – ScienceDirect