当前位置: X-MOL 学术Grassl. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Simple in‐field evaluation of moisture content in curing forage using normalized differece vegetation index (NDVI)
Grassland Science ( IF 1.3 ) Pub Date : 2020-02-18 , DOI: 10.1111/grs.12275
Jihyun Lim 1, 2 , Nariyasu Watanabe 1 , Rena Yoshitoshi 1 , Kensuke Kawamura 3
Affiliation  

Production of hay at a proper moisture level is critical to reduce the spontaneous heating and nutrient loss during the preservation phase. Herein, we explored a new method for estimating the moisture content (MC) of field curing forages that uses a portable spectroradiometer (400–900 nm) and a hand‐held normalized difference vegetation index (NDVI) meter. The spatial distributions were assessed by a multispectral camera with unmanned aerial vehicle (UAV) platform. Field spectral measurements were conducted daily at 10 random plots over six trials at four forage fields across the entire curing period. Multispectral imagery acquisition by UAV flights was conducted at one trial. The MC (wet basis) was determined using a forced‐air oven. For 400–900 nm spectral reflectance measured by the spectroradiometer, we conducted linear regression analyses between the MC and all available combinations of a normalized difference spectral index (NDSI(Band1, Band2) = (ρBand1 − ρBand2)/(ρBand1 + ρBand2), where ρλ is the apparent reflectance and λ is the wavelength in nm). The combinations that are generally used as greenness indices showed high coefficients of determination, for example, red and near infrared (R2 = .76, RMSE = 10.66%) and green and red (R2 = .81, RMSE = 9.57%). The NDVI meter and multispectral imagery showed the feasibility of NDVI (R2 = .79, RMSE = 8.58% and R2 = .89, RMSE = 6.74%, respectively) as a parameter to estimate the MC. We were able to verify the spatial variability of the MC in the field based on the NDVI imagery, which indicates that our method provides information for site‐specific management (e.g., partial swath manipulation) and for decision‐making regarding the harvest time and location.

中文翻译:

使用归一化植被指数(NDVI)对草料中的水分进行简单的现场评估

在适当的湿度水平下生产干草对于减少保存阶段的自发加热和养分流失至关重要。本文中,我们探索了一种使用便携式分光辐射计(400–900 nm)和手持式归一化植被指数(NDVI)仪估算田间固化草料的水分(MC)的新方法。通过具有无人飞行器(UAV)平台的多光谱相机评估空间分布。田间光谱测量每天在整个固化期间的四个草场上进行的六次试验中,随机选取10个样地进行。在一次试验中,进行了无人机飞行的多光谱图像采集。使用强制通风烤箱确定MC(湿基)。对于用分光辐射计测量的400–900 nm光谱反射率,(频带1,波段2)  =(ρ频带1  -  ρ波段2)/(ρ频带1  +  ρ波段2),其中ρ λ是表观反射率和λ是波长)。通常用作绿色指数的组合具有较高的测定系数,例如红色和近红外(R 2  = .76,RMSE = 10.66%)和绿色和红色(R 2  = .81,RMSE = 9.57%)。 。NDVI仪和多光谱图像显示了NDVI的可行性(R 2  = .79,RMSE = 8.58%和R 2 分别为0.89,RMSE = 6.74%)作为估算MC的参数。我们能够基于NDVI图像验证田间MC的空间变异性,这表明我们的方法为特定地点的管理(例如,部分条带操纵)以及有关收获时间和地点的决策提供了信息。
更新日期:2020-02-18
down
wechat
bug