Estimation of the nutritive value of grasslands with the Yara N‐sensor field spectrometer

Abstract

Forage crops are a cornerstone of the agricultural industry in Nordic countries. Economic and ecological performances are directly linked to adapted farming practices, which require timed and precise information on the nutritive value of the forage. Field spectrometers could offer an interesting alternative to time‐consuming laboratory measurements, as they provide near real time information. We used a handheld version of a field spectrometer already commercialized for cereal adjustable rate fertilization, to evaluate its potential for grassland nutritive quality estimation. Spectral data and samples were acquired over experimental fields and plots in four locations in Northern Sweden; samples were analyzed using wet chemistry to determine the crude protein concentration, the in vitro true digestibility, the neutral detergent fiber and the neutral detergent fiber digestibility. Grid‐based adjusted spectral indices, partial least squares, random forest and support vector machine were tested to link the spectral data to the nutritive traits. Partial least squares and support vector machine outperformed the adjusted spectral indices and random forest. Best predictions were obtained with partial least squares for in vitro true digestibility and neutral detergent fiber (R2 of 0.64 and 0.78 and normalized root mean square error [nRMSE] of 2.1 and 8.0%, respectively) and with support vector machine for crude protein and neutral detergent fiber digestibility (R2 of 0.49 and 0.65 and nRMSE of 13.0 and 3.8%, respectively). These results suggests that there is a potential for this affordable, industry‐ready spectrometer to be used as a practical farming tool, although more comprehensive datasets are needed to ensure that robust models are developed.

Vallkonferens 2023

“…När dessa spektra används med lämpliga matematiska verktyg kan de härledas till relevant information för praktiska ändamål. Till exempel har flera studier redan bekräftat potentialen hos fältspektrometrar för att uppskatta vallars kvalitet (Morel et al, 2022;Parsons et al, 2020;Sun et al, 2021). Dessa studier utfördes dock mestadels på ett begränsat geografiskt område, vilket gjorde det svårt att validera robustheten hos de spektrometerbaserade modellerna.…”

Fractionation of mixed grass and clover stands using a leaf stripper

“…Improving field models could potentially be achieved by the inclusion of additional equipment, capable of predicting nutritive value. Field spectrometers have been shown to have success in estimating nutritive value(Morel et al, 2022;Zhou et al, 2019), however currently the price is an obstacle for practical application. Alternatively, NIR sensors or spectrometers mounted to the harvest machinery, such as John Deere's HarvestLab or Zeiss' Corona extreme, could allow for continual adjustment of leaf stripper settings based on nutritive value measurements in real time.The botanical composition of the sward, represented by the CF percent in this analysis, can be an important factor in determining the nutritive value of the LSF fraction and was included in three of the four field models (Table3).…”

Narrativas Médicas Sobre Feminilidade Nas Publicações Da Liga Brasileira De Higiene Mental (1925-1947)

“…A construção das condutas ocorre mediada pela percepção da diferença, isto é, do comparativo superioridade versus inferioridade, destacadamente, em relação aos marcadores gênero, raça e classe, considerados desqualificadores do brasileiro comum, pois "invertidos", "inferiores" e pobres. Qualquer desajuste ou ação contrária às preconizadas como "verdadeiramente saudáveis", física e mentalmente, poderiam acarretar intervenções médicas e jurídicas, além dos "medos sociais" (FERLA, 2005;FAUSTO, 2000;MONTEIRO;CARNEIRO, 2013).…”