caa a22 4500 445864400 CHVBK 20180317145453.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s11119-011-9227-4 doi (NATIONALLICENCE)springer-10.1007/s11119-011-9227-4 Calibration of a capacitance probe for measurement and mapping of dry matter yield in Mediterranean pastures [Elektronische Daten] [João Serrano, José Peça, J. Marques da Silva, Shakib Shahidian] The main objective of this study was to calibrate a commercial capacitance probe for measuring pasture dry matter yields under Mediterranean conditions. The standard method of assessing pasture biomass is based on cutting all the forage within a specified area and requires great effort and expense to collect enough samples to accurately represent a pasture. The field tests were carried out in 2007, 2008 and 2009 on different dates (phenological stages), and on five dairy farms, representing typical pastures in the region (grasses; legumes; and bio-diverse flora, mixture of grasses, legumes and others species). The linear regression techniques used in 2007 to relate the weight of the herbage (direct measurements) to the meter reading of capacitance (indirect measurements) led to high regression coefficients in grasses (R2=0.90; P<0.01) and heterogeneous botanical composition (R2=0.87; P<0.001) and moderate regression coefficient in legumes species (R2=0.48; P<0.05). The validation of the calibration equations in 2008 and 2009 in two sites showed RSME values of 130kgha−1 in heterogeneous botanical composition and 456kgha−1 in legumes. The results indicated that the capacitance probe together with a GPS receiver might support site-specific management of pastures which would be useful in large areas. Springer Science+Business Media, LLC, 2011 Calibration nationallicence Capacitance probe nationallicence Pastures nationallicence Serrano João ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut Peça José ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut Marques da Silva J. ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut Shahidian Shakib ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut Precision Agriculture Springer US; http://www.springer-ny.com 12/6(2011-12-01), 860-875 1385-2256 12:6<860 2011 12 11119 https://doi.org/10.1007/s11119-011-9227-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11119-011-9227-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Serrano João ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut NATIONALLICENCE 700 1- Peça José ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut NATIONALLICENCE 700 1- Marques da Silva J. ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut NATIONALLICENCE 700 1- Shahidian Shakib ICAAM, Rural Engineering Department, University of Évora, 7000, Évora, Portugal aut NATIONALLICENCE 773 0- Precision Agriculture Springer US; http://www.springer-ny.com 12/6(2011-12-01), 860-875 1385-2256 12:6<860 2011 12 11119 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer