Calibration of GrassMaster II to estimate green and dry matter yield in Mediterranean pastures: effect of pasture moisture content
João Serrano A B , Shakib Shahidian A and José Marques da Silva A
+ Author Affiliations
- Author Affiliations
A ICAAM, University of Évora, PO Box 94, 7002-554 Évora, Portugal.
B Corresponding author. Email: jmrs@uevora.pt
Crop and Pasture Science 67(7) 780-791 https://doi.org/10.1071/CP15319
Submitted: 17 January 2015 Accepted: 29 January 2016 Published: 7 July 2016
Abstract
Accurate assessment of standing pasture biomass in livestock production systems is a major factor for improving feed planning. Several tools are available to achieve this, including the GrassMaster II capacitance meter. This tool relies on an electrical signal, which is modified by the surrounding pasture. There is limited knowledge on how this capacitance meter performs in Mediterranean pastures. Therefore, we evaluated the GrassMaster II under Mediterranean conditions to determine (i) the effect of pasture moisture content (PMC) on the meter’s ability to estimate pasture green matter (GM) and dry matter (DM) yields, and (ii) the spatial variability and temporal stability of corrected meter readings (CMR) and DM in a bio-diverse pasture. Field tests were carried out with typical pastures of the southern region of Portugal (grasses, legumes, mixture and volunteer annual species) and at different phenological stages (and different PMC). There were significant positive linear relations between CMR and GM (r2 = 0.60, P < 0.01) and CMR and DM (r2 = 0.35, P < 0.05) for all locations (n = 347). Weak relationships were found for PMC (%) v. slope and coefficient of determination for both GM and DM. A significant linear relation existed for CMR v. GM and DM for PMC >80% (r2 = 0.57, P < 0.01, RMSE = 2856.7 kg ha–1, CVRMSE = 17.1% to GM; and r2 = 0.51, P < 0.01, RMSE = 353.7 kg ha–1, CVRMSE = 14.3% to DM). Therefore, under the conditions of this current study there exists an optimum PMC (%) for estimating both GM and DM with the GrassMaster II. Repeated-measurements taken at the same location on different dates and conditions in a bio-diverse pasture showed similar and stable patterns between CMR and DM (r2 = 0.67, P < 0.01, RMSE = 136.1 kg ha–1, CVRMSE = 6.5%). The results indicate that the GrassMaster II in-situ technique could play a crucial role in assessing pasture mass to improve feed planning under Mediterranean conditions.
Additional keywords: indirect forage mass evaluation, precision agriculture, site-specific management.
References
Aiken GE, Bransby DI (1992) Observer variability for disk meter measurements of forage mass. Agronomy Journal 84, 603–605.| Observer variability for disk meter measurements of forage mass.Crossref | GoogleScholarGoogle Scholar |
Blackmore S (2000) The importance of trends from multiple yield maps. Computers and Electronics in Agriculture 26, 37–51.
| The importance of trends from multiple yield maps.Crossref | GoogleScholarGoogle Scholar |
Cauduro GF, Carvalho P, Barbosa C, Lunardi R, Pilau A, Freitas F, Silva J (2006) Comparision of indirect methods for measuring forage mass under annual ryegrass ((Lolium multiflorum Lam.)). Ciência Rural 36, 1617–1623.
| Comparision of indirect methods for measuring forage mass under annual ryegrass ((Lolium multiflorum Lam.)).Crossref | GoogleScholarGoogle Scholar |
Currie PO, Hilken TO, White RS (1987) Evaluation of a single probe capacitance meter for estimating herbage yield. Journal of Range Management 40, 537–541.
| Evaluation of a single probe capacitance meter for estimating herbage yield.Crossref | GoogleScholarGoogle Scholar |
Donald GE, Scott JM, Vickery PJ (2013) Satellite derived evidence of whole farmlet and paddock responses to management and climate. Animal Production Science 53, 699–710.
| Satellite derived evidence of whole farmlet and paddock responses to management and climate.Crossref | GoogleScholarGoogle Scholar |
Efe Serrano J (2006) ‘Pastures in Alentejo: technical basis for characterization, grazing and improvement.’ (Ed. Universidade de Évora ICAM) (Gráfica Eborense: Évora, Portugal)
ESRI (2009) ArcView 9.3. GIS Geostatistical Analyst. Environmental Systems Research Institute, Redlands, CA, USA.
Fricke T, Richter F, Wachendorf M (2011) Assessment of forage mass from grassland swards by height measurement using an ultrasonic sensor. Computers and Electronics in Agriculture 79, 142–152.
| Assessment of forage mass from grassland swards by height measurement using an ultrasonic sensor.Crossref | GoogleScholarGoogle Scholar |
Ganguli A, Vermeire L, Mitchell R, Wallace M (2000) Comparison of four nondestructive techniques for estimating standing crop in shortgrass plains. Agronomy Journal 92, 1211–1215.
| Comparison of four nondestructive techniques for estimating standing crop in shortgrass plains.Crossref | GoogleScholarGoogle Scholar |
Hanna M, Steyn-Ross D, Steyn-Ross M (1999) Estimating biomass for New Zealand pasture using optical remote sensing techniques. Geocarto International 14, 89–94.
| Estimating biomass for New Zealand pasture using optical remote sensing techniques.Crossref | GoogleScholarGoogle Scholar |
Hirata M (2000) Quantifying spatial heterogeneity in herbage mass and consumption in pastures. Journal of Range Management 53, 315–321.
| Quantifying spatial heterogeneity in herbage mass and consumption in pastures.Crossref | GoogleScholarGoogle Scholar |
Hutchings NJ (1991) Spatial heterogeneity and other sources of variance in sward height as measured by the sonic and HFRO sward sticks. Grass and Forage Science 46, 277–282.
| Spatial heterogeneity and other sources of variance in sward height as measured by the sonic and HFRO sward sticks.Crossref | GoogleScholarGoogle Scholar |
Jamieson PD, Porter JR, Wilson DR (1991) A test of the computer simulation model ARCWHEAT1 on wheat crops grown in New Zealand. Field Crops Research 27, 337–350.
| A test of the computer simulation model ARCWHEAT1 on wheat crops grown in New Zealand.Crossref | GoogleScholarGoogle Scholar |
Karl MG, Nicholson RA (1987) Evaluation of the forage disk method in mixed grass rangeland in Kansas. Journal of Range Management 40, 467–471.
| Evaluation of the forage disk method in mixed grass rangeland in Kansas.Crossref | GoogleScholarGoogle Scholar |
King WM, Rennie GM, Dalley DE, Dynes RA, Upsdell MP (2010) Pasture mass estimation by the C-DAX Pasture meter: Regional calibrations for New Zealand. In ‘Proceedings 4th Australasian Dairy Science Symposium’. pp. 233–238. (Caxton Press: Christchurch, New Zealand)
Laca EA, Demment MW, Winckel J, Kie JG (1989) Comparison of weight estimate and rising-plate meter methods to measure herbage mass of a mountain meadow. Journal of Range Management 42, 71–75.
| Comparison of weight estimate and rising-plate meter methods to measure herbage mass of a mountain meadow.Crossref | GoogleScholarGoogle Scholar |
McCormick S, Jordan C, Bailey J (2009) Within and between-field spatial variation in soil phosphorus in permanent grassland. Precision Agriculture 10, 262–276.
| Within and between-field spatial variation in soil phosphorus in permanent grassland.Crossref | GoogleScholarGoogle Scholar |
Ogura S, Hirata M (2001) Two-dimensional monitoring of spatial distribution of herbage mass in a bahia grass (Paspalum notatum Flugge) pasture grazed with cattle. Grassland Science 47, 453–459.
Peralta NR, Costa JL (2013) Delineation of management zones with soil apparent electrical conductivity to improve nutrient management. Computers and Electronics in Agriculture 99, 218–226.
| Delineation of management zones with soil apparent electrical conductivity to improve nutrient management.Crossref | GoogleScholarGoogle Scholar |
Reese G, Bayn R, West N (1980) Evaluation of double-sampling estimators of subalpine herbage production. Journal of Range Management 33, 300–306.
| Evaluation of double-sampling estimators of subalpine herbage production.Crossref | GoogleScholarGoogle Scholar |
Sanderson MA, Rotz CA, Fultz SW, Rayburn EB (2001) Estimating forage ass with a commercial capacitance meter, rising plate meter, and pasture ruler. Agronomy Journal 93, 1281–1286.
| Estimating forage ass with a commercial capacitance meter, rising plate meter, and pasture ruler.Crossref | GoogleScholarGoogle Scholar |
Schellberg J, Hill MJ, Gerhards R, Rothmund M, Braun M (2008) Precision agriculture on grassland: Applications, perspectives and constraints. European Journal of Agronomy 29, 59–71.
| Precision agriculture on grassland: Applications, perspectives and constraints.Crossref | GoogleScholarGoogle Scholar |
Scrivner JH, Center DM, Jones MB (1986) A rising plate meter for estimating production and utilization. Journal of Range Management 39, 475–477.
| A rising plate meter for estimating production and utilization.Crossref | GoogleScholarGoogle Scholar |
Serrano J, Peça J, Marques da Silva J, Shahidian S (2011) Calibration of a capacitance probe for measurement and mapping of dry matter yield in Mediterranean pastures. Precision Agriculture 12, 860–875.
| Calibration of a capacitance probe for measurement and mapping of dry matter yield in Mediterranean pastures.Crossref | GoogleScholarGoogle Scholar |
Sharrow S (1984) A simple disc meter for measurement of pasture height and forage bulk. Journal of Range Management 37, 94–95.
| A simple disc meter for measurement of pasture height and forage bulk.Crossref | GoogleScholarGoogle Scholar |
Shi Z, Wang K, Bailey JS, Jordan C, Higgins AH (2002) Temporal changes in the spatial distributions of some soil properties on a temperate grassland site. Soil Use and Management 18, 353–362.
| Temporal changes in the spatial distributions of some soil properties on a temperate grassland site.Crossref | GoogleScholarGoogle Scholar |
Silva SC, Cunha WF (2003) Indirect methods for estimating herbage mass in Cynodon spp. swards. Pesquisa Agropecuaria Brasileira 38, 981–989.
Stockdale C, Kelly K (1984) A comparison of a rising-plate meter and an electronic capacitance meter for estimating the yield of pastures grazed by dairy cows. Grass and Forage Science 39, 391–394.
| A comparison of a rising-plate meter and an electronic capacitance meter for estimating the yield of pastures grazed by dairy cows.Crossref | GoogleScholarGoogle Scholar |
Suzuki Y, Okamoto H, Takahashi M, Kataoka T, Shibata Y (2012) Mapping the spatial distribution of botanical composition and herbage mass in pastures using hyperspectral imaging. Grassland Science 58, 1–7.
| Mapping the spatial distribution of botanical composition and herbage mass in pastures using hyperspectral imaging.Crossref | GoogleScholarGoogle Scholar |
Trotter M (2010) Precision agriculture for pasture, rangeland and livestock systems. In ‘Food security from sustainable agriculture. Proceedings 15th Australian Agronomy Conference. 15–18 November, Lincoln, New Zealand. (Australian Society of Agronomy, The Regional Institute: Gosford, NSW)
Trotter MG, Schneider D, Lamb D, Edwards C, McPhee M (2012) Examining the potential for active optical sensors to provide biomass estimation in improved and native pastures. In ‘Capturing opportunities and overcoming obstacles in Australian agronomy. Proceedings 16th Australian Agronomy Conference’. 14–18 October, University of New England, NSW. (Australian Society of Agronomy, The Regional Institute: Gosford, NSW)
Tsutsumi M, Itano S (2005) Variant of estimation method of above-ground plant biomass in grassland with gamma model 1. Use of an electronic capacitance probe. Grassland Science 51, 275–279.
| Variant of estimation method of above-ground plant biomass in grassland with gamma model 1. Use of an electronic capacitance probe.Crossref | GoogleScholarGoogle Scholar |
Vickery PJ, Nicol GR (1982) An improved electronic capacitance meter for estimating pasture yield: construction details and performance tests. Animal Research Laboratories technical paper, no. 9. pp. 1–22.
Virkajarvi P (1999) Comparison of three indirect methods for prediction of herbage mass on timothy-meadow fescue pastures. Soil and Plant Science 49, 75–81.
Vrindts E, Mouazen A, Reyniers M, Maertens K, Maleki MR, Ramon H, De Baerdemaeker J (2005) Management zones based on correlation between soil compaction, yield and crop data. Biosystems Engineering 92, 419–428.
| Management zones based on correlation between soil compaction, yield and crop data.Crossref | GoogleScholarGoogle Scholar |
Xu HW, Wang K, Bailey J, Jordan C, Withers A (2006) Temporal stability of sward dry matter and nitrogen yield patterns in a temperate grassland. Pedosphere 16, 735–744.
| Temporal stability of sward dry matter and nitrogen yield patterns in a temperate grassland.Crossref | GoogleScholarGoogle Scholar |
Zanine AM, Santos EM, Ferreira DJ (2006) Main methodologies for evaluation of pastures. Revista Electrónica de Veterinaria VII, 1–13.
