Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Precision agriculture

Developing digital tools that combine proximal sensors, GPS and GIS for mapping and monitoring our soils and landscapes. These tools provide paddock–scale detail of spatial variability – the information required for optimising resource use in our productive landscapes.

Proximal sensors

Proximal sensor research includes evaluating the potential of selected sensors for non–destructive field assessment of soils. Vis–NIR spectrometry is being trialled in the field to collect diffuse reflectance soil spectra which are then used to assess specific soil properties, e.g. soil carbon and nitrogen. Also an electromagnetic (EM) sensor is being trialled for soil mapping.

Monitoring and mapping of soils and landscapes at the paddock scale

An electromagnetic sensor is being used in a mobile system with GPS, dataloggers and on–board computer, for soil mapping. This rapid technique provides information about soil spatial variability – a prerequisite for precision agriculture. EM–derived maps are being assessed as a rapid reconnaissance soil mapping tool, and also for their ability to be used for site–specific management by identifying management zones.

Optimising irrigation water use efficiency

Our research is using EM–derived maps to predict soil available water holding capacity spatially across the landscape, by developing relationships between EM, soil moisture and soil texture. The research aims to fine–tune application of irrigation waters – optimising its use and minimising losses below the rooting zone.


  • Hedley C, Ekanayake J, Roudier P 2012. Wireless soil moisture sensor networks for precision irrigation scheduling. In: Currie LD, Christensen CL ed. Proceedings: Advanced Nutrient Management: Gains from the Past - Goals for the Future, Massey University, Palmerston North, New Zealand, February 2012. Pp. 10.
  • Roudier P, Hedley C, Ross C 2012. Farm-scale mapping of soil organic carbon using visible-near infra-red spectrscopy. In: Currie LD, Christensen CL ed. Proceedings: Advanced Nutrient Management: Gains from the Past - Goals for the Future,, Massey University, Palmerston North, New Zealand, February 2012. Pp. 7.
  • Hedley CB, Yule IJ, Tuohy MP, Kusumo BH 2010. Proximal sensing methods for mapping soil water status in an irrigated maize field. In: Viscarra Rossel RA, McBratney AB, Minasny B ed. Proximal soil sensing. Progress in Soil Science. Dordrecht, Springer. Pp. 375–385.
  • Hedley C 2010. Variable rate irrigation. Soil news 58(2): 65-66.
  • Hedley CB, Yule IJ 2009. A method for spatial prediction of daily soil water status for precise irrigation scheduling. Agricultural water management 96: 1737-1745.
  • Hedley CB, Yule IJ 2009. Soil water status mapping and two variable-rate irrigation scenarios. Precision agriculture 10(4): 342-355.
  • Hedley CB, Yule IJ, Tuohy MP, Vogeler I 2009. Key performance indicators for simulated variable-rate irrigation of variable soils in humid regions. Transactions of the ASABE 52(5): 1575–1584.[volume=52&issue=5&conf=t&orgconf=t2009]&redirType=toc_journals.asp&dabs=Y
  • Kusumo BH, Hedley CB, Hedley MJ, Hueni A, Tuohy MP, Arnold GC 2008. The use of diffuse reflectance spectroscopy for in situ carbon and nitrogen analysis of pastoral soils. Australian Journal of Soil Research 46(6-7): 623-635.
  • Hedley CB, Yule IJ, Eastwood CR, Shepherd TG, Arnold G 2004. Rapid identification of soil textural and management zones using electromagnetic induction sensing of soils. Australian Journal of Soil Research 42: 389-400.
  • Hedley CB, Pollok JA, Ross C, Dando J 2001. Monolith making to demonstrate land-use effects on the Ohakune soil profile. New Zealand soil news 49(5): 96-100.
All Publications