Twelve months ago, the Western District branch of Grasslands Society of Southern Australia (GSSA) in conjunction with Glenelg Hopkins CMA formed Pasture Tech – a group of young farmers with a common interest in road testing new technology to assist in making ‘informed’ decisions for sustainable management. Measuring and estimating pasture growth using satellite data The first focus of the group was to determine the merits of using satellite technology to measure pasture growth.
Pastures From Space (PFS) was used as the data platform and over a series of months the group monitored the portal results across their own properties. Infield pasture estimates and visual measurements were compared under the guidance of pastures expert Geoff Saul. The group typically found that PFS was reasonably accurate (within 200kg Dry Matter per hectare) in determining historical pasture growth rate and the historical green ‘food on offer’ for paddocks. It did however struggle with periods of high cloud cover and rapid change in season and/or stocking rates.
Despite this it was agreed that using satellite technology (particularly high resolution Normalised Difference Vegetation Index (NDVI) images) in conjunction with infield estimates will play an expanding role in long-term decision making around seasonal pasture budgeting, paddock renovation priorities, identifying drainage issues and establishing pasture utilisation deficiencies. Undertaking precision agriculture mapping In partnership with Precision Agriculture, the Pasture Tech group road-tested the use of Soil Grid Mapping to establish paddock nutrient maps for pasture based enterprises.
The soil grid maps can be converted into digital form and used for variable rate application of fertiliser, lime, spraying and other inputs. Each participant’s properties were mapped for pH, Phosphorus, Potassium, Sodium, Magnesium and Aluminium. Many participants were surprised with the insights that the mapping provided about long-term paddock history and nutrient movement from stock grazing habits. It was commonly agreed that soil grid mapping can play a key role in monitoring and managing farm inputs. When combined with infield assessment and other technologies, such as NDVI satellite data, the soil grid mapping results can also help farmers make informed decisions regarding potential sub division, pasture improvement priorities, drainage management and water point placement.
For further information on the group please contact Jonathan Jenkin at Glenelg Hopkins CMA on 03 5571 2526. This project was supported by funding provided by the Australian Government’s National Landcare Program.