The objective of “Precision Mapping: does it tell us anything we don’t already know?” was to assess the applicability of precision mapping technologies in potato production systems in South Australia (SA). The intent was to quantify whether precision based monitoring and analysis techniques that assess soil fertility and crop performance could identify anything that can’t be seen by eye.  

The project was funded by the South Australian Potato Industry Trust, with the initial aim of conducting activities at Parilla and Kangaroo Island (Map 1). Complementary funding was sourced from the South East and SA Murray Darling Basin Natural Resource Management Boards, enabling additional activities to be conducted at Pinnaroo and Kalangadoo. The project was delivered by PIRSA and Potatoes South Australia.

 Untitled100

The core activities and key outcomes from the project have been captured in case-study format to provide a summary of the types of technologies that are applicable to potato production systems and examples of their local application.

There were four main technologies tested in the project, the key messages for each include:

Electromagnetic Induction sensing of the soil using EM38 at Kalangadoo and Parilla proved to be useful in sandy soils, and when combined with soil chemical data, it provides an indication of changes in soil type.

Grid soil sampling was used to assess soil nutrient fertility and pH at Kangaroo Island, Kalangadoo and Parilla; it was found to accurately distinguish spatial soil type variability and quantify soil chemical properties.

For EM38 and grid soil mapping, the results confirm that with thorough ground-truthing of the data, paddocks can be separated into management zones by soil properties, reducing future sampling and analysis costs. Prescription rates of fertilisers, amendments and irrigation can be applied to each zone, further reducing production costs and minimising the degradation of soil and water resources. The results can be found in Case Study 1 in the full report (from page 5).

Elevation mapping and drainage modelling conducted at Kalangadoo was found to be very useful to model drainage designs at the paddock or pivot scale to inform cut/fill activities to reduce the impact of waterlogging. Cut/fill maps can be loaded into tractor software platforms to inform and/or automate machinery operations. Precisely graded topographical surfaces will reduce crop losses from waterlogging, ponding and poor drainage. To learn more, see Case Study 2 (Page 11).

Remotely sensed hyperspectral imagery, including normalised difference vegetation index (NDVI), chlorophyll index, canopy temperature and water stress, was collected at Pinnaroo and Parilla on six dates from tuber initiation through to bulking. The imagery has proven to be a highly valuable tool for assessing potato plant performance and crop vigour characteristics and was able to detect things that couldn’t be seen by eye.

Imagery provided accurate maps to quantify yield variability and confirmed that soil type has a strong relationship with final tuber yields, with fragile deep sandy soils resulting in >30% yield reduction, in comparison to the sandy loams and sandy clay soils on the pivot at Parilla. It also confirmed the importance of seed source and quality, showed the impact of a non-uniform fertiliser application and the long lasting impact of early crop water stress. Chlorophyll index at tuber bulking may be a useful indicator of potential yield and can be used to assist forecasting assessments; a methodology is proposed, but has not yet been validated commercially. See Case Study 3 for the full methodology (Page 15).

To view the full report, click here

 


 

Following our ‘Industry Update’ Workshop at Mt Gambier on 4 October, 2018, the following presentations are provided:

General Industry Workshop content:

The afternoon session was devoted to Precision Ag(riculture).  The presentations below demonstrate the Association’s priority to research, trial and introduce new technology options to the industry.  There will be updates as further research projects/trials are undertaken with our members and corporate partners.

Precision Decisions:

potatoes


Where to go for more information:

Society of Precision Agriculture Australia

Society of Precision Agriculture Australia:  Factsheet - Airborne Imagery

Society of Precision Agriculture Australia:  Factsheet - Proximal Soil Sensing