Sum15-05 Tactical N, N-Gauge, Mingenew


Evaluate nitrogen-rich strips (N Gauges) and Normalised Difference Vegetation Index (NDVI) measurement as decision support tools for economic application of nitrogen during the growing season.
Testing NDVI usage in the Summit In-Season Nitrogen Calculator predictions of yield on a light sand-dominated site.

For further details contact your local Area Manager or the Summit Research Team

Table 1: Soil Analysis
Fig 1: Yield and Protein


The Summit In-season Nitrogen Calculator gave a reasonable indication of performance potential based on N Gauge and paddock practice NDVI differences.
The recommended N rate (Treatment 4) optimized both yield and gross margin returns compared to where N was either 50% less than (Treatment 3) or 50% greater than (Treatment 5) the recommended rate (Figure 4.). Differences were significant.

The results also highlight to the value of including some N in the starter fertilizer mix. Comparing  Treatments 1 and 4 where similar total N was applied, applying 6 kg/ha N at seeding using MAPSZC (compound NPKS fertilizer) in this trial translated to >0.3 t/ha yield than nil N at establishment.
This yield increase occurred in spite of Treatment 4 receiving 32% less urea than Treatment 1 in the mid-season application.

N-rich strips and the In-Season Nitrogen Calculator show real promise as a N decision support tool for growers on sandy soils in the northern agri region and will be further tested under different conditions.