At this stage, the risk of poor establishment in the crop, in this case maize, after the sub-soil manuring is a major barrier to farmers adopting this practice.  Farmers require more certainty on how to implement the practice change to ensure no negative impact on the first crop following the amelioration.  More information is required about the benefits in subsequent years.

It would be beneficial to have a soil specialist advising on the soils that would benefit from amelioration, as well as the timing and implementation of the practice.  In this focus paddock, the low lying nature of the site has made it prone to waterlogging, so drainage may need to be addressed as well.

The paddock has various amendments applied at depth, surface and incorporated, after visually not noticing any differences throughout the growing season in any year, soil tests were conducted to understand what was going on in the paddock. While the yield did not vary, the area that had Chicken Litter strip tilled was able to maintain a higher level of Nitrogen in the soil, this did not alter yield response though.

When choosing an area to ameliorate you need to be sure you are targeting low performing areas to see any financial return on the time and amendment costs. Some soils are achieving capacity through crop type, therefore focus on the areas within your farm that are under performing.

While there was no significant results within the 3 years of this project it remains an area of interest for our growers and we would like to understand the impact of irrigation on the Nitrogen Banking in cropping season.

The 2019/20 season was regarded as one of only moderate mite pressure, Two Spotted Mite control of some form was required at Byrneside in Northern Victoria. 

The commercial release of Persimilis could be considered as a viable alternative to the application of a foliar miticide, although timing, and crop monitoring is essential. The effectiveness of Califonicus needs further investigation. It is typically released earlier in the season, almost as a prophylactic treatment in that it can survive on pollen & stops mite numbers from building up.

Economics: 

Cost of one application of Zeal® (product and application/ha) = applied 350 ml/ha via helicopter = $56.61+$42= $98.61 (plus GST)

Cost of Persimilis (insects and drone application/ha) = $210 (plus GST)

Cost of Califonicus (insects and drone application/ha) = $150 (plus GST)

In a typical pest pressure year more than one application of Zeal® would be expected, whereas only one application of Persimilis may be required as once established they would keep building up within the field over the season.  This would need to be evaluated in a high pest pressure year though prior to growers considering commercial adoption.

Late (Z39+) application of N resulted in yield and protein increase over the control.

There is a difference between maximising biomass and the optimal biomass for maximum yield in a particular environment.

Maximising biomass creates agronomic problems such as increased foliar disease and early weed competition.

Irrigation can supply moisture during grain fill but cannot control the temperature - many of the winter wheats mature too late to avoid heat stress during grain fill. 

There is a difference between maximising biomass and the optimal biomass for maximum yield in a particular environment.

Maximising biomass creates agronomic problems such as increased foliar disease and early weed competition.

Irrigation can supply moisture during grain fill but cannot control the temperature - many of the winter wheats mature too late to avoid heat stress during grain fill. 

Bannister was the highest yileding variety from either sowing date.

The theoretical N contribution from faba stubbles is 20 kg N/tonne of stubble. However this assumes all residue is mineralised. 

Stubble retained on the soil surface is broken down more slowly than residues present in the soil.

A 6 t/ha bean crop resulted in approximately 140 kg N/ha being released for the following season. 

The faba crop contributed a significant amount of N, resulting in less symptoms of waterlogging during winter, reduced N applied through the season but insignificant yield effects and changes to barley grain quality.

Increased rates of N resulted in increased biomass, but the relationship between stubble N content and applied N was poor.

Higher applied  N resulted in higher Harvest Index

Harvest Index ranged from 0.45 to 0.47. 

Adding 70 kgN/ha prior to stubble incorporation addressed in crop N tie-up.

No fertiliser had any effect at any rate on the establishment of canola when watered up.

Lodging was reduced in scout wheat with the application of Moddus Evo at GS31, but yield was not affected.

 

The PGR trinexapac ethyl reduced plant height and improved lodging resistance but no PGR influenced yield.

Only the Chlormequat + Tebuconazole treatment reduced crop height (100 mm). No lodging, yield or grain quality differences where significant.

No PGR had any effect on plant hieght, lodging or yield.

Trinexapac-ethyl resulted in shorter crop height and higher screenings from th late application. There were no effects on yield or crop lodging.

The high rate of gypsum (3.0 t/ha) was the best ameliorant, with all other ameliorants and rates performing better than the control (no ameliorant).

• The ameliorants were applied in 2014, where 3.0 t/ha of gypsum proved to be the most effective in increasing establishment.
• However all treatments have had no effect in subsequent seasons.

Fungicides had no effect on grain yield.

No treatment resulted in any yield effects. No disease was detected on the controls throughout the season.

Consistent performance from Cobra, Beaufort and Scout.

The wet winter and subsequent waterlogged conditions through June and July resulted in reduced tillering, particularly in the earlier maturing varities, and overall yield performance was reduced.

Early sowing resulted in excessive vegetattive growth and also provided excelelnt conditions for ryegrass that proved difficult to control.

No treatment resulted in any yield effects. No disease was detected on the controls throughout the season.

The Plant Growth Regulator trinexapac-ethyl (Moddus Evo) has been shown in previous trials to increase yield in irrigated barley, but not necessarliy due to reduced lodging. This trial appears to indicate that the PGR resulted  increased tiller survival in lower plant populations of certain varieties. 

Some varities have shown no yield response to PGR application.

Selection of a variety that is not prone to lodging may be a better choice than applying a PGR.