• Legume pasture species and management practices have been investigated to determine the most important factors for improving nitrogen inputs to the soil.
• Results have shown significant improvements in the soil available nitrogen after growing pastures with a high proportion (>75%) of legumes.
• The increased soil nitrogen from good stands of pasture legumes is also reflected in the yield and quality of wheat grown the following year.
• A short pasture (2-3 seasons) will provide a significant increase in soil nitrogen and a yield and/or protein response. A long pasture (5 seasons) may not provide more nitrogen than one of 4 seasons.
• No legume species has performed consistently better than any other species.
• Sowing a mixture of inoculated pasture legume species that are suited to the region is important to spread the risk and ensure a good stand of legumes is achieved.
• Weed control using grazing management and/or chemical control is seen as the best way to maintain a high level of legumes in the paddock and therefore increase soil nitrogen

• Volatilisation losses were small on Mallee sandy loam at Walpeup where 4mm of rain fell two days after fertiliser application.
• Volatilisation losses from the application of urea to Wimmera clay was as high as 26 percent with small rainfall events (< 4mm) in the 20 days after application.
• Significant nitrogen losses were experienced when ammonium sulphate and liquid UAN were applied to Wimmera clay. Both products lost 12 percent of applied.

• Grain yield was driven by biomass production rather than harvest index.
• Timing of nitrogen had relatively little impact on yield or nitrogen response.
• Nitrogen rate had little effect on total crop water use.
• Nitrogen use efficiency and water use efficiency were improved with additional water availability (irrigated treatment).

•  There was no protein or yield penalty in delaying all nitrogen to four weeks after emergence.
•  Delaying all nitrogen application to 10 weeks after emergence resulted in reduced grain yield due to little follow-up rain.

• All varieties responded similarly to applied nitrogen.
• Hindmash and Commander yielded well; all varieties achieved malt.

There wass no significant difference in the way varieties respond to various amounts of nitrogen (N). Results indicate that for all varieties, as N increases, yield increases incrementally. the most profitable N rate for Commander, Buloke and Hindmarsh is 80kg N/ha, whilst Gairdner was still more profitable at 120kg N/ha

• Varieties responded similarly in yield and many quality measurements to applied N, but showed differences in protein levels.
• New higher yielding durum varieties required more N to reach target protein of 13%
• The later application of N at GS47 was the most effective to achieve 13% protein

• With a soil nitrogen (N) content of 103 kg N/ha at sowing, Mace wheat yielded 3.1 t/ha with no N fertiliser applied and contained 6.6% protein.
• Optimum gross margins were recorded with 75 kg N/ha, though none of the N levels up to 100 kg N/ha reached 9% protein.
• Yield response was greatest for N application timings at sowing, GS31, or a split application between GS31 and GS39.
• A crop sensor was used to measure in season nitrogen responsiveness and was able to predict the optimal N rate.

In a dry year hybrid RR canola with no applied nitrogen produced the best returns to growers. RR hybrids had higher oil and applying N reduced oil more than it increase yield. With TT technology CB Telfer the most popular variety in the low rainfall area produced the best combination of oil and yield. Hybrid TT was not superior to OP TT’s at Grass Patch in 2012. Late applications of N produced similar yield responses to earlier N applications.

• At Minnipa the late sown (resown due to mice damage) wheat gave a yield response to 20 units of up-front N, but not to N applied in-crop in 2010.
• At Mudamuckla there was no response to applied N above base rates on soil with adequate N content in 2010.

• Products with low cost per unit N were the most profitable in 2013.
• Very high N treatment increased quality but reduced yield.
• Some products that claim to increase N efficiency require further investigation.

• Small differences in yield with extra N under conditions at this site.
• Very dry spring needs to be taken into consideration when interpreting results.
• High rates of N early did not have significant impact on number of tillers.
• Grain quality higher for all N treatments.
• Further work required with ENTEC, eNtrench and Biopolymer urea coated product.

• At two sites, excessive application of nitrogen caused haying off of Gairdner barley in 2002.
• Increasing nitrogen application had a greater effect on quality than yield. Yield was limited by moisture not nitrogen.

 The application of nitrogen as urea did not increase grain yield in this trial, with only the application of manure increasing yield. Manure applied with 225 kg/ha N yielded 0.55 t/ha more than the same rate of N applied alone.
 The reasons for the manure response are not clear, as the site had high background N and P levels and the response came over and above high application rates of both nutrients.
 There was no effect of nutrition on grain quality or lodging.

 A grain yield of close to 6t/ha was achieved where a high rate of nitrogen fertiliser was combined with the application of animal manure to replicate high fertility soils.
 The manure alone increased yield by 0.75t/ha and raised the bar on our understanding of achievable yield for canola for this environment.
 Yields responses to granular urea N peaked at 150kg N/ha and similar yields were achieved between 150, 225, and 300kg/ha of applied N.

 A grain yield of close to 5t/ha was achieved where a high rate of nitrogen fertiliser combined with the application of animal manure to replicate high soil fertility.
 The manure alone increased yield by 0.77t/ha. The high rate of manure applied may not always be profitable but shows that yield is being limited by nutrition beyond just fertilisernitrogen application.
 Yield responses to applied nitrogen fertiliser plateaued at 75kg N/ha and similar yields were achieved between 75, 150, 225, and 300kg/ha of applied N (urea).

 Lodging of Hyola Feast CL increased with increasing nutrition, to the point where at the highest nutrition rates the plots were close to completely flat.
 There was no effect of nutrition on grain yield or grain quality.

There was no effect of nitrogen applied as granular urea on grain yield of the winter cultivar Hyola Feast CL.
 Where pig manure was applied, grain yield increased by 0.57 t/ha compared to where N alone was applied.
 There was no effect of nutrition on oil, protein or test weight, but seed size increased with higher nutrition.
 

 Nitrogen fertility (from the soil and from fertiliser) is crucial for growing Hyperyielding canola:
o The highest N rate was the highest yielding treatment at 5.44 t/ha.
o The overall fertility of the paddock was strong, with a yield of 4.14 t/ha where only the base level 45 kg/ha N (130 kg/ha MAP and 150 kg/ha SOA) was applied.

 The oil penalty from extra N application may not be as pronounced in Hyperyielding environments:
o Canola oil concentration typically declines (in low-medium rainfall environments) with increased nitrogen application. This was not the case in this trial with N rates from 45 to 225 kg/ha.

 All nitrogen treatments yielded more than nil N and 100% Upfront (all N applied at sowing) treatment.
 N was possible lost from denitrification just after sowing as the site became waterlogged.
 There was no yield difference between nitrogen timing for all treatments applied after sowing.
 Oil concentration was highest where nil N was applied.
 A nitrogen trial will be sown in 2021 with the inclusion of a winter cultivar.

 The application of all nitrogen at sowing either or alone or with pig manure was higher yielding than the lower N rates (16 and 46 kg/ha N) and where all N was applied at bud visible stage.
 The GEM trial showed that the spring cultivars were likely biomass limited but the winter cultivars were likely harvest index limited, therefore the nutrition trial will be conducted in a winter and a spring cultivar in 2021 to determine optimum strategies for these diverse types.
 There was no effect of nitrogen management on oil concentration. The ‘soft’ spring environment here may have limited the effect of nitrogen on oil, as N will generally reduce oil in low-medium rainfall environments.

Four nitrogen fertiliser products were compared for efficacy in relation to providing the crop with sufficient N to optimize production at two sites, Birchip and Marnoo. The products compared were: granular Urea, granular Calcium Ammonium Nitrate (CAN), liquid Urea Ammonium Nitrate (UAN) and liquid Urea. The products were applied three times (pre-sowing; at the five leaf stage and at the end of tillering).

• The influence of nitrogen on grain yield and protein depends on the amount of fertilizer applied, the timing and the growing season.
• Fertilising to increase grain protein is profitable if farmers are being paid a premiums for protein above 10.5 -11%.
• Multiple wheat varieties responded to nitrogen when applied at GS31, particularly at the high rate of 100 kg/ha.
• A 7.2% yield increase was observed by treating SQP-Revenue with fungicide 

• The influence of nitrogen on grain yield and protein depends on the amount of fertilizer applied, the timing and the growing season
• Fertilising to increase grain protein is profitable if farmers are being paid a premiums for protein above 10.5 -11%.
• Multiple wheat varieties responded to nitrogen when applied at GS31, particularly at the high rate of 100 kg/ha.
• A 7.2% yield increase was observed by treating SQP-Revenue with fungicide

• Grain yields of wheat were higher when additional nitrogen was applied at sowing compared to when applied at GS31.
• Timing of nitrogen application is essential to maximise plant growth and achieve yield potential.
• Grain protein was only higher when delayed nitrogen application was applied, which resulted in reduced wheat yield.
• Starting soil moisture, paddock rotation history and potential yield of crop are important factors to consider when deciding amount of nitrogen to apply and timing.
   

• Grain yields of wheat were higher when additional nitrogen was applied at sowing compared to when applied at GS31
• Timing of nitrogen application is essential to maximise plant growth and achieve yield potential
• Grain protein was only higher when delayed nitrogen application was applied, which resulted in reduced wheat yield
• Starting soil moisture, paddock rotation history and potential yield of crop are important factors to consider when deciding amount of nitrogen to apply and timing

• The trial responded by 800kg/ha to 30kg N/ha and 1200kg/ha to 60kg N/ha.
• However, there were no significant responses to splitting or delaying the nitrogen applications.

For further information see Payne, RA and Ladd, JN (1993) Soil organic matter and nitrogen management in dryland cropping systems, Part II: Nitrogen requirements for dryland cereal crops. Dept Primary Industries of SA. Technical Report No. 212 (Agdex 536).

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits. The grower mentioned the usefulness of the Greenseeker map to provide a visual overview of how the crop was growing and where nitrogen was being used. This has helped with understanding how different soil types perform and allow extraction of nitrogen during a growing season.

• The airport paddock at MAC was starved for nitrogen in 2009.

Key findings:

• This site was fairly unresponsive to nitrogen (N) application. Yield and screenings did not significantly change with increasing rates of N, but there were moderate responses in grain protein to all rates of applied N in all varieties.
• The 40 kg N/ha at sowing + 40 kg N/ha in crop treatment had a significant increase in grain protein above the 40 kg N/ha at sowing only treatment in all varieties, but was not significantly different from the 80 kg N/ha at sowing treatment

Results:

There were moderate responses in grain protein to all rates of applied N in all varieties. The 40 kg N/ha at sowing + 40 kg N/ha in-crop treatment showed a significant increase in grain protein above the 40 kg N/ha at sowing only treatment in all varieties, but was not significantly different from the 80 kg N/ha at sowing treatment. Screening levels were low, with only Dart above 5% in some treatments. Dart, being the quickest variety in this trial, flowered and reached grain filling ahead of the other varieties, most likely causing it to be filling grain and losing green leaf during the hotter and drier part of September. The slower varieties probably benefited more from the late spring rains in this season

• This site was very responsive to nitrogen (N) application. Yield and protein increased in all varieties, even up to the highest applied rate of 160 kg N/ha.
• Yield averaged across varieties increased from 2.80 t/ha with no application of N up to 3.58 t/ha with the application of 160 kg N/ha.
• Grain protein levels across varieties rose from 9.8% (nil applied N) to 12.4% with 160 kg N/ha.
• Screening levels were not affected by N application rates up to 80 kg N/ha but rose slightly from 2.7% to 3.8% with 160 kg N/ha.
• Kiora was the only variety which produced screening levels above 5% which were exacerbated by higher N application rates of 80 and 160 kg N/ha.
   

• There was a significant response in yield and grain protein across increasing rates of applied nitrogen (N) in all varieties.
• Yield averaged across varieties rose from 2.88 t/ha with no applied N, to 4.06 t/ha with 160 kg/ha of applied N.
• Grain protein levels across varieties increased from 9.0% (nil applied N) to 12.2% with 160 kg/ha of applied N.
• Screening levels were not significantly affected by increasing N application rates in any variety and averaged close to 6% across varieties and N rates.

Key findings:

• This site was only moderately responsive to nitrogen (N) application. Yield and protein generally increased in all varieties with the 20 kg N/ha and 40 kg N/ha rates. However, yield decreased with higher application rates.
• Protein and screening levels increased with N rates above 40 kg N/ha.
• KioraA produced the highest screening levels. The sowing date of 5 May at Nyngan is probably a bit late for KioraA, which would have exacerbated screenings.
• Varieties with comparatively lower biomass such as DartA, LancerA, SpitfireA and SunmateA maintained higher yield and lower screening levels even with the higher N application rates with a corresponding lower impact on harvest index also observed in these varieties.

Conclusions:

Conditions at sowing were very wet. There was no effective in-crop rainfall after August and combined with temperatures above 35⁰C in September resulted in a hard finish to the season.

This site had a high background starting N level (233 kg N/ha) which was surprising given the history of continuous cropping – 17 years of crop (Wheat 40%, canola 20%, barley 20%, pulse 20%) with additional N (above starter fertiliser application) only applied once in 1999. The lower rates of 20 and 40 kg N/ha gave modest yield increases in most varieties however rates higher than this tended to reduce yield and also caused screenings levels to increase in this trial. Protein levels increased with N application rates of 40 kgN/ha and above as seed size decreased.

Biomass and harvest index data (data not shown) showed that increasing N rate in heavier strawed varieties such as EGA_Gregory, Viking, Kiora produced more dry matter with comparatively less grain yield i.e. lower harvest index.

Key mesages:

• There was a decline in yield with all rates of applied nitrogen (N), which was likely to be associated with high levels of residual soil N at the site.
• Grain protein increased with all rates of applied N in all varieties, most likely due to decreased grain size.
• Sowing time had the greatest influence on yield, with the earlier sowing time yielding close to 1 t/ha better than the later sowing time for each variety.

Conclusions:

This trial site had a high starting soil N level of 233 kg N/ha (0–120 cm) which probably contributed to declining yield with increasing rates of N application. However, protein levels still increased with increasing rates of N application, but this was most likely due to decreased grain size. Most varieties yielded almost 1 t/ha higher with TOS 1 compared with TOS 2. Sunmate and Suntop generally performed similarly at both sowing times. They were the highest yielding varieties at each sowing date, but also had lower protein achievement. Lancer and Spitfire also performed similarly at the two sowing dates and were generally lower yielding than Sunmate or Suntop at each sowing time, but obtained higher grain protein levels.

• The experiment was highly responsive to nitrogen application (N).
• Averaged across the two sowing dates, yield ranged from 0.89 t/ha in LRPB DartA without applied N to 4.95 t/ha in LRPB FlankerA with the highest application rate of 160 kg N/ha.
   

• A mean yield of 5.97 t/ha was achieved for teh 2009 nitrogen response trial at the Inverleigh site.
• There was no significant differences in yield across the trial.
• The variety used for this trial was Preston.
• Grain quality achieved AGP1 for all treatments with low test weights and low protein levels the contributing factors.
• For further take home messages please see attached trial report.

Farmers in this situation can be confident that since the NDVI and the N sensor measurements complement one another, the low producing areas can be farmed differently to the high producing areas. In order to maximise profits on farm, growers ought to consider varying inputs according to productive potential of their paddocks. Soil types vary considerably throughout the Upper North and can also be quite variable within paddocks. Considerable cost benefits can be made over time by using variable rate technology in paddocks with high variability. While the upfront costs might be large, the investment quickly pays itself off, giving farmers increased confidence in using the technology. Some training is often required when using new monitors and equipment however regular use and familiarity of products improves ease of operation.

• Technical difficulties limited the value of data collected from this trial.
• There was no yield response to nitrogen rate, source or placement but protein increased with N rate.
• Nitrogen-use efficiency was in general poor across all treatments although banded treatments were slightly better than broadcase applications.

• Urea increased wheat grain yield significantly over the nil when banded at sowing.
• There was no significant difference between urea, UAN or MAXamFLO when applied at the same rate of nitrogen and incorporated by sowing, banded or applied at pre-sow, banded and post.

With extremely dry conditions following both sowing on 6 June and nitrogen application, there was no response to nitrogen application in this trial, despite the low level of available soil nitrogen (52kg/ha N, 0-130cm) recorded at the start of the season. • With yields in the range of 1.3-1.6t/ha, there was no response to applied nitrogen regardless of the timing or product used. • There was no evidence to indicate that, under these conditions, liquid fertiliser (Easy N - 32% w/w (16% urea, 8% nitrate and 8% ammonium) or Green Urea 14 (an agrotain urease inhibitor coated urea) were superior to straight urea (46%N).

• Later applications of nitrogen (GS30 & GS37) were the most profitable with the highest yield and quality, for malt barley in 2010.
• There was no significant differences in yield of varieties between early and later sowings.
• Crop sensors provide a good measure of nitrogen response and can improve nitrogen use efficiency.

Crop growth and yield potential were severely limited by one of the driest seasons on record at this site. Hence, the very poor grain yields and no response to nitrogen applications.

Results are complex and its difficult to separate the effect of waterlogging and crop development stage.
Results not statistically significant but suggest:

• Double application of nitrogen increased the crop yield,
• Potentially there is a benefit in applying nitrogen once waterlogging abating, and
• Quality increased with late application of nitrogen but yield did not increase.

The site at the BCDS looked the most promising of all 14 sites, unfortunately the frosts in late September and early October reaped havoc on grain yield.

Variable rate fertiliser application has a real and profitable place in the Mallee when combined with good paddock science. The precision technology gives the ability to examine the yield data for many effects including other possible influencing factors such as elevation, slope aspect or orientation to the sun, and probably many others. Grain yield was recorded continuously during harvest and logged against GPS position. From the resultant yield map it was possible to isolate treatment strips and EM38 zones within these strips and determine the yield for individual strips and therefore treatments, and also where these treatments intersect with the paddock zones. Trial was statistically analysed and Table 1 above shows there was no significant difference between treatments.

There was a significatn difference (P < 0.05) in the yield and protein levels between varieties but there was no difference in yield and protein due to the different fertiliser treatments within a variety.

• In a variable trial there were no significant differences in grain yield (machine harvested) due to row spacing 500mm v 750mm (20” v 30”), plant population (85,000 v 120,000 pl/ha) or N rate 300 v 450 kg N/ha).
• Overall grain yield average in the trial was 16.47 t/ha.
• Although no yield differences were recorded it was noted that narrower row spacing produced more overall harvest biomass, particularly at the lower plant population.
• Since there were no difference in grain yield associated with narrow row spacing and lower plant population, harvest index was reduced.
• Crop canopies at harvest contained more nitrogen than was applied as fertiliser indicating that at 300 kg N/ha applied as much as 235 kg N/ha was supplied from the soil.
• Increasing N fertiliser applied from 300 to 450 kg N/ha did not result in any greater N offtake in the crop at harvest, indicating that N was either left in the soil or lost.

• The average grain yield (header harvest) of the trial was 17.12t/ha with no indication that increased nitrogen rate (from the use of pre-drill urea) significantly increased yield when 207kg N/ha was subsequently applied in crop as fertigation.
• The lowest plant population 79,287 plants/ha resulted in the lowest yields with no grain yield difference between 91,864 and 103,620 plants/ha. 91,864 plants/ha was the most profitable.
• Normalised differential vegetative index (NDVI) assessments indicated that ground cover was significantly lower in the lowest plant population across all assessment timings up to V8.
• The most efficient recovery of nitrogen applied was recorded with plant populations of approximately 92,000 plants/ha with N applied by fertigation totalling 207 kg N/ha.

• The average grain yield (header harvest) of the trial was 16.33t/ha with an uneconomic trend for higher yields if N rate and seedrate was increased.
• Plants populations of 80,000, 93,333 and 102,222 gave no statistical difference in grain yield, grown in a maize-on-maize rotation position.
• There was a trend suggesting a response to nitrogen at higher plant populations, but this was not significant. Highest yields were associated with N uptake at harvest of 400 – 450kg N/ha.
• Grain maize established on grain maize stubble in 2020/21 was approximately 1 t/ha lower yielding than the trial in the same paddock in 2019/20 when grain maize was established in oaten hay stubble.
• Comparing the two seasons there was a significant reduction in yield last season when the population was reduced from approximately 92,000 to 79,287 plants/ha. There was no difference in this experiment with maize grown on maize stubbles.
• In terms of profitability using the yields generated, the highest margin was generated with approximately 80,000 plants/ha and 230kg N/ha applied as fertigation.
• The additional cost of N ($1.74kg/N and seed required for 17t/ha in this trial exceeded the value of 0.7t/ha grain maize valued at $210/ha, hence lowest N rate and seedrate were most cost effective.
• Last season with slightly higher yields it was the 92,000plants/ha with 297kg N/ha was most profitable.

• Grain yield was significantly higher in the narrower row spacing (500mm) at both high and low plant populations (nominally 85,000 v 106,000 plants/ha) (Caution different harvest methods were engaged for logistical reasons – see note below).
• Overall grain yield average in the trial was 16.53 t/ha.
• Total crop biomass (dry matter) at maturity was similar across all treatments suggesting narrower row spacing combined with lower plant population significantly improved harvest index and therefore grain yield.
• Of the three components (row spacing, plant population and N rate), N rate (either 300 or 450kg N/ha) had minimal influence on the yield and biomass results, since the lower rate of 300 kg N/ha met the N requirement of yield (already established 240N optimum N rate-see Trial 2).
• Row spacing and plant population did interact in the analysis of the trial data, making the assessment of the contribution of these factors difficult.
• Nitrogen use efficiency (NUE) was greatest with narrow rows, low population and 300N at 16.15kg N applied for each tonne of grain produced and 25.57kg N/t if 188kg N/ha soil supply was added to fertiliser applied (see Trial 2)

• Although increasing the frequency of N applications appeared to slightly increase grain yield (machine harvested) compared to all “up front” in seedbed yield differences were not statistically significant.
• As a general comment, timing of N application did not affect the grain yield, whether it be all up front or split over 4 timings up to V6.
• The nil applied N treatment yielded 9.49t/ha.
• However N content of the grain at harvest was greater where split applications involving later timings were compared to all the nitrogen applied at sowing indicating greater N fertiliser efficiency
• However, unless there is a premium for the maize protein in the grain resulting from later N timings the difference may be of little value to the grower.
• Soil N prior to sowing and watering up was 25 kg N/ha (0-60cm). The nil treatment contained a total of 147 kg N/ha at harvest, suggesting in-crop mineralisation resulted in 122 kg N/ha released to the crop.

• In all treatments where N fertiliser was applied there were no statistically significant differences in grain yield.
• The highest yield achieved was 16.82 t/ha with the total applied N of 300 kg N/ha, applied as 100 kg N/ha at sowing, then 3 subsequent topdressings of 66 kg N/ha up to tasselling, but achieved similar yields to applying 300 kg N /ha at sowing only.
• The nil applied N treatment yielded 10.61 t/ha and had a dry matter of 19.58t/ha and a N content of 176kg N/ha at harvest.
• Soil available N prior to sowing and watering up was 44 kg N/ha (0-60cm).
• The nil N applied treatment contained a total of 176 kg N/ha at harvest, suggesting in-crop mineralisation resulted in 132 kg N/ha being released from the soil during the course of the season.
• In this trial as long as at least 100 N (and 200 kg N/ha in total) was applied beginning at sowing, product or timing did not influence yield.

• The highest grain yield (machine harvested) achieved was 16.36 t/ha with the applied N rate of 240 kg N/ha in a crop producing 30.63 t/ha dry matter at 50.45% harvest index.
• N applications above 240kg N/ha were uneconomic in the trial.
• The nil control treatment yielded 10.89 t/ha in a crop producing 26t/ha dry matter at 51% harvest index.
• Available Soil N prior to sowing and watering up was 34 kg N/ha (0-60cm). The nil control N offtake at harvest was 241 kg N/ha, suggesting in-crop mineralisation resulted in 207 kg N/ha of the N taken up.
• At the highest level of N (560kg N/ha) there was no advantage to applying 80 Kg N/ha of the dose very late at tasselling.

• The highest machine harvested yield achieved was 16.42 t/ha with the applied N rate of 560 kg N/ha, however this was not statistically different to the yield where 240 kg N/ha was applied.
• Yield plateaued beyond the ‘240 kg N/ha’ treatment (16.18t/ha), mirroring the 2019/20 results which produced a similar N applied optimum.
• Where no N fertiliser was applied the yield was 9.70 t/ha with a dry matter of 21.8t/ha at harvest compared to 16.18t/ha and 35.79t/ha for the optimum N rate of 240kg N/ha.
• The N offtake at harvest revealed an average N content of approximately 188-448kg N/ha in the crop with the 240N treatment giving an offtake of 395kg N/ha with 58% of the N in the grain.
• Increasing N rate from 240kg to 560kg N/ha applied did not significantly increase dry matter present at harvest, although there is evidence of additional N content in the dry matter above 240kg N/ha.
• Soil N prior to sowing and watering up was 32 kg N/ha (0 – 60cm). One month after sowing and wetting up this figure had risen to 107kg N/ha.
• The nil N treatment contained a total N content of 188 kg N/ha at harvest, suggesting in-crop mineralisation through the course of the season resulted in 156 kg N/ha released.
• In-crop mineralisation in the 2020/21 season was lower than in 2019/20 (241kg N/ha) but still contributed a significant portion of the crop N budget.

• Header grain yields averaged 18.2t/ha with no yield benefit observed from applying pre-drill urea in the trial when N was applied post sowing as fertigation.
• In a trial with an overall dose of post sowing N of 207 kg N/ha applied via fertigation there was no significant yield increase from the earlier pre-drill N applications of between 0 – 315kg N/ha.
• The economic optimum level of nitrogen applied was 252kg N/ha (45N pre-drill + 207kg N as fertigation).
• No significant differences were recorded in total dry matter (DM) content at V6 or at harvest with an average DM content of 34.6t/ha.
• The N content at harvest revealed an average N content of 462kg N/ha with a range of approximately 415-530kg N/ha in the crop, but there were no statistical differences.
• The N offtake at harvest indicated soil mineralisation provided up to 165kg N/ha to grow the crop with lower N efficiency recorded from applied fertiliser at higher overall N rates.
• There were no significant differences in test weight (mean 81.1) or harvest index (mean 51.7%).

• Header grain yields averaged 17t/ha with no yield benefit observed from applying pre-drill urea in the trial when N was applied post sowing as fertigation (230kg N applied).
• In a trial with an overall dose of post sowing N of 230 kg N/ha applied via fertigation there was no value to the earlier pre-drill N applications of between 0 – 315kg N/ha.
• No significant differences were recorded in dry matter (DM) accumulation at V5 or NDVI at V7.
• The N offtake at harvest revealed an average N content of 420kg N/ha with a range of approximately 395-460kg N/ha in the crop.
• The N uptake at harvest indicated soil mineralisation provided up to 79kg N/ha to grow the crop with lower N efficiency recorded from applied fertiliser at higher overall N rates.
• There were no significant differences in test weight (mean 80.7kg/hL)
• Dry matter at harvest showed no differences with an average reading of 35.3t/ha and harvest index mean of 46.9%.
• Exactly two thirds of the N removed in the crop was present in the grain with an average of 280kg N/ha in the grain and 140kg N/ha in the stover.

• With an average grain yield of 18.28t/ha there were no significant differences in header grain yield from varying nitrogen rate or timing of prilled urea (46%N).
• Where no nitrogen was applied early in the season a significant decrease in nitrogen content was observed in the stalk of the plants at harvest, but there no influence on grain N content.
• Test weight was significantly reduced when only 207kg N/ha was applied to the crop, there was no significant benefit in test weight when the highest rate of nitrogen was applied.

• With an average grain yield of 17.29t/ha there were no significant differences in header grain yield from varying nitrogen rate or timing of prilled urea (46%N) when 230 kg N/ha was applied as fertigation post sowing.
• Dry matter was between 30 and 35t/ha at harvest with approximately 50% of this dry matter present as grain and the remaining 50% as stover.
• In terms of nitrogen uptake in the crop at harvest 70% of the N on average was in the grain with 30% in the stover (leaves, stalk and cob husk).
• There was some evidence that additional N increased grain N content, but this was not associated with yield increases.
• The trial results are similar to the same trial run in 2019/20 which following oaten hay had an average yield of 18.2t/ha compared to 17.3t/ha when sown maize on maize.

•  Delaying post sowing applications of nitrogen (92 kg/ha N) to the flag leaf stage for both Kellalac and MacKellar at the Gnarwarre site, resulted in the best grain yield and grain quality.
• Application of nitrogen (35 kg/ha N) to barley at the early jointing stage (GS32), gave the best grain yield and quality at Gnarwarre.
• Late nitrogen applications appeared to result in more flower sites (florets) filling with grain for both wheat and barley. 
• For further conclusions please see the attached trial report.

• Early sulphur application supported higher tiller numbers although this did not translate into yield
• Site was very responsive to at least 79kg nitrogen application.
• An additional 50kg urea (23kg N), resulted in slightly higher protein readings.
• Site was unresponsive to sulphur application.
• Timing and splitting of in-crop fertilisation conferred no yield advantage • Good utilisation of applied N and S in spite of high rainfall year.

To manage N2O emissions in low to medium rainfall environments, growers need to match nitrogen supply to crop demand. Lowest emissions were measured where nitrogen levels were least, while highest emissions occurred where nitrogen levels were greatest. Applying late nitrogen to increase wheat protein is not economic when segregation price differentials are small.

• Work conducted in low and medium rainfall environments indicate that N2O emissions are low from an overall national perspective. • Results showed that there was no clear response of N2O emissions to nitrogen applied at sowing and post sowing. • High pre-seeding soil mineral nitrogen raises the possibility of higher N2O losses over the fallow period following significant rainfall.

• Work conducted in low and medium rainfall environments indicate that N2O emissions are low from an overall national perspective. • Results showed that there was no clear response of N2O emissions to nitrogen applied at sowing and post sowing. • High pre-seeding soil mineral nitrogen raises the possibility of higher N2O losses over the fallow period following significant rainfall.

Preliminary results showed the level of nitrous oxide emissions did not increase over the 2013 winter as a result of near capacity soil water contents coupled with increased nitrate nitrogen levels resulting from seeding and in-crop nitrogen applications on the canola compared with a pulse crop and legume pasture.

Preliminary results showed the level of nitrous oxide emissions did not increase over the 2013 winter as a result of near capacity soil water contents coupled with increased nitrate nitrogen levels resulting from seeding and in-crop nitrogen applications on the canola compared with a pulse crop and legume pasture.

• Nitrous oxide (N2O) emission into a closed chamber was found to be linear over our standard closure time of 60 minutes in three of the four chambers tested.
• Beginning N2O sampling at 9:00–9:30 am appeared to underestimate the daily average N2O flux, although there was no significant time effect in the higher emitting treatment. The sampling time was changed for the following season to start at 10:00–10:30 am.
• The average flux from the four manual chamber locations used in the main experiments (irrigated furrow, non-irrigated furrow, fertilised side of plant bed, non-fertilised side of plant bed) were found to give a good approximation of the N2O flux averaged across 12 chambers covering all possible locations in a two metre cross section of the cotton field.
• These tests validated the assumptions made in devising the sampling strategy used in subsequent experiments.
   

• N2O losses appear to be minimal from dryland low to medium rainfall farming systems; peak emissions of only 4.0 gN2O-N/ha/day were measured following rainfall.
• N2O emissions from legume stubble over summer and with synthetic fertiliser applied in-crop were low.
• An increase in soil water was the major driver of N2O emissions.

• N2O losses appear to be minimal from dryland low to medium rainfall farming systems; peak emissions of only 4.0 gN2O-N/ha/day were measured following rainfall.
• N2O emissions from legume stubble over summer and with synthetic fertiliser applied in-crop were low.
• An increase in soil water was the major driver of N2O emissions.

• N2O losses appear to be minimal from dryland low to medium.
• Rainfall farming systems; peak emissions of only 4.0 g N2O-N/ha/day were measured following rainfall.
• N2O emissions from legume stubble over summer and with synthetic fertiliser applied in-crop were low.
• An increase in soil water was the major driver of N2O emissions.

• Wheat established by no-till yielded at least as well as full cut sowing on stony soils in 2009.
• Seed scattered on soil surface germinated at Lock in 2009!
• Hydraulic tines, K-Hart discs and Canadian designed points are excellent options for no-till on stony soils.

• Peat and liquid formulations were the most consistent inncoulants across all pulses, having the highest nodule scores and equal or highest grain yields, compared with the remaining treatments. 
• Without inoculation, faba bean and chick pea failed to nodulate indicating host rhizobia were absent at this site. This consequently lowered the grain yields. 
• On the other hand, lupin, field pea and lentil effectively nodulated without inoculation, indicating their respective rhizobia had colonised this site. 
• Fungicide seed dressing (P-Pickel T) did not affect pulse nodulation, but did increase grain yeild in chickpea. Further investigation is needed to establish the reasons. 

• Chickpea and lupin failed to nodulate without inoculation.
• Inoculation formula had minimal effects on growth and yield of pulses at this site.
• Peat and liquid formulations were consistently reliable inoculants across all pulses based on nodulation and grain yield
• Differences measured in nodulation were not reflected in differences measured in crop growth and grain yield, suggesting soil nitrogen reserves were sufficient to make up most of the crop’s needs.
• Field pea and lentil rhizobia appear more widespread in this environment and better adapted to the acidic soils, while chickpea rhizobia appear less adapted.

• There was no significant yield difference between Tambla and Tantangara, however Yambla was significantly higher yielding than Gairdner. 
• For further conclusions, please see the attached trial report.