• The following observations were made on the same farm using similar management, but it was not possible to conclude exactly what factors were responsible for the differences observed (since this has not been statistically compared).
• Grain maize following a terminated faba bean crop planted into the previous maize residues generated higher dry matter offtakes and grain yields than leaving the land fallow over winter and spring.
• Grain maize yielded 21.13 t/ha (14% moisture) following the terminated faba beans and 19.29t/ha following winter fallow (recorded from hand harvested quadrats which are typically higher yielding than machine harvested plots).

• Foliar application of a micronutrient mixes failed to provide in any yield improvement over and above the standard nutrition adopted.
• Tissue testing prior to, and at tasselling, revealed no micro or macro nutrient deficiencies, and no response to the additional nutrient applications..

• With an average grain yield of 16.51t/ha there were no significant differences in header grain yield from varying nitrogen rate or applying liquid potassium products.
• Applying Calcium Nitrate Ca (NO3)2 caused a decrease in yield when it was combined with an additional application of pre drill 90 kg/ha of nitrogen.
• There was evidence that additional nutrients significantly interacted (p=0.044) with the overall level of N fertiliser applied with liquid calcium nitrate giving greater benefits with 230N (applied as fertigation than when N was application was increased to 320kg N/ha (predrill urea = fertigation).

• Application of different DMI (triazoles) and QoI (strobilurins) fungicides at either 8 leaf (V8) or tasselling (VT) resulted in no yield response over the untreated crop.
• There was no observed effects of a fungicide application on green leaf retention post application.

• There were no significant yield effects of fungicide application at either V9 (9 leaf) or VT (Tasselling) development stages.
• Low levels of disease were observed in the trial but there was little evidence to suggest that fungicides improved green leaf retention when assessed at R4.
• Late infection of Common rust (Puccinia sorghi) was detected in upper canopy

• 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)

• 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 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 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 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.

• The Yenda site had a Potassium (K) soil level (0-10cm) that exceeded 500 ppm (Colwell K) at sowing and showed no yield response to additional K applied post sowing in crop.
• Application of K as potassium sulphate at V4 and or V8 saw no change in leaf tissue levels when compared to the control (no added K) when tissues were assessed at V8 or tasselling.
• Harvest results showed no response to added potassium, indicating that the soil was able to supply the required potassium to the crop.
• There was no evidence of luxury uptake of K in tissue and grain samples (assessed in untreated and 80 kg /ha K).

• The Kerang site had a Potassium (K) soil level (0-10cm) that exceeded 600 ppm (Colwell K) at sowing and showed no yield response to additional K applied in crop.
• As was the case at Yenda the application of K as potassium sulphate at V4 or V8 saw no change in leaf tissue levels when compared to the control (no added K) assessed at V10 or tasselling.
• Harvest results showed no response to added potassium, indicating that the soil was able to supply the required potassium to the crop.
• There was no evidence of luxury uptake of K in tissue and grain samples (assessed in untreated, 40 (tissue only) and 80 kg /ha K).

• 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.

• 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.

• 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.

• 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.

• 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%).

• 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.

•  There were no significant yield effects of fungicide application at either V8 (8 leaf) or VT.
• No disease was observed in the trial and there was little evidence to suggest that fungicides improved green leaf retention when assessed at V14, V15 and V16.

• There was a significant interaction between fungicide product and the timing of application with propiconazole being more effective than prothioconazole at the later VT timing and visa versa at V8, however there is no evidence that this is a real effect.
• Application of three different fungicide active ingredients (four products) at either V8 (8 leaf) or VT tasselling produced no yield response at the Kerang site
• Application of a fungicide at either 8 leaf or tasselling did not result in an extended period of green leaf retention during grain fill.
• No disease was evident in the trial for the duration of the season. 

• Application of three different fungicide active ingredients (four products) at either V8 (8 leaf) or VT tasselling produced no yield response at the Yenda site.
• Application of a fungicide at either 8 leaf or tasselling did not result in an extended period of green leaf retention during grain fill.  
• No disease was evident in the trial for the duration of the season.

• Decreasing row spacing from 750mm (approx. 30 inch) to 500mm (approx. 20inch) significantly increased grain yield with a 3.21 t/ha yield increase (trials hand harvested).
• There were no significant effects of plant population in the trial when 90,000, 105,000 and 120,000 plants/ha were compared.
• Variable wind damage resulted in hand harvest quadrats being used as the basis of yield this invariably increases overall yields compared to machine harvest.
• There was no interaction between plant population and row spacing evident within the trial.
• At 500mm row spacings there was a significant increase in dry matter production and nitrogen uptake in the canopy compared to the 750mm row spacing when recorded at harvest.
• A Strong linear relationship between dry matter production and nitrogen content was present throughout the growing season observed at V6 (R2=0.867) and at harvest (R2 = 0.824).