• The relative sensitivity to manganese deficiency is broadly : bread wheat (least), barley, durum wheat (most).
• The relative sensitivity to zinc deficiency is broadly: barley (least) bread wheat, durum wheat (most).
• With a very inefficient variety adding a micronutrient fertiliser may not be sufficient to overcome the deficiency.
• Special attention needs to be given to the micronutrient requirements of durum wheat especially where high rates of N and P fertilisers are used.

• Further analysis using yield monitor data will allow for a comparison of fertiliser rates on the different productivity zones in the paddock which should enable us to determine the benefit from applying lower fertiliser rates to the poorer productivity areas.
• Overall the lower, more conservative, upfront fertiliser applications were the best strategy and there is still an opportunity to add more nitrogen later, depending on the season.

Inoculant and MAP fertiliser improved biomass yield and plant height of vetch during early vegetative stage at Kimba, Coomandook and Mundulla. This highlights the importance of adequate fertiliser and inoculant for early plant growth.

A negative grain yield and harvest index response to inoculant and MAP fertiliser was observed at Kimba under drought conditions.

There were no production responses in vetch to sulphur application.261 Very few positive responses or more often negative responses were observed in response to gibberellic acid. Further work needs to be done in this area to determine the best use for gibberellic acid in pulse production.

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 water use efficiency concept as developed by Reg Smith and and Jeff Schultz in SA provides us with a technique for assessing the performance of a crop in terms of the quality of the grain produced per millimitre of rainfall which falls over the growing season.

• A mixture of Moddus and Cycocel at GS 24 will reduce wheat plant height more reliably compared to the other treatments applied on their own.
• Plants sown into situations of higher fertility will produce taller plants that may respond better to the use of PGRs to control plant height and biomass which may improve WUE.
• For season long plant growth regulation a follow up PGR may well be required later in the season to stop plant 'bounce back'.

• Concentrating the header trash into rows prevents spreading of weed seeds across the paddock. Additionally, it allows for site specific weed management and weed seed destruction through strategic burning.
• A low cutting height (10cm) can allow greater than 95% weed seed capture and placement
  into rows. However this harvest height can impact harvest cost, speed and efficiency.

This study has shown that substantial savings can be made with the use of this technology. It essntially allows the farmer to have a zero tolerance on summer weeds, without having to apply economical thresholds. The study also identified that the savings will not always result. If there is consistently, 60-70% ground cover, the economical returns may not be as great. This is due to the way the technology is designed. Often in relatively high densities, two sensors would come on to spray one weed, hence twice the amount of water. This is most likely the cause of more water being used in the areas with the High density. Overall, the Weed Seeker technology has the potential to reduce chemical costs and increase the efficiency of spray applications.

• Sowing date combined with appropriate variety selection and adequate nitrogen supply was key to increasing grain yields.
• Nitrogen fertiliser decision needs to consider the maximum attainable yield and be adjusted for the seasonal conditions and initial available soil nitrogen.

There are still many answers required before we can be confident on how to manage this important and expensive input to our farming systems.

• There are still many answers required before we can be confident on how to manage this important and expensive input to our farming systems.
• There is little chance that we can work out a profitable N management system if we do not know what happens to applied nitrogen in our cropping soils.

• Wheat yields were relatively good at all three sites considering the season.
• There were yield responses from the N topdressed fertiliser at the N response sites, Birchip and Charlton.

• Our standard package of 100 kg 18:20/ha at seeding under the seed row (to avoid fertiliser toxicity), Jockey-treated seed, endosulfan and simazine pre-seeding, a follow up spray of atrazine and a grass herbicide mid-season, and two top-ups of nitrogen during the season (50 kg N/ha as broadcast urea each time) gave us a clean, high yielding and good quality crop with no pests or diseases.
• There was no evidence that extra management options provided any further benefits to canola performance (ie a fungicide spray, B fertiliser or use of a growth regulant) under the conditions of last year’s trial.
• However, it would appear that we may have been a bit generous with our N and P inputs in the standard package because we could halve the mid-season N rate and not suffer any yield or quality loss. Additionally, leaving out P altogether had little impact so a rate lower than 20 kg P/ha may have been the best compromise last year.
• There seems little reason to change from a management strategy of plenty of N at seeding (providing you can avoid seedling toxicity by separating the N and the seed) followed up by an early season top-up. Delayed aapplications of N produced yields or quality no better than our standard.

• The yield of wheat and barley was double on cultivated fallow compared to chemical fallow medic pasture.
• Cultivation is also known to reduce the numbers of nematodes.

This is the first experiment to evaluate the effect of canopy architecture on wheat yield in Australia. The results show that leaf erectness appears to be an important trait for wheat in Western Australia. Erect leaves allow greater light penetration into the lower canopy.  As a result a larger leaf area and longer duration of greenness is maintained in the canopy over time (Fig. 2), both of which could increase photosynthesis and improve yield (Fig. 3). More data across a wide range of environments are needed to prove the hypothesis, and test other effects on weed competition and disease incidence. We will continue to evaluate this hypothesis with WMG in 2017, and look to broaden our evaluation with future projects beyond that.

• Grain yields increased with the addition of nitrogen, producing a maximum of 4.64 t/ha, with 75 kg N/ha.
• Nitrogen application timing produced no significant differences to grain yield.
• Crop sensors used at early stem elongation, were able to accurately measure crop nitrogen uptake and tiller number.

• Nitrogen application timing produced no significant differences to grain yield.
• Grain yield was reduced by 12% with the presence of ryegrass.
• Crop sensors were able to accurately measure crop dry matter.

The slower development of MacKellar compared to Kellalac was associated with a higher tiller count in spring. However this did not translate to higher ear numbers, since with Kellalac 75% of tillers produced an ear, compared to 65% with
MacKellar (in Hamilton the opposite occurred).g/ha Sulphur.

It is important to consider the seasonal risk posed by diseases when developing an appropriate disease management strategy. Avoiding susceptible barley and wheat varieties will significantly reduce the risk of grain yield and quality loss due to disease Both foliar and fertiliser fungicides can both provide effective disease management when applied to coincide with the critical development stages of disease epidemics.

Seed and fertiliser dresings and in-crop fungicides did not give a response in wheat in a drought year. Ventura and H45 yielded better than Diamondbird.

• Seed and fertiliser dresings and in-crop fungicides gave responses in wheat that were inconsistant.
• Stripe rust varieties gave less reponse.
• Generally the best response came from spraying at full tillering (Z31).

• Fertiliser dressings gave responses in wheat during 2008.
• There were no responses to in-crop fungicides.
• During the four year of the experiment, the best fungicide treametns have benn the seed and fertiliser treatments and the in-crop fungicide sprays at growth stage Z 39 (flag leaf emergence).

• Similar yields can be obtained using a number of combinations of seed and fertiliser.
• Low tiller numbers can be recovered by using light amounts of nitrogen.
• There may be opportunities to use much lower inputs and still produce high-yielding and profitable crops.

• Trial reveals that 70 plants per square metre (about 35kg seed) and 5-10 kilograms per hectare of phophorus represent the optimal target plant density and phosphorous input level for wheat.
• Similar yeild results can be obatained using a number of combinations of seed and fertiliser.
• Low tiller numbers can be recovered by using light amounts of nitrogen.

• Wheat responded to up to 12 kilograms per hectare of phrosphorus (P) without added nitrogen (N) and to 6kg/ha of phosphorus with added nitrogen.
• Higher fertiliser rates did not improve yield or tiller numbers.

Two years of trials at Forbes on low Zn soils show no indication of wheat response to Zn fertiliser. There is some evidence that Zn deficiency in wheat can be intensified by SU herbicides. However, the critical soil Zn levels needed to justify Zn fertiliser use in wheat grown on lower pH soils treated with SU herbicides is unknown. Fertiliser test strips over a number of years have an important role to play in determining potential Zn responsiveness.

• Nitrogen applied during stem elongation significantly improved grain yield and protein.
• The higher density crop produced greater yields for both row spacings.
• There was little difference in grain yield between the row spacings.

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.

• There was no yield response to increased P rates in any variety tested suggesting that adequate available soil P masked any purported difference in P use efficiency between varieties.
• However, there was a trend in that the grain yield of the variety Axe increased in response to higher levels of P in both the replicated and broad acre studies.

• Early sowing increased grain yields in all of the wheat varieties trialed, however, the size of the increase was dependent on the variety.
• Nitrogen application increased grain yield in the early sown treatments and increased grain protein especially in late sown crops.

Nitrogen use has resulted in great improvements in crop yield in favourable seasons.
In dry seasons too much applied nitrogen can result in haying-off and lower yields.
Good guidelines are now available for nitrogen use to reduce the risk of crop failure resulting from applying too much fertiliser nitrogen.
The critical factors are:
• Stored soil water (control summer weeds)
• Measure how much nitrogen is in the soil prior to sowing
• Calculate nitrogen requirement from the target yield
• Do not pre-drill more than 60 kg/ha of urea in the 350mm rainfall zone (100kg/ha in the 450mm zone)
• Split applications are safer
• Topdress with urea if the soil test indicates a need, the crop is healthy, and the outlook is for an average to wet season

30 years after application, water soluble P leaches to depth on grey sands but is still effective for the growth of deep rooted blue lupins.  On the one-hand, the citrate-soluble P in C-500 releases more slowly through time and so has a longer term residual effect than water soluble P. On the other hand, higher rates of C-500 are required than superphosphate to reach maximum yield when soil P levels are low.  It is less likely to leach and so pollute ground waters. If cheap enough, C-500 could be used as a maintenance P fertiliser.  Much work is still to be done on this trial site.

Calculating N supply in a highly variable climate is a difficult task and delivering split applications is attractive when aiming to minimise the risk of over- or under-fertilising.

• Canola grown in wide rows (50-60cm) yielded well enough to consider this row spacing as an option.
• Canola plants were able to compensate for being sown in wide rows - biomass similar to narrow rows.
• We may be able to reduce input costs, seed and fertiliser by refining the production package in wide rows.
• Wide rows offer benefits of reduced fuel costs at seeding, easy stubble handling and safety of IBS herbicides.

• Canola grown in wide rows (50-60cm) yielded well enough to consider this row spacing as an option.
• Canola plants were able to compensate for being sown in wide rows - biomass similar to narrow rows.
• We may be able to reduce input costs, seed and fertiliser by refining the production package in wide rows.
• Wide rows offer benefits of reduced fuel costs at seeding, easy stubble handling and safety of IBS herbicides.

• Canola grown in wide rows (50-60cm) yielded well enough to consider this row spacing as an option.
• Canola plants were able to compensate for being sown in wide rows - biomass similar to narrow rows.
• We may be able to reduce input costs, seed and fertiliser by refining the production package in wide rows.
• Wide rows offer benefits of reduced fuel costs at seeding, easy stubble handling and safety of IBS herbicides.

• The main difference in yield may have been due to poor tillage in the 500mm spaced crop.
• The entire crop was reliant on the soil nutrition from the pasutre as no fertiliser was applied to the paddock prior to and following seeding.
• Later sowing of the trial may have jeopardised the wide row's yield capacity therefore it would be encouraged that when considering sowing in wide rows early seeding is preferable.
• It may be noted that if nutrition was not a limiting factor for the 500mm crop, the water supply from the wide row may have increased yield to similar or better than that of the 250mm crop.

• Spring barley germplasm cv Planet following canola with an estimated 146 kg N/ha available soil mineral N (0-90cm) gave a small response to applied nitrogen fertiliser with yield maximised (9.74 t/ha) with 80 kg of applied nitrogen per hectare.
• The highest yield (10.1 t/ha) was achieved with an application of 240 kg N/ha; however, this was not significantly higher than the yield achieved (9.74 t/ha) when 80 kg N/ha was applied.
• No lodging was observed in this trial.
• When 200kg N/ha or more was applied grain protein was higher than 12.0% and grain was no longer classed as malt quality.
• There was a significant increase in final dry matter production associated with 80 kg N/ha in comparison to the unfertilised (14.83t/ha increased to 17.7 t/ha).
• At higher rates of nitrogen, the dry matter steadily increased to 20.8 t/ha at the highest rate of 320kg N/ha.
• Since there were no significant yield increases associated with higher N rates harvest index (proportion of harvest dry matter harvested as grain) decreased at higher N inputs, however the differences were not statistically significant varying from 51.8 to 42.3%.
• There was no statistical difference in nitrogen offtake in the crop canopy at harvest in the grain & straw between 200-320kg N/ha applied an uptake of 238-292kgN/ha assuming straw and grain was removed from the paddock.
• N uptake associated with applied N rates above 160N were not translated into higher grain yields but were associated with higher grain protein.
• N offtake in the crop canopy peaked at 292kg N/ha when 280kg N/ha was applied.
• Head number was significantly increased by nitrogen applied although there were no yield increases associated with head numbers above 840 heads/m2 in this trial.

• Lodging began in early October with the general trend being more lodging as the N rate increased but not necessarily as a lineal progression.
• The uptake of N by the crop did increase as rates applied increased. This resulted in higher total biomass but not necessarily higher grain yield. Of the two rates assessed, the uptake of applied N was approximately 45%.
• Highest yielding treatments were those that received 80 – 280 kg N/ha. 0 kg N/ha or the highest rate of 320 kg N/ha resulted in decreased yield.
• While 120 kg N/ha did not see a yield increase over the 80 kg N/ha treatment, it did see grain protein high enough to meet malting specification.
• As a general trend, higher applied N resulted in higher grain protein and lower retention. Using the yield results from the 120 kg N/ha treatment, the Nitrogen Use Efficiency was 30 kg N required per tonne of grain.
• WUE of the trial averaged 19 kg/mm.

• Barley yields cv RGT Planet of over 6t/ha were achieved in 106 days from sowing to harvest with no applied nitrogen.
• Yield was maximised with no addition of nitrogen fertiliser.
• At the highest rate of 240 kg N/ha, there was a significant reduction in yield (6.03t/ha) compared to where no nitrogen was applied (6.24 t/ha).
• There was no difference in grain yield when nitrogen application timing was varied.
• Grain protein increased as higher rates of N were applied up to 160 kg N/ha. Between 160 and 240 kg N/ha, there was no difference in grain protein.
• The grain protein was too high to achieve malt quality in all application timings and rates of nitrogen in this trial.

• There was no interaction between nitrogen rates and nitrogen timing in this trial.
• With moderately high soil fertility following canola (146 kg N/ha available mineral N (0-90cm)) there was no significant difference in grain yield at N rates between 80 – 240kg N/ha (identical result to Trial 1).
• Delaying nitrogen application to GS32 (second node) and GS37 (flag leaf visible) gave a significantly higher yield (9.95 t/ha) than applying nitrogen at sowing and GS30 application (9.37 t/ha).

• Delaying the nitrogen applications to the development window GS32-GS37 increased protein slightly and although the effect was not statistically significant the risk of not achieving malt quality is increased at higher N levels.
• Grain protein increased as higher rates of N were applied, at 160 - 240 kg N/ha, protein was above the maximum 12% required to achieve malt quality irrespective of N timing.
• There was no significant differences in test weight (data not shown), although it was a factor in some treatments not achieving a malt quality grade.
• N uptake in the crop at harvest indicated that over 200kg N/ha had been taken up in the crop.

Wheat, barley and canola were tested in 2018, and wheat and barley in 2019, representing a range of quality segregations. Trials were located close to Hyden, Kojonup, Jerramungup, South Stirling, Mt Madden, Munglinup, Gibson and Scadden and Salmon Gums.

The 2018 season was characterised by significant autumn rainfall and below average seasonal rainfall for most sites. The first time of sowing was seeded dry for most cereal and canola trials and the second sowing followed opening rains.

There was little evidence from the eight locations in 2018 to support the idea that the latest varieties differ in their response to increasing N and P inputs in wheat, barley and canola such that it could be exploitable by growers. Some interactions between variety and N and P nutrition were identified but responses were isolated and varied with crop and site. For example, significant interactions were measured for wheat yield at Gibson and protein percent at South Stirling; barley yield at Jerramungup, protein at Hyden, protein at South Stirling and screenings at Kojonup; canolayield at Gibson and oil content at Hyden.

In 2019 the Western Australian wheatbelt experienced a late start to the winter growing season and one of its driest. Data from the Bureau of Meteorology show all sites tested in 2019 experienced a Decile 1 season with well below average seasonal rainfall.

The 8 locations for wheat and barley in 2019 tested N rate and timing and supported the findings of 2018 with very little evidence to support the idea that varieties differed in their response to increasing N inputs. In fact, the opposite was true with the four varieties of wheat and barley tested responding in very similar ways for yield and grain quality.

The lack of consistent variety x fertiliser interactions in these environments suggests growers need only consider a crop and not specific varieties in their agronomic management.

N and P nutrition in 2018 and N nutrition in 2019 data supports current farmer practices of adequate basal nutrient upfront for the season, followed by post-emergent nitrogen as season and yield potential warrant.

Conclusions of this study are limited by the site-specific growing conditions and choice of varieties.

Take Home Messages

• Near perfect growing season for canola, provided ideal opportunity to assess the residual N feeding effect of the legumes.

• All legumes sown in 2016 – peas, lupins, sub clover and faba beans had similar starting soil N levels and soil water nitrate readings throughout the year which was reflected in similar grain yields inferring that all legume species were equal in terms of their N fixing capabilities.

• The average amount of N fixed by the legumes was calculated as ~86kg/ha.

• Growing adequately nodulated legumes can give rise to a ~1t/ha canola yield advantage compared with a non-legume.

• Linseed used more moisture, from a greater depth, than the faba beans in 2016. Resultantly more moisture was extracted by the canola crop sown on the faba bean stubble in 2017, and yet there is still more  residual moisture left.

Similar to trials undertaken in previous years, the fungicide trials undertaken in 2005 indicated there was no fungicide activity on Yellow Leaf Spot (YLS) when applied early post emergent (GS13 – three leaf stage). Fungicides applied to fertiliser or as a foliar application did not reduce the level of YLS in the crop and showed no yield benefits. Zincsol® applied to crops in paddocks which have had a good zinc fertiliser history also showed no benefit in reducing YLS pressure. After several years work the BCG conclude that spraying fungicides for YLS is not a successful practice.

Similar to trials undertaken in previous years, the fungicide trials undertaken in 2005 indicated there was no fungicide activity on Yellow Leaf Spot (YLS) when applied early post emergent (GS13 – three leaf stage). Fungicides applied to fertiliser or as a foliar application did not reduce the level of YLS in the crop and showed no yield benefits. Zincsol® applied to crops in paddocks which have had a good zinc fertiliser history also showed no benefit in reducing YLS pressure. After several years work the BCG conclude that spraying fungicides for YLS is not a successful practice.

• An increase of wheat grain yields released between 1957 and 2007 was found.
• Yields have increased because of improved harvest index, more biomass at flowering, and increased grain number.
• Nitrogen is critical in allowing each variety to reach its potential through increasing growth rate between stem elongation (GS31) and flowering.
• WUE has improved over the 1957-2007 timescale through increased yields, not greater extraction of water.

• APSIM simulations, accessed through the Yield Prophet web interface, were evaluated for their ability to forecast nitrogen fertiliser responses at the canopy management trial in the Wimmera.
• Yield Prophet accurately simulated crop yield and protein for a range of nitrogen fertiliser application rates and timings.
• Yield Prophet was able to estimate likely nitrogen fertiliser responses and dollar returns during the season.
• For accurate simulations Yield Prophet requires good soil characterisation data (crop lower limit, drained upper limit and bulk density) and pre-sowing measurements of soil water and available nitrogen.

• There have been findings that Wyalkatchem is generally more frost prone than other varieties.
• If you are cropping a high frost risk area, good management would suggest minimising input costs (e.g. fertiliser) in these areas.
• Due to the large LSD there were no statistically different treatments. However there seems to be a trend that the lower seeding rate improved yield.
• There was no significant yield difference between retaining stubble and burning the stubble at both seeding rates.

• Zinc in shoots at tillering was much higher in plants supplied with fluid phosphorus than with granular phosphorus.
• Given that in both sets of treatments zinc was supplied as zinc chelate at quite a low rate (0.75 kg zinc/ha) in a fluid below the seed row (except in fluid treatments it was mixed with TGMAP) these results suggest that mixes of trace elements with NP fluid fertilisers may be a more effective technique for supplying trace elements to broad acre crops.
• Conditions in both trials were not zinc deficient for wheat production so the absence of zinc in fertilisers at seeding had no impact on the productivity of either wheat at either site, or on their response to phosphorus fertilisers.

• Wheat grain Zn concentration decreased with P fertiliser addition.
• Wheat grain Zn concentration was lower after canola than after either linola or clover pasture.
• Wheat receiving P fertiliser had lower mycorrhizal colonisation than that with no P added.
• Wheat after canola had lower mycorrhizal colonisation than that wheat after linola or clover pasture.
• It was hypothesised that Zn uptake was reduced where mycorrhizal infection was lower.

• Compared some of the physiological differences in two bread wheat genotypes (Stylet (Zn-efficient) and VM506 (Zn-inefficient).
• Results indicate that higher zinc efficiency may be achieved through greater distribution to younger parts and lower internal requirement.
• Selection for such attributes can be considered in breeding programs aiming to develop zinc efficient genotypes for cropping zinc deficient soils.

• Twenty five genotypes of oilseed rape (canola and mustard) were tested under varied supply of zinc in pot experiments in soil culture to determine the genotypic variation in tolerance to the zinc-deficient condition.
• On the basis of the pot experiments, ten genotypes were tested in 1995 under varied supply of zinc on a zinc-deficient field in South Australia.
• Zinc efficiency in pot Experiment 1 varied from 35% for 92-13 to 74% for Siren. Narendra, Dunkeld, Barossa, Oscar and Xinza 2 performed well under low zinc conditions zinc efficiency in Experiment 2 varied from 32% for Wuyou 1 to 62% for Pusa Bold.
• Root dry matter accumulation was significantly higher in zinc-efficient genotypes.
• With few exceptions, the ranking of genotypes in pot and field experiments indicates similarity in their response to zinc deficiency.
• Zinc-efficient genotypes had lower zinc concentration in roots and higher zinc concentration in youngest fully opened leaf blades, indicating a better transport of zinc.
• This, together with a higher zinc uptake, appears to be the basis of expression of zinc efficiency.

• The application of zinc had no effect on yield or grain protein.
• Zinc coated products are effective in supplying zinc.

• There was no significant difference between treatments, water use efficiency is very high indicating we do need to consider Jan to April rainwall as well.
• There as a trend for yields to increase with increasing rate of P applied.
• For further conclusions please see the attached trial report.

• Five year trial examining strategies for application of zinc to field pea.
• Zinc applied to soil, to seed or as foliar spray.
• Zinc application did not increase grain yield of field pea.
• Seed zinc concentration was 20% higher when foliar zinc applied to field pea.

• Yields may be limited by zinc even where deficiency symptoms are not apparent.
• Responses to zinc are common on clays in the Wimmera and sands in the Mallee.
• Phosphorus is required to make zinc fertiliser effective.
• Grain protein is not increased by zinc application.
• Applications of zinc are recommended every second or third crop as zinc has some residual value in the soil.
• Zinc is typically applied in a mixture with phosphorus fertiliser.
• 2 - 2.5 kg /ha zinc should be sufficient for 4-6 years.

In previous years, trials and demonstrations have highlighted zinc deficiencies in both cereals and pulses, which could provide farmers substantial profits over the cost of zinc. Six trial sites were chosen, all with adequate zinc histories, to demonstrate advantages of supplying extra zinc to wheat crops. As there were no significant yield responses to the various applications of zinc, it was concluded if adequate zinc enriched granular fertiliser had been regularly applied in previous years there was no benefit from the application of additional zinc.

• Over a five year period incorporating either foliar or seed coated zinc increased wheat grain zinc concentration above soil applied zinc fertiliser.
• Neither timing or application type (on seed, in soil or foliar) or rate had any effect on grain yield, protein or screenings at this site.
• Copper was applied every two years in some treatments but it had no apparent effect on grain yields or grain or tissue copper concentrations.

• Comprehensive fertiliser trial at >20 sites across the Wimmera and elsewhere in Victoria in 1938 .
• Results showed that Wimmera soils were responsive to zinc but not other areas of the State.
• Under low rainfall conditions 5-10 lbs/acre were as effective as higher application rates of zinc sulphate.
• Increased yields are to be expected when superphosphate and zinc are applied together on most black soils in the Wimmera.
• Effects on oats, clover and peas were greater than for wheat.
• Red and loamy soils responded variably the zinc application

• Two pot experiments were conducted to evaluate the response of wheat to 3 rates of zinc sulphate on 3 contrasting black earths.
• On all 3 soils zinc concentration plant tops increased with application of zinc but declined as the application of phosphorus increased due to dilution from increased plant growth.
• The results of these experiments suggest that response to zinc fertiliser only occurred on the alkaline soils where the available zinc was less than 1 ppm.
• No evidence was obtained that phosphorus supply had any effect on the availability of zinc for plant uptake but other experiments indicated that zinc absorption was reduced by increasing phosphate concentrations in solution.