• A literature search was conducted of research into trace elements in crop production systems of south eastern Australia.
• References found in the "grey" literature (primarily printed material not available on-line) was summarised into key points and entered into the On Farm Trials database.
• All of these entries, plus those found from searching the international peer reviewed journal literature were entered into an Endnote database.
• The Endnote database is made available here, along with a text version for use by researchers.
• This activity was funded by the GRDC More Profit from Crop Nutrition program.
• Keywords: zinc, manganese, molybdenum, iron, copper, boron, trace elements, micronutrients.

• A literature search was conducted of research into trace elements in crop production systems of south eastern Australia.
• References found in the "grey" literature (primarily printed material not available on-line) was summarised into key points and entered into the On Farm Trials database.
• All of these entries, plus those found from searching the international peer reviewed journal literature were entered into an Endnote database.
• The Endnote database is made available here, along with a text version for use by researchers.
• This activity was funded by the GRDC More Profit from Crop Nutrition program.
• Keywords: zinc, manganese, molybdenum, iron, copper, boron, trace elements, micronutrients.

• Application of trace element (Mn,Cu, Zn) mix or manganese did not improve yield at the two sites.
• Application at sowing of fungicide with the separate (split) addition of 40kg/ha urea reduced Rhizoctonia seminal root infection at both sites.
• Phosphoric acid resulted in higher yields than granular P in two of the three years of the trial at the highly calcareous site (Streaky Bay) but not in the wet year; whereas at the other site (Waramboo) on the red sandy loam there was a small yield response in the wet year.

From this trial:

Soil applications from 2015 were poorly effective at improving grain yield. Foliar applications of sulphate increased yield by about 1t/ha. Best yield increases of more than 2t/ha were achieved with a combination of soil and foliar applications. 

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Manganese. Plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Manganese. Plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Zinc. Soil and plant tests were in the deficient range. As a foliar spray, sulphate was as effective as two chelate sources for increasing leaf zinc at Z30.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Zinc. Soil and plant tests were not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Zinc. Soil and plant tests were in the deficient range. Zinc applied at seeding either as a granular fertiliser or as a fluid fertiliser increased leaf zinc Z14.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

• Current guideline of YEB values at tillering greater than 15mg Mn/kg indicative of adequate status still appear appropriate.
• No yield response recorded to application of Mn in different form or timing.

• Nutrient omission experiment at 7 sites • Take homes messages were that phosphorus was a limiting factor to grain yield in 2015. Zinc was limiting yield at three locations • Iron was a limiting factor on a grey-brown vertosol with a 50 year cropping history • 12 treatments were; Zero nutrients, All nutrients, - N, - P, - K, - Ca, - B, - Cu, - Zn, - Mn, - Mg, - Fe • Application method varied between nutrients. Both P and N were applied at sowing, at 10 kg P/ha as Trifos and 10 kg N/ha as urea, respectively. Ca, Mg, Zn, Mn, Cu and Fe were applied as chelates in a foliar spray. K was applied as Potassium citrate and B as Boron ethanolamine as foliar sprays. N and P applied at sowing, all other nutrients sprayed at mid vegetative stage. PBA HatTrick was sown at all sites at 30 plants/m2 • Sites differed in responses • Rowena showed no significant responses to applied nutrients • The Trangie, Edgeroi and Coonamble sites showed yield responses to applied Zn of, 28, 18 and 7%, respectively. Coonamble, Nowley, Moree and North Star had responses to applied P of, 4, 15, 15 and 11%, respectively • Also at the Coonamble site, a grey-brown vertosol which has been cropped since the early 1960s, also showed an 8% yield response to applied Fe • Older cropping country is showing responses to applied P as well as Zn and in one instance Fe

From this trial:

• The site was severely deficient in Cu for wheat. 
• Under these severely deficient conditions, soil applications of Cu were poorly effective compared to foliar sprays but fluid applications performed better than Cu enriched granular fertilisers.  However, soil applications of Cu can persist for decades.
• There was no evidence that a chelated source of Cu as a foliar spray was more effective than a sulphate source and less Cu seemed to end up in the grain with the chelated source.
• A single foliar spray of Cu prior to flowering is often sufficient to protect a cereal crop from Cu deficiency but under the severe deficiency encountered in 2015, two foliar sprays were necessary to overcome the problem completely (one at first node, the second prior to flowering).
• Cu deficiency can make a crop more sensitive to adverse conditions.  In this trial, the hot drying conditions of the early October weekend, severely scorched all plots with no or poorly effective Cu management strategies.
• The soil and leaf tests taken during this trial support that the current guidelines for Cu deficiency are still relevant to modern farming systems and varieties.  A DTPA Cu level in soil of less than 0.3 ppm in the top 10 cm is considered deficient, and 1.3 ppm Cu in YEBS is considered very deficient for wheat.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No change in crop performace with the addition of Manganese. As a foliar spray, sulphate was as effective as an EDTA chelate at increasing leaf manganese at Z30. Halving the recommended rate of sulphate decreased leaf manganese levels.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Manganese. Plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of Zinc. Soil and plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of zinc. Soil and plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

Grain yield increased by 7% with the addition of zinc. Effectiveness of fertiliser strategies could not be assesed with such a small increase in yield. Soil and plant tests were in the deficient range. At Z14 zinc enriched fertilisers at sowing increased leaf zinc. At Z30 a sulphate as a foliar was as effective as an EDTA chelate. 

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

• Zinc diffusion was assessed for three fertilizers in three soils of varying pH.
• The fertilizer (zincSO4-coated monoammonium phosphate, MAP; zincSO4-coated diammonium phosphate, DAP; or zincSO4 alone) was applied in the centre of a Petri dish filled with soil.
• The zinc diffusion zone was visualized at various incubation times (1, 7 and 18 days) by exposing a CaCO3-impregnated filter paper on the soil surface and colouring the zinc captured on the filter paper using dithizone.
• The extent of diffusion was also assessed through concentric sampling and chemical analysis of soil sections.
• The visualization results agreed with the chemical analyses and demonstrated the effects of soil properties and fertilizer formulation on zinc diffusion.
• Combining zinc with P fertilizer restricted its diffusion, particularly with DAP fertilizer or in high pH soils.
• Solubility considerations indicated that this was due to the formation of zinc phosphate minerals.

From this trial:

No crop response to the addition of copper. Soil and plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

 

From this trial:

No crop response to the addition of Manganese. Plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

From this trial:

No crop response to the addition of zinc. Soil and plant tests not in the deficient range.

From the whole project:

Current guidelines are still relevant and effective for TE management.

Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.

No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.

Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.

Generally, all sources of foliar TE were equally effective.

• The critical zinc concentration in shoots ranged from 22 to 29 mg /kilogram across the 5 durum varieties • There was no difference in shoot zinc concentration of the 5 varieties within any of the zinc treatments, ranging from 0.025 to 5 mg / kilogram of soil • There was some evidence that zinc sensitive genotypes were more likely to suffer from crown rot

• Zn deficiency was evident at mid-tillering at one site only (Streaky Bay) in treatments where zinc had not been applied.
• Manganese deficiency was not identified via tissue testing at Streaky Bay despite treatments with added manganese having better earlier growth.

• Across three years addition of trace elements and fluid fungicide in-furrow did not provide increases in emergence, tillering or final yield - although this contradicts what other farmers have reported.
• Liquid N at sowing can improve crop emergence and early vigour, especially under dry conditions .
• Full liquid systems did not provide a profit benefit (due to higher input costs) even where they did provide increased yield which was not in all years.
• Recommendation most likely to provide higher returns for this area will be an in-furrow fertiliser system that incorporates some elements of liquid nitrogen and phosphorus fertiliser ,trace elements, fungicides and granular phosphorus and nitrogen fertiliser.

• Boron phosphate compounds were synthesized by mixing boric acid and phosphoric acid (1:1 molar ratio) and heating at temperatures of 25 to 1000 °C for 1 or 24 h.
• X-ray diffraction patterns and chemical analysis results showed formation of boron phosphate compounds at low temperature • These compounds gradually crystallized with increasing temperature and heating time.
• The compounds synthesized at 300°C or less were hygroscopic, while those synthesized at 500 to 1000°C were non-hygroscopic and free-flowing.
• The solubility of all compounds decreased with increasing synthesis temperature • The solubility of compounds synthesized at 500 and 800°C increased with increasing pH.
• The compound synthesized at 1000°C was nearly insoluble and the solubility was not pH dependent.
• The release of B from the boron phosphate synthesized at 800°C for 1 hour was approximately 70% after 150 days, which confirmed its slow release.
• The characteristics of the compounds synthesized at temperatures 500 and 800°C showed that it can be used as raw materials for co-granulation with macronutrient fertilisers such as mono-ammonium phosphate.
• Such co-granulated products are currently being tested.

• Commercial granular and liquid monoammonium phosphate fertilizers enriched with zinc were incubated under dry and wet conditions to test the effects of dry sowing on fertilizer diffusion, lability, and subsequent availability to wheat (Tritium aestivum L. ‘Axe’) plants in the growth chamber using isotopic techniques.
• Fertilizer incubated in dry soil tended to have a much greater lability than in wet soil, but diffusion was limited.
• The restricted diffusion during the incubation did not negatively impact nutrient availability to plants subsequently grown in the growth chamber, however, and simulated dry sowing was not shown to have a detrimental effect on fertilizer efficiency.

• Simulated dry sowing was not shown to have any detrimental effect on Zn fertiliser use efficiency.

• zinc oxide fertilisers had lower solubility and dissolution than zinc sulphates • zinc oxide was as effective as zinc sulphate if it was mixed with the soil but not when banded near the seed • zinc sulphate would be preferable to zinc oxide in no-till systems where fertiliser is banded

• Glasshouse experiments measured plant DM response and recovery of Zn fertilisers in oxide and sulfate form using three placement treatments - banded, mixed throughout the soil volume, and applied to the soil surface • Also plant recovery of Zn from pure Zn phosphates and carbonates, which are likely reaction products of banded Zn fertilisers in soil, was measured. Recovery of Zn from Zn phosphates, carbonates and oxides was lower than that of Zn sulfates when banded • Placement was the major factor controlling plant responsiveness to Zn • Zinc oxide fertilisers had very low water solubility and slow dissolution rates in water, which is related to the high pH when the oxide is dissolved in water • There was significantly less recovery of fertiliser Zn by plants from Zn oxides than from Zn sulfates when the fertiliser was banded near the seed, likely due to higher pH in the band as the oxide dissolved • However, the Zn supply to plants was the same for both sources of Zn when fertilisers were mixed through the soil, as the soil likely buffered any dissolution-induced pH increases • This means that Zn oxides, despite their low water solubility, can be effective fertilisers if uniformly mixed throughout the crop rooting depth but Zn sulfate is preferable for banding or surface application.

• A full liquid system including N, P, Trace elements and fungicides provided the greatest yield response and was significantly better than district practice granular treatments.
• Liquid N gave the most significant response of all liquid treatments in terms of mid-season biomass and yield.
• Full liquid and liquid N treatments provided similar returns to that of traditional treatments and greater returns than liquid P only.

• Applying N at GS31 increased yield but no response to manganese was measured.

• No further yield benefit was measured from applying other nutrients (S, K, Mg) and trace elements (Zn, Mn, Cu) over and above that from applying nitrogen and phosphorus alone.

There was a dry matter response measured at anthesis to all treatments with application of manganese but due to dry season this was not translated into yield increases.

• Zinc efficient and inefficient wheat cultivars were grown in soil cores in the glasshouse • The calcareous soil had low micronutrient levels and high pH and boron • Although cultivar Gatcher produced 47% more dry weight of tops and double the root length density of cultivar Excalibur at maturity, cultivar Excalibur was much more efficient in terms of zinc uptake by roots and sevenfold more efficient than cultivar Gatcher in partitioning zinc to grain

• Zinc-efficient (Excalibur) and inefficient (Gatcher) wheat cultivars grown in calcareous subsoil with low micronutrient levels, high pH and B • Treatments were +/- basal nutrients (exc Zn) and +/-Zn • Gatcher produced 47% more DM tops and double the root length density of Excalibur by maturity Excalibur was far more efficient in Zn uptake and seven times more efficient than Gatcher in partitioning zinc to grain.

• With high grain prices, small increases in productivity can significantly improve farm profitability • At Goolagong, NSW, wheat yields were significantly increased by the use of a balanced fertiliser regime including N, P, K, S, Mg and Zn • An analysis of gross margins showed that the application of secondary and trace elements would have significantly improved farm profitability • Zinc-efficient (Excalibur) and inefficient (Gatcher) wheat cultivars grown in calcareous subsoil with low micronutrient levels, high pH and B. Treatments were +/- basal nutrients (exc Zn) and +/-Zn • Gatcher produced 47% more DM tops and double the root length density of Excalibur by maturity • Excalibur was far more efficient in Zn uptake and 7 times more efficient than Gatcher in partitioning zinc to grain • Simulated dry sowing was not shown to have any detrimental effect on Zn fertiliser use efficiency • Method: Commercial granular and liquid monoammonium phosphate fertilizers enriched with isotopic Zn were incubated under dry and wet conditions to test effects of dry sowing on fertiliser diffusion, lability and subsequent availability to wheat (Axe). • Result: Fertiliser incubated in dry soil tended to have greater lability but diffusion was limited, although this did not have any effect on availability to subsequent wheat.

• Fluid trace elements banded under the seed row is an effective system for delivering these nutrients to cereal crops.
• Rates of trace element application as banded fluids may be lower than for other seeding strategies and cheap sulphates can be used • Mixes of trace elements as banded fluids are effective.
• Trial was not trace element deficient.

• A potted history and review of research into trace element deficiencies in South Australia (PDF available).

• Soil and solution culture studies were conducted to examine the relative contribution of different mechanisms of zinc efficiency at the whole plant level in bread and durum wheat during early vegetative stage.
• While there are a number of mechanisms of zinc efficiency, zinc uptake appears to be the most important mechanism • Seed zinc remobilisation and root to shoot translocation do not appear to be important to zinc efficiency.
• Visual scores of zinc deficiency were significantly correlated with zinc efficiency, and they provide a useful criterion for an initial screen of zinc efficiency.
• This study was based on vegetative growth and the conclusions need to be verified under field conditions.
• The percentage deviation technique provided a straight forward means of comparing the relative effects of different components of zinc efficiency and the method could be extended to studies that use grain yield as the measure of zinc efficiency.

• Wheat yields were improved by using a combination of N,P,K,Mg,S,Zn fertilisers • Canola yields were improved by using a combination of N,P,S and Zn fertilisers • Gross margins suggested balanced crop nutrition could improve farm profitability despite dry conditions and high fertiliser prices

• Incorporating clay that has high calcium carbonate (lime) content has potential to cause extreme manganese deficiency although this can be addressed with addition of micronutrient fertiliser either shallow or deep.

• 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.

• Investigated infertile soils over clay in SA and Victoria.
• Earlier work showed that a "shotgun" mix of N, P, zinc, copper and manganese placed at 40cm regularly doubled cereal yields.
• Have shown that such applications have onging residual benefits.
• Need at least 25cm of sand or haying off can occur in dry years.
• Deep ripping tyne type and spacing appear to be less important than depth of application at 40cm.
• Apply nutrients at a rate which would double current yields.
• Management of erosion after ripping is the primary challenge.
• Addition of deep nutrient during ripping would appear to be a good option with reliable benefits.

X-rays of small dishes of soil to which fertiliser had been added in the centre showed that fluid forms of copper, zinc and manganese are more mobile (diffuse further) in soil compared to granular forms.

• Trace elements can be added to a farming system via a fluid delivery system.
• Economic responses to trace elements did not occur in non-responsive situations regardless of form of application.
• Addition of N and P to trace element fluid fertiliser did not appear to enhance trace element uptake.
• Lower cost foliar applied trace elements offer a cheaper approach to trace element application whilst still providing economic returns.

• Wheat grown on highly calcareous soils responded to zinc and manganese applications.
• Micronutrients were most effective when they were applied in fluid form which provided economical responses.
• There was no grain yield response when granular micronutrients were applied as a dry blend with granular NP fertiliser or as a coating on granules.

• Movement of water towards P fertiliser granules occurs and in calcareous soils this causes P to form a solid precipitate with calcium ions and prevents P moving away from where it is applied and reduces likely availability.
• Manganese from fluid fertilisers moves further away from point of application compared to a granular source of Mn and was potentially more available.
• Movement of zinc away from point of application was restricted regardless of the source and in both soils but fixation of zinc was less when the sources was fluid rather than granular.

• 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.

• Glasshouse experiments and field experiments in South Australia and Victoria were conducted to examine wheat tolerance to heast stress as related to zinc nutrition • The results showed that good zinc nutrition could preserve membrane integrity and photosynthesis during heat stress • Supplementary zinc nutrition was shown to increase canopy cooling through evaporation • The field and glasshouse experiments showed that the combinaiton of heat stress and poor zinc nutrition were more damaging when they occurred together • Zinc sufficient plants had higher quality grain (glutenin:gladin) and better bread making qualities

• Applying trace elements at sowing or as a foliar mid-season were equally effective in this particular year.
• Response of wheat plants to DAP with trace elements in the fertiliser compared to other methods for trace element application was variable and needs further investigation.