• 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 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.

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 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.

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.

• 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.

• 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.

• A diagnostic service is available to farmers and industry for diseased plant specimens.
• Samples of all leaf and aerial plant parts should be kept free of moisture and wrapped in paper not a plastic bag. Roots should be dug up carefully, preserving as much of the root system as possible and preferably kept damp. Samples should be sent to the following address:

SARDI Diagnostic Centre
Plant Research Centre
Hartley Grove
Urrbrae SA 5064

• 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.

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.

• 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.

• 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.

• 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.

• The laboratory analysis indicated the site would be zinc responsive.
• Zinc sulphate was no applied and no zinc deficiency symptoms were observed.
• Extensive trials in the Forbes district have never shown a response to zinc fertiliser in wheat.

• Trace elements applied to the soil (either shallow at seeding or deep prior to seeding) two years previously benefitted wheat at a clay spread site.
• Accross all sites and six years of measurements there were no measurable residual responses to deep placed nutrients.

• Fluid fertilisers performed better (increased early growth and grain yield) with the addition of low rates of micronutrients.
• Foliar micronutrients were more economic than granular.

• Zinc treatments (1-5 kg/ha) did not increase grain yield or protein .
• Neither timing nor application type (on seed, in soil or foliar) nor rate had any effect on grain yield or protein at this site.

• Clay spreading with calcareous clays can induce manganese deficiency .
• Single foliar application of trace elements may not be sufficient to overcome this deficiency.

• A very dry year and indicative problems with wheat accessing trace elements in dry soils.
• There were signifcant yield reponses to zinc and magnesium.

• 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.

• The +Zn treatment received 7 kg Zn/ha at sowing plus 2 foliar sprays of 0.33 kg Zn/ha.
• Generally, yield responses to Zn are greater in durum and bread wheat than in barley.
• The most inefficient lines of wheat and barley showed distinctive symptoms of Zn deficiency, such as reduced growth, pale leaves with chlorotic and necrotic lesions along the mid-vein.
• In 1999 a dry spring limited the yield response to Zn to about 0.5 t/ha, whereas, in 1998 yield increases up to 1 t/ha were measured.
• The disparity between the vegetative and the yield responses has tended to be greater in barley than in wheat.
• The wheat cultivars Goldmark and Kukri have low Zn efficiency, whereas the widely adapted, high yielding cultivars Trident, Krichauff and Worrakatta are Zn-efficient.
• Within barley, a number of Japanese breeding lines (eg SBWI-1) are very inefficient, but many current cultivars from SA as well as Arapiles (Vic.) and Stirling (WA) show a high level of efficiency.
• Pot assays for Zn efficiency have been developed and generally show similar rankings to the field tests.
• Wheat double haploid populations derived from the cross between Trident (efficient) and Songlen (inefficient) have been produced to develop molecular markers for Zn efficiency.

• All treatments with zinc sulphate or commercial fungicide Tilt reduced yellow leaf spot infection but only Tilt treatments had increased grain yield.
• Despite yield increase the Tilt treatment was not economic.
• Triadimefon and copper sulphate did not reduce yellow leaf spot infection.

• We examined the interaction between zinc nutrition and heat stress on the photosynthetic activity and grain yield of wheat plants under both field and growth room conditions.
• The zinc inefficient cultivar Goldmark was found to have an improved chlorophyll fluorescence ratio (Fv/Fm), a measure of injury to photosynthesis, under heat stress when supplied with elevated levels of zinc compared to plants where less zinc was applied.
• However supplementary zinc did not prevent a decline in kernel weight or grain yield under high temperature conditions.
• The results indicate that supplementary zinc nutrition, in a zinc inefficient genotype at least, can provide thermotolerance to the photosynthetic apparatus of wheat.

• Studies examined the interaction between Zn nutrition and heat stress on the photosynthetic activity and grain yield of wheat plants under both field and growth room conditions.
• The Zn inefficient cultivar Goldmark was found to have an improved chlorophyll fluorescence ratio (Fv/Fm), a measure of injury to photosynthesis, under heat stress when supplied with elevated levels of Zn compared to plants where less Zn was applied.
• However supplementary Zn did not prevent a decline in kernel weight or grain yield under high temperature conditions.
• The results indicate that supplementary Zn nutrition, in a Zn inefficient genotype at least, can provide thermotolerance to the photosynthetic apparatus of wheat.

• Chlorsulfuron (eg Glean) was found to reduce wheat yields at some sites.
• No zinc (Zn) responses were recorded at any of the sites.
• Phosphorus (P) response was closely correlated with soil P levels.
• Increasing Zn and P nutrition did not reduce the Chlorsulfuron effect.

• There were no advantages gained by using seed treatments when sowing wheat with granular NP fertilisers.
• On grey calcareous soils all fluid fertilisers increased early plant vigour and grain yield, and on red soils fluids containing zinc and manganese increased grain yields.
• In this season there were no differences in dry matter or yield between crops grown from certified or local seed.

• 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.