Ysgellog Project Introduction: Micronutrient availability in grassland soil: its role in promoting grass production

Site: Ysgellog, Rhosgoch, Amlwch, Anglesey

Technical Officer: Non Williams

Project Title: Micronutrient availability in grassland soil: its role in promoting grass production

 

Introduction to project: 

A total of sixteen elements are required for plant nutrition, which are commonly classified as macro and micro nutrients (Teagasc, 2020). Some micronutrients are deemed less significant than others in terms of soil health. Nevertheless, achieving an appropriate balance between macronutrients and micronutrients is fundamentally important in ensuring optimum performance from grassland.

Prescriptive soil analyses are commonly used to determine concentrations of the major macronutrients (i.e. nitrogen, phosphorus, potassium) in agricultural soils. However, soil sampling for micronutrients is not as commonly practised, despite both macro and micro nutrients interacting with each other.

Micronutrient deficiency in soils can lead to major constraints to crop productivity. The importance of micronutrients in soils for animal health and productivity is under-researched (Kao et al., 2020), despite it being imperative to their performance due to the fact that there is no direct relationship between the level of micronutrients contained in the soil, those which are selectively taken up by the plant and what the animal subsequently absorbs from the ration. Livestock differ in micronutrient requirements to those required for grass growth. Soil characteristics, e.g. pH value can influence the soil’s micronutrient status and how much of these trace elements are taken up by the plant. In addition to this, soil micronutrient supply in agricultural systems is often driven by other management practices, e.g. slurry and muck spreading. Careful interpretation of soil, farmyard manure (FYM) and forage mineral results side-by-side provides an opportunity to understand the recycling of micronutrients on the farm and the impact of one element (e.g. use of FYM) on another (soil nutrient profile).

Without sufficient data on soil micronutrients from grazed fields, and those cut for silage, it is very difficult to determine whether micronutrient deficiencies result in reduced grass growth and quality. Detailed analysis of micronutrient quantity in soils is therefore imperative in the context of promoting grass growth.

 

Kao, P.T., Darch, T., McGrath, S.P., Kendall, N.R., Buss, H.L., Warren, H., Lee, M.R.F., 2020. Factors influencing elemental micronutrient supply from pasture systems for grazing ruminants. Advances in Agronomy 164, 161-229.
Teagasc, 2020. Major & Micro Nutrient Advice for Productive Agricultural Crops. Available at: https://www.teagasc.ie/media/website/publications/2020/Major--Micro-Nutrient-Advice-for-Productive-Agricultural-Crops-2020.pdf. Accessed 25/01/21.

 

Project objectives:

The overarching aim of the project will be to determine the micronutrient status of the farm’s soils in the context of promoting grass growth and to evaluate the implications of the results on the farm’s management practices.

The objectives are as follows:

  • Determine the micronutrient status and variation of the farm’s grazed and silage fields (in the soil, correcting and comparing with the resulting forage)
  • Determine the micronutrient status of the FYM and consider its role in terms of recycling micronutrients on the farm
  • Examine the potential reasons for any differences in micronutrient status between fields (if any)
  • Detect where there is any correlation between soil micronutrient status and grass growth
  • Identify areas where micronutrient supplementation may be/not required, and the associated cost/saving

Key Performance Indicators set:

It is infeasible to set specific and measurable Key Performance Indicators (KPIs) at the outset. The KPIs will be confirmed once initial soil analysis has been carried out and may be based on the following:

  • Maintain/adjust micronutrients to be at target level (i.e. change nutrient applications)
    • Examples include low copper lock-up potential, higher dry matter production
  • To ensure soil nutrients are balanced, therefore reducing antagonisms which may be affecting the availability of a range of other elements. The potential to reduce fertiliser cost with a more targeted nutrient approach
  • More appropriate mineral buying decisions, both product and cost (determine the cost implication of necessary/unnecessary livestock supplementation relative to the cost of soil sampling/analysis/interpretation)
  • Production of high-quality forage - reducing feed cost and improving growth rates

This project may be carried out as an active management change trial should the initial soil analysis indicate that immediate corrections are required (with the resulting forage following corrections also analysed). However, it is likely that some aspects of the project will focus on the data-gathering element in advance of future management changes. The investigation will provide baseline data that should be of benefit to the farmer for signposting any potential livestock trace element problems to look out for.

 

Timeline and milestones: