Advances in nutrition management of radiata Graham Coker, Peter Clinton
Research Aim 1.2 Enhancing the productivity of older stands RA GOALS Identify and screen new treatment options Better understand which nutrients are limiting crop growth and why (process and mechanisms). Establish field trials to investigate wood quality and environmental effects TODAYS PRESENTATION Overview of the approaches taken Describe some of the results Summarise advances in our understanding OUTCOMES by 2019 Better understanding of the role of nutrients in wood formation A new understanding of the role of nutrients in signalling stress Better methods for predicting responses to mid-rotation interventions and updated DSS response functions
Overview mechanisms for change
% Productivity gain over the control Advance 1 Identified new treatment options, screening trials in 2016 18 16 14 12 10 8 6 4 2 DAP 20 kg/ha Urea 20 kg/ha Urea 16 Phos-Pot 4 L/ha GA 3 20g/ha PerkSupa 5 L/ha Phos-Pot 10 Urea 435 0 20 40 60 80 100 120 140 Cost ($) of product per hectare Control = untreated above ground biomass of GF19 s http://grochem.co.nz/portals%5c537%5clabels/phospot_20l.pdf http://www.keyindustries.co.nz/product/perk+supa-1018.htmx
Advance 2 Investigated genotype responses, interim results, 2017 (%) Height gain over control 28 24 20 16 12 8 4 0 PerkSupa 2 L/ha Urea 16 PerkSupa 5L/ha Phos-Pot 2 Urea 20 Phos-Pot 4 GA 4/7 6.6g/ha Amino-max 10L/ha 0 20 40 60 80 100 120 140 Cost ($) of product per hectare Control = untreated height of 12 genotypes, each having 18 reps, Trts :. 216 individual plants
Trials to date show 1. Foliar applications of nitrogen and phosphorus are more cost efficient compared with conventional operations, based on results to date. These treatment options will help growers better match crop demands with supply at all stages of stand development, where intervention is justified. 2. The relationship between productivity and foliar applied N is consistent across the rates applied. Every dollar spent on N provided a 2% gain in productivity.
Advance 3 Improved understanding of foliage nutrient ratios 100 % of foliage nutrients by mass in relation to N 61.7 Eg. 1.42% N * (61.7/100) = 0.876 % K 13.2 9.4 7.0 6.8 2.0 1.2 0.30 0.28 0.08 0.04 N K Ca P S Mg Al Mn Zn Fe B Cu Bown et al 2007: Tree Physiology, 27, 335-
Advance 4 Identified Mehlich 3 soil extraction analysis method, suitable for forestry, (its widely used in agriculture and a cost effective indicator of soil chemistry) 10000 Nutrients (mg/kg = ppm) log scale 1000 100 10 1 0.1 Al Fe Ca Mg K Na Mn P Zn Cu B Berwick Kinleith Kaingaroa Waimea Tairua
Advance 5 Identified and recommend soil nutrient targets to better identify limits on growth, an example based on the mid-rotation trials 100000 50000 Nutrients (mg/kg = ppm) 10000 1000 100 10 1 5000 2000 600 280 250 225 50 25 22 22 6 3 0.7 0.1 C N Ca Al P K Mg Fe Mn Na S Zn Cu B Average Target McKibben W L, 2012: The Art of Balancing Soil Nutrients a practical guide to interpreting soil tests. Acres USA, 240 pp
Advance 6 Improved understanding of the influence of soil ph ph is influencing soil phosphorous availability Soil microbial activity decreases with acidity Cations buffer rapid ph change Stevenson and Cole (1990)
Overview mechanisms for change
Advance 7 Improved understanding of sites that are unlikely to respond to granular P fertiliser Veritec soils database, sample size 432 N addition Number of sites Al & Fe inhibition Mn toxicity Lime
How we are taking advantage of these advances 1. Focusing on foliage N & P, because its relevant to all sites across NZ 2. Informing GxE discussion/understanding 3. Improved understanding of nutrient limitations at sites 4. More accessible soils information for management considerations 5. Better target applications and sites 6. Establishing new trials to test our hypotheses
In summary Foliage applications of N & P are potentially more efficient than current practices Check foliage nutrition in relation to foliar N levels Use Mehlich 3 as part of your future soils analyses Protect soil ph, because it influences phosphorus availability and lots more
Graham Coker, Project Leader graham.coker@scionresearch.com http://research.nzfoa.org.nz www.scionresearch.com www.gcff.nz 29/03/2017 Thanks to the team: David Henley, Rodrigo Osorio, Tony Evanson, Stephen Pearce, Max Novoselov, Alex Manig, Jessica Shailer, Jianming Xue, Loretta Garrett, Bernadette Nanayakkara, Stefan Gous, Kaye Eason, Forest Industry collaborators and others
Benefits of foliar applications Target the crop rather than the soil processes Potentially available N pool (NH4) 3% Mobile N pool (NO3) 1% Add small quantities of fertiliser relative to the soil nutrient pools for growth gains. Organic N - locked in dead fauna and fauna (amino acids & protiens) 96%
Benefits of foliar applications foliar applied N is 10-12% more efficient than granular applied Urea because less plant energy is required Granular Urea Amines to Nitrates Granular Urea made mobile Nitrates to amines Microbial conversion Foliar applied Urea Amines to amino acids Amino acids to protein Nutrients are in a formulation closer to what the plant needs.