GRDC Crop Nutrition Technical Workshop

Transcription

1 GRDC Crop Nutrition Technical Workshop Rob Norton Adelaide, August. Ballarat, September. Wagga Wagga, September Best Management Practices (BMPs) Definition - Research proven practices that have been tested through farmer implementation to optimize production potential, input efficiency, and environmental protection (Griffith and Murphy 1991). Fertilizer best management practices, integrated plant nutrient management, integrated soil fertility management, code of best agricultural practices, site-specific nutrient management, et Goal ensure plant nutrients are use efficiently and effectively in ways that are beneficial to society without adversely impacting our environment. 1

2 International Fertilizer Industry Association (IFA) initiative on fertilizer BMPs International workshop in Brussels (2007) to define principles of FBMPs and a strategy for wider adoption The concept was further developed by IPNI scientists (Bruulsema et al. 2008) 4R Nutrient Stewardship The 4Rs are the foundation and guiding principles of nutrient BMPs (Roberts 2007) Approach is simple apply the correct nutrient in the amount needed, timed, and placed to meet crop demand Source Time Rate Place The 4R s is both: a process (what needs to be considered) and an outcome (how the pieces fit together) Fixen s global FBMP framework (2007) Fertilizer stewardship goals Fertilizer management objectives Economic Agronomic Environmental Right product Right rate Right place Social Right time Fundamental scientific principles Global Site & grower-specific fertilizer BMPs Refinement et et et et System assessment 2

3 One potencal global framework with FBMP example. Fertilizer stewardship goals Economic Agronomic Environmental Social Fertilizer management objectives Right product Right rate Right place Right time Fundamental scientific principles Global Assess soil nutrient supply Assess non-soil nutrient sources Assess plant demand Predict fertilizer use efficiency Consider soil resource impacts Site & growerspecific fertilizer BMPs Assess soil nutrient supply Use Mehlich III soil test for P, K, and Zn with target levels of 25, 150, and 1 ppm, respectively based on annual 0-15 cm soil samples. Use omission plots for determination of soil N and S supply. Et Yield Response vs. Nutrient Use Efficiency 100 N 2 O and rate Yield potential, % Low yield and highest nutrient use efficiency Increasing nutrient input and decreasing nutrient use efficiency Highest yields and lowest nutrient use efficiency wi th N rate, lb/a Soil NO3-N in upper 10 ft, lb/a NO 3 leaching and rate 4R Nutrient Stewardship Biodiversity Resource use efficiencies: Energy, Labor, Nutrient, Water Soil erosion PRODUCTION SYSTEM OBJECTIVES Healthy environment Nutrient loss Water & air quality AdopBon Nutrient balance Soil producbvity Yield Net profit ProducCvity Durability Ecosystems services Farm income Profitability Return on investment Quality Yield stability Working condibons 3

4 The basic sciencfic principles of managing crop nutrients are universal Appropriately assess soil nutrient supply Assess all available indigenous nutrient sources Assess plant demand Predict fertilizer use efficiency Supply in plant available forms Suit soil properties Recognize synergisms among elements Blend compatibility Source Rate Time Place Assess timing of crop uptake Assess dynamics of soil nutrient supply Recognize timing of weather factors Evaluate logistics of operations Recognize root-soil dynamics Manage spatial variability Fit needs of tillage system Limit potential off-field transport Right source, rate, time, and place science-based principles not static Interdependent & applied in cropping systems The 4Rs provide flexibility to nutrient management recognizing that FBMPs are site and crop specific depending on soils, climatic conditions, crop and cropping history, and management expertise, and can be applied in large-scale, extensive agriculture or small family farms. Ignorance more frequently begets confidence than does knowledge. Charles Darwin System changes & responses 4

5 Urea placement & Canola Birchip Cropping Group, 1998 MAP plus urea MAP plus urea MAP plus urea % Urea in seedrow Emergence Pl/m2 Yield t/ha all half none Source/Rate/Place combinations Right Place 20 cm 30 cm 125 mm Share Spear Point 13 8 Maximum urea (kg N) rates Rate Source Place Time Crop Soil SBU % 8% 17% 25% 33% Cereal Light Medium Canola Light Medium Worst Case Canola, Light Soil, Urea/MOP, low SBU Best Case Cereals, heavy soil, Super/MAP, high SBU 5

6 The Nitrogen Quiz 1 4R manual+ 1 Transit 1 4R manual 1 Transit 10. Coffee Cup+ 09. Transit 08. Coffee cup 07. Transit 06. Better Crops+ 0 Better Crops 0 IPNI Hat+ 0 IPNI Hat 0 IPNI Pen 0 IPNI Pen Concluding Comments Manage or be managed Regulations on nutrient management Reef Regulations on sugar industry in the wet tropics Use of soluble P fertilizers on the Swan coastal plain. Fertilizer management in the Mississippi Basin. N application in UK. Regulations on N use on particular dairy pastures in New Zealand. Right source, right rate, right time, and right place is a simple slogan that integrates a century of science and experience into nutrient stewardship. Research backstops the principles of 4Rs with science, but the stakeholders decide what is right. New/Old Products Evidence from Trials Appropriate controls Replicated Randomised Repeatable Reasonable Mass balances? Magic or special? Laws of physics/chemistry Test it yourself, be skeptical its your $ and your reputation. Ask How do you know that? 6

7 Be#er Crops, Be#er Environment through Science 7