Improving N Management Improving N Management in Crop Production - - PowerPoint PPT Presentation

Reducing Risk from Reactive N Reducing Risk from Reactive N in the U.S.: in the U.S.:

Improving N Management Improving N Management in Crop Production in Crop Production

Paul E. Fixen Paul E. Fixen EPA SAB Integrated N Committee EPA SAB Integrated N Committee April 10, 2008 April 10, 2008

To develop and promote scientific To develop and promote scientific information about the responsible information about the responsible management of plant nutrition for the management of plant nutrition for the benefit of the human family. benefit of the human family.

Mission Mission

• 23 Ph.D. scientists in 8 program areas

– 6 scientists in North America – 13 scientists in International regions – 4 in management

Brazil Northern Latin America North America China Southeast Asia Latin America Southern Cone India Eastern Europe and Central Asia

IPNI Programs

Main Points Main Points

• 1. Today’s market and the presence of new technologies

provide a great opportunity to make improvements in integrated N management.

• 2. Agricultural productivity must increase and

environmental N policy will be more effective if it facilitates that increase.

• 3. Nitrogen is managed as an integral component of a

cropping system based on system objectives with performance assessed at a system level.

• 4. Average is the enemy of efficient and effective N

management … and policy.

• 5. Research and education focused on improving N use

efficiency in systems producing near genetic yield potential levels are greatly needed.

• 1. Today’s market and the presence of new

technologies provide a great opportunity to make improvements in integrated N management.

Net Cash Farm Income, 1997 Net Cash Farm Income, 1997-

• 2008f

2008f

Billion dollars

$5 corn/$0.50 N vs $2 corn/$0.20 N $5 corn/$0.50 N vs $2 corn/$0.20 N

• Price ratio the same … optimum rate the same
• But the economic penalty for over or under

estimating need or for nutrient loss is much greater with today’s higher prices … greater risk

• Greater economic justification for:

– Precision input application, enhanced efficiency N sources – Guidance systems – Soil testing and plant analysis, soil or plant imaging – On-farm strip trials, omission plots – Other forms of decision support including simulation models – Investing in determination of right source, rate, time and place for nutrients … risk management tools

Nitrogen check yields and net returns in Nitrogen check yields and net returns in university corn studies in Iowa and Illinois university corn studies in Iowa and Illinois

Previous crop Region

• No. of

sites N check, %

• f opt. yd

Net return to N, $/A Soybean IA 147 71 188 Soybean Central IL 148 58 281 Corn IA 73 44 326 Corn Central IL 53 49 315

http://extension.agron.iastate.edu/soilfertility/nrate.aspx; $5/bu; $0.50/lb N

At risk:

• $60 to $90/A of input costs
• 30% to 55% of total yield
• $200 to $300/A net income from one input

Decision support and risk Decision support and risk management tools management tools

Variable Rate Applicator with GreenSeeker

A user friendly simulation model A user friendly simulation model developed for on developed for on-

• farm use

farm use … … site site specific attainable yields & N needs specific attainable yields & N needs

http://www.hybridmaize.unl.edu/ http://www.hybridmaize.unl.edu/

U n d e r d e v e l

• p

m e n t U n d e r d e v e l

• p

m e n t

30 35 40 45 50 55 60 65 70 75 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Kg grain per kg N .

Corn grain produced in the U.S. per Corn grain produced in the U.S. per unit of fertilizer N used, 1964 to 2005. unit of fertilizer N used, 1964 to 2005.

43 43 64 64

*

*Application rate for 2004 estimated as avg of 2003 & 2005.

Data sources: USDA Ag Chem Use Survey & Annual Crop Production.

51% increase in N efficiency 12% increase in N fertilizer use Since 1975: Grain N recovery efficiency usually remains < 50% … room for improvement.

Snyder, in press

Do today Do today’ ’s elevated prices enable s elevated prices enable farmers to continue to improve their farmers to continue to improve their resource stewardship? resource stewardship?

• To evaluate adoption of higher cost but more

efficient technologies;

• To experiment with alternative approaches to N

management;

• To break tradition and attempt improvements in

cropping systems.

• 2. Agricultural productivity must

increase and environmental N policy will be more effective if it facilitates that increase.

Not doing so will contribute to the global expansion of land in agriculture.

y = 16.47x - 31,445 R ² = 0.98 y = 15.03x - 28,575 R ² = 0.87 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800 1975 1980 1985 1990 1995 2000 2005 2010 Million metric tons Y ear (2007 =2007/08)

Domestic consumption Production

1998-2007 y = -1.89x + 3816 R ² = 0.93 5 10 15 20 25 30 35 40 1975 1980 1985 1990 1995 2000 2005 2010 % of consumption Y ear (2007 =2007/08)

Ending stocks

USDA-FAS, 12/2007

World wheat plus coarse World wheat plus coarse grains, 1978 grains, 1978-

• 2007

2007

1998-2007 y = -23.57x + 47,563 R ² = 0.89 100 200 300 400 500 1975 1980 1985 1990 1995 2000 2005 2010 Million metric tons Y ear (2007 =2007/08)

Ending stocks

U.S. corn exports at record high in 2007 U.S. corn exports at record high in 2007 with 25% of crop used for ethanol with 25% of crop used for ethanol

USDA-FAS, 12/2007.

Continuation of this accomplishment will be challenging.

y = 1.829x - 3522 r2 = 0.84 20 40 60 80 100 120 140 160 180 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Corn yield, bu/A

U.S. corn yields, 1964 to 2006. U.S. corn yields, 1964 to 2006.

43 years of 1.8 bu/A/yr 43 years of 1.8 bu/A/yr

Concept by Cassman, 2006 G e n e t i c G e n e t i c i m p r

• v

e m e n t i m p r

• v

e m e n t Expansion of Expansion of irrigation irrigation I n c r e a s e i n I n c r e a s e i n N f e r t i l i z a t i

• n

N f e r t i l i z a t i

• n

Soil testing & balanced Soil testing & balanced NPK fertilization NPK fertilization I P M I P M Transgenic Transgenic traits traits Cons. Cons. tillage tillage

y = 1.829x - 3522 r2 = 0.84 25 50 75 100 125 150 175 200 225 250 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 Corn yield, bu/A

43 years of 1.8 bu/A/yr 43 years of 1.8 bu/A/yr

Genetic improvement in corn yields Genetic improvement in corn yields promised by the seed industry promised by the seed industry

3 % / y r 3 % / y r

Breaking the 1.8 barrier without causing negative environmental Breaking the 1.8 barrier without causing negative environmental impacts will require more than genetics impacts will require more than genetics … … and involve research & and involve research & educational efforts focused on the entire agro educational efforts focused on the entire agro-

• ecosystem.

ecosystem.

The U.S. is blessed with some of the world The U.S. is blessed with some of the world’ ’s s most productive soils most productive soils

Along with this blessing comes responsibility to sustainably manage them to contribute to society’s global needs.

• 3. Nitrogen is managed as an integral

component of a cropping system based

• n system objectives with performance

assessed at a system level.

Some key best management practices to Some key best management practices to ensure the ensure the right N source right N source is applied at the is applied at the right rate, time, and place right rate, time, and place

• Crediting previous crops and applied manure.
• Determining yield goals from reliable information.
• Maintaining non-limiting levels of other nutrients.
• Crop management and hybrid selection for maximum

economic yield.

• Timing supply to match plant need, by either controlling

release or split application.

• Placement below soil surface, or incorporated where possible.
• Maintaining and calibrating application equipment.
• Designing the crop rotation to capture surplus N.
• Evaluating success using on-farm trials & soil & stalk nitrate

tests.

ECONOMIC ECONOMIC SOCIAL SOCIAL ECOLOGICAL ECOLOGICAL

Productivity Profitability

Cropping System

Sustainability

Biological & Social

Environment Source Time Place Rate

Net profit Adoption Return on investment Yield stability Soil productivity Water & air quality Farm income Working conditions Nutrient balance Nutrient loss Yield Quality Soil erosion Biodiversity Ecosystem services

Resource use efficiencies:

Water Nutrient Labor Energy

Global Framework Global Framework for Fertilizer for Fertilizer BMPs BMPs

N management N management effects are effects are complex complex

Policy should recognize the Policy should recognize the linkage between N and C linkage between N and C

Soil OM Molecule Soil OM Molecule

Schulten & Schnitzer, 1997 Schulten & Schnitzer, 1997

N N C C

• 4. Average is the enemy of efficient and

effective N management … and policy.

Management success

“ “One stave in the barrel of a One stave in the barrel of a management program is the management program is the appropriateness of a generalized appropriateness of a generalized management practice to local management practice to local

• conditions. Everything else could
• conditions. Everything else could

be correct, but if this stave is be correct, but if this stave is short, the whole program fails. short, the whole program fails.” ”

• T. Scott Murrell
• T. Scott Murrell

One generalized practice not appropriate for local conditions

“ “New genetics change crop demand, New genetics change crop demand, and new technologies change the ways and new technologies change the ways in which the demand can be met. in which the demand can be met.” ”

60 120 180 50 100 150 200 N Applied, lb/A Yield, bu/A

• ld hybrid

new hybrid

A new hybrid yields more with less N, compared to one popular 20 years ago. Mean of 4 years’ data (Below, 2007).

50 100 150 200 250 50 100 150 200 N Applied, lb/A Yield, bu/A single triple

A “triple-stack” Bt-rootworm hybrid responds differently than one with a single herbicide resistance trait (2006 data; Below, 2007). 1980s Improved capture of soil N

Bruulsema, 2007

New N products designed to facilitate New N products designed to facilitate timing of N supply and plant demand timing of N supply and plant demand

• Polymer coated sources
• Chemically stabilized
• Urease inhibitors
• Nitrification inhibitors
• Combinations

Risk management tools

Points towards policy approaches allowing Points towards policy approaches allowing producers to make site producers to make site-

• specific, data

specific, data-

• driven

driven decisions for improving N use efficiency in contrast decisions for improving N use efficiency in contrast to use of generalized, historical averages. to use of generalized, historical averages.

• 5. Research and education focused on

improving N use efficiency in systems producing near genetic yield potential levels are greatly needed.

Priority research needs Priority research needs

• Development of nutrient decision support systems:

– That integrate soil tests, plant indicators, and weather-based predictions of supplemental N needs – That simultaneously address spatial and temporal variation and their interaction.

• Participatory research with producers & advisers to test feasibility of

integrated decision support tools that employ local weather monitoring

– Just-in-time approaches to N application often appear efficient in research plots but at a farm scale may result in substantial risk of income loss should logistical problems arise. A more quantitative understanding of these risks & approaches to alleviate them would be beneficial.

• Determination of the fate of N not recovered in the harvested crop in

intensively managed systems & the impact of new N technologies.

• More needs to be known about field scale N losses and greenhouse gas

emissions.

• See page 21 of the IPNI GHG review for additional topics related to GHG

emissions associated with N fertilizers.

Main Points Main Points

• 1. Today’s market and the presence of new technologies

provide a great opportunity to make improvements in integrated N management.

• 2. Agricultural productivity must increase and

environmental N policy will be more effective if it facilitates that increase.

• 3. Nitrogen is managed as an integral component of a

cropping system based on system objectives with performance assessed at a system level.

• 4. Average is the enemy of efficient and effective N

management … and policy.

• 5. Research and education focused on improving N use

efficiency in systems producing near genetic yield potential levels are greatly needed.