Research Challenges from and for High Yield Growers

1
Research Challenges from and for High Yield
Growers
Scientists and farmers

• International Conference on Precision Agriculture
• Minneapolis, MN
• July 26, 2004
• Paul Fixen
• Potash Phosphate Institute

2
Is this session appropriate for a precision
agriculture conference?
Precision in management gets more critical as
yield potential climbs - agronomic reasons -
environmental reasons
3
Is this session appropriate for a precision
agriculture conference?
Precision in management gets more critical as
yield potential climbs - agronomic reasons -
environmental reasons
4
SummaryResearch challenges from high yield
growers

• A large gap exists between maximum attainable and
  typical yields
• Observing the practices of high yield growers
  through the lens of scientific principles and
  controlled research can be revealing and lead to
  researchable questions for scientists and farmers
• Modern technologies should facilitate narrowing
  the gap between attainable and typical yields

5
Exploitable yield potential in corn
Iowa example







1965-1991 2.0 bu/A/yr

IA Contest Winners



IA State Average 1.7 bu/A/yr
6
Top corn yields from researchers in 1982
Dr. Roy Flannery New Jersey 338 bu/A
Dr. Sterling Olsen Colorado 332 bu/A
7
From Saybrook, IL to Manchester, IA
Manchester, IA
Growing season precip very similar at
27-28 Growing degree Days Manchester - 2980
Urbana 3513
Property Childs Warsaw
Soil type Kenyon loam
Parr silt loam Taxonomy Typic Hapludolls
Oxyaquic Argiudolls Org. mat., 5.5-6.0
4.5-5.8 pH 5.3-6.1 6.0 P1, ppm 126
(VH) 81 (VH) K, ppm 374 (VH) 400
(VH) Source Childs Murrell and Childs, 2000
Smith,2000 Dobermann, 2002 Warsaw PPI, 1986.
Saybrook, IL
8
From Saybrook, IL to Manchester, IA Soil OM
Manchester, IA
Warsaw 20 years of intensively managed
continuous corn Childs 35 years of
intensively managed continuous
corn
Saybrook, IL
9
From Saybrook, IL to Manchester, IA Practices
Manchester, IA
Practice Childs
Warsaw Fall
tillage Mini MP 14 deep
CH 14 deep Hybrid 2001-34M95
2002-34N44 FS 854 Harv. Population
34,000 - 40,000 36,000 Row
spacing 2001-30 2002-20
28 Manure High rates in past
20 T/A annually
Fall P2O5K2O none
250250 Fall N, lb/A
50(UAN) 45(DAP) Preplant N
250(NH3 sep. stab.) 300(UAN)
100(AS) Starter, NP2O5K2O 61515ACA
262626 Popup, NP2O5K2O
494 none Postplant N
50(UAN) 75(UR) 2.5-4 tall
N 50(UANGuardian)
None Fert N, lb/A 410(1.0 bu/lb)
546(0.7 bu/lb) Other nutrients
Boron Sulfur
Saybrook, IL
10
Research challenges Which practices are critical
and at what level?

• Determination of site-specific attainable yield
  estimates (crop models)
• Carbon cycling crop and environmental impacts
• Crop rotation vs monoculture
• Tillage requirements no till/strip till
• Minimum N requirements, NH4 vs NO3-, timing
• Minimum soil test P and K requirements
• Role of subsoil fertility, organic matter, etc.
  (P. Nowak)
• Role of manure application
• Role of secondary and micronutrients
• Importance of starter fertilizer (0.5 P at V3-V4
  for max kernel initiation/ear)

11
http//www.hybridmaize.unl.edu/
12
(No Transcript)
13
Real time yield prediction of current season
U. of Nebraska EI Study - Lincoln July 25, 2004
349
279
251
14
Early Plant P status Impacts corn yield potential
(outdoor hydroponics study)
Barry Miller, 1989

• P concentrations below 0.5 prior to V3-V4 (ISU
  System), reduced kernels initiated per ear and
  grain yield
• If kernel abortion is limited, final kernel
  number should be correlated with kernels
  initiated
• High early plant P concentrations should be
  important for conserving yield potential in high
  yielding environments

P in Herman Warsaws corn
1981 1982 1983 1984 1985
Seedling P, Seedling P, Seedling P, Seedling P, Seedling P,
0.57 0.64 0.53 0.57 0.54
15
Soil Test P and K requirements for very high
yields Classical theory

• For soil immobile nutrients like P or K, the STL
  vs yield relationship should not vary with site
  yield potential unless plant population increases
  enough for adjacent roots to compete with each
  other for P and K (Bray, 1954 Bray, 1963).
• Roots normally occupy less than 1 of soil volume
  (Barber, 1984) an increase in size of the root
  system translates into a greater volume of soil P
  or K being available for uptake.
• As long as the size of the root system increases
  proportionally with yield, a higher yielding crop
  should not need a higher P or K concentration at
  the root surface should not require a higher
  soil test level.

16
Soil Test P and K requirements for very high
yields Conditions that could lead to higher
requirements

• Shoot growth increases that exceed root growth
  increases as yields climb
• Redistribution of roots from the surface soil to
  a low P or K subsoil
• soil factors (organic matter, pH, structure,
  etc.)
• varietal factors vertical vs lateral rooting
  tendencies
• Each increase in yield has greater economic
  value want to be further up the response curve

17
Is subsoil fertility more important to todays
high yield potential stay-green hybrids?

• Probably taking up nutrients later in the season
  when surface soils are dryer
• Higher of active roots located deeper in profile

Is manure important because it moves P into
subsoils?
18
Impact of hybrid on the influence of N rate on
yield response to plant population
Colorado
S.R. Olsen, reported by W. M. Stewart, 2000
19
Risk/benefit evaluation of yield improvement
phases
Phase Yield benefit and risk
Fully implement standard agronomic BMPs (site-specific) Minor
Experiment with optimizing sets of easily controlled factors for higher yield levels Ex population, nutrients, hybrid Moderate
Experiment with system-level changes, then re-optimize Ex tillage, row spacing, rotation Major
Long-term soil quality improvement with continuous re-optimization Ex organic matter, subsoil properties, tilth Long-term major
20
SummaryResearch challenges from high yield
growers

• A large gap exists between maximum attainable and
  typical yields
• Observing the practices of high yield growers
  through the lens of scientific principles and
  controlled research can be revealing and lead to
  researchable questions for scientists and
  farmers.
• Modern technologies should facilitate narrowing
  the gap between attainable and typical yields
• Simulation models to help define attainable
  yields and researchable questions
• Improved weather data and management tools
• Site-specific technologies for greater efficiency
• Biotechnology for yield protection and building

21
Research Challenges from High Yield Growers

• InfoAg 2003
• Indianapolis, IN
• August 1, 2003
• Paul Fixen
• Potash Phosphate Institute