1. Farming Systems Research

2. Charles Darwin 1809-1882 Published 1881 Based on life-long study
1880
Published 1881
Based on life-long study
Habits & effects of earthworms
“Worms prepare the ground in an excellent manner for the growth of fibrous-rooted plants and for seedlings of all kinds…like a gardener who prepares fine soil…In this state it is well fitted to retain moisture and to absorb all soluble substances, as well as for the process of nitrification.” (pp )

3. Justus von Liebig 1803-1873 German chemist Downplayed soil humus
Ammonia & inorganic minerals more important
Substituted chemical fertilizers for biologically based soil fertility

4. “Living soil” - biologically regulated interconnections in the soil ecosystem play key roles in maintaining desirable soil physical and chemical conditions
Kristiansen & Merfield, Organic Agriculture: A Global Perspective (2006)
Lady Eve Balfour,The Living Soil (1943)
Sir Albert Howard,The Soil & Health (1947)
Agriculture & food issues: obesity & diabetes,consumer food safety,CO2 emissions & climate change, fossil fuels & energy, water quality & supply, immigration & farm workers, development & biodiversity

5. Sampling variables site characteristics
topography, air, water, soil, climate, weather
history
year/season
genetic cultivar
pest & pathogen pressure
handling, storage & processing
farming practices
e.g. fertility management

6. Sustainability of three apple production systems
Reganold, Glover, Andrews & Hinman
Nature 410: 926, 2001
Crop quality
Soil quality
Farm profitability
Environmental risks of agrochemicals
Energy efficiency
Apple orchard productivity and fruit quality under organic, conventional, and integrated management
Peck, Andrews, Reganold & Fellman
HortScience 41:99, 2006

7. Planted to Golden Delicious on M.9 rootstock in 1994
Yakima Valley
Virgin pasture site
Planted to Golden Delicious on M.9 rootstock in 1994
Randomized complete block
Managed by grower

9. Crop yield ns

10. Profitability * * * * * Breakeven point Organic 6 years
Culls ~15% & price premium ~50% for organic apples * * ns
Profitability depends on: Orchard establishment costs,non-harvest production costs,harvest production costs,marketing & price, net returns ,time-value of $, diversification to reduce risk.
When we adjusted the economic analysis by eliminating the effects of russetting, but maintaining the same size and grade and assuming a 15% cullage rate (average for Golden Delicious in Washington), the organic system was the most profitable in 1997 and 1998, and the breakeven points were much shorter.
Without price premiums for organic fruit, the conventional system would breakeven first. For breakeven points to match the conventional, price premiums would have to be 12-14% for the organic. *
Breakeven point
Organic 6 years
Conventional 8 years * *

11. Pesticide environmental impacts
Similar to Cornell Univ. Environmental Impact Quotient, Stemilt RC rating based on: chemical efficacy, potential farmworker & consumer exposure, leaching potential, soil sorption, chemical half-life, and effects on beneficial organisms. Compared to the organic system, the total potential negative environmental impact rating from the use of agrichemicals was about 6X higher for the conventional system and 5X higher for the integrated system. When we included a non-PMD conventional system for comparison, the conventional system was almost 8X higher than the organic. The products used in the organic system were Dipel, Isomate C, Microthiol sulfur, and Superior oil.

12. Energy efficiency
1.11
1.18
Energy accounting was divided into inputs, output (yield), and output:input ratios (energy efficiency). The major differences in energy inputs was higher weed control, insecticide, and fertilizer inputs for conventional and integrated system, and higher fungicide and labor inputs for the organic system. The organic system was 7% more energy efficient than the conventional system and 5% more efficient than the integrated system.

13. Soluble solids & acidity* ns * * * * ns ns
Ratio of soluble solids to acidity is an indication of sweetness. Organic Golden Delicious fruit was usually sweeter than conventional fruit both at harvest and after CA storage, due to a combination of higher soluble solids and lower acidity.
Golden Delicious
Gala
Golden Delicious
Gala

14. Fruit firmness * * * * * Golden Delicious Gala ns ns ns 1998 1999 2002
2003

15. Taste preference Golden Delicious
Firmer
Sweeter
Tarter ns * ns * ns *
Taste preference by untrained sensory panels confirmed the lower acidity of organic apples by indicating that they were less tart, but they couldn’t detect the differences in texture that we measured by firmness or in overall acceptance.

16. Taste preference Gala * * * * * * * Intense Prefer
Taste preference by untrained sensory panels confirmed the lower acidity of organic apples by indicating that they were less tart, but they couldn’t detect the differences in texture that we measured by firmness or in overall acceptance.

17. Antioxidant activity Gala
Skin 5X activity of flesh * ns * * * *
2002
2003
Peck, MS thesis (2004)

18. Soil organic matter * * * * * * * ns

19. Earthworms * * *

20. Soil nitrogen * * * ns

21. Microbial biomass * * * *

22. Soil biological properties
Biological property ( )
Conventional
Organic
Microbial biomass C
(mg C/kg soil)
305
471 *
Microbial biomass N
(mg N/kg soil) 58
81 *
C mineralization enzymes*
(μg p-nitrophenol/g soil/2 hr)
312
473 *
L-asparaginase
(g NH4-N/g soil/2 hr) 59
96 *
Relative potential N2O emission
0.73
0.38 *
*L-glutaminase & β-glucosidase activities
Glover et al, 2008

23. Nitrogen losses N fertilizer apps: 67 kg N/ha on Fall 2002
N2O
“greenhouse”gas
N fertilizer apps:
67 kg N/ha on Fall 2002
45 kg N/ha on Spring 2003
Fertilizer forms:
CON: Ca(NO3)2
ORG: composted chicken manure or alfalfa meal
Leaf N: %
NO3-
leaching
Kramer et al, Proc Natl Acad Sci US 103:4522, 2006

24. Nitrogen losses a a ab b b b

25. Strawberry study 13 matched pairs of organic & conventional farms
soil, topography, microclimate & cultivars
Cultivars
Diamante
San Juan
Lanai
Vertically oriented, quality attribute extensive studies with:
matched soil, microclimate & crop variety
alternatives in distribution system for storage, processing, transport & marketing
consumer handling & preparation

26. Study location

27. Coastal Watsonville
Inland Watsonville
Castroville
Salinas

30. Antioxidant activity CON ORG p = 0.02
Average for 5 sampling dates in 2004 & 2005
CON
ORG

31. Vitamin C & phytochemicals
Phenolics
Anthocyanins
p = 0.009
p < 0.005
p = 0.10

32. Ellagic acid ns

33. Quercetin Diamante Lanai San Juan April harvest p < 0.05 ns

34. Soluble solids & titratable acidity
Diamante * *

35. Consumer preference * * * * Diamante All varieties Diamante Diamante

36. Consumer preference histogram
35% prefer CON
46% prefer ORG

37. Consumer preference
Driscoll tasters
WSU tasters

38. Soil biological properties
Biological property ( )
Conventional
Organic
Total C (mg C/kg soil)
8,251
10,035 *
Total N (mg N/kg soil)
641
912 **
Organic matter (mg/kg soil)
1.46
1.84 *
Microbial biomass (g CO2-C/g soil) 96
249 ***
Dehydrogenase (g TPF/g soil)
0.65
1.382 ***
Phosphatase (g p-nitrophenol/g) 60
126 **
Readily mineralizable C (g CO2/g)
14.1
17.7 **
Basal respiration (g CO2/g)
0.35
0.47 *
*p<0.05, **p<0.01, ***p<0.001

39. “Dilution effect”
Concentration of an element (or phytochemical) is decreased, caused by change in environmental conditions (e.g. light, temperature, soil properties)
Jarrell & Beverly, Adv Agron 34:197, 1981
Genetic selection for high-yielding, large-fruited cultivars (soil biology & N forms?)
“Nutrient density”: amount of nutrients per calorie

40. Food composition changes
Between 1950 and 1999 for 43 garden crops
Davis et al, J Amer College Nutrition 23:669, 2004

41. Genetic dilution
Side-by-side data of 45 maize cultivars (1920 to 2001)
All significantly different than 0
Protein
Oil
Starch
Lys
Try
Met
Davis, HortScience 44:15, 2009 (calculated from data of Scott et al., 2006)

42. Phytochemicals are “diluted” in fruit of:
Tomato experiment
Phytochemicals are “diluted” in fruit of:
high-yielding, large-fruited cultivars
plants fertilized with high N-available sources
BIOAg (WSU-CSANR) project
greenhouse experiment growing small-, medium- & large-fruited tomato cultivars under conventional & organic fertility management
evaluate tomatoes for relationship between fruit size & phytochemical concentrations

43. Tomato cultivars (F1 hybrids)
‘Big Beef’
large-sized (10-12 oz.)
Beefsteak type
70 days
‘First Lady II’
medium-sized (5-7 oz.)
improved ‘Early Girl’
65 days
‘Octavio’
small-sized (3-1/2 oz.)
73 days

44. + Potting media Conventional Organic 100% 75% 20% + 5% soil CON ORG
Total N (%)
Avail. P (g/g)
Avail. K (g/g)

45. Fertilizers Conventional Organic 20-20-20 General Purpose
5-5-5 All Purpose
Conc (ppm) CON ORG
NO3-N
NH4-N
Total N
Avail. P
Avail. K

46. Nitrogen fertilizers

47. Experiment

48. Fruit yield & plant growth

49. Antioxidant activity
Big Beef
R = –0.12
R = –0.29

50. Antioxidant activity
First Lady
R = –0.09
R = –0.63

51. Total phenolics
First Lady
R = –0.16
R = –0.81

52. Vitamin C
First Lady
R = 0.14
R = –0.46

53. Lycopene
First Lady
R = 0.48
R = –0.03

54. Biotic & abiotic stress resistance (chaperone & defense genes)
Secondary metabolites
C assimilation (RuBPcase)
Delayed senescence (CK)
N metabolism (SAMdc)
C assimilation (PEPcase)
Amino acid accumulation
Secondary metabolites
Flavonoids (isoflavones) mediators in tripartite relationship between arbuscular mycorrhizal fungi, rhizobacteria, and legume roots (Soil Biol Biochem 2006).
Other functuions of flavonoids, anthocyanins, phenolics: UV light protection, pollinator attraction, phytohormone regulation, facilitation of nutrient uptake
Volatile emissions (2,3-butanediol & acetoin) from rhizobacteria stimulate plant growth (PNAS 2003) (other possible mechanisms involve cytokinins, gibberellins & auxins).
Growth-differentiation balance (N:C balance)
N assimilation (NiR, GS)
OM decomposition
Cytokinin signaling (CKR)
Microbial biodiversity
amino acidsNH4+NO3–

55. Funding