The document discusses soil nutrient management, emphasizing the importance of maintaining a balanced calcium to magnesium ratio and adequate micronutrient levels for crop yields. It highlights the significance of soil organic matter in nutrient cycling, water dynamics, and soil structure, as well as the impact of different treatments and management practices on soil quality and crop performance. Additionally, it underscores the role of soil microbes and the effects of cover cropping and no-till practices on soil health and aggregate stability.

1. Great Plains Growers Conference
Tim Reinbott
University of Missouri
Columbia MO 65201

8.  Ca:Mg Ratio-68:12
• What Does Too Much Mg
Do?
 K-Balance: 2-5%
 P-Adequate Amounts
 Sulfur-Is it important?
 Micros-Cu, B, Zn

9. Does The Ca:Mg Ratio Really Make A
Difference?
Are Micros Really That Important
Sulfur?

10. Original
Soil
Analysis
-Very Balanced
-Required N,P, K, S
-Micros-Zn, Cu, B
-Pell Lime

12. Depth pHs OM P Ca Mg K CEC Mn
Inches % lb/acre lb/acre lb/acre lb/acre meq/100g ppm
0-3 5.6 4.2 16 3393 279 170 12.4 25.2
3-9 6.0 3.2 8 4211 318 85 14 25.0
9-12 6.0 2.5 7 3513 480 136 13.5 4.3
12-18 5.4 2.4 3 5459 1262 285 23.8 0.1
18-24 4.8 2.2 1 4598 1393 340 23.7 0.7
24-29 5.1 1.6 16 5101 1525 308 24 16.2
29-36 5.4 0.9 28 3728 906 267 16.4 35.4
36-48 5.7 0.9 32 4102 1244 244 17.8 26.0
From MU Bradford-2012

13. No P, K, S, Micros or anything else except
N
Kinsey Recommendations
NPKS only not micros
Kinsey Recommendations except KMg
used
Kinsey Recommendations except KMg
and no Pell lime
N plus micros only

16. Treatment kg/ha (bu/acre)
N only 10819 (161) c
Kinsey Recommendations 13642 (203) a
NPKS only 12298 (183) a
Recom:+Mg 11693 (174) bc
Recommendations: No Lime+Mg 12432 (185) ab
N and Micros only 11962 (178) bc
Letters indicate significance at the 0.10 probability level

17. No Pell Lime Recommendations

18. Treatment kg/ha (bu/acre)
N only 12365 (184) abc
Kinsey Recommendations 11558 (172) c
NPKS only 12970 (193) ab
Recom+Mg 13306 (198) a
Recom:No Lime+Mg 13306 (198) a
N and Micros only 12298 (183) abc
P and K only-MU 11626 (173) c
Letters indicate significance at the 0.10 probability level

19. Mg Level has gone
up.
Much more Ca is
Needed to keep
balance

20. Ca:Mg is now 57:14
Requires Lime and
Mg

22. Treatment Yield
Control 42
Recommendations 45
PKS only 43
Recom.+Mg 41
Recom. No lime +Mg 39
Micros only 40
P and K only 35

23. Following the Kinsey/Albrecht
Recommendations increased corn and
Soybean yield
• Additional Mg did not reduce corn in Year 1 and 2
but did reduce soybean yield in Year 3
Additive effects of PKS and Micronutrients
Importance of following soil test
recommendations each year

26. The soil microbes in the plow layer
has the mass equivalent of two
cows (2400 lbs) per acre that need
to be fed
Soil organisms are
much like cows, they
need inputs of plant
residues for food
and energy
Specifically, they
need the carbon that
is contained in plant
residue and soil
organic matter

28. 28

30. With grain production that means cover crops

33. Small changes in SOC resulting from changes in
management practices can have large effects on
soil behavior and microbial processes.

34. LONG TERM PASTURE
TILLED IN A
CORN/SOYBEAN/WHEAT ROTATION

35.  Nutrient Cycling
• Nutrient Holding Capacity
• Pool of Nutrients
• Food for soil organisms
 Water Dynamics
• Improves water infiltration
• Improves water holding
capacity
 Structure
• Reduces crusting,
compaction, erosion
• Encourages root
development

38. Scientists describe 3 pools of soil organic matter
**really is a continuum of decomposition
38
Passive SOM
500 – 5000 yrs
C/N ratio 7 – 10
Active SOM
1 – 2 yrs
C/N ratio 15 – 30
Slow SOM
15 – 100 yrs
C/N ratio 10 – 25
• Recently deposited organic material
• Rapid decomposition
• 10 – 20% of SOM
• Intermediate age organic material
• Slow decomposition
• 10 – 20% of SOM
• Very stable organic
material
• Extremely slow
decomposition
• 60 – 80% of SOM

39. Results are read in a spectrometer in lab or
field or from a color card
Potassium
Permanganate Test
KMnO4 oxidizes active carbon. The
purple color of the chemical
changes to pink the more active
carbon there is in a soil sample.

42. Active Carbon
Treatment mg C/kg
N only 548 bc
Kinsey Recommendations 603 a
NPKS only 616 a
Recommendations+Mg 595 ab
No Lime+Mg 627 a
N and Micros only 533 c
P and K only-MU 526 c
Letters indicate significance at the 0.10 probability level

43. Soil C and Soil N
Percent Percent
Treatment Soil C Soil N
N only 1.65 b 0.182 b
Kinsey Recommendations 1.70 b 0.191 bc
NPKS only 1.80 ab 0.199 a
Recommendations+Mg 1.73 b 0.194 b
Recom. No Lime+Mg 1.85 a 0.206 a
N and Micros only 1.68 b 0.190 b
P and K only-MU 1.70 b 0.190 b
Letters indicate significance at the 0.10 probability level

46. No-Till With Cover Crops
No-Till In A Corn/Soybean Rotation
Tilled Each Year in a Corn/Soybean Rotation

47. Fencerow
Native Warm Season Grass
Cool Season Grass Mix
Restored Native Prairie

51. Soil Structure
• arrangement of soil solids and voids
• influences water infiltration and retention, erosion,
crusting, nutrient recycling, root infiltration and crop
yield
• expressed as degree of aggregate stability
• aggregation is controlled by SOC, microorganisms,
ionic bridging, clay
http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_soil_structurehttp://ecomerge.blogspot.com/2010/05/what-soil-aggregates-are-
and-how-its.html

52. Soil Structure
 The grouping or arrangement
of individual soil properties into
a larger grouping.
(Also called aggregate, ped)
Formation of Soil
Structure
 Flocculation: Bringing the
particles close together,
enhanced by polyvalent
cations (Al+++, Ca++,
etc.). Mg is not as good
as Ca in flocculation.
 Stabilization: Providing
durability to maintain the
arrangement. Some clay;
organic matter; oxides of
Fe and Al.

53. 53

54. From Muneer and Oades, 1989

55. From Muneer and Oades, 1989

56. Water Aggregate Stability After Two Years
Rotation Water Aggregate Stability (g/g)
Corn/Soybean 38 b
Corn/rye/Soybean/rye 41 a
Corn/rye/Soybean/hairy vetch 43 a
Corn/rye/Soybean/HV+rye 44 a
Letters indicate significant difference at the 0.10 probability level
From Villamil, et al., 2006

57. Granular Prismatic Blocky Platey
Flocculated by Ca Restricted
Enhanced by OM Movement

58. Aggregate
Stability
Fungal-produced glomalin helps
bind aggregates
Measured with wet sieving
http://ed.fnal.gov/trc_new/pandp/soil_research/soil_aggregates.html
Wright, et al., 1999

59. My son doing his favorite thing After a two inch rain

60. Water Infiltration
Good infiltration
allows for less
runoff and erosion
Soils with poor
aggregate stability will
crust, damaging
emerging seedlings and
increasing runoff

61. Aggregate Stability-Better Water
Infiltration
Fungal-produced
glomalin helps
bind aggregates
http://ed.fnal.gov/trc_new/pandp/soil_research/soil
_aggregates.html
Wright, et al., 1999

62. Tillage reduces aggregate stability and
sizes
Chen et al., 2000

64. Soil Microbial biomass is important
Interaction of soil microbe excretions and
Ca on soil aggregate stability
Balanced soils produce more biomass;
above and below ground and in return feed
microbial system

65. Tim Reinbott
University of MO
ReinbottT@missouri.edu