Mais conteúdo relacionado Semelhante a Soil Fertility Research in High Tunnels (20) Mais de University of Minnesota-Horticulture (20) Soil Fertility Research in High Tunnels1. Soil Fertility
Research in
High Tunnels
Carl Rosen, Terry Nennich, & Jerry Wright
University of Minnesota
High Tunnel Workshop
Alexandria, MN
© 2009 Regents of the2009
December 2-3, University of Minnesota
2. Topics
Background (review)
Fertigation study –
Tomato 2008 and 2009
Cucumber 2009 (spidermite problem in 2008)
Compost vs. compost + fertigation
© 2009 Regents of the University of Minnesota
3. Yield Potential & Nutrient Needs
Yields in a high tunnel can be 2 to 4 times the
yield obtained in the field
Higher yields will required more nutrients, but
knowing how much to apply is a challenge
Lack of nutrients – deficiencies
Excessive nutrients – salt build up
Both situations affect yield and quality
© 2009 Regents of the University of Minnesota
4. Tomato nutrient uptake
N P K
Plant Part -------- lb per ton F.W. ------------
Fruit 3.4 0.4 6.0
Vines 2.6 0.4 3.4
Total 6.0 0.8 9.4
A 50 ton yield/A would require:
300 lbs N/A
40 lbs P/A (92 lbs P2O5)
470 lbs K/A (564 lbs K2O)
© 2009 Regents of the University of Minnesota
5. Staples Fertigation Study
High amounts of compost are often used
in high tunnels
Objective:
To determine if fertigation is needed for
tomato when compost is used
Conducted at the Central Lakes College Ag
Center in©Staples in the University of2009
2009 Regents of 2008 & Minnesota
7. Soil Test Properties in the Spring-
2008 (before compost application)
Soil Depth pH Organic Matter Soluble Salts
Inches % mmhos/cm
0-6 7.0 6.4 0.9
6-12 6.9 5.4 0.7
Soil Depth NO3-N Bray-P K
Inches lb/A --------- ppm ----------
0-6 61 174 89
6-12 43 144 103
P was in the very high range, K was medium
© 2009 Regents of the University of Minnesota
8. Soil Amendments & Treatments
2008
Yard waste compost added in 2008
~ 2.5 tons fresh (~50% moist) spread evenly
~ 5 lbs fresh per square ft
0.64% N, 0.12% P, 0.18% K; C/N: 26.8
725 lb N/A, 313 lb P2O5/A, 245 lb K2O/A
Two treatments
Fertigation
UAN, Potassium nitrate, and Calcium nitrate
No fertigation
Two replications for tomato
Nine© 2009 Regents of the University of Minnesota
plants per replication
9. Procedures - 2008
‘Cobra’ tomato
(indeterminate)
Transplants planted May 9
Double row beds 4 ft apart; 2
ft between plants
One cup 20-20-20 (1 oz/gal)
applied to each transplant
© 2009 Regents of the University of Minnesota
10. Procedures - 2008
Plots set up so that half
received fertigation and
the other did not
Each plot received the
same amount of water
Plants pruned periodically
Tomatoes harvested:
July 24 – October 16
© 2009 Regents of the University of Minnesota
11. Staples High Tunnel in 2008
Not Fertigated
Fertigated
© 2009 Regents of the University of Minnesota
12. Fertigation Dates and Rates - 2008
Date Source oz N/100' lb N/A oz K2O/100' lb K2O/A
2-Jun 28% 0.48 3.2 0.0 0.0
11-Jun 28%+Knit 0.72 4.9 1.5 10.2
17-Jun 28%+Knit 0.72 4.9 1.5 10.2
24-Jun 28%+Knit 0.72 4.9 1.5 10.2
1-Jul 28%+Knit 0.82 5.6 2.0 13.6
8-Jul Knit+CaNit 1.03 7.0 2.0 13.6
15-Jul Knit+CaNit 1.03 7.0 2.0 13.6
22-Jul Knit+CaNit 1.03 7.0 2.0 13.6
29-Jul Knit+CaNit 1.03 7.0 2.0 13.6
15-Aug Knit+CaNit 1.03 7.0 2.0 13.6
12-Aug Knit+CaNit 1.03 7.0 2.0 13.6
18-Aug Knit+CaNit 1.03 7.0 2.0 13.6
28-Aug Knit+CaNit 1.03 7.0 2.0 13.6
10-Sep Knit+CaNit 1.03 7.0 2.0 13.6
Total © 2009 Regents of 12.7 University of Minnesota
the 86.5 24.5 166.6
13. Tomato Early Yields 2008
- First 3 Weeks-
Marketable
Treatment fruit number/plant fruit wt (lbs/plant)
Fertigated 7.5 ± 0.9 2.5 ± 0.3
Non-fertigated 8.8 ± 0.0 3.3 ± 0.1
Fertigation tended to delay yield
© 2009 Regents of the University of Minnesota
14. Marketable Tomato Yields - 2008
Treatment fruit number/plant fruit wt. (lbs/plant)
Fertigated 27.5 + 0.3 10.1 + 0.3
Non-fertigated 29.9 + 3.1 13.2 + 1.1
Non-fertigated as good or
better than fertigated
Compost supplied enough
nutrients
© 2009 Regents of the University of Minnesota
15. Soil Test after Final Harvest
– Fall 2008
With fertigation
Soil Depth NO3-N Bray-P K Soluble Salts
Inches lb/A --------- ppm ---------- mmhos/cm
0-6 50 181 117 0.4
6-12 37 161 101 0.4
Without fertigation
Soil Depth NO3-N Bray-P K Soluble Salts
Inches lb/A --------- ppm ---------- mmhos/cm
0-6 36 193 76 0.4
6-12 26 145 75 0.3
© 2009 Regents of the University of Minnesota
17. Soil Test before Planting
– April 2009
With fertigation
Soil Depth NO3-N NH4-N Bray-P K Soluble Salts
Inches ----------- lb/A ----------- --------- ppm ---------- mmhos/cm
0-6 84 10 167 146 0.8
6-12 44 6 109 96 0.7
Without fertigation
Soil Depth NO3-N NH4-N Bray-P K Soluble Salts
Inches ----------- lb/A ----------- --------- ppm ---------- mmhos/cm
0-6 78 8 160 101 0.9
6-12 30 6 134 73 0.5
© 2009 Regents of the University of Minnesota
18. Soil Amendments & Treatments
2009
No amendments added before planting
Two treatments (same as in 2009)
Fertigation
UAN, Potassium nitrate and Calcium nitrate
No fertigation
Tomato and cucumber evaluated
Two replications for tomato; one rep for cucumber
Nine plants per replication
© 2009 Regents of the University of Minnesota
19. Procedures - 2009
‘Cobra’ tomato and ‘Sweet Success’ cucumber
Transplants planted May 7
Double row beds 4 ft apart; 2 ft between
plants for tomato and 18” apart for cucumbers
One cup 20-20-20 (1 oz/gal) applied to each
transplant
Plants pruned periodically
Cucumbers harvested June 19 – October 8
Tomatoes harvested July 30 – October 8
© 2009 Regents of the University of Minnesota
20. Not Fertigated
Fertigated
© 2009 Regents of the University of Minnesota
21. Not Fertigated
Fertigated
© 2009 Regents of the University of Minnesota
22. Fertigation Dates and Rates - 2009
Date Source oz N/100' lb N/A K2O/100' lb K2O/A
1-Jun 28% 0.48 3.2 0 0
8-Jun 28%+Knit 0.72 4.9 1.5 10.2
15-Jun 28%+Knit 0.72 4.9 1.5 10.2
24-Jun 28%+Knit 0.72 4.9 1.5 10.2
1-Jul 28%+Knit 0.82 5.6 2 13.6
8-Jul Knit+CaNit 1.03 7 2 13.6
15-Jul Knit+CaNit 1.03 7 2 13.6
23-Jul Knit+CaNit 1.03 7 2 13.6
29-Jul Knit+CaNit 1.03 7 2 13.6
5-Aug Knit+CaNit 1.03 7 2 13.6
12-Aug Knit+CaNit 1.03 7 2 13.6
19-Aug Knit+CaNit 1.03 7 2 13.6
27-Aug Knit+CaNit 1.03 7 2 13.6
2-Sep Knit+CaNit 1.03 7 2 13.6
9-Sep Knit+CaNit 1.03 7 2 13.6
17-Sep Knit+CaNit 1.03 7 2 13.6
25-Sep Knit+CaNit 1.03 7 2 13.6
Total © 2009 Regents of the University of
15.8 Minnesota
107.5 30.5 207.4
23. Tomato Early Yields 2009
- First 3 Weeks-
Treatment fruit number/plant fruit wt. (lbs/plant)
Fertigated 5.9 + 0.5 2.3 + 0.3
Non-fertigated 4.8 + 0.7 2.1 + 0.3
Slight increase with fertigation
© 2009 Regents of the University of Minnesota
24. Marketable Tomato Yields – 2009
Treatment fruit number/plant fruit wt. (lbs/plant)
Fertigated 33.1 + 1.5 12.8 + 0.8
Non-fertigated 31.6 + 1.9 13.0 + 0.3
Non-fertigated as good or
better than fertigated
© 2009 Regents of the University of Minnesota
25. Marketable Cucumber Yields – 2009
Treatment fruit number/plant fruit wt. (lbs/plant)
Fertigated 22.5 36.4
Non-fertigated 22.7 37.3
Non-fertigated as good or
better than fertigated
Is compost the only source
of nutrients???
© 2009 Regents of the University of Minnesota
26. What’s in the Water???
Sample pH EC Nitrate-N Ammonium-N P K
mmhos/cm --------------------- ppm ---------------------
Irrigation Water 8.2 61 24 <1 <1 2
Fertigation water 8.2 85 56 5 <1 79
Water without fertigation 8.4 61 25 <1 <1 1
Water after fertigation 8.2 61 25 <1 <1 2
24 ppm nitrate-N in irrigation water
0.67 gal/min/100 sq. ft.
1 hour per irrigation & 96 irrigation events
~ 85 lb N/A
© 2009 Regents of the University of Minnesota
27. Soil Test after Final Harvest
– October 2009
With fertigation
Soil Depth NO3-N NH4-N Bray-P K Soluble Salts
Inches ----------- lb/A ----------- --------- ppm ---------- mmhos/cm
0-6 47 6 148 110 0.5
6-12 32 4 132 82 0.4
Without fertigation
Soil Depth NO3-N NH4-N Bray-P K Soluble Salts
Inches ----------- lb/A ----------- --------- ppm ---------- mmhos/cm
0-6 24 5 127 44 0.4
6-12 17 5 132 48 0.3
© 2009 Regents of the University of Minnesota
28. Summary
Compost applied at high rates
before planting can reduce or
eliminate the need for fertigation
Lack of response to fertigation in
this study was also in part due to
high nitrate in irrigation water
Soil tests at harvest suggest that
potassium will be limiting in the
nonfertigated treatment next
year © 2009 Regents of the University of Minnesota