1. Phosphorus Fertilization in Sugar Beets

2. Introduction
In-furrow P applications at planting and broadcast P applications have generally given some level of sugar beet root yield response in southern Alberta soils that are moderately P deficient.

3. Alberta phosphorus trials ‘Root yield’ responses – tons/acre
Treatment
Yield gain
2003
Check (tons/acre)
(32.2)
Broadcast P
+2.5
LSD (.05)
1.8
Broadcast P = 60 lbs P2O5/ac, Moderately P deficient soil

4. Alberta phosphorus trials ‘Root yield’ responses – tons/acre
Treatment
Yield gain
2004
2005
2007
Check (tons/acre)
(21.3)
(27.3)
(27.8)
In-furrow P
+2.9
+3.0
+0.7
Broadcast P
+4.2
+5.1
+2.4
Bcast + In-furrow P
+5.3
+6.2
+2.6
LSD (.05)
2.4
1.5 NS
Broadcast granular P = 60 lbs P2O5/ac,
In-furrow P = 12 lbs P2O5/ac (3 US gallons/ac )
Moderately P deficient soils

5. 2013 Phosphorus Trials
There was interest in evaluating whether banding P directly under the row before planting could increase the efficiency of P uptake.

6. JD Flexi-planter modified for banding P fertilizer under the row

7. Elmer’s Strip Tiller for banding P fertilizer under the row

8. Lime Treatments before incorporation

9. 2013 Alberta phosphorus trials ‘Root yield’ responses – tons/acre
Treatment
Yield gain
2013 – test A
2013 – test B
Check (tons/acre)
(32.0)
(30.9)
Broadcast P
+1.5
+2.2
P under the row
+0.6
+4.0
PCC – 2.2 tons/ac
+1.0
+1.8
PCC – 4.4 tons/ac
+2.3
LSD (.05)
0.9
1.8
Broadcast & under the row P = 50 lbs P2O5/ac
Moderately P deficient soils

10. 2014 Phosphorus Trials
Under the row P treatments were expanded in 2014.
Sites were not as P deficient as in 2013.
Trials in 2014 had some of the same trends as in 2013, but differences were not statistically significant.

11. 2014 Alberta phosphorus trials ‘Root yield’ responses – tons/acre
Treatment
Yield gain
2014 – test A
2014 – test B
Check (tons/acre)
(35.7)
(32.2)
Broadcast P
+1.5
+1.3
P ‘deep’ under row
+0.1
+0.6
P ‘shallow’ under row
+0.7
+1.7
PCC – 2.75 tons/ac
PCC – 5.5 tons/ac
+1.0
LSD (.05) NS
Broadcast & under the row P = 50 lbs P2O5/ac
P under the row is an average of Zone tillage and JD 71 Flexi-planter treatments

12. 2015 & 2016 Phosphorus Trials
An opportunity presented itself to conduct trials on soil that was ‘very’ deficient in P.
Alfalfa breaking in both years. (No P fertilizer for 7 & 8 years)
Soil P levels were less than 10 lbs/acre (<5ppm) in both years.

13. Treatments 2015 – 2 tests (18 total treatments)
test (12 treatments)
Main treatments I will focus on:
Untreated check
Broadcast granular P (50 lbs P2O5/ac) as
In-furrow P (8 lbs P2O5/ac) as (2 US gal/ac)
In-furrow P (2 US gal/ac) + granular broadcast P (50 lbs P2O5/ac)
Liquid P under the row at 2 depths (50 lbs P2O5/ac as )
Broadcast PCC (2.75 and 5.5 tons/ac)
Other liquid in-furrow treatments responded the same as

14. 2015 Alberta phosphorus trial A ‘Vigour’ responses: 1-9 scale
Treatment
June 26
July 20
Oct 1
Check treatment
5.8
4.4
Broadcast P
7.3
8.0
7.0
In-furrow P
7.7
6.8
Broadcast + In-furrow P
7.9
LSD (.01)
0.8
1.2
1.3
Broadcast P = 50 lbs P2O5/ac
In-furrow P = 8 lbs P2O5/ac

15. 2015 Alberta phosphorus trial A ‘Root yield’ responses – tons/acre
Treatment
Yield gain
2015 – test A
Check (tons/acre)
(23.9)
Broadcast P
+8.7
In-furrow P
+2.6
Broadcast + In-furrow P
LSD (.05)
2.6
LSD (.01)
3.5
Broadcast P = 50 lbs P2O5/ac
In-furrow P = 8 lbs P2O5/ac

16. 2015 Alberta phosphorus trial B ‘Root yield’ responses – tons/acre
Treatment
Yield gain
2015 – test B
Check (tons/acre)
(21.4)
Broadcast P
+9.6
P ‘deep’ under the row (4”)
+10.3
P ‘shallow’ under the row (2”)
+10.7
PCC – 2.75 tpa
+8.3
PCC – 5.5 tpa
+10.4
LSD (.01)
3.0
Broadcast & under the row P = 50 lbs P2O5/ac

17. 2016 Alberta phosphorus trial ‘Root yield’ responses – tons/acre
Treatment
Yield gain
(tons/ac)
Check
(16.0)
Broadcast P
+12.0
In-furrow P
+5.4
Broadcast + In-furrow P
+12.7
LSD (.01)
3.6
Broadcast P = 50 lbs P2O5/ac
In-furrow P = 8 lbs P2O5/ac

18. 2016 Alberta phosphorus trial ‘Root yield’ responses – tons/acre
Treatment
Yield gain
(tons/ac)
Check
(16.0)
Broadcast P
+12.0
P ‘deep’ under the row (4”)
+12.5
P ‘shallow’ under the row (2”)
+12.8
PCC – 2.75 tpa
+11.7
PCC – 5.5 tpa
+13.6
LSD (.01)
3.6
Broadcast & under the row P = 50 lbs P2O5/ac

19. 2016 Alberta phosphorus trial ‘Extractable Sugar per Ton’ responses
Treatment
EST gain
(lb/ton)
Check
(330.8)
Broadcast P
+18.4
In-furrow P
+6.4
Broadcast + In-furrow P
+14.2
LSD (.01)
11.6
Broadcast P = 50 lbs P2O5/ac
In-furrow P = 8 lbs P2O5/ac

20. 2016 Alberta phosphorus trial ‘Extractable Sugar per Ton’ responses
Treatment
EST gain
(lb/ton)
Check
(330.8)
Broadcast P
+18.4
P ‘deep’ under the row
+14.8
P ‘shallow’ under the row
+10.0
PCC – 2.75 tpa
+11.8
PCC – 5.5 tpa
+20.8
LSD (.01)
11.6
Broadcast and under the row P = 50 lbs P2O5/ac

21. Check treatment in July 2016

22. In-furrow P (8 lbs P2O5/ac) in July 2016

23. Broadcast P (50 lbs P2O5/ac) in July 2016

24. 5.5 tons/ac PCC in July 2016

25. Banded P (50 lbs P2O5/ac) in late August 2016

26. Soil Phosphorus Treatment 2015 2016 Soil P before the trial started
(lbs/ac)
2016
Soil P before the trial started
<10
Check (after the trial) 10
Broadcast P (after the trial) 12
2.75 tons/ac PCC (after the trial) 14
5.5 tons/ac PCC (after the trial) 22 20
Broadcast P = 50 lbs P2O5/ac

27. Conclusions for ‘very deficient’ P soils (2015 and 2016)
There was a significant increase in early season vigour with broadcast P, P under the row, in-furrow P and PCC, but vigour for in-furrow treatments did not carry through to harvest.
In-furrow P increased yield by an average of 4.1 tons/ac, but in-furrow applications did not provide enough phosphorus to maximize production on soils very deficient in P.
A combination of in-furrow and broadcast P was not better than broadcast P alone. (but these trials were not conducted under cool early season conditions)
Different in-furrow fertilizer products ( , Aventine Complete and PowerStart – data not shown) performed the same.

28. Conclusions for ‘very deficient’ P soils (2015 and 2016)
There were no significant differences in root yield or quality between broadcast P and P banded under the row.
Broadcast and banded P applications increased yield by an average of 11.3 tons/ac.
Spring PCC applications of 2.75 and 5.5 tons/ac increased root yield by and average of 10.0 and 12.0 tons/ac, respectively.
PCC applications of 5.5 tons/ac had equivalent or better P supplying power as 50 lbs P2O5/ac fertilizer treatments.
PCC applications of 5.5 tons/ac raised the available soil P level.

29. Questions?