College of Agriculture and Life Sciences Impacts of 4R Management on Drainage Water Quality Matt Helmers – Director of the Iowa Nutrient Research Center, Professor in Dept. of Ag. And Biosystems Engineering and Dean’s Professor in the College of Ag and Life Sciences
39
Embed
Impacts of 4R Management on Drainage Water Quality · Matt Helmers – Director of the Iowa Nutrient Research Center, Professor in Dept. of Ag. And Biosystems Engineering and Dean’s
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
College of Agriculture and Life Sciences
Impacts of 4R Management on Drainage Water Quality
Matt Helmers – Director of the Iowa Nutrient Research Center, Professor in Dept. of Ag. And Biosystems Engineering and Dean’s Professor in the College of Ag and Life Sciences
NWRF Drainage NERF Drainage
COBS
SERF Drainage
Replicated subsurface drainage plots to evaluate performance of various in-field management practices
Gilmore City DRF
172 monitored plots~4000 samples per year
Subsurface Drainage Layout
Flow Monitoring System
NWRF Drainage NERF Drainage
COBS
SERF Drainage
Replicated subsurface drainage plots to evaluate performance of various in-field management practices
Combined Corn-Soybean System – Same N management – Early Spring Sidedress at 150-160 lb-N/acre
N-Rate versus Concentration
N Application Rate (lb/acre)
0 50 100 150 200 250 300
Nitr
ate-
N C
once
ntra
tion
(mg/
L)
0
5
10
15
20
25
30
Timing Study at ADW
NWRF Drainage NERF Drainage
COBS
SERF Drainage
Replicated subsurface drainage plots to evaluate performance of various in-field management practices
Gilmore City DRF
Treatments
Treatment Number Tillage Nitrogen Application
Time
Nitrogen Application Rate
(lb N/acre)*1 Conventional tillage* Fall (anhydrous
ammonia with nitrapyrin)**
135
2 Conventional tillage Spring (anhydrous ammonia)
135
3 Conventional tillage Split with variable N at sidedress (40 lb/acre of
urea 2x2 starter at planting plus in-season agrotain treated urea)
135
4 Conventional tillage None 0
* Fall chisel corn stalks with spring disk/field cultivate, and spring disk/field cultivate soybean stubble.**In fall of 2014 freezing conditions occurred early and prevented fall application. Application occurred in early spring 2015.
Corn Yield
*Means with the same letter in the same year are not significantly different, P=0.05.
2015
Fall N
Spring
NSpli
t NNo N
Cor
n Yi
eld
(bu/
acre
)
0
50
100
150
200
250
2016
Fall N
Spring
NSpli
t NNo N
Cor
n Yi
eld
(bu/
acre
)
0
50
100
150
200
250
a a ab
a a a
b
Fall N
Spring
NSpli
t NNo N
Cor
n Yi
eld
(bu/
acre
)
0
50
100
150
200
250
a a b
c
2017
Fall N
Spring
NSpli
t NNo N
Cor
n Yi
eld
(bu/
acre
)
0
50
100
150
200
250
a a a
b
2018
Soybean Yield
*Means with the same letter in the same year are not significantly different, P=0.05.
2015
Fall N
Spring
NSpli
t NNo N
Soyb
ean
Yiel
d (b
u/ac
re)
0
20
40
60
80
2016
Fall N
Spring
NSpli
t NNo N
Soyb
ean
Yiel
d (b
u/ac
re)
0
20
40
60
80
2016
Fall N
Spring
NSpli
t NNo N
Soyb
ean
Yiel
d (b
u/ac
re)
0
20
40
60
80
2017
Fall N
Spring
NSpli
t NNo N
Soyb
ean
Yiel
d (b
u/ac
re)
0
20
40
60
80
2018
Flow-weighted Nitrate-N Concentration
*Means with the same letter in the same year are not significantly different, P=0.05. Analyzed across corn and soybean phase
Fall N
Spring
NSpli
t NNo N
Flow
-wei
ghte
d N
itrat
e-N
Con
c. (m
g/L)
02468
1012141618
Corn Phase - 2015-2018a ab
dc de
Fall N
Spring
NSpli
t NNo N
Flow
-wei
ghte
d N
itrat
e-N
Con
c. (m
g/L)
02468
1012141618
Soybean Phase - 2015-2018
bcab
dce
NWRF Drainage NERF Drainage
COBS
SERF Drainage
Replicated subsurface drainage plots to evaluate performance of various in-field management practices
Gilmore City DRF
Management Systems for 2008-2015 Study
Treatment Timing and source of N
Target N Rate kg ha-1
Crop rotation Tillage
SU168 Spring UAN-
168-
CornSoybean
Chisel plow corn fallField cultivate spring
SU168NT+R Spring UAN-
168-
Corn + Rye cover cropSoybean + Rye cover crop
No-TillNo-Till
FM168 Fall Manure-
168-
CornSoybean
Chisel plow corn fallField cultivate spring
FM168/112 Fall ManureFall Manure
168112
CornSoybean
Chisel plow corn fallField cultivate spring
FM168NT Fall Manure-
168-
CornSoybean
No-TillNo-Till
FM224CC Fall ManureFall Manure
224224
Continuous Corn Chisel plow fall Field cultivate spring
FM224CC-S Fall ManureFall Manure
224224
Continuous Corn withStover removal
Chisel plow fall Field cultivate spring
Nitrate-N Loss from 2008-2015
No-till
Till
Management systems for 2016 - 2018 studySystem Application timing and N
sourceCrop Tillage N rate
(lb/ac) 1 Spring UAN
-Corn
SoybeanChisel plow
Field cultivate150
-2 Early fall manure
-Corn
SoybeanNo-tillNo-till
150-
3a Late fall manure + Instinct Continuous corn Chisel plow 200
3b Spring manure Continuous corn Chisel plow 200
4a Late fall manure Continuous corn Chisel plow 200
4b Late fall manure + 1 ton/ac gypsum
Continuous corn Chisel plow 200
5 Early fall manure-
Corn + Rye coverSoybean + Rye cover
No-tillNo-till
150-
6 Late fall manure-
CornSoybean
No-tillNo-till
150-
Research funded by Iowa Pork Producers Association and Calcium Products Inc.
Corn phase: Flow-weighted Nitrate-N Concentration
*Means with the same letter in the same year are not significantly different, P=0.05.