Nutrient cycles and flows in agroecosystems

1
Nutrient cycles and flows in agroecosystems
What is missing?
Dissipation into the surrounding environment
2

3

4
Key terms
Fertilizer raw materials
Cycles Flows Stocks
Soil nutrient reserves
5
Total N inputs to IL soils
(alfalfa and other forage legumes)
Mg 1 x 106 g 1000 kg 1 metric ton
6
Total N outputs from IL soils
7
Crop specific harvests of N
8
N inputs vs. river export
Net input Gross inputs - outputs
1993
9
Mining Prairie N
Anthropogenic N inputs
10
Units are 1000 metric tons N / yr
11
Why does so much N get into Illinois rivers ???
12
Approximately 40 of IL fields have artificial
drainage
13
Yield maps have made drainage problems much more
obvious
14
Redistribution of nutrients
excess
15
Mid-Atlantic Manure P and N Surplus
State P N --Million Lbs in
Excess-- DE 7.3 14.6 MD
10.4 19.6 NJ 0.9 1.8 NY 3.3
4.2 PA 23.7 33.8 VA 24.8 42.3
(Source USDA, 2001)
16
Nutrient depletion in Africa
http//www.fao.org/docrep/006/y5066e/y5066e02.jpg
17
Nutrient budgets on organic farms
a review of published data
N
Most organic farms in developed countries do not
have nutrient deficits even though they dont use
conventional fertilizers.
P
K
http//www.organic.aber.ac.uk/library/Nutrient20
budgets20on20organic20farms.pdf
18
(No Transcript)
19
Daily inputs and outputs of dry matter, P and N
http//edis.ifas.ufl.edu/DS096
20
N 20 maintenance
P 13 maintenance
K 12 maintenance
20
27
13
60
60
75
urine
feces
N
50
50
P
10
90
K
90
10
http//extension.oregonstate.edu/catalog/html/em/e
m8586/
21
Nitrogen budget for a dairy in
Florida (lbs of N/acre)
http//edis.ifas.ufl.edu/DS096
22
Nitrogen budget for 4 dairies in New
York
http//www.dairyn.cornell.edu/pages/10concerns/15n
utrient.shtml
23
Annual manure production and nutrient value for
100 cows
2 X in 2008
Table 3.
24
P inputs for 33 hog and beef
operations in NE