Crop absorption of immobile nutrients (P and K).
8
OSU Soil Fertility 04 01 Crop absorption of Crop absorption of immobile immobile nutrients (P nutrients (P and K). and K). Absorption is from just a thin cylinder of soil around each root.
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Absorption is from just a thin cylinder of soil around each root. Crop absorption of immobile nutrients (P and K). A-y for x1 and D y 1. D y 2. Yield (y). D y 1. x 1 x 2. Increasing level of growth factor (nutrient, x). Plant Growth and Soil Nutrient Supply Relationships - PowerPoint PPT Presentation
Transcript of Crop absorption of immobile nutrients (P and K).
OSU Soil Fertility 04 01
Crop absorption of Crop absorption of immobileimmobile nutrients (P and K).nutrients (P and K).
Crop absorption of Crop absorption of immobileimmobile nutrients (P and K).nutrients (P and K).
Absorption is from just a thin cylinder of soil around each root.
OSU Soil Fertility 04 01
Plant Growth and Soil Nutrient Supply Relationships
•Mitscherlich (1909)“…increase in yield of a crop as a result of increasing a singlegrowth factor is proportional to the decrement from the maximum yield obtainable by increasing the particular growthfactor.”
dy/dx = (A - y) c
Law of “diminishingreturns”
Plant Growth and Soil Nutrient Supply Relationships
•Mitscherlich (1909)“…increase in yield of a crop as a result of increasing a singlegrowth factor is proportional to the decrement from the maximum yield obtainable by increasing the particular growthfactor.”
dy/dx = (A - y) c
Law of “diminishingreturns” x1 x2x1 x2
y2y2
y1y1
A-y for x1 and y1
A-y for x1 and y1
Yie
ld (
y)
Yie
ld (
y)
Increasing level of growth factor (nutrient, x)Increasing level of growth factor (nutrient, x)
OSU Soil Fertility 04 01
Plant Growth and Soil Nutrient Supply Relationships
•Bray “…as the mobility of a nutrient in the soil decreases, the amount of that nutrient needed in the soil to produce a maximum yield (the soil nutrientrequirement) increases from a value determined by the magnitude of the yieldand the optimum percentage composition of the crop, to a constant value.”
Plant Growth and Soil Nutrient Supply Relationships
•Bray “…as the mobility of a nutrient in the soil decreases, the amount of that nutrient needed in the soil to produce a maximum yield (the soil nutrientrequirement) increases from a value determined by the magnitude of the yieldand the optimum percentage composition of the crop, to a constant value.”
% of MaximumYield or “Yield Possibility”
% of MaximumYield or “Yield Possibility”
Soil Phosphate (P) or Potassium (K) Supply(soil test index)Soil Phosphate (P) or Potassium (K) Supply(soil test index)
100100
5050
7575
10 40 70 10010 40 70 100
Bray mobile nutrientBray mobile nutrient
OSU Soil Fertility 04 01
Plant Growth and Soil Nutrient Supply Relationships
•Mitscherlich– Soil deficiency levels could be expressed as a “percent sufficiency”
Plant Growth and Soil Nutrient Supply Relationships
•Mitscherlich– Soil deficiency levels could be expressed as a “percent sufficiency”
% of MaximumYield or “Yield Possibility”
% of MaximumYield or “Yield Possibility”
Soil Phosphate (P) or Potassium (K) Supply(soil test index)Soil Phosphate (P) or Potassium (K) Supply(soil test index)
100100
5050
7575
10 40 70 10010 40 70 100
OSU Soil Fertility 04 01
Plant Growth and Soil Nutrient Supply Relationships
•Mitscherlich
Soil Test Correlation and Calibration
Soil Test Percent FertilizerP Index Sufficiency P2O5
0 25 8010 45 6020 80 4040 90 2065+ 100 0
Plant Growth and Soil Nutrient Supply Relationships
•Mitscherlich
Soil Test Correlation and Calibration
Soil Test Percent FertilizerP Index Sufficiency P2O5
0 25 8010 45 6020 80 4040 90 2065+ 100 0
OSU Soil Fertility 04 01
Wheat Response to Fertilizer-P at STP of 20Wheat Response to Fertilizer-P at STP of 20
2020
2525
3030
3535
4040
4545
00 1010 2020 3030 4040 5050
P2O5 Rate (lb/acre)P2O5 Rate (lb/acre)
Yie
ld (
bu
/ac
re)
Yie
ld (
bu
/ac
re)
OSU Soil Fertility 04 01
Y = YG [ PSP +(2 FP/DP) (100 - PSP) - (FP/DP)2 (100 - PSP)]/100Y = YG [ PSP +(2 FP/DP) (100 - PSP) - (FP/DP)2 (100 - PSP)]/100
General response of crops to fertilizer PGeneral response of crops to fertilizer P
Where:•PSP = Percent sufficiency P determined from calibrated soil test.•FP = Rate of Fertilizer P2O5 applied.•DP = P2O5 deficiency determined from calibrated soil test
Where:•PSP = Percent sufficiency P determined from calibrated soil test.•FP = Rate of Fertilizer P2O5 applied.•DP = P2O5 deficiency determined from calibrated soil test
Y = YG [ PSP +(2 FP/DP) (100 - PSP) - (FP/DP)2 (100 - PSP)]/100Y = YG [ PSP +(2 FP/DP) (100 - PSP) - (FP/DP)2 (100 - PSP)]/100
Y = YG [ a + x b1 - x2 b2]/100Y = YG [ a + x b1 - x2 b2]/100
OSU Soil Fertility 04 01
01020304050
60708090
100
5 35
65
95
125
155
185
215
245
275
305
335
365
395
425
455
485
Feet North
STP
(lb
/acre
)
5 East
01020304050
60708090
100
5 35
65
95
125
155
185
215
245
275
305
335
365
395
425
455
485
Feet North
STP
(lb
/acre
)
5 East
0
10
20
30
40
50
60
70
80
90
100
5
35
65
95
12
5
15
5
18
5
21
5
24
5
27
5
30
5
33
5
36
5
39
5
42
5
45
5
48
5
Feet North
ST
P (
lb/a
cre
)
25 East
0
10
20
30
40
50
60
70
80
90
100
5
35
65
95
12
5
15
5
18
5
21
5
24
5
27
5
30
5
33
5
36
5
39
5
42
5
45
5
48
5
Feet North
ST
P (
lb/a
cre
)
25 East
