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Legumes in Farming systems

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Among the leguminous plants chick pea is the most soil exhausting, although this ... Faba beans are not a burdensome crop to the ground, they even seem to manure it. ... – PowerPoint PPT presentation

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Title: Legumes in Farming systems


1
Legumes in Farming systems
  • I. Papastylianou
  • Senior Researcher
  • Head Dept. of Horticulture
  • Agric. Res. Inst./Cyprus

2
1st document on the role of legumes in farming
systems
  • Among the leguminous plants chick pea is the
    most soil exhausting, although this crop is in
    the ground only a very short time. Faba beans are
    not a burdensome crop to the ground, they even
    seem to manure it. People of Macedonia and
    Thessaly turn over the ground when faba is in
    flower
  • Theophrastus (370-285 B.C.)

3
Historical scientific roots of N2 fixation by
legumes
  • Saussure, 1806
  • Soil and not the atmosphere was the source of
    plant nitrogen
  • Jean Baptiste Boussingault (French), 1838
  • Legumes enriched the soil by introducing N from
    the air
  • Lawes and Gilbert (British), 1850
  • Confirmed Boussingault finding in Rothamsted
    in field experiments

4
  • Hellriegel and Wilfarth (German), 1880
  • Legumes utilize atmospheric N2
  • Legumes-microorganisms symbiosis
  • Root nodules are the centers of N2 fixation
  • Beijerinck, 1888 isolated the Rhizobium
    leguminosarum

5
Symbiosis(S??ß???leaving together in harmony)
  • Legumes offer carbohydrates
  • Rhizobium offers nitrogen
  • Legumes vs non legumes
  • Lechemoglobin (O2 control)
  • Nitrogenase
  • Nitrogenase
  • N2 NH3 amino acids
    proteins
  • ATP
  • H
  • Low oxygen tension

(Courtesy of Oklahoma St. University)
6
Factors affecting N2 fixation
  • Presence of Bacteria
  • Species by strain compatibility
  • Survival of Bacteria
  • Climatic factors temperature, light
  • Soil factors nutrients availability (P, N, K,
    micronutrients), moisture, acidity
  • Crop management Defoliation, competition, pest
    and pathogen control

7
Methods of Estimating N2 fixation
  • Lysimeter studies (Total N)
  • Determines amount of N2 fixation
  • 15N 1949 KamenGest (15N2), 1970 FriedBroeshart
    (A-value method)
  • Determines percentage of N2. N2 x yield
    amount of N2 fixation
  • Acetylene (1966, Dilworth)
  • Determines rate of N2 conversion
  • System approach (Papastylianou, Agronomy J. 1999
    329-334)
  • Determines the total amount of N2 fixation

8
Estimating N fixation within a system
  • Variables needed
  • S1n sum from Year 1 to Year n
  • N2 Kg N fixed per year of legume
  • n years of the study
  • x number of phases in the cycle
  • y portion of the legume in the rotation cycle
  • Foliage Zone data
  • L Kg N harvested legume tops
  • F Kg N in tops of the harvested non-N2-fixing
    crop subsequent to legume
  • M Kg in tops of the harvested non-N2-fixing crop
    grown in monoculture

Continued on next slide
9
  • Root Zone Data
  • o Kg N in soil before the legume
  • fl Kg N in soil after the legume
  • fs Kg N in soil after the non-N2-fixing crop
    grown in rotation with the legume in phase-entry
    studies
  • fm Kg N in soil after the non-N2-fixing crop
    grown in monoculture
  • fls kg N in soil in the areas where the legume
    and non-N2-fixing crops were rotated in
    non-phase-entry studies

10
Formulas used
Single year Crops
  • N2L(fl-o)
  • N2L-M
  • N2 (L-M)(fl-o)-(fm-o)
  • N2S1nL(fl-o)/n
  • N2S1n(L-M) /n
  • N2S1n(L-M) (fl-o)-(fm-0)/n
  • N2S1n(L-M) (fl-fm)/n

Long-term monoculture
11
Long term rotation systems
  • N2S1n(LF)y(fl-o)(fs-o)/x/ny
  • N2S1n(LF)(fls- 0)/ny
  • N2S1n (LF) xM/n
  • N2 S1n (LF) xMy(fl-o)(fs-o)/x-(fm-
    o)/ny
  • N2 S1n(LF) xM(fls-o)-(fm-o)/ny
  • N2 S1n (LF) xMy(fls-fs)/x-fm/ny
  • N2 S1n (LF) xM(fls-fm)/ny

12
Amount of N2 fixation
  • N15 method vs. System approach method
  • 50-200 Kg N/ha
  • Average100 Kg N/ha
  • Grain legumes-100 Kg N/ha
  • Clover 150 Kg N/ha
  • Contribution of legumes worldwide
  • 250 000 000 ha (140 Kg N/ha fixed)
  • 35 000 000 000 Kg N fixed worldwide

13
Value of N2 fixation
  • High protein products
  • Fertilizer replacement
  • Improvement of soil fertility

REDUNDANT
14
R
NR
Productivity of barley in vetch-barley (VB) and
continues Barley (CB) systems under various N
fertilizer rates
15
Role of legumes (in farming systems) for long
term sustainability
16
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