The document discusses the effect of chemical composition of plant residues on nitrogen mineralization in soil. It presents findings from several case studies and research papers. The chemical composition of different plant residues like lignin, polyphenols and C:N ratio affects their decomposition rate and impacts nitrogen mineralization. Plant residues high in nitrogen and low in lignin and polyphenols decompose faster, releasing nitrogen for plant uptake. The studies show crop residues and tree leaves with higher lignin and polyphenol content immobilize soil nitrogen during decomposition.

2. “Effect of Chemical Composition of Plant
Residues on Nitrogen Mineralization in
Soil”
Presented By:
Vikram Singh
M.Sc. (Agri.) Soil Science student
Reg. No: 2010115095
Presented By:
Vikram Singh
M.Sc. (Agri.) Soil Science student
Reg. No: 2010115095
Major Guide :
Dr. J. N. Nariya
Professor
Dept. of Agril. Chem. and Soil
Science
JAU , Amreli
Major Guide :
Dr. J. N. Nariya
Professor
Dept. of Agril. Chem. and Soil
Science
JAU , Amreli
Minor Guide:
Dr. P. K. Chovatia
Associate Professor
Department of Agronomy
JAU , Junagadh
Minor Guide:
Dr. P. K. Chovatia
Associate Professor
Department of Agronomy
JAU , Junagadh

3. 3
Contents…
Introduction
Facts about nitrogen
Transformation of nitrogen in soil
Chemical composition of plant residues
Decomposition rates of crop residues
Research finding
Conclusion

4. Use of plant residues as organic nutrient source is
relatively simple for the farmers compared to the application of
manure. Incorporating plant residues into agricultural soils can
sustain organic carbon content, improve soil physical
properties, enhance biological activities and increase nutrient
availability.
In the short-term, incorporation of plant residues provides
the energy and nutrients for microbial growth and activity, acts
as a driving force for the mineralization-immobilization
processes in the soil and is a source of nitrogen (N) for plants
.In the long-term, incorporation of crop residues is important for
the maintenance of organic C and N stocks in the nutrient pool
of arable soils. The N availability from these residues depends
on the amount of N mineralized or immobilized during
decomposition. 4
Introduction

5. Residues: Whatever remains after something else has been taken,
separated, removed, or designated; remnant; remainder.
Crop/Plant residues: Defined as the vegetative plant(crop/trees/shrubs)
material left on a ground after its harvesting, pruning or processing or
grazing. Ex: stalks, stems, leaves, roots, penicles and weeds.
5

6. Crop residues
Field residues Process residues
Types of crop residues
Stalks and Stubble
Leaves, and Seed pods.
Husks, Seeds, Bagasse and
Roots.
6

7. Nitrogen
 Nitrogen is most important primary nutrient which is
required in large quantity for plant growth.
 Most widely distributed element in atmosphere.
Preferred as nitrate (NO3
-
) and ammoniacal (NH4
+
)
Nitrogen by plants.
Nitrogen makes up 78 % of atmospheric air
N N
7

8. Very small amount of soil nitrogen is available to
plants. Total nitrogen in furrow slice(0-15 cm) soils generally varies
from 0.02 to 0.44 per cent by weight.
Role of Nitrogen
An essential constituent of proteins and is present in many compounds of great
physiological importance in plant metabolism
 Is an integral part of chlorophyll.
 Imparts vigorous vegetative growth and dark green colour to plants.
 Governs utilization of potassium, phosphorus and other elements.
Facts about nitrogen
8

9. Sources of Nitrogen :
• Fertilizers
• Organic manures
• Plant residues
• Bio-fertilizers
• Green manure
• Rain water
• Bacterial nitrogen fixation
9

10. Transformation of Nitrogen in soils
Various pathways of N transformation
 Mineralization
 Immobilization
 Fixation in soil
 Losses of N( Volatilization)
• Nitrogen in crop residue become available after
mineralization
• Available nitrogen includes NH4
+
and NO3
-
10

11. Mineralization
“Process by which nitrogen in organic
compounds is converted to inorganic ammonium and
nitrate ions carried out by micro-organisms.”
11
Mineralization process operates through three reactions
namely:
1.Aminisation
2.Ammonification , and
3.Nitrification

12. 1. Aminisation:
Process of release of amines and amino acids from combined N
compounds (proteins).
Proteins R-NH2 + CO2 + Energy + Other products
(Amines)
Heterotrophic
Micro-organisms
12
Organic N
R-NH2
(Amine)
NH4
+
(Ammonium)
NO2
-
(Nitrite)
NO3
-
(Nitrate)
Aminization Ammonification Nitrification

13. Aminisation occurs both in aerobic and anaerobic condition
End products
(NH4)2 SO4 H2O, and CO2Under aerobic condition
Under anaerobic condition
NH3, NH2
-
, CO2
,
organic acids, H2S etc
13

14. 2.Ammonification
Process of reduction of amines to ammonical
compounds.
R-NH2 + HOH
NH3 + R-OH + energy
H2O
NH4 + OH-
14
 Under anaerobic condition (due to more
hydrogen)Org.N NH4
+
-N
Lack of O2 in soil

15.  Under aerobic condition the process continues
NH4
+
-N NO3
-
-N
NO2
-
-N
Nitrification
3. Nitrification
15
Process of microbial oxidation of
ammonical nitrogen to nitrate form of
nitrogen.

16. 16
Fig. 01: Sketch of three different process types regarding the effects
of returning plant residues on soil inorganic nitrogen over the
limited experimental period.
Chen et al. (2014) France

17. 17
Fig. 2. Diagram illustrating some processes in the nitrogen cycle in
soils.
HawaiiJonathan (2006)

18. Plant residues /material may be classified under three major chemical
groups:
Polysaccharides: These are large group of carbon compounds, and
made up of simple monosaccharides units like glucose etc. cellulose
and hemicellulose are most important polysaccharides and they
accumulate in plants tissues. They form the skelton of plant tissues.
Lignins: These are complex carbon compounds. They are found in
woody tissue. It is binding material and covers the cell walls and fibro-
vascular bundles. Lignin is one of the most abundant organic polymers
in plants, just behind cellulose. It is the exclusive chemical composition
of gymnosperm and angiosperm. The content of lignin in wood and
Gramineae is 20–40% and 15–20 %, respectively.
Proteins :They are nitrogenous substances, it`s predominant in cell
protoplasm. Simple forms of protein is amino acids.
18
Chemical composition of plant residues:

19. 19
Fig 3: Composition of Plant Materials
Source: Brady And Wail (2012)

20. Rapid
Very slow
Sugars ,Starch and simple protiens
Crude proteins
Hemicellulose
Cellulose
Fats, Waxes and Oils
Lignins and phenolic compounds
20
Decomposition Rates of Crop residues

21. Resource
quality category
Resource quality
parameters (g kg-1
)
Nitrogen supplying
capacity
High quality N >25
Lignin <150
Polyphenol <40
High and immediate
Intermediate-high
quality
N >25
Lignin >150
Polyphenol >40
Delayed, short or long term
Intermediate-low
quality
(Short-term)
N<25
lignin<150
polyphenol <40
Low–short term
immobilization
Low quality
(Long-term)
N <25
Lignin >150
Polyphenol >40
Very low and possible long
term immobilization
Mohanty et al. (2013)
21
NAAS, New Delhi

22. 22
Source: Brady And Wail (2012)

23. Research findings
23

24. 24
Carbon and nitrogen mineralization
potential of biofuel crop(Jatropha curcas L.)
residues in soil
CASE STUDY- 01

25. Soil location pH EC(ds/m) CaCO3
(%)
O.C C/N Total N
(g/kg)
Available
N (mg/kg)
Texture
Inside –canopy soil 7.41 0.14 0.92 0.67 9.57 0.72 47.6 Loam
Outside –canopy
soil
7.31 0.11 0.92 0.60 8.57 0.72 41.3 Loam
TABLE:2..Characteristics of soil used for incubation study
Chaudhary et al.(2014) 25
Bhavnagar ,Gujarat

26. 26
Jatropha
residues
C (%) N (%) C/N Cellulose
(%)
Hemi
cellulos
e (%)
Lignin
(%)
Phenolics
(mg/g)
Cake 46 3.30 13.94 14.44 12.46 1.25 1.91
Leaf 43 1.22 35.25 8.96 17.71 5.48 3.32
Fruit shell 42 0.98 42.86 6.85 15.78 1.82 0.46
Chaudhary et al.
(2014)
Bhavnagar ,Gujarat

27. Chaudhary et al. (2014) 27Bhavnagar ,Gujarat

28. Chaudhary et al. 28Bhavnagar ,Gujarat

29. Rate at
day
C N Cellulose Hemicellulose Lignin Phenolic C/N
ratio
1 0.95 0.97 0.94 -0.91 -0.59 0.01 -0.94
9 0.95 0.97 0.94 -0.92 -0.61 -0.02 -0.94
21 0.96 0.99 0.95 -0.93 -0.61 -0.01 -0.96
33 0.97 0.99 0.96 -0.93 -0.61 0.01 -0.96
64 0.98 0.99 0.98 -0.88 -0.52 0.11 -0.98
94 0.99 0.99 0.98 -0.85 -0.48 0.17 -0.98
29
Chaudhary et al. (2014) Bhavnagar ,Gujarat

30. 30
Case Study- 02
Effect of organic matter and soil fertility on nitrogen
mineralization and its uptake by cassava (Manihot
esculenta Crantz).
Andy , 2015 Java,Indonesia

31. Treatments 20 o
C 25 o
C 30 o
C
Soil that planted with cassava less than 10 years
Only Groundnut (G) 550.6 773.8 1015.6
Only Maize (M) 435.2 704.9 872.3
G : M (1:1) 533.8 943.0 1036.0
G : M (2:1) 589.6 1011.8 1086.2
G : M (1:2) 459.4 710.5 851.9
Control (Without
Organic Matter)
347.8 459.4 450.1
TABLE 05: Cumulative nitrogen mineralization (mg kg-1
) for 12
weeks at various temperatures and biomasses application.
Andy (2015) Java,Indonesia 31

32. 32
Treatments 20 o
C 25 o
C 30 o
C
Soil that planted with cassava more than 30 years
Only Groundnut
(G)
496.6 738.4 747.7
Only Maize (M) 388.7 556.1 638.0
G : M (1:1) 444.5 634.3 638.0
G : M (2:1) 526.4 738.4 783.1
G : M (1:2) 375.7 647.3 758.9
Control (Without
Organic Matter)
264.1 437.1 394.3
TABLE:6..Cumulative nitrogen mineralization (mg kg-1
) for 12
weeks at various temperatures and biomasses application.
TABLE:6..Cumulative nitrogen mineralization (mg kg-1
) for 12
weeks at various temperatures and biomasses application.
Andy (2015) Java,Indonesia

33. 33
Case Study-03
Effect of Chemical Composition of Plant Residues
on Nitrogen Mineralization
Srinivas et al.(2006) CRIDA, Hyderabad

34. Srinivas et al.(2006) CRIDA, Hyderabad 34
TABLE 07: Chemical composition of different tree residues.
Plant residues C(%) N% Ligni
n
%
Polyphen
ol
%
C/N Ligni
n/N
Polyphen
ol/N
Lignin+Polyph
enol/N
C.calothyrsus 41.5 2.46 7.21 7.04 a 16.9 2.93 2.86 5.79
C.siamea 42.1 2.07 7.64 3.88 20.3 3.69 1.88 5.57
D.sissoo 40.1 2.42 8.69 2.44 16.6 3.59 1.01 4.60
G.sepium 40.9 3.16 6.84 2.02 12.9 2.16 0.64 2.80
H.binata 40.1 1.91 10.21 3.74 21.0 5.35 1.96 7.31
L.leucocephala 39.5 3.59 6.87 3.10 11.0 1.92 0.87 2.78
P.juliflora 40.7 1.96 8.29 4.02 20.7 4.23 2.05 6.28
T. indica 41.3 1.62 10.15 4.83 b 25.6 6.29 2.99 9.28

35. 35
Plant
residues
C % N % Lignin
%
Polyphenol
%
C/N Lignin/
N
Polyphenol/
N
Lignin+Polyphenl/
N
Caster 41.2 0.95 6.07 0.74 43.4 6.39 0.78 7.17
Horse gram 39.5 1.22 5.36 1.68 32.4 4.39 1.38 5.77
Paddy 40.4 0.48 5.19 0.61 84.2 10.81 1.27 12.08
Pearl millet 42.1 0.84 6.24 0.49 50.1 7.43 0.58 8.01
Sorghum 39.8 0.55 6.81 0.55 72.4 12.38 1.00 13.38
Sugarcane 43.0 0.51 7.54 0.37 84.3 14.78 0.73 15.51
Sunflower 40.2 1.06 8.10 0.82 37.9 7.64 0.77 8.42
TABLE 08: Chemical composition of different crop residues
Srinivas et al.(2006) CRIDA,Hyderabad

36. Fig:6..Plant residue quality and nitrogen mineralization
36
G.sepium
C. siamea
Paddy
Sugarcane
L.leucocephala C. cajan
Srinivas et al.(2006) CRIDA,Hyderabad

37. FIG:7.. Relationships between residue quality parameters and N mineralization
for All residues
37
Srinivas et al.(2006) CRIDA,Hyderabad

38. 38
Case Study-04
Impact of the addition of different plant residues on
nitrogen mineralization–immobilization turnover and
carbon content of a soil incubated under laboratory
conditions
Abbasi et al. (2015) (PAKISTAN)

39. g kg-1
Plant residues
(Treatments)
Plant
organs
Total
N
Total
C
Lignin
(LG)
Polyphen
ols(PP)
C /N LG /
N
PP /
N
LG+PP
/N
Glycine max shoot 35.2 447 11 13.1 12.7 0.3 0.4 0.7
Glycine max Root 12.8 466 29 26.9 36.4 2.3 2.1 4.4
Zea mays Shoot 9.6 472 41 29.5 49.2 4.3 3.1 7.3
Zea mays Root 4.0 486 48 31.4 121.5 12.0 7.9 19.9
Trifolium repens Shoot 27.4 397 13 18.0 14.4 0.4 0.6 1.1
Trifolium repens Root 16.0 423 21 20.2 26.4 1.3 1.2 2.5
Populus euramericana Leaves 20.8 435 34
53.8
20.9 1.6 2.6 4.2
Robinia pseudoacacia Leaves 33.3 404 28 32.3 12.1 0.8 1.0 1.8
Elaeagnus umbellata leaves 34.7 418 32 38.7 12.1 0.9 1.1 2.0
LSD (p= 0.05) - 3.14 14.16 4.53 3.77
TABLE:9..Mean biochemical composition of the plant residues used
in the experiment
39
Abbasi et al. (2015) Pakistan

40. Days after plant-residue addition
Treatments 0 7 14 21 28 42 60 80 100 120 CD
(p=0.05)
mg Nkg-1
soil
Control 13.7 13.9 12.9 17.1 30.9 65.9 63.1 75.6 77.7 51.7 2.88
T1 14.8 39.2 49.2 76.8 96.7 158.1 165.2 174.1 188.7 160.9 7.90
T2 13.7 8.1 5.2 8.3 11.8 13.8 28.4 50.4 49.4 27.7 8.15
T3 13.7 7.4 6.2 6.9 10.5 23.1 21.2 36.1 46.7 21.0 5.34
T4 14.3 7.4 9.4 7.7 8.8 15.3 22.2 21.4 32.4 26.4 4.30
T5 14.1 19.0 21.6 55.5 62.5 86.8 127.6 150.8 145.8 93.3 7.31
T6 15.5 8.2 5.2 23.9 34.0 85.3 98.0 149.9 130.2 85.8 9.46
T7 13.0 5.7 4.1 8.6 22.6 55.5 73.1 106.8 87.3 66.9 8.39
T8 13.9 7.4 9.2 23.6 46.6 91.3 111.0 138.9 127.8 93.7 7.83
T9 12.9 9.4 14.5 25.3 51.1 80.1 92.7 140.0 116.4 93.5 6.88
CD (p
=0.05)
2.43 4.77 3.12 5.11 7.63 8.23 6.37 9.23 8.27 7.34
TABLE:10..Mean changes in the concentration of total mineral N of a soil
amended with different plant residues and incubated at 25 0
C under controlled
laboratory conditions during a 120-day period .
40
T1-Glycine max shoot,
T2-Glycine max root;
T3-Zea mays shoot,
T4-Zea mays root;
T5-Trifolium repens shoot;
T6 -Trifolium repens root
T7 -Populus euramericana leaves;
T8-Robinia pseudoacacia leaves;
T9-Elaeagnus umbellata leaves.
Abbasi et al. (2015) Pakistan

41. FIG:8..Net cumulative N mineralized from the added plant residues at different incubation
periods.
41
T1-Glycine max shoot
T2-Glycine max root
T3-Zea mays shoot
T4-Zea mays root
T5-Trifolium repens shoot
T6 -Trifolium repens root
T7 -Populus euramericana leaves
T8-Robinia pseudoacacia leaves
T9-Elaeagnus umbellata leaves
Days after residues amendments
Abbasi et al. (2015) Pakistan

42. 42
Singh And Kumar (2006) HAU, Hisar
Case Study-05

43. Legumes
residues
OC (g/kg) Total N g/kg C:N ratio Lignin
(g/kg)
Polyphenols
(g/kg)
Black gram 428 23.3 18.4 75.0 22.4
Cluster bean 452 18.2 24.8 80.0 44.4
Cowpea 446 21.4 20.8 71.2 27.6
Green gram 416 26.0 16.0 54.1 30.9
Sesbania 440 22.6 19.5 73.9 26.7
Soyabean 462 21.4 21.6 61.2 35.7
Sunhemp 438 20.1 21.8 64.3 32.2
43Singh And Kumar (2006) HAU, Hisar
TABLE:11..Characteristics of legumes residues

44. FIG:9..Commulative Nitrogen MineralizationFIG:9..Commulative Nitrogen Mineralization
44
Singh And Kumar (2006) HAU, Hisar

45. TABLE:12..Cumulative net N mineralized and amounts of added
N mineralized from legume residues after 56 days of incubation
period
Legumes residues Net N mineralized (mg/kg) Amount of added N
mineralized (%)
Hisar Karnal Hisar Karnal
Black gram 84 87 72.1 74.7
Cluster bean 53 55 58.2 60.4
Cowpea 71 73 66.4 68.2
Green gram 96 99 73.8 76.1
Sesbania 74 76 65.5 67.3
Soyabean 75 77 70.1 72
sunhemp 65 67 64.7 66.7
45
Singh And Kumar (2006) HAU, Hisar

46. 46
Oglesby And Fownes (2002) Hawaii
Case Study-06

47. TABLE:13..Characteristics of green manures used in the
experiment
Species Polyphenols (%) N (%) Lignin
(%)
Leaves Twigs Average
Calliandra calothyrsus 4.99 1.95 4.06 2.85 13.4
Cassia reticulata 2.10 0.89 1.99 2.65 9.9
Cassia siamea 4.60 1.27 3.92 2.31 10.3
Gliricidia sepiurn 2.07 0.35 1.84 3.43 8.6
lnga edulis 4.71 1.70 3.83 2.51 18.3
Leucaena leucocephala 3.52 1.49 2.93 3.74 11.1
Sesbania sesban 2.60 0.56 1.38 1.39 14.5
47
Oglesby And Fownes (2002) Hawaii

48. Week N (%) Polyphenols (%) Lignin (%) Polyphenol:N Lignin:N
1 0.24 -0.78 -0.13 -0.89 0.00
2.5 0.29 -0.80 -0.48 -0.94 -0.21
4 0.44 -0.71 -0.80 -0.88 -0.56
8 0.37 -0.79 -0.79 -0.90 -0.46
12 0.11 -0.59 -0.79 -0.53 -0.32
TABLE:14.Correlation coefficients of cumulative % N mineralized at
each time interval versus initial green manure properties.
48
Oglesby And Fownes (2002) Hawaii

49. 49
FIG:10..N Mineralization pattern
Oglesby And Fownes (2002) Hawaii

50. 50
FIG:11..Relationship between N mineralized at 8 weeks and Polyphenol
: N ratio (Y = 79.4 - 39.5X, n = 7, r 2 = 0.81).
Oglesby And Fownes (2002) Hawaii

51. 51
Mafongoya et al. (2008) Florida
Case Study-07
Mineralization of nitrogen from decomposing leaves
of multipurpose trees as affected by their chemical
composition

52. TABLE:15..Chemical composition of leaves of MPT species (on
oven-dry matter basis).
Mafongoya et al. Florida 52
Treatment N
g/Kg
NDF-N
g/Kg
Lignin
g/Kg
SP phenol
g/Kg
Acacia angustissima 25b 19a 143b 122b
Gliricidia sepium 18c 9d 111c 23d
Flemingia macrophylla 18c 11c 193a 105b
Sesbania sesban 28ab 5c 67d 112b
Calliandra calothyrsus 27ab 12b 114c 154a
Cajanus cajan 31a 12b 140b 42d
Leucaena leucocephala 31a 11c 120c 122b
Acacia+sesbania 27b 12b 105c 117b
Cajanus+sesbania 30a 9d 104c 77c
Values followed by different letters in each column are significantly different from each other at P~0.05 using
Duncan’s Multiple Range Test.
NDF-N=neutral detergent fraction),
SP= Soluble polyphenols

53. 53
FIG:12.. N mineralization pattern
Mafongoya et al. (2008) Florida

54. TABLE:16..Correlation coefficients relating the cumulative amount of net N mineralized
to initial chemical properties of multi purpose tree (MPT) leaves during incubation with
soil.
TABLE:16..Correlation coefficients relating the cumulative amount of net N mineralized
to initial chemical properties of multi purpose tree (MPT) leaves during incubation with
soil.
54
Times
(weeks)
NDF-N Lignin SPphenol Tannins L/N P/N L+P/N NDF-N/N
1 -0.64 -0.78 -0.39 -0.01 -0.68 -0.59 -0.78 -0.73
2 -0.70 -0.75 -0.53 -0.23 -0.51 -0.64 -0.68 -0.61
3 -0.61 -0.70 -0.44 -0.06 -0.59 -0.59 -0.72 -0.68
4 -0.66 -0.73 -0.54 0.10 -0.61 -0.71 -0.79 -0.71
5 -0.65 -0.75 -0.53 0.07 -0.64 -0.71 -0.81 -0.72
6 -0.62 -0.73 -0.55 0.07 -0.62 -0.72 -0.80 -0.68
7 -0.63 -0.68 -0.57 0.19 -0.54 -0.71 -0.74 -0.62
8 -0.68 -0.71 -0.56 0.33 -049 -0.67 -0.68 -0.59
Mafongoya et al. (2008) Florida

55. 55
Nitrogen Mineralization from Soil Amended with Gliricidia andNitrogen Mineralization from Soil Amended with Gliricidia and
Sorghum Residues:Sorghum Residues:
Case Study-08
ICRISAT, HydrabadSridevi et al. (2006)

56. TABLE:17..Residue fractionation:
Residue Soluble fractions
(% )
Fiber
(%)
N g kg-1
C/N
Sorghum straw 21.4 78.6 5.32 77.3
Glyricidia prunings 53.3 46.7 28.60 13.4
56
ICRISAT, HydrabadSridevi et al. (2006)

57. Amendment N
added
(mg/
kg)
Incubation period in days N
mineralized
after 90
days
(% of
added)
0 5 15 30 45 60 75 90
Control - 7.8
4
14.4
6
24.
31
31.
44
35.2
8
37.6
3
39.
19
40.
42
-
Sorghum
straw
24.39 7.8
4
4.52 12.
41
19.
91
25.1
5
30.3
3
34.
17
39.
06
5.6
Gliricidia
prunings
24.39 7.8
4
12.5
8
32.
5
44.
86
51.2
9
56.7
5
60.
31
62.
04
88.6
57
ICRISAT, HydrabadSridevi et al. (2006)
Table:18..Nitrogen mineralization

58. 58
 N concentration and C:N ratio are sound criteria for predicting
nitrogen release in few crop residues while in other residues
polyphenol/N ratio, ( lignin + polyphenol ) to N ratio play a role in
percent N mineralized.
 The composition of residues in terms of soluble and fiber fractions
determines whether and to what extent, N is immobilized or
mineralized.
 The decomposition and nutrient release rates of residues are often
regulated by environmental factors, such as temperature and soil
moisture, and biochemical composition of plant materials and their
interaction. The biochemical composition or quality parameters such as
total N concentration, lignin (LG), polyphenols (PP), carbon : nitrogen
(C/N) ratio, LG/ N, PP /N and (LG, C, PP) /N ratios are useful
indicators that control decomposition and N release of added plant
residues.
Conclusion of seminar

59. 59