Crop residue has important effects on soil quality in rice-based cropping systems. When crop residues are removed, it leads to decreased soil fertility and lower crop production. Incorporating crop residue into the soil improves various indicators of soil quality, including physical properties like aggregation and porosity, chemical properties like soil organic matter and nutrient levels, and biological properties like microbial population and enzyme activity. Proper crop residue management can help sustain soil quality and fertility in rice fields over the long term.

1. Hriday Kamal Tarafder
and
Dr. P. K. Mani
1
Department of Agricultural Chemistry and Soil Science
Faculty Of Agriculture
Bidhan Chandra Krishi Viswavidyalaya
Management of Crop Residue
and Its Effect on Soil Quality in Rice Based
Cropping System

2. Crop residue is defined as the vegetative crop material
left on the field after a crop is harvested, pruned or
processed.
The removal of crop residues leads to low soil fertility
and thereby decreased crop production.
The straw of most cereal crop contains about 35,10 and
80% of the total N, P and K taken up by the crop.
(Barnard and Kristoferson,1985)

3. Crops Asia Africa S. America World
R-straw 771804 25968 24153 844782
R-husk 154361 5194 4831 168956
Wheat 379788 27395 25539 946734
Barley 34097 6753 2141 208229
Sugarcane 53855 8561 41880 125227
Cotton 6378 315 69 6801
Oats 2424 342 1604 51604
Corn 166205 38729 54626 604031
Table1: Residue production (x 103t) by rice and different crops grown in rotation
with rice in the tropics in 1998
Global Availability of Crop Residue
Source: Larson et al., (1978), Bharday (1995), Beri and Sidhu
(1996)

4. Crop Residue
(mt)
Nutrients * (103) tones
N P2O5 K2O N+P2O5+ K2O
Paddy 225.9 1220 542 2417 4179
Wheat 98.9 534 237 1058 1824
Pearl millet 12.0 62 28 124 214
Maize 11.5 59 26 116 201
Sorghum 10.9 65 29 128 222
Barley 2.6 14 6 2747 47
Others 4.1 10 43 75
Table 2: Estimated cereal residues and nutrient present in the cereal residue of
major crop of India
Availability of Crop Residue in India
Beri et al., (1998)

5. Residue burning
Baling and removing the straw
Surface retention and mulching
Residue incorporation

6. Advantage:
It facilitate timely
planting of the following
crops.
It clears the land
quickly of residues
before the next crop.
It kills soil borne
deleterious pests and
pathogens.
Disadvantage:
It cause significantly
air pollution
Kills beneficial soil
insects and micro-
organism
Loss of soil organic
matter (SOM).

7. Used for
 livestock feed,
 fuel,
 building materials,
 livestock bedding,
 bedding for vegetables cultivation and
 mulching for orchards and other crops.

8. It is a practice that leaves straw residues from a previous
crop on the soil surface without any form of incorporation.
It helps to protect the fertile surface soil against wind
and water erosion. This method is prevalent in no-till or
conservation tillage practice where at least 30% of soil
surface is covered with crop residue.

9. Crop residue is incorporated completely or partially
into soil mostly by ploughing.
Aboveground portion chopped into small size and
can be incorporated by power-tiller.
Incorporation of straw increase soil organic matter
and soil N,P and K content as compared to other
management option.

10. Immobilization of mineral nutrients
Phytotoxicity associated with crop
residue incorporation into the soil

11. Figure 1: Effect of pre-decomposition period of rice straw on
mineral N (NH4 + N03) dynamics in soil
(Yadvinder-Singh et al., 2004)Soil amended with 100 mg N kg-1 and incubated at
75% field capacity moisture regime at 30°C

12. Figure 2: Temporal changes in volatile organic acid concentrations in the soil
solution collected at 100 mm soil depth as affected by added rice
straw.
(Sharma et al., 1989)
How to overcome the problem of Phytotoxicity?

13. Effect of crop residue
on
Soil quality

14. Soil quality is…
“ the capacity of a specific kind of soil to
function, within natural or managed
ecosystem boundaries, to sustain plant
and animal productivity, maintain or
enhance water and air quality, and
support human health and
habitation.”
(Karlen et al., 1997)

15. Soil Quality Indicators
 Physical
 Chemical
 Biological
 Organic Matter
Chemical
PhysicalBiological
OM

16. Monitoring of Trends
SoilQuality
Time
Aggrading
Sustaining
Degrading
Baseline
(Seybold et al., 1998)

17. Aggregation
Porosity
Hydraulic Conductivity
Infiltration
Bulk Density
Effect on Physical Quality

18. Figure 3: Soil aggregates stabilization by various sources
of organic matter.
(Dalal and Bridge, 1996)

19. Table 3: Effect of crop residues on soil aggregation in 23 years old
rice-wheat cropping system
(Bandyopadhyay et al., 2009)
TREATMENT WSMA
(%)
AR AS
(%)
MWD
(mm)
GMD
(mm)
Fallow 76.8 3.31 76.75 1.57 1.14
Control 41.0 0.69 39.3 0.60 0.70
NPK 63.2 1.72 63.20 0.01 0.73
NPK+PS 74.2 2.88 73.24 0.89 0.89

20. Table 4: Effect of straw application on Bulk density, Hydrolic
conductivity,WSA and Porosity
Bellakki et al.,1998
Treatment To
Sumer Rice
Bulk Density
(Mg/m3 )
Hydraulic
Conductivity
(cm/h)
Water Stable
Aggregate
(%)
Porosity
(%)
NPK 1.43 1.18 37.6 46.0
Rice Straw
To Meet
50% N
1.26 1.93 51.3 52.0
Rice Straw
To Meet
25% N
1.27 1.78 49.6 52.0

21. Soil Reaction
Redox Potential and Electrical Conductivity
Soil Organic matter
Soil Macronutrient and Micronutrient

22. Crop residues influence soil pH through
accumulation of CO2 and organic acids during
decomposition
A sharp decrease in soil pH of flooded soils due
to application of rice straw has been recorded by
Murty and Sing (1976).
Soil Reaction

23. Straw incorporation hastened and
intensified soil reduction and also increase pH
and E.C of acid soils
(Beye et al.,1978)
 Decreased soil pH and E.C of alkaline soils
under submergence
(Yodkeaw and Datta,1989)

24. Yadvinder-Singh et al. (2004) reported that rice residues
incorporation increased organic carbon content of sandy loam
soil more significantly than straw burning or removal after 7
years.
Table 5: Effect of crop residue management on organic carbon content of soil
*Beri et al.,1995,;**Yadvinder-Singh et al.,2004
Type of Crop Residue
and Soil
Duration
(Yr)
Residue
Management
Organic Carbon
(%)
Rice Straw in Wheat
And Wheat Straw In
Rice ;
Sandy Loam*
10
Removed 0.38
Burned 0.43
Incorporated 0.47
Rice Straw in Wheat
Wheat in Rice
In Rice-wheat
Rotation ;
Sandy Loam**
7
Removed 0.38
Burned 0.39
Incorporated 0.50
Soil organic matter(SOM)/ Soil organic carbon(SOC)

25. Within 3 years of incorporation of rice straw at 6-7 t ha-1, total N
content in soil increased by 0.021% over the straw removal
treatment.
Table 6: Effect of straw management on the nutrient status of
Mahaas clay of five cultivars
(Ponnamneruma.1984)
Treatment Organic C
(%)
Total N
(%)
Olsen P
(Mg /Kg)
Exchangeable
K
(Mg/Kg)
Removed 1.81 0.167 9 10.5
Burned 1.94 0.173 11 12.5
Incorpora
ted
2.17 0.182 12 11.6
Soil Macro and Micronutrient

26. Table 7: Effect of crop residues on soil chemical
indicator
SS: Sorghum Stover; GL: Glyricidia Lopping NR: No Residue
(Sharma et al.,2005)
Trea
tme
nt
pH OC N P K Ca Mg S Zn Fe Cu Mn B
SS 6.3 6.2 216 46 208 4.5 1.4 8.8 1.2 10.1 0.8 25.3 0.9
GL 6.2 6.4 251 46 247 4.7 1.4 6.9 1.3 9.6 0.7 27.4 1.3
NR 6.1 4.0 227 38 201 4.6 1.4 6.1 1.2 9.5 0.8 24.6 1.3

27. Microbial Population
Enzymatic Activity
Microbial Biomass C and N
Carbon and Nitrogen mineralization

28. Table 8: Microbial population as affected by residue
management in Rice-Wheat rotation
Population Burning Removal Incorporation
After rice
Bacteria(*105) 59.6 15.6 115.4
Fungi(*103) 69.0 13.5 143.0
After wheat
Bacteria(*105) 16.2 13.9 126.6
Fungi(*103) 34.5 33.2 133.6
Sidhu et al., (1995)

29. The enzyme activity in the soil environment is
considered important in contributing the overall
soil microbial activity and soil quality. (Jordan et
al.,1995)
Enzymes are involved in the dynamics of soil
nutrient cycling and energy transfer.
Different crop residues incorporation were
significantly higher the enzymes activity than the no
residues. (Bandick and Dick, 1999)

30. Table 9: Changes of soil enzyme activities after I5 years of
cultivation with rice-wheat copping sequence
(Ghosal, 2004)
Treatment Dehydroge
-nage
Acid
Phosphatase
Alkaline
phosphatase
Urease Arylsulph-
atase
Control 22.87 75.69 54.49 9.04 7.76
NPK 20.34 76.08 47.11 10.42 9.52
NPK+PS 24.82 85.01 57.45 12.14 9.96
Fallow 30.40 69.02 56.44 14.43 9.32

31. Microbial biomass is a small (1-5% by weight) but active
fraction of soil organic matter.
Soil microbial biomass acts as a reservoir of plant nutrients
(like N,P and S) and its availability .
After straw incorporation MBC increase by 2-5 fold in 10
days and reached highest by 30 days.
 MBC increased by 45 % and N by 60% in residue retention
over residue removal. (Kushwaha et al.,2000)

32. Table 10: Carbon, Nitrogen and biomass C in surface soil
under different residue management
(Monneveux et al.,2006)
Treatment Organic C(%) Total N(%) Biomass
C(µg/g)
No residue 1.92b 0.14b 47.4c
Maize residue 2.01a 0.13a 71.5
Maize and
Jackbean
residue
2.01a 0.16a 114.9

33. Table 11: Microbial biomass C (MBC), mineralizable C (minC), basal
soil respiration (BSR) and microbial quotient (MQ) in soils
Treatments at P ≤ 0.05 by Duncan’s multiple-range test
Majumder et al., 2008
Treatment MBC Min C
(0-24 days)
BSR( 10-24 d) MQ
(g C Kg-1) g CO2-C kg-1C d-
1
Kg minCKg-1
TOC
Control 0.28d 1.15c 0.21c 0.023c
NPK 0.41c 1.65b 0.31b 0.029b
NPK+PS 0.48ab 1.76ab 0.31b 0.032a
At soil depth of 0 to 0.2m under different treatments after 19 yr of rice-wheat cropping

34. 1. Crop residue for reclamation of
salt affected soil
2. Biological N₂ Fixation
3. Weed Control

35. Rice straw incorporation decreased the
precipitation of Ca and carbonate
Increased removal of Na in drainage water
Decreased the pH and EC of soil

36. (Yoo et al.,1990) reported that surface application
of rice straw increased flood water pH to an
optimum level for N2-fixing organism, and thereby
increased the N2-fixtion by heterotrophic bacteria
and blue green algae.
Roper(1983)observed that a positive correlation
between(r=+0.98) between nitrogenase activity and
wheat straw decomposition.

37. Crop residues can suppress weeds
in many ways reported by Kumar and
Goh (2000) for example.
 Through there physical presence on
the soil surface as mulch and by
restricting solar radiation reaching
below the mulch layer.
 By direct suppression caused by
allelopathy.
 By controlling N availability.
 Burning of residue can help in effective
removal of weed seed and weeds.

38. Crop residue incorporation improve physical,
chemical and biological properties of soil.
In long-tem incorporation of crop residue
increased the productivity.
Overall, incorporation of crop residues appears to
be a better management option.
Incorporation should be done at least 10 d and
preferably 30 d before the establishment of
succeeding crop.
CONCLUSION