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Nutrient Analysis of Three Earthworm Cast-Types collected from Ikenne, Ogun State.

Authors:
  • Federal University of Agriculture, Abeokuta

Abstract

Tel: +234 val (2002), that nutrients from both particles of organic and inorganic matter that would otherwise remain unavailable to plants are liberated in castings. The humus-rich earthworm casting has been shown to play important role in soil fertility and productivity. According to Faniran and Areola (1980) earthworm casting stores and supplies about 90-95% of soil nitrogen, 50% of phosphorus and 80% of sulphur. Earth-worm casting shares the ability of clay to hold and exchange cation nutrients on nega-ABSTRACT Three types of earthworm cast, i.e. pellet cast, turret cast and mass cast, were analysed for physico-chemical characteristics, nutrient composition and compared with impact on soil fertility. The standard methods of AOAC was used to analyse the pH, moisture content, cast profile, cations (Ca, Mg, Na, K, Mn, Cu and Zn), anions (P, PO4, NO4, NO3, N), Organic Carbon and Organic Matter. Pellet cast recorded a significantly higher pH of 8.60±0.01 while the mean pH of 8.09±0.01 and 7.81±0.01 were obtained for turret and mass cast respectively (p<0.05). On the other hand, pellet cast recorded the lowest moisture content (29.42%) compared with 45.60% and 47.19% obtained for mass cast and turret cast respectively. The % organic matter (1.05±0.02), % organic carbon (0.61±0.01), % Nitrite (0.008±0.001), % Nitrate (0.018±0.001), % Nitrogen (0.063±0.001) and % Phosphorus (0.39 ± 0.001) obtained for Pellet Cast were significantly higher (p<0.05) than those obtained for mass and turret casts. Pellet cast had higher Ca (11.04±2.80 mg/dL), Mn (113.08±38.45 mg/dL) and Zn (8.54±2.62 mg/dL) than turret (9.64±0.77, 77.0±17.02, 6.68±1.65 mg/dL) and mass cast types (4.54±0.25, 19.12±6.82, 2.04±0.70) mg/dL). This study indicated that pellet cast has poor water holding capacity whereas it has higher nutrient concentration compared with mass and turret casts. On the overall, pellet cast, mass cast and turret cast all played synergistic role in soil fertility.
NUTRIENT ANALYSIS OF THREE EARTHWORM
CAST-TYPES COLLECTED FROM IKENNE, OGUN
STATE, NIGERIA
1 A.A. ALADESIDA, *1G.A, DEDEKE, 1K. ADEMOLU AND 2F. MUSELIU
1Department of Biological Sciences, Federal University of Agriculture, Abeokuta, Nigeria
2Department of Biochemistry, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
*Corresponding author:gabrieldedekson@gmail.com Tel: +234
val (2002), that nutrients from both particles
of organic and inorganic matter that would
otherwise remain unavailable to plants are
liberated in castings.
The humus-rich earthworm casting has been
shown to play important role in soil fertility
and productivity. According to Faniran and
Areola (1980) earthworm casting stores and
supplies about 90-95% of soil nitrogen, 50%
of phosphorus and 80% of sulphur. Earth-
worm casting shares the ability of clay to
hold and exchange cation nutrients on nega-
ABSTRACT
Three types of earthworm cast, i.e. pellet cast, turret cast and mass cast, were analysed for physico-
chemical characteristics, nutrient composition and compared with impact on soil fertility. The standard
methods of AOAC was used to analyse the pH, moisture content, cast profile, cations (Ca, Mg, Na, K,
Mn, Cu and Zn), anions (P, PO4, NO4, NO3, N), Organic Carbon and Organic Matter. Pellet cast rec-
orded a significantly higher pH of 8.60±0.01 while the mean pH of 8.09±0.01 and 7.81±0.01 were
obtained for turret and mass cast respectively (p<0.05). On the other hand, pellet cast recorded the
lowest moisture content (29.42%) compared with 45.60% and 47.19% obtained for mass cast and
turret cast respectively. The % organic matter (1.05±0.02), % organic carbon (0.61±0.01), % Nitrite
(0.008±0.001), % Nitrate (0.018±0.001), % Nitrogen (0.063±0.001) and % Phosphorus (0.39 ± 0.001)
obtained for Pellet Cast were significantly higher (p<0.05) than those obtained for mass and turret
casts. Pellet cast had higher Ca (11.04±2.80 mg/dL), Mn (113.08±38.45 mg/dL) and Zn (8.54±2.62
mg/dL) than turret (9.64±0.77, 77.0±17.02, 6.68±1.65 mg/dL) and mass cast types (4.54±0.25,
19.12±6.82, 2.04±0.70) mg/dL). This study indicated that pellet cast has poor water holding capacity
whereas it has higher nutrient concentration compared with mass and turret casts. On the overall,
pellet cast, mass cast and turret cast all played synergistic role in soil fertility.
Keywords: Earthworm casts, moisture content, nutrient composition, organic matter, soil fertility
INTRODUCTION
A worm casting is a biologically active
earthen mound containing thousands of
bacteria, enzymes, and remnants of plant
materials and animal manure, that were not
digested by the earthworm (Appelhof,
1982). An important component of casting
is humic acid, which provides binding sites
for plant nutrients such as calcium, iron,
potassium, sulphur and phosphorus and
releases them on demand to the plants
(Holcombe and Longfellow, 1995). This
indicates as suggested by Delahaut and Ko-
J. Nat. Sci. Engr. & Tech. 2014, 13:36-43 36
Journal of Natural
Science, Engineering
and Technology
ISSN:
Print - 2277 - 0593
Online - 2315 - 7461
© FUNAAB 2014
A.A. ALADESIDA, G.A, DEDEKE, K. ADEMOLU AND F. MUSELIU
tive exchange surface sites (Faniran and
Areola, 1980). Comparatively, the analyses
of castings and their surrounding soils have
shown that castings contain seven times
more phosphorus, five times more nitrogen,
eleven times more potassium and three
times more exchangeable magnesium and
one and one-half times more calcium (de
Vleeschauwer and Lal, 1981; Brady and
Weil, 1999; Delahaut and Koval, 2002). In
addition, studies have shown that cast pro-
duction by earthworms is an important ac-
tivity that contribute greatly to soil fertility
by stimulating natural activity of beneficial
microorganisms, promoting the activity of
enzymes and natural growth regulators and
as such are beneficial to plants (Feller et al.,
2003). The study of Vinotha et al. (200) and
Sabrina et al. (2009) showed that earthworm
cast contains population of beneficial mi-
croorganisms, microbial enzymes, micro-
and macro-nutrients. Card et al. (2004) re-
ported that earthworm casts had 10-20
times microbial activities than the parent
organic material ingested by the earth-
worms.
Three major earthworm cast types are rec-
ognized in the Nigerian ecological zones,
each of which is produced by different
groups of earthworms. The granular (pellet)
casts are produced by Eudrilus spp, Agrotoreu-
tus spp, Eutoreutus spp. Turret (funnel shaped)
casts are produced by Hyperiodrilus africanus,
Ephyriodrilus afroccidentalis and the mass
(mouldy) cast is produced by Libyodrilus vio-
laceus and Alma millsoni (Madge,1966; Madge
and Sharma, 1969; Sims, 1971; Segun,
1976). Since the various earthworms differ
in their ducts and digestive activities, their
characteristic cast types are expected to dif-
fer in organic and nutrient composition as
well as their relative contribution to soil fer-
tility.
The objective of this study therefore is to
determine the organic and nutrient composi-
tion of Pellet, Turret and Mass Casts, and
ascertain their relative contribution to soil
fertility.
MATERIALS AND METHODS
Cast collection
Cast samples were collected in three repli-
cates of 50 g each, at the Ikenne Campus of
Olabisi Onabanjo University, Ogun State,
Nigeria. Turret casts (Plate 1) were collected
from under hedgerows within the University
Campus, while the Mass (Plate 2) and Pellet
(Plate 3) Casts were collected 300 cm away
from the hedgerows. The different Cast sam-
ples were collected into various pre-labelled
polythene bags and taken immediately to the
laboratory for air drying. The soil samplings
were analysed for organic and nutrient com-
position at the ROTAS Soil Laboratory, Iba-
dan, Oyo State for analysis.
Physicochemical analysis of casts
The pH of the casts was measured using top
loading O’Hauz Digital pH meter. Moisture
content was determined by conventional
means of oven drying to a constant weight.
Particle size grades was mechanically ana-
lysed by hydrometer method (Boyoucos,
1951; Anderson and Ingram, 1993). Percent-
age organic carbon and organic matter were
determined by the Walkey-Black method
(Walkey and Black, 1934). Available Phos-
phorus was determined by the Bray (1)
method (Bray and Kurtz, 1945). The phenol-
disulphonic acid colorimetric method was
used to determine the percentage nitrate of
the Cast while the total nitrogen was deter-
mined using the Kjeldahl method. Atomic
absorption spectrophotometer was used to
determine the Ca, Mg, Na, K, Mn, Cu and
Zn in mg/dL (AOAC, 1995).
37
J. Nat. Sci. Engr. & Tech. 2014, 13:36-43
NUTRIENT ANALYSIS OF THREE EARTHWORM CAST-TYPES...
Plate 1: Finger-like turret casts in the under-growths
The finger-like turret cast
Plate 2: Faecal-like mass cast in more open marshy habitat
Faecal-like mass cast
Fig. 3: Granular pellet cast under leaf litters
Granular pellet casts
38
J. Nat. Sci. Engr. & Tech. 2014, 13:36-43
A.A. ALADESIDA, G.A, DEDEKE, K. ADEMOLU AND F. MUSELIU
Statistical Analysis
Using the Statistical Package for the Social
Science (SPSS) version 17.0, the results ob-
tained in the study was subjected to statisti-
cal analysis; these included descriptive sta-
tistics, analysis of variance (ANOVA), and
Duncan Multiple Range test.
RESULTS
The Descriptive statistics of the physical
and organic properties of the casts are
shown in Table 1. The pellet casts had the
highest mean pH (8.60±0.01), while the
mass cast had the lowest pH (7.81±0.01).
However, all three cast types had basic pH
values. The turret cast had significantly
higher moisture content (47.10±0.14%)
than both mass cast (45.60±1.09%) and the
pellet cast (29.43±0.08%).
Sand content was highest in the pellet cast
(79.47±3.06%), but lowest in the turret cast
(76.47±3.06%). There was however no sig-
nificant difference in the % sand contents of
the three cast types. Silt content on the other
hand was higher in the mass cast than the
other two cast types. There was no signifi-
cant difference between the silt composition
of the turret and mass casts, but both were
significantly higher than in the pellet cast.
Though the % clay content was not estab-
lished by experiment, the sum of the % silt
and sand content showed that the pellet cast
has the highest clay content.
The pellet cast had the highest % organic
carbon and organic matter (0.62% and
1.05% respectively). There was a significant
difference in the % organic matter of the
pellet cast and the other two cast type. Tur-
ret cast, however, also had significantly high-
er % organic carbon (0.42%) and organic
matter (0.72%) than mass cast (table 1).
39
Table 1: The Descriptive Statistics of the Physical and Organic properties of the
Casts
Physical & organic properties Earthworm cast types
Pellet Cast
(Mean±SD) Turret Cast
(Mean±SD) Mass Cast
(Mean±SD) P-value
pH (n=5) 8.60±0.01a 8.09±0.01b 7.81±0.01c 0.000
% Moisture (n=10) 29.43±0.08c 47.10±0.14a 45.60±1.09b 0.000
% Sand (n=3) 79.47±3.06a 76.47±3.06a 77.13±5.77a 0.975
% Silt (n=3) 14.07±2.31b 20.07±1.16a 21.40±0.00a 0.002
% Organic Carbon (n=3) 0.62±0.01a 0.42±0.01b 0.36±0.01c 0.000
% Organic Matter (n=3) 1.05±0.02a 0.72±0.02b 0.63±0.09c 0.000
Means with the same superscript in a row are not significantly different
J. Nat. Sci. Engr. & Tech. 2014, 13:36-43
NUTRIENT ANALYSIS OF THREE EARTHWORM CAST-TYPES...
The calcium (11.04±2.80mg/dL), manga-
nese (113.08±38.45mg/dL) and Zinc
(8.54±2.62mg/dL) composition of the pel-
let cast were significantly higher than that of
the mass cast (4.50.25mg/dL,
19.12±6.82mg/dL and 2.04±0.70mg/dL).
However, though it was higher than that of
the turret cast (9.60.77mg/dL,
77.0±17.02mg/dL and 6.68±1.65mg/dL),
the difference is not statistically significant
(table 2).
Mass cast had the highest mean composi-
tion of magnesium (1.75±0.49 mg/dL), so-
dium (1.26±0.32mg/dL) and copper
(0.63±0.10mg/dL). These were significantly
higher than in the other two cast types in the
case of copper and potassium (P<0.05) but
not significantly different than that of mag-
nesium and sodium composition in pellet
and turret cast types (table 2).
Percentage phosphorus, nitrate, nitrite and
nitrogen were significantly higher (P<0.05)
in the pellet casts (11.27, 0.018, 0.008, and
0.063%, respectively) than in the turret and
mass casts. However, phosphate was signifi-
cantly higher in both the pellet (0.039%) and
turret casts (0.030%) than in the mass cast
(0.023%).
40
Table 2: The Descriptive Statistics of some cationic and anionic components
of the Casts
Cast components Earthworm cast types
Pellet Cast
(Mean±SD) Turret Cast
(Mean±SD) Mass Cast
(Mean±SD) P-value
Cations
Ca (n=3) (mg/dL) 11.04±2.80a 9.64±0.77a 4.54±0.25b 0.007
Mg (n=3) (mg/dL) 1.71±0.25a 1.70±0.19a 1.75±0.49a 0.981
Na (n=3) (mg/dL) 1.02±0.09a 1.02±0.12a 1.26±0.32a 0.311
K (n=3) (mg/dL) 0.62±0.07b 0.93±0.19a 0.07±0.07c 0.001
Mn (n=3) (mg/dL) 113.08±38.45a 77.00±17.02a 19.12±6.82b 0.010
Cu (n=3) (mg/dL) 0.45±0.05b 0.50±0.05bc 0.63±0.10a 0.051
Zn (n=3) (mg/dL) 8.54±2.62a 6.68±1.65a 2.04±0.70b 0.012
Anions
% Av. Phosphorus (n=3) 11.27±2.02a 9.50±1.40b 6.33±0.70c 0.017
% Phosphate (n=3) 0.039±0.001a 0.030±0.001a 0.023±0.001b 0.000
% Nitrate (n=3) 0.018±0.001a 0.013±0.001c 0.015±0.001b 0.000
% Nitrite (n=3) 0.008±0.001a 0.003±0.001c 0.005±0.001b 0.000
% Nitrogen (n=3) 0.063±0.001a 0.048±0.001c 0.054±0.000b 0.000
Means with the same superscript in a row are not significantly different.
J. Nat. Sci. Engr. & Tech. 2014, 13:36-43
A.A. ALADESIDA, G.A, DEDEKE, K. ADEMOLU AND F. MUSELIU
DISCUSSION
Physical Properties and Implication on
Soil fertility:
Comparatively, the significantly higher pH
and lower moisture content recorded for
pellet cast suggests that pellet cast is signifi-
cantly more alkaline and have lower water
holding capacity than turret and mass casts.
This lower water holding capacity of pellet
casts is in conformity with its physical struc-
ture.
Physically, pellet cast is made up of tiny ag-
gregates or granules that were loosely held
together, easily crumbled at the touch of a
finger and highly porous, whereas the other
two cast-types have larger aggregates whose
granules were more tightly cemented to-
gether to form either a finger-like erect
structure (turret cast) or a mass much like
faecal deposit on top of the soil (mass cast).
These two cast-types do not crumble easily
to touch and were not as porous as pellet
cast thereby reducing their tendency to lose
water quickly. In addition, the higher silt
content in turret and mass casts gives great-
er allowance for these cast types to retain a
higher amount of moisture in them than
pellet cast.
Although the pH value (8.60) obtained for
pellet cast was significantly higher than that
of turret and mass casts (p<0.05), on the
overall, values obtained for the different
cast types confirms that earthworm casts
are generally alkaline. However, English and
Costello (2005) and Owa et al. (2008) identi-
fied a pH range of 5.0-7.4 for earthworm
distribution and abundance in soils. Accord-
ing to these authors soils within this pH
range support earthworm survival and in
those outside these range earthworms were
rarely found. The implications of this to the
present result would be that as the soil pass-
es through the earthworm gut the pH is al-
tered by enzymatic activity or and microbial
activity in the earthworm gut.
By implication therefore, turret and mass
casts having much higher water holding ca-
pacity would enhance the soil to retain a
higher amount of its moisture for a longer
period than pellet cast. Furthermore, the al-
kaline nature of these casts would make
them useful in ameliorating acidity in the soil
and the pellet cast with a significantly higher
pH could contribute more in this respect.
Nutrient & Organic Properties and Im-
plication on soil fertility:
The significantly higher mean calcium, zinc,
available phosphorus, phosphate, nitrate,
nitrite and nitrogen in pellet cast than turret
and mass casts indicate that pellet cast con-
tains a significantly higher nutrient content
than the other two cast-types, hence would
likely contribute significantly more nutrient
to enhance soil fertility.
Also we infer that the higher nutrient con-
tent of pellet cast indicated a higher energy
and electron source. Atlas (1997) reported
that a higher energy and electron source will
stimulate higher microbial proliferation
which in turn will facilitate faster degradation
of organic matter hence production of more
organic carbon and release of other nutri-
ents, thereby helping in building soil fertility
or in the amelioration of less fertile soils for
horticultural purposes.
From the foregoing, though pellet cast con-
tained a comparatively higher nutrient con-
tent than turret and mass casts, the nutrient
contents of the other two types of earth-
worm cast-types were still higher than the
surrounding soil. This therefore suggests a
synergy between these cast-types in enhanc-
41
J. Nat. Sci. Engr. & Tech. 2014, 13:36-43
NUTRIENT ANALYSIS OF THREE EARTHWORM CAST-TYPES...
ing soil fertility. Stewart et al. (1988) had ear-
lier reported that earthworm casts act as
time-release nutrient capsules (releasing
over a longer period of time).
Our study hereby clarified that turret and
mass cast by their physical structure will fit
the report of Stewart et al. (1988), acting as
time-release nutrient capsules while pellet
cast on the other hand acts as quick-release
nutrient capsule (releasing quickly in a
shorter period of time) with a larger dose of
nutrient released to the soil. This suggests
that while turret and mass casts released
their nutrients gradually to the soil and en-
hance the latter growth periods of plants,
the pellet cast acting as a quick release nutri-
ent capsule would make its nutrients availa-
ble to germinating seedlings, at a time when
the seedlings need such nutrient boost,
thereby helping them to proliferate faster.
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J. Nat. Sci. Engr. & Tech. 2014, 13:36-43
... It is also estimated that for a single acre of cultivated land, earthworms move 8 tons of earth in a year, enough to form a new layer o f earth 2 inches thick, rich in nitrogen, phosphorus and calcium (Megrow, 2012). Earthworm casts have higher available N, P, K and Ca contents than surrounding soil, as well as a higher cation-exchange capacity (Jones, 2013;Aladesida et al, 2014;Sherman, 2017). The excrement of earthworms are rich in micronutrients, such as Zn and B through chelation. ...
... The increase in porosity created by earthworms facilitating quick water infiltration into the soil and reduce the effects of compaction is highly advantageous in the no-till systems of farming. pH buffering action of organic molecules produced in the gut of worms is another advantage of earthworms (Jones, 2013;Aladesida et al, 2014;Sherman, 2017). Decomposition of waste materials using earthworms is known as vermicomposting (Sharma, 2009;Ansari and Ismail, 2012). ...
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This study was to investigate if residual earthworm products in a soil left to dry up for five months would still be able to stimulate seed germination. Soil pots were treated with different levels of earthworms and planted with Amaranthus seed which grew for 36 days before they were harvested by uprooting. The pots were left to dry for five months simulating the dry season. The levels of germination correlated with the level of earthworm treatments. This suggests that earthworm products survive in the soil during the five months dry season experienced in this part of Nigeria. Leftover earthworm products must therefore be important to seed germination during the early cropping with the first rains before the earthworms populations build up. That the earthworm products improve total germination suggests that they may contain some enzymatic/catalytic component that affects the efficient utilization of the endosperm such that the embryo survives before the depletion of the endosperm. This may be related to the fact that the earthworm produce plant growth hormones that stimulate cell proliferation and elongation in the radicle. Fast development of the radicle ensures stabilization before depletion of the endosperm.
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Because soil structure seems to benefit from the period under grass in a normal rotation, it is widely assumed that grass roots are primarily responsible (Strutt, 1970). Due credit is also given to efficient drainage, adequate inputs of organic matter, lime and microbial activity. However, it is not clear whether the earthworm is a passive exploiter or a causal agent of structure improvement. When the pressures of production end up in severe soil structure deterioration, or when massive soil disturbance and stockpiling ends up in soils restored with little residual structure, experimental evidence suggests that the role of the earthworm is crucial. Evidence will be presented to show how earthworms, in association with all the other factors normally held to be responsible, initiate the development of water-stable, soil granulation. However, evidence will also be presented which shows how certain features of modern agriculture are, to some extent at least, antagonistic to earthworms. In utilizing degraded land, it may be necessary to farm initially for the benefit of the earthworm rather than for yield. This approach must be maintained despite the fact that, in the early stages, it may result in a phase of greater waterlogging and susceptibility to poaching.