AJCS 12(11):1743-1749 (2018) ISSN:1835-2707
Improvement of soil quality using bokashi composting and NPK fertilizer to increase shallot yield
on dry land
Sri Anjar Lasmini*1, Burhanuddin Nasir2, Nur Hayati1, Nur Edy2
1Department of Horticulture, University of Tadulako, Palu - 94117, Indonesia
2Department of Plant Pest and Disease, University of Tadulako, Palu - 94117, Indonesia
*Corresponding author: firstname.lastname@example.org
The use of NPK fertilizer and bokashi composting, which is a fermented organic matter combined with microbial stock, have been
reported as potential agricultural practices to enhance the farming land and crop production. The aim of this research is to
understand the type of bokashi fertilizer and the correct dosage of NPK inorganic fertilizer in improving entisol soil quality and
shallot yield in the dry land. The research used the split-plot design, which was divided into two factors. The first factor of the main
plot was the bokashi type consisting of two levels: 3 t ha-1 of bokashi compost of Gliricidia sp. tree leaves (B1); and bokashi cow
manure 3 t ha-1 (B2). The second factor as the subplot was the NPK inorganic fertilizer dose which were consisted of four levels:
without fertilizers (K0), NPK 100 kg ha-1 (K1), NPK 200 kg ha-1 (K2), and NPK 300 kg ha-1(K3). By combination of these two factors 8
combined treatments with 3 replications totally 24 units were obtained. The result of the research showed that application of 3 t
ha-1 bokashi cow manure (B2) coupled with NPK inorganic fertilizer at 200 kg ha-1 (K2) caused a decrease in evaporation of its land
and soil temperature, while increase shallot bulb yield compared with other treatments. The analysis of soil and soil microbes
showed an increase in soil fertility by elevated levels of C-organic from 0.66 % to 3.28 %, N-fixing bacteria from 27 x 105 CFU ml-1 to
47 x106 CFU ml-1 and phosphate solubilizing bacteria from 20 x103 CFU ml-1 to 90 x103 CFU ml-1. The shallot bulb yield increased
from 4.79 t ha-1 to 11.74 t ha-1.
Keywords: Bokashi; Dry land; Shallot; Soil quality; NPK inorganic fertilizer.
Abbreviations: N_Nitrogen; P_Phosphorus; K_Potassium, NPK_Nitrogen Phosphorus Potassium; CFU_Colony Forming Unit;
CEC_Cation Exchange Capacity; EM_Effective Microorganisms; WAP_Week After Planting; HSD_Honeystly Significant Difference;
Shallot cultivation in the dry land is still facing many
obstacles, mainly from biophysical factors such as soil
fertility, water shortage and less suitable climate for plant
growth, especially on soils that have high porosity, low
organic matter as well as the conditions of extreme
temperatures. Dry land at Palu valley, including Sigi district,
Donggala and Palu encompasses 1.07556 million ha or 15%
of the total dry land area out of 7.16962 million ha in Central
Sulawesi (Central Bureau of Statistics of Central Sulawesi,
2016). The potency of broad dry land can be optimized for
improving crop production by overcoming the existing
obstacles. The main limiting factors in the development of
shallot cultivation in the dry land are water availability,
nutrient retention and low content of organic matter. The
dry land characteristic at Palu valley has shown the relatively
low binding capacity of soil moisture, so it is not good in
water retaining. This condition causes the falling water have
percolation directly and capillary water is easily separated
because of evaporation. Evaporation rate is very important
in saving soil moisture so it can be used for plant growth.
The rate of evaporation can be retained by the addition of
organic fertilizer (El-Aswad and Groeenevelt, 1985).
The organic ingredient is one of the very important soil
constituents that maintain the function of soil to support
plant growth. Organic matter above the surface of the soil is
usually in the form of litter and partly in decomposed form,
while underground is generally in the form of humus
compound. Humus has hydrophilic colloid property. It can
clump as gel-shape. It plays a role in saving water because it
has a high water holding capacity so the soil does not dry
quickly in the dry season. Humus is also able to bind water
four to six times of its weight and the water bound by humus
will be able to reduce the evaporation of water through the
soil (Fitter and Hay, 2002).
The high organic content can increase water retaining
capacity of the soil. The addition of organic matter can be
done by giving organic fertilizer. The benefit of organic
fertilizer addition into the soil is to increase nutrients,
improve soil properties through increasing soil water
content, soil organic carbon, cation exchange capacity (CEC)
and pH, improving the soil structure, aeration and water-
holding capacity of land and to influence or regulate soil
temperatures that can help plant growth (Agegnehu et al.,
Bokashi (organic material rich in microbial biological
resources) is the result of organic material fermentation
with stocks of effective microorganisms. This can be used as
an organic fertilizer to nourish the crops, increase the
growth and production of plants (Karimuna et al., 2016;
Zaman et al., 2016; Anhar et al. 2018), improve better soil
structure (Xiaohou et al., 2008; Hernández et al., 2014;
Barajas-Aceves 2016), and increase the volume of water
contained and stored in the soil which means increasing the
water available to the plants (Djajadi et al., 2011;
Yulnafatmawita et al., 2010).
The use of bokashi in plants increased the concentration of P
and K and also increased the number, length, and diameter
of Alpinia purpurata plant stems (Hernández et al., 2014). It
also has increased production, dry weight of seeds and
weight of 100 corn seeds and peanut crops (Karimuna et al.,
2016) and reduced the need for inorganic fertilizers of about
50% in corn crops (Pangaribuan et al., 2011; Yuliana et al.,
2015) and the canola plant (Brassica napus L.) (Kazemeini et
al., 2010). Bokashi manure also has promoted the growth of
plant seeds of okra (Abelmoschus esulentus (L.) Moench
(Uka et al., 2013).
The use of cow dung bokashi as an organic fertilizer on
shallot plant is very necessary because it can add nutrients,
improve the physical of soil so that the soil becomes fertile,
loose and easily processed and improve the ability of soil in
the binding of nutrients that cannot be replaced by artificial
fertilizers. Bokashi of cow dung contains many elements of
nitrogen (N), phosphorus (P) and potassium (K), which most
needed by plants, thereby reducing the use of NPK inorganic
fertilizers. The aim of this research is to know the bokashi
type and dosage of NPK fertilizer under the appropriate
recommendation standard in improving soil quality and
shallot yield in the dry land.
The influence of the growing environment
Bokashi of cow manure at a dose of 3 t ha-1 combined with
NPK inorganic fertilizer at a dose of 200 kg ha-1 (B2K2)
showed the lowest soil evaporation (8.67g) during the day
(07:00 am to 12:00 pm) and (5.00g) for the afternoon (01:00
pm to 05:00 pm) (Figure 1). The lowest soil temperature
fluctuations was 2.14 0C (Figure 2).
Influence on soil physical and chemical properties
Bokashi of cow manure at a dose of 3 t ha-1 combined with
NPK inorganic fertilizer at a dose of 200 kg ha-1 (B2K2) has
shown the best average value for physical and chemical
properties of the soil (Table 1).
Influences on plant growth and yield
Bokashi of cow manure at 3 t ha-1 combined with NPK
inorganic fertilizer dose of 200 kg ha-1 (B2K2) produced
the highest of plant high, i.e. 28.12 cm, root length of 16.73
cm, root dry weight of 2.40 g and shallot bulb yield of 11.74
t ha-1 (Table 2). The increasing of the shallot bulb was getting
along with the increased content of C-organic (Figure 3).
Response on bacteria populations on N-fixation and
Organic fertilizer bokashi can increase the population of
beneficial microorganisms. Treatment with 3 t ha-1 bokashi
cow manure along with NPK inorganic fertilizer at a dose of
200 kg ha-1 (B2K2) showed the highest population of N-fixing
bacteria and the highest phosphate solubilizing bacteria. The
population of N-fixing bacteria was increased from 27 x 105
CFU ml-1 to 47x106 CFU ml-1 and phosphate solubilizing
bacteria from 20 x 103 CFU ml-1 to 90 x103 CFU ml-1 (Table
The role of organic fertilizer on the soil is in relation to
changes in soil properties i.e. physical, chemical and
biological properties of the soil. Bokashi of cow dung
treatment with the dose of 3 t ha-1 and NPK inorganic
fertilizer with the dose of 200 kg ha-1 had significant
differences on all observed components. The weighing result
showed that treatments were able to reduce the rate of
evaporation during the day or late evening, as well as
decrease in the soil temperature fluctuations. This condition
happened because bokashi of cow manure in the soil were
able to form soil granulation to play a role in contributing
the formation of a stable soil aggregate, so, reduction in
absorption of solar energy during the day. Through the
application of bokashi organic fertilizer, the previously heavy
soil re-structured crumb, the infiltration becomes better and
it could absorb water faster to reduce the flow of the
surface. Application of bokashi could also increase the
content of organic materials which also increase humus
levels in the soil. Humus is hydrophilic; therefore, humus can
increase water absorption in the soil and improve water
storage so the evaporation is reduced. The increase in soil
organic matter will improve the ability of soil in holding
water; thus, reducing the rate of evaporation that occurs in
the soil. The increase in holding water capacity of the soil is
related to the application of organic material. It will increase
the volume of water contained and stored in the soil, which
means increasing the water availability in plants.
Bokashi of cow manure is able to reduce the fluctuation of
the soil temperature because it can increase soil porosity so
that the soil aeration is better. The high content of organic
material in bokashi will increase the water storage of the
soil. Holding water by soil organic matter can reduce water
loss through percolation and evaporation. In addition,
bokashi also helps to reduce the radiation received and
absorbed by the soil. The supply of organic matter by mulch
can increase the soil water level by 6-7%. The storage of
groundwater is greater so it will increase the productivity of
the plant (Agbede et al., 2017; Chang et al., 2016; Edwards
et al., 2000; Sudaryono, 2001; Wang et al., 2009).
Bokashi fertilizer has also positive effects on root growth by
increasing root length and root dry weight in the rhizosphere
conditions. Organic matter serves as a granulator to improve
soil structure, as source of N, P, K nutrients and other
microelements. A good soil structure can guarantee a better
root development so the area of nutrient uptake is wider.
This can keep the process of photosynthesis optimal
Table 1. Results of soil analysis before and after treatment.
Bulk Density (g.cm-3)
Permeability (cm. hour-1)
C/N Ratio (%)
P-total (mg 100g-1 )
K2O (mg 100g-1)
CEC (meq 100g-1)
Numbers followed by the s ame letter in the same row are not significantly different at the 0.05 α HSD test. B1: Bokashi leaf of Gliricidia sp., B2: Bokashi cattle manure, K0: without NPK, K1: 100 kg
ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK.
Fig 1. Soil evaporation on the application of bokashi and NPK inorganic fertilizers. B1: Bokashi leaf of Gliricidia sp., B2: Bokashi
cattle manure, K0: without NPK, K1: 100 kg ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK. Data are means + SD. Similar bar
colour followed by the same letter are not significantly different at the 0.05 α HSD test.
Table 2. Growth and yield responses of shallot on the application of bokashi and NPK inorganic fertilizer.
Root length (cm)
Root Dry Weight (g.plan-1)
Numbers followed by the same letter in the same column are not significantly different at the 0.05 α HSD test. B1: Bokashi le af of Gliricidia sp., B2: Bokashi cattle manure, K0: without NPK, K1: 100
kg ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK.
Fig 2. Soil temperature fluctuations on the application of bokashi and NPK inorganic fertilizer. B1: Bokashi leaf of Gliricidia sp., B2:
Bokashi cattle manure, K0: without NPK, K1: 100 kg ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK. Data are means + SD. Similar
bar colour followed by the same letter are not significantly different at the 0.05 α HSD test.
Table 3. N-fixing bacteria populations and phosphate solubilizing bacteria before and after treatment.
N-fixing bacteria population
Phosphate solubilizing bacteria population
B1: Bokashi leaf of Gliricidia sp., B2: Bokashi cattle manure, K0: without NPK, K1: 100 kg ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK.
Fig 3. The relationship between the content of soil Organic-C and the increasing of shallot bulbs yield per hectare. B1: Bokashi leaf
of Gliricidia sp., B2: Bokashi cattle manure, K0: without NPK, K1: 100 kg ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK.
Fig 4. The Development of shallot bulbs at age of 7 WAP on bokashi and NPK inorganic fertilizer treatment. B1: Bokashi leaf of
Gliricidia sp., B2: Bokashi cattle manure, K0: without NPK, K1: 100 kg ha-1 NPK, K2: 200 kg ha-1 NPK, K3: 300 kg ha-1 NPK.
(Shaheen et al., 2007). This is consistent with those reported
by Efthimiadou et al. (2010) that the cow manure can
increase the rate of photosynthesis in sweet corn compared
with inorganic fertilizers.
Bokashi treatment tends to increase the nutrient content of
total N, P, and K, so it will reduce the use of inorganic
fertilizers until below of standard recommendation. The
increased nutrient showed that the treatment given, mainly
organic matter can increase absorption. Thus, it will improve
the soil capacity in holding nutrients from the mineralization
The role of organic fertilizer towards changes in soil chemical
properties is well-known. Also, it can increase the cation
exchange capacity (CEC) of the soil and improve fertilization
efficiency. Organic fertilizer addition can increase the weight
of the fruit and also improve soil properties through
increasing soil water content, soil organic carbon, cation
exchange capacity and pH as well as the increase of P and K
in plants and reduce the use of inorganic fertilizers by 50%
(Agegnehu et al., 2016; Gobbi et al., 2016; Kaplan et al.,
2016; Sumarni et al., 2009; Yuliana et al., 2015; Salo, 2002;
Sorensen, 1996; Pire et al., 2001).
The results showed that the interaction between cow
manure bokashi (at 3 t ha-1) with NPK inorganic fertilizer of
200 kg ha-1 can increase the yield of shallot bulbs per
hectare. This means that bokashi and NPK inorganic fertilizer
dosage given in this study are appropriate and have positive
effects on yield of shallot bulb.
The role of organic fertilizer in improving the physical and
chemical properties refers to the increase of organic-C soil
and CEC of soil (Agegnehu et al.,2016). This will help the
development and activity of plant roots in absorbing the
nutrients needed for the growth and development of plants.
Adequate soil organic matter and the right dose of N, P, and
K will rise chlorophyll content, which further increase the
rate of photosynthesis. The increasing of photosynthesis
rate will increase the amount of biomass that resulted in the
enhancement of food reserves, by which the tuber yield
increases (Abdel-Aziz et al., 2016; Al-Sherif et al., 2015; Liu et
al., 2017; Mete et al., 2015; Munyahali et al., 2017;
Nurudeen et al., 20 15; Singh et al., 2001; Siavoshi et al.,
2011; Zayed et al., 2013).
Bokashi fertilizer of cow manure and NPK inorganic fertilizer
treatment also increase the population of beneficial
microbes such as N-fixing bacteria and phosphate
solubilizing bacteria, because the organic material serves as
a source of nutrients and energy for soil organisms. In
addition, organic fertilizers play a role in changing soil
biological properties by increasing the diversity and
population of soil organisms (microbial and soil microbes)
and increasing soil fertility characterized by increased
microbial activity (Lee, 2010; Zhang et al., 2017).
Materials and Methods
The plant materials was shallot (Allium cepa L. var,
aggregatum). Before planting the shallot, seedbeds were
made, which was 1.20 m x 3 m in the north to the south. The
distance between the sequences was 60 cm, the distance
between plots was 60 cm, and planting distance was 15 cm x
20 cm. The seedbed was made at a depth of 40 cm which
could serve as a drainage channel. Shallot planted was
watered in the morning and evening, or in accordance with
the soil conditions.
Study site and experimental design
The research was conducted in the Guntarano Village,
Tanantovea District, Donggala Regency, Central Sulawesi,
with an altitude of 110 m above sea level. The type of soil
was inceptisol and an average temperature of 39ᵒC. The
study carried out from April 2016 to October 2016.
This study used a split-plot design consisting of two factors.
For the first factor, the main plots were assigned to the
bokashi type, which is consisting of two levels, namely: B1 =
3 t ha-1 of Bokashi gliricidia leaf, B2 = 3 t ha-1 Bokashi cow
manure dose. The second factor as the subplot was NPK
inorganic fertilizer dose, consisted of 4 levels, i.e. K0 =
without fertilizer, K1 = NPK 100 kg ha-1, K2 = NPK 200 kg ha-1
and K3 = NPK 300 kg ha-1. The combination of the two
factors created 8 treatment combinations with 3
replications, so there were 24 units of experiment.
Organic fertilizer (bokashi) preparation
Bokashi as effective microorganism compost (Higa and Parr,
1994) was made from cattle manure, leaf of Gliricidia sp.,
and effective microorganism solution (EM4, PT.
Songgololangit Persada, Indonesia). According to
manufacture, the EM4, contained microorganisms such as
Lactobacillus (8.7 x 105 cell/ml), phosphate solubilizing (7.5 x
106 cell/ml), and yeast (8.5 x 106 cell/ml). Additionally, EM4
also contained organic-C (27.05%), N (0.07%), P2O5 (3.22
ppm), K2O (7675 ppm), Ca (1676.25 ppm), Mg (597 ppm),
Mn (1.90 ppm), Fe (5.54 ppm), Zn (1.90 ppm), B (< 20
ppm), and Cu (< 0.01 ppm). Bokashi of cattle manure and
leaf of Gliricidia sp. were made in different composting
boxes at room temperature. The effective microorganism
solution (EM4) was prepared followed by the manufacture
instruction (5 ml of EM4+10 ml of molasses + 1985 ml of
dechlorinated water). The cattle manure and leaf of
Gliricidia sp. were sprayed by EM4 solutions and mixed.
Bokashi was remixed after 2 days to control the temperature
that should not go above 40oC in fermentation.
The observed variables include: (a) changes in physical and
chemical properties of soil (Eviati et al., 2009: Kurnia et al.,
2006), (b) soil evaporation which were measured by
gravimetry method (Prijono, 2008), (c) soil temperature, (d)
plant height, (e) root length, (f) the dry weight of roots, (g)
shallot bulbs yield per hectare, and (h) the total population
of N-fixing bacteria and phosphate solubilizing bacteria
(Sasrawati et al., 2006).
The obtained data was analyzed by F-test to know the effect
of treatment. If there is a significant difference between the
treatments then it was tested by the honestly significant
difference (HSD) at the level of 5%.
Bokashi of cow manure treatment at dose of 3 t ha-1
combined with NPK inorganic fertilizer application of 200 kg
ha-1 can reduce the evaporation rate and soil temperature
fluctuation, and also increase the yield of shallot. Results of
soil and microbial analysis showed that an increase in soil
fertility increased levels of C-organic from 0.66% to 3.28%,
N-fixing bacteria from 27 x 105 CFU ml-1 to 47 x 105 CFU ml-1,
phosphate solubilizing bacteria from 20 x 103 CFU ml-1 to 90
x103 CFU ml-1 and shallot yield increased from 4.79 t ha-1 to
11,74 t ha-1.
We thank the Indonesian Ministry of Research, Technology
and Higher Education for funding this study.
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