Characterization of Earthworms (Lumbriscus terestris) Population Under Several Area of Shallots Cultivation

In General, the problem of shallot commodities development was still used common farming without considering land suitability and other specific soil condition including aspect cultivation. The objective of this study was to clasify several lands characteristics 209 Firmansyah et al.: Characterization of Earthworms (Lumbriscus terestris) Population for shallots cultivation and to observe earthworm (Lumbriscus terrestris) population based on their land suitability classes. The methodology used was land evaluation approach and field observation. This study was performed during rainy season in 2018 at three locations with different soils, namely, peat soils/Histosol (IST), buried soil of Quartzipsamment above peat soils (ENT), and dry land of Dystropept (EPT). The population of earthworms is obtained by digging up an area of 1 m 2 with depth of 20 cm at in four places of location of study. The calculation of earthworms is conducted by hand sorting. The results showed that the highest land suitability class at EPT S3tr, rt, nr, while for other locations are not suitable. The location of IST is classified into N3fb with several limiting such as flooding hazard during rainy season, while for ENT location, classified into Nrt, limiting factor is rough texture. High suitability class is not identical with high earthworm population density. Cultivation aspect that is able to increase soil pH become neutral condition and lower pesticide application affect earthworm populations. ENT locations that have neutral soil pH with lower pesticides applcation have the highest earthworm populations. Earthworm population density from high to low involve ENT> IST> EPT or 74> 33> 31 tails/m 2 .


INTRODUCTION
In Central Kalimantan, shallot has been cultivated since 2013 (Firmansyah and Anto, 2013). Generally, the development of shallot was caried out at locations based on the willingness of farmers when they accept shallot development programme established by government, so that, it has not been cultivated based on criteria refering to crop requirements. Even, the farming of shallots was carried out during the off-session or during rainy season, when many farmers did not grow this commodity in Java. One of several important factors that should be taken into account for farming activities is land suitability and other related factors that influence crop growth. This study was then conducted in order to obtain further information about land condition under areas of shallot cultivation. Therefore, the resulting analysis can then be used as recommendation for optimum cultivation. The land condition for crop growth of shallot with high inputs of organic fertilizers, inorganic fertilizers and pesticides may affect earthworm populations, in the soils. Although earthworms (Lumbriscus terestris) have a relatively wide distribution in terms of various land cover involving forest areas, gardens, bare lands, rice fields areas, organic and inorganic agriculture as well (Firmansyah et al, 2017;Qudratullah et al, 2013;Jayanthi et al., 2014). Nutrient availability in the soils affects number of earthworms, the application of compost up to 30 tons/ha, almost 1,077 tails/2 m 2 can be found compared 309 tails/2 m 2 with control treatment (Firmansyah and Atikah, 2019). Soil types that can support the life of earthworms are also found to be very broad ranging from mineral to peat soils (Dwiastuti et al., 2018;Maftu'ah et al., 2005). Specifically, for earthworms found on river banks of Kahayan river and Barito river in Central Kalimantan, shows that shallow ground water surface with rough texture are not suitable for earthworm habitats (Firmansyah et al., 2014).
The increase of earthworm population density is dominantly affected by soil biological processes, ecosystem health, improved water management and degraded soil, and balance of greenhouse gases as well (Supriati et al., 2011;Mayilswami and Reid, 2010;Dewi and Senge, 2015). The objectives of this study was to classify land suitability to three soil ecosystems used shallots development in Palangka Raya, while at the same time observing the earthworm populations as bio-indicators of land quality.
Many studies have shown that the use of inorganic fertilizers and excessive pesticides will adversely affect earthworms. Earthworm populations exposed by high levels of inorganic fertilizers and pesticides will decrease (Yulipriyanto, 2009). However, rainfall and physical properties of soil have more influence to biomass of earthworm compared to chemical factors (Lalthanzara et al., (2011). This study was the conducted to to clasify several lands characteristics for shallots cultivation and to observe earthworm population based on their land suitability. The resulting information can then be used to cultivate land based their suitability for shallot farming with soil macro-fauna support. Therefore, the objective of this study was to clasify several lands characteristics for shallots cultivation and to observe earthworm (Lumbriscus terrestris) population based on their land suitability classes

MATERIALS AND METHODS
The study was conducted during rainy season in 2018. Administratively, location of study have been choosen involving Sabangau district for peat soils (IST or Haplohemist); Jekan Raya District for mineral soils above peat soils (ENT or Quartzipsamment above Haplohemist), and Bukit Batu district for dryland mineral soils (EPT or Dystropept) . For the last 2 years, each land areas has been utlized for shallot farming. Therfore, these site locations were selected based on dominant areas for shallot cultivation.
The observation of earthworms was carried out in the morning to noon at area of 1 m 2 with a depth of 20 cm. The earthworms samples were collected at 4 locations proportionally in which each of the locations in beds and mounds. Earthworms are collected by hand sorting to calculate, wet weight, dry weight and water content. Calculation of earthworm population density using the formula of Suin (2014) where Population Density = Number of individual earthworms/Soil volume The temperature data is collected before obtaining earthworms, in the morning and noon include temperature and air humidity (1 meter above ground level) and for soil sample, it was measured 20 cm in depth. Physical soil sample was obtained at the depth of 0-20 cm using a ring sample to analyze bulk density (BD), KAT (B/V), Porosity, MAT. Soil chemical properties that were analyzed involve pH H2O, organic C, Total N, K, Na, Ca, Mg exchangeable, base saturation, CEC, Al exchangeable, H exchangeable, and Texture (Sand, silt, clay).
Rainfall data used in this study is over a 10-year period, for Sabangau and Jekan Raya areas taken from the BP3K Kalampangan in Sabangau district because the coveraged areas is within radius of 3 km. Rainfall data is available for 2008 to 2017. Another location in Bukit Batu district used rainfall data from BP3K Tangkiling for the years of 2009 to 2018. This rainfall data was used to classify climate types based on Schmidt and Ferguson and Oldeman climate type and also to determine land suitability class of shallots.
Determination of land suitability class for shallot use crop requirement criteria for shallot (Ritung et al., 2011). Land suitability classification was conducted at sub-class level.

Agricultural Input on The location
The cultivation of vegetables that has a short life is conducted several times in a one year period. Generally, planting vegetables with different types of plants is performed three times or more. Based on interviews with farmers who manage the lands, it was found that the use of organic fertilizer include chicken manure, lime and inorganic fertilizer of NPK 16:16:16 (Table  1). The pesticides used in study areas involve herbicides, fungicides, bactericides, insecticides, nematicides (Table 2). Pesticide residues that are retained in the soil directly affect earthworm population. The high input of dossage was applied to overcome low soil fertility.

Characteristics of the Location
The condition of monthly average rainfall based on the last 10 years in both locations, IST and ENT located in Sabangau district was 2,927 mm/year, while for location of EPT in Bukit Batu district reached 2,862 mm/year. The annual average rainfall for 10 years in Bukit Batu district is 2,927 mm/year and Sabangau district is 2,867 mm/year. Number of rainy days in Sabangau district was 160 days, while in Bukit Batu district 137 days (Figure 1 and 2).
Based on Schmidt and Ferguson rainfall system, the location of Bukit Batu has wet month throughout the year, whereas in Sabangau, it also has no dry month but this location has 11 wet months so that these locations is categorized as very wet rainfall types. Based on Oldeman climate type, Sabangau has 7 consecutive wet months and Bukit Batu has 8 consecutive wet months, so that both of these locations are classified as B rainfall type.
The condition of air temperature was 30.2-40.1 o C, while for soil temperature is 31.2-40.6 o C. Air humidity ranges from 43.3-76%, while for soil moisture is 37.0-86.9% (Table 3). Morning air temperature is lower than daytime. On the aother hand, morning soil temperature at ENT and EPT, comparing to daytime.
The soil characteristics was very different within each location. In location of IST, bulk density is very low, but it has very high soil water content up to 319.59% and based on weight and high porosity that reach 82.70, it indicates that the soil is filled with water. Other locations show that ENT which is sandy soil ( Table 5) piled on peat soil is more dense according to BD of KAT and porosity compared tothe EPT, namely soil with sandy clay loam texture in dry land. Whereas based on groundwater level, the two locations of IST and ENT are located on swampland with a groundwater level of 33-75 cm, while EPT is a typology of dry land with groundwater level reach 308 cm (Table 4).

Earthworms Population
The highest earthworm population condition was found in location of ENT with a total number of 74 earthworm/m2, followed by IST, 33 tails/m2and EPT, 31 tails/m2 (Table 5). Based on earthworm density score (Bierman, 2007), the density score at all study areas is 4 and this indicate that the condition is good, because earthworms are found in large numbers between 31-250 tails/m2.
The high density of earthworm populations in location of ENT can be caused by soil conditions with pH approaches neutral 7.1. While for other locations, they have acidic soil condition. However, in several locations such as IST and EPT, earthworms are still found, so that this indicates that earthworms have adaptation to soil acidity. Earthworms that are intolerant of acid will not be found and at several locations with acid soil environment, they can be found with low population (Siun, 2012). Neutral pH conditions are very suitable for earthworms. The decrease of soil pH and organic matter will affects the decrease in population (Puspitasari, 2016).
The high population of earthworms in location of ENT is caused by having a neutral soil pH and also cultivation techniques without the use of nematicides such as carbofuran which reacts directly in soil. In addition, this conditions also supported by shallow ground water levels so that soil moisture will support earthworm life. Tribrata et al, (2015) stated that the relative density of earthworms is lower in locations exposed to pesticides (mankozeb 0.035 mg / kg and propineb 0.014 mg / kg) than land not exposed to pesticides. Araneda et al. (2016) added that high carboxylesterase enzym (CbE) in earthworms is an indicator of pesticide exposure.
Based on the use of chemical fertilizers in study locations which ranged from 1.15 tons/ha/year to 3.5 tons/ha/year, itdoes not affect earthworm population, especially on mortality rate. The use of single or compound chemical fertilizers will have an impact on the death of earthworms 32% to 100% especially for using doses around 12-24 tons/ha (Shruthi et al., 2017). Even by not using urea at study locations, it will support optimum life for earthworms. Rai et al. (2014) added that the use of urea is harmful to earthworms (Esenia foetida) so tha the use of urea must be limited in orer to achieve optimum condition of environment.
The use of pesticides as shown at Table  2 has an influence to the population of earthworms, the use of pesticides at location of IST and EPT was quite large compared to other locations. The use of pesticides such as herbicides have different effects on the level of earthworm populations (Iordache and Borza, 2011). The herbicide type of Gardoprim Gold 500 SC is able to kill earthworms within 24 -72 hours after application. In contrast, the Helmstar 75 WG herbicide can still be tolerated with earthworms.
The location of EPT has the lowest population numbers due to several main things, namely application of lower organic fertilizer, and also condition of the deep planting water level. This can cause the scope of earthworms life to be relatively drier due to the lack of vertical seepage from the ground water level to surface, so that in some cases these conditions inhibit development of earthworms.
However, the presence of earthworms in study site, including endogaesis earthworms, is an indicator that cultivation of shallot is still managed environmentally. The existence of largest number of earthworms in location of ENT, can be categorized as the most environmentally friendly cultivation system compared to other locations. the presence of endogaesis earthworms is an indicator of environmentally friendly agriculture (Subowo and Purwani, 2013).

Land Suitability Classification
Land characteristics used to determine land suitability classes for off-season shallot development showed that there are several significantly differences, especially for the presence or absence of inundation (Table 6). At location of IST when the data was collected in January 2018 showed that floods had occurred two weeks earlier as high as 50 cm for two days. Flooding is an absolute criterion for land characteristic for shallots development. This resulted in failure of shallots farming in location, because the plants will die due to submergence and resulting in moler attack (Fusarium oxysporum (Hanz)), anthracnose (Colletotricum gleoeosporoides), and purple spots (Alternaria porii).
Based on land characteristics and quality in the three location of study in which compared to the crop requirements of shallots, land suitability class will then be determined. The land characteristic of temperature and water availability in all locations is relatively the same so that they are classified into suitability class S3 (marginal) and S2 (moderate).
As a result of land evaluation, limiting factor found at IST locations is flooding hazard, and this is due to condition of land when planting shallots, climate condition is in rainy season. Therefore, the lands was flooded and resulted in crop failure. Flooding hazard at IST location caused this areas are classiffied into not suitable or Nfh. The location of ENT is an area which is made from deposition of quartz sand soils on peat soils. The limiting factor is rooting condition, with very rough texture. This location is then classified into not suitable or Nrc (Table 7).
The location of EPT has limiting factors that are not as severe as the two previous locations. Several limiting factors include temperature, rooting condition, and nutrient retention. This location is then classified into marginally suitable symbolized as S3tc, rc, nr.
Based on actual land suitability class for shallot development, it does not seem to be directly proportional between the level actual land suitability class with earthworm populations. The location of ENT with not suitable class (Nrt) in which higher than EPT (S3 tc,rc,nr) show that limiting factor that affect growth and production of shallot, is not in line with the needs of breeding for earthworms. Lemitiri et al (2014) and Gonzalez et al. (2012) have stated that the number of earthworms is influenced by soil management practices. Bhadaura and Saxena (2010) added that agroecosystem with high production have earthworm population 75 earthworms/m 2 and 25 earthworms/m 2 . ---S1 S1 S2 S1 S2 S3 S1 ---S1 S1 N S1 S1 S3 S2 S3 N S1 S2 ---S2 S1 S1 S2 ---S1 S1 S1 S1 S1 S3 S2 S2 S3 S1 S1 ---S2 S1 S3 S2 ---S1 S1 S1 S1 S1 Actual Land Suitability Class N fh N rc S3 tc, rc, nr Source: Ritung et al, (2012) The other relevant information to support the analysis include data shallots production for such study area. The production of Pikatan variety at EPT reach 10.36 ton/ha (Firmansyah and Karjo, 2018) and production of Sembrani variety at IST is 9.13 ton/ha (Firmansyah et al., 2014). While at EPT with use of Bima Brebes variety, the production reach 15 ton/ha (Firmansyah et al., 2019).

CONCLUSION
The highest earthworm populations is in location of ENT because soil pH is neutral and this lead to optimum condition to support proliferation of earthworms, besides low use of pesticides with have relatively contact with the soil such as nematicides or herbicides. The actual land suitability of location IST is classified into not suitable with flooding hazard as limiting factor (Nfb), while for location of ENT is also not suitable with rooting conditon as limiting factor (Nrc) and for the best location is EPT classified as marginal ly suitable with several limiting factor involving temperature, rooting condition, and nutrient retention (S3 tc, rc, nr).