The carbon footprint from ruminant livestock in the breeding-green farm in Jember

Livestock, especially ruminants, potentially emit nitrous oxide (N2O) and methane (CH4) gas through enteric fermentation activities from the eructation process and dung management (DM) activities. This study aims to determine the emissions gas of CH4 and N2O from livestock ruminants in the livestock breeding-green in Jember. The gas emission calculation method follows an international agreement initiated by the Intergovernmental Panel on Climate Change (IPCC) 2006, with Layer-2 for CH4 and Layer-1 for N2O. The results showed that the amount of CH4 emission from enteric fermentation was 103,321 tons CO2-eq per year, higher than DM, which is 4,510 tons CO2-eq /year. The amount of indirect N2O emissions from DM is 0.0763 tons CO2-eq /year, higher than direct N2O emissions from DM, which is 0.0527 tons CO2-eq /year.


Introduction
The Earth's surface emits infrared rays from the sun's light waves which have wavelengths greater than 4 μm and cannot be released into space because of being absorbed by gases in the atmosphere [1].The gases, called greenhouse gases (GHG), emitted into the atmosphere due to human activities including carbon dioxide (CO2) is around 76%, followed by methane (CH4) at approximately 16%, then nitrous oxide (N2O) at 6%, and fluorinated gases (F-gases) of 2%.A global warming potential (GWP) is based on gas emission of CO2-eq, in which CH4 gas is 28 times CO2-eq gas emissions, while N2O gas is 298 times CO2-eq gas emissions [2].These gases cause the greenhouse effect which is the cause of global temperature increase.Global warming is the reason for the formation of commitments for countries that are obliged to plan emission reductions (Nationally Determined Contribution).Indonesia plans an emission reduction target of 29% (unconditional) in CM1 to 41% (conditional) in CM2, which is equal to Business as Usual (BAU) in 2030.Nationally, in the agriculture sector in 2020, the total accumulated emissions amounted to 98,702 Gg CO2-eq, with 33,182 Gg CO2-eq per year from the livestock sub-sector [3].
The livestock subsector was based on two main activities, namely enteric fermentation (EnF) and dung management (DM), and potentially emitted gases of CH4 and N2O.The gas emission of CH4 and N2O was based on [4], which showed that CH4 emissions amounted to 1.1466 Gg per year, and N2O emissions amounted to 535.73 kg per year.Methane gas from enteric fermentation occurs during digestion when microorganisms in livestock, particularly ruminants, break down carbohydrates [5].Ruminants contribute to GHG emissions in the livestock subsector.The specialized digestive system in ruminants, such as cattle, goats, and sheep, releases methane gas into the atmosphere through belching or eructation [6].N2O gas is formed during the storage and management of livestock manure.UPT Pembibitan Ternak dan Hijauan Makanan Ternak Jember (UPT PT-HMT Jember) /Technical Implementation Unit for Livestock Breeding-Green Forage Jember (TIU-LBGF Jember) is in Silo District, Jember Regency with an altitude of 560 meters above sea level (ASL), an average temperature of 23 o C, and an average rainfall of 2000 mm/year.Land utilization in Silo District is mostly green areas which include: plantations, forestry, and rice fields [7].This condition is very strategic in developing various commodities, one of which is ruminant livestock.The total population of ruminants is based on data from the TIU-LBGF Jember with a total of 626 heads including 480 sheep, 120 goats, 15 dairy cows, and 11 beef cows [8].This study aims to determine the GHG emission of CH4 and N2O from ruminants in TIU-LBGF Jember through emission inventory.The location of the TIU-LBGF Jember is shown in Figure 1.

Methods
The GHG emission calculation method follows the international agreement initiated in 2006 by the Intergovernmental Panel on Climate Change (IPCC), with the emission factor of layer 2 nd for CH4 emissions and layer 1 st for N2O emissions [10]

Methane emission (CH4)
The emission of CH4 from EnF and DM was formulated by the IPCC 2006 with the 2 nd layer method in which Equations 10.19 and 10.22, are attached in Equation 1.

Nitrous Oxide emission (N2O)
The emission of N2O in DM is divided into direct and indirect emissions which use the 1 st layer [10] with Asian default emission factors.Emission factors from the ratio of the formation of nitrous oxide to the N present in livestock manure, are attached in Table 1.Quoted as the actual source: Table 10.21 [10] The fraction of total N excreted and the default value of the rate of defecation of manure for each type of livestock each year is attached in Table 2.The portion of total yearly defecation of N in each type of livestock T is attached in Table 3.The emission factors (EF4(s)) of Indirect DM are attached in Table 4.The percentage of livestock manure that is volatilized to NH3 and NOx (%) is attached in Table 5.

Results and Discussions
The data of the TIU-LBGF Jember includes livestock population, average livestock weight, and livestock ruminant management system, which is used to calculate the baseline emissions.The total livestock population is 626 head, with an average weight of beef and dairy cows of 400 kg.The average weight of goats is 22 kg, followed by sheep weighing 21 kg.TIU for Livestock Breeding-Green Forage Jember applies a different management system between goats, sheep, and cattle.A pit storage system is used for managing sheep and goat manure.Each cage is constructed as a stage with a holding hole underneath, about 2 meters taller.The cage's wooden foundation is hollow, allowing the manure to fall directly into the hole.When compared to dairy and beef cows, whose cages do not have holes, manure falls at the cattle's feet, where it is routinely cleaned and removed for being spread over the field on a daily basis.Livestock population by sub-category and DM is presented in Table 6.

Methane emission (CH4)
The sources of emission of CH4 at TIU-LBGF Jember are the activities of enteric fermentation and DM.The total CH4 emission from enteric fermentation activities (103,321 tons CO2-eq per year) was higher than it was in DM (4.51 tons CO2-eq per year).Figure 2 shows the comparison of the two activities.The largest emission of enteric fermentation activity by sheep was 60,217 tons of CO2-eq /year, while the smallest emission by beef cows was 12,460 tons of CO2-eq /year.In DM activities, the largest emission by dairy cows was 2,551 tons of CO2-eq /year, while the smallest emission by goats was 0.091 tons of CO2-eq /year.A similar study on the emission of CH4 from EnF on dairy cows in Lembang District, West Bandung Regency, by using the IPCC the 2 nd layer method [12].An example is a mature sub-category in Pagerwangi Village, with a population of 215 heads.The results showed that the emission was 464.382 kilotons CO2-eq /year or 2.159 kilotons CO2-eq /year/head.The emissions in [12] with TIU for Livestock Breeding-Green Forage Jember is the same as the emissions of 5 mature dairy cows in TIU Jember, which is 10.800 kilotons of CO2-eq /year or 2.150 kilotons of CO2-eq /year /head.The previous research [4] stated that the emission of CH4 in livestock from EnF is influenced by livestock type and population.

Nitrous Oxide emission (N2O)
The emission of nitrous oxide in DM is formed directly and indirectly.The emission of N2O from beef and dairy cows, goats, and sheep in TIU Jember is attached in Figure 3. Based on the data in the figure, indirect N2O emissions (N loss in NH3 and NOx) are the largest contributor to emissions, amounting to 0.0763 tons CO2-eq per year.Direct N2O emissions (a combination of denitrification and nitrification of N) contributed amounting to 0.0527 tons CO2-eq / year.Beef and dairy cows based on the EF3(S) value in Table 2, have a factor rate of 0 (kg N2O-N/kg N), resulting in emissions of 0 tons of CO2-eq /year.The emissions are influenced by the number and type of livestock, livestock weight, and DM system.Goats and sheep manure are managed with storage pits, while beef and dairy cows are covered on the land every day.Similar research was conducted by [13] on direct and indirect N2O emissions from DM in beef cows in Cikalong Village, West Bandung Regency, using the IPCC 2006 the 1 st layer method.The total of 649 head (NT) or animal units in dry lot manure management, shows that the amount of direct N2O emissions is 2.978 tons CO2-eq /year or 0.004 tons CO2-eq /year/head, and indirect N2O emissions amounted to 189.51 kg CO2-eq /year or 0.0003 tons CO2-eq /year/head.The quantity of emissions in [13] with TIU for Livestock Breeding-Green Forage Jember showed a difference in value.With 11 beef cows in TIU Jember, direct N2O emissions amounted to 0 tons of CO2-eq per year or 0 tons of CO2-eq /year/ head, and the indirect emissions amounted to 0.0009 tons CO2-eq /year or 0.0001 tons CO2-eq /year/head.The value was influenced by the DM system and livestock weight.The DM system affects the value of the emission factor (EF3) as well as the percent of manure vaporized (FracGasMS).The dry lot DM system has an EF3 of 0.02 kg N2O-N/kg N and FracGasMS of 20%, attached in Table 1 and Table 5.

Emission reduction strategy
Total livestock emissions of CH4 and N2O at TIU for Livestock Breeding-Green Forage Jember were 107.83 kilotons CO2-eq /year and 0.129 tons CO2-eq /year, respectively.To minimize GHG emissions, appropriate adaptation and mitigation methods are required.Furthermore, as part of Indonesia's contribution to the conditional NDC commitment (CM2).GHG emission reduction techniques that can be used in the livestock sub-sector include livestock feed quality refinement, public biogas livestock, organic fertilizer processing, and manure storage systems.Referring to [14].

Livestock Feed Quality Refinement
The quantity of methane gas produced is influenced by the type of feed given to cattle.With the application of supplementation techniques, such as the combining of concentrate forage and leguminous leaves, good feed quality can be obtained.Corn (single or mixed feed), cassava, bran, and palm kernel cake are all examples of concentrates that can be administered.Cassava leaves, indigofera, lamtoro, and gliricidia are examples of legumes that can be given as supplements [15].

Public Biogas Livestock
The biogas process occurs when livestock manure is directed into the biodigester, causing biotransformation.This step involves anaerobic microorganisms that prevent methane gas from cattle manure emit into the atmosphere.Large amounts of methane gas trapped in the biodigester are used as an alternative energy source for household purposes [15,16].

Organic Fertilizer Processing
The Organic Fertilizer Processing Unit (UPPO) is an action to improve soil fertility and agricultural productivity.Organic fertilizer processing unit building, fermentation tub building, compost house building, organic fertilizer processing equipment (APPO), communal cattle pen building, 3-wheeled vehicles, and cattle are some of the facilities used.The use of UPPO can raise the Carbon content of the soil.Emissions from applying this fertilizer can be reduced if the dose used is sufficient to replace urea fertilizer [15].4. Manure Storage System (Straw Cover) Straw covers are frequently utilized since they are inexpensive and effective at decreasing emissions [16].When straw is blown into the fertilizer storage area, it produces an organic bed that floats on the surface of the manure.To keep the straw afloat or the top dry, the ideal straw thickness is 30 cm.Straw absorbs gas and acts as a biofilter as a result [17].

Conclusion
The methane gas (CH4) emission from ruminants in TIU-LBGF Jember was calculated using the IPCC 2 nd layer method.Total emissions from the activity of EnF were 103.321 tons CO2-eq / year, higher than emissions from DM, which was 4.510 tons CO2-eq per year.The amount of N2O emissions from DM calculated by using the IPCC 1 st layer method, emission from direct N2O is 0.0763 tons CO2-eq / year, higher than direct N2O emissions, which are 0.0527 tons CO2-eq / year.
The direct emissions of N2O produced from DM in which Equation 10.25 and 10.30 in IPCC 2006, are attached in Equation 2 and Equation 3 below.N2O = [∑S [∑T (N(T) × Nex(T) × MS (T,S))] × EF3(S)] × 44/28 (2) Nex(T) = Nrate(T) × TAM/1000 DM (kg N2O/year) N(T) = total of livestock (heads) Nex(T) = average defecation of N per year (kg N/head/year) MS(T,S) = fraction of total yearly defecation of N in each type of livestock T, based on the S livestock ruminant management system EF3(s) = direct dung emission factor (kg N2O-N/kg N) 44/28 = molecular weight of N2O/Molecular weight of N2 Nrate(T) = rate of default defecation N, (kg N/1000 kg)/day TAM(T) = average weight of livestock for each type of livestock (kg/head) ) = indirect emission of N2O from DM (kg N2O/year) Nvaporisation-mms = contaminants lost due to vaporisation of NH3 and NOx (kg N/year) N(T) = total of livestock (heads) Nex(T) = average yearly defecation of N (kg N/head/year) MS(T,S) = portion of total yearly defecation of N in each livestock type T, based on livestock ruminant management system FracgasMs = percent of manure vaporised to NH3, and NOx (%) EF4(s) = indirect factor of emission in livestock manure (kg N2O-N/kg N)

Table 6 .
[8] population of livestock is based on sub-categories and DM[8].