Oil Palm Fruit Bunches Research Articles

Deteksi Tingkat Kematangan Tandan Buah Segar Kelapa Sawit dengan Algoritme K-Means

Oil extraction rate (OER) of fresh fruit bunches (FFB) of palm oil is depend on the stage of ripeness. The process of detecting the ripeness of oil palm FFB has difficult by manually. Farmers find it difficult to reach the fruit to detect ripeness with the eye, when the palm tree is tall. So farmers need a system that is able to detect the maturity level of oil palm FFB based on color. The K-Means method is capable of clustering based on the closest mean value to the centroid from a number of objects to cluster k. Data obtained from 2 oil palm plantations in East and North Kalimantan. In this study, the clustering of fresh fruit bunches of oil palm has four levels of maturity based on the calculation of the elbow method. The training data used in this study is 80 data. The test image data used in this study is 40 data. There are 36 appropriate data based on the classification method so the accuracy obtained in grouping using the k-means clustering segmentation method is 90%.

Pengaruh Pupuk Rock Phosphate dan Pupuk Dolomit Terhadap Produksi Kelapa Sawit (Elaeis guineensis Jacq.) di Divisi I PT. Dwi Mitra Adiusaha

Oil palm in the process of development is grown in low or marginal nutrients and has a moderate acidity level. In the development process, oil palm requires high enough nutrients for the process of spurring the production process in order to get the expected results, therefore fertilization is carried out optimally with doses according to the recommendations that have been set so that the plants can meet the required nutrients. To increase the yield of fertilization, using rock phosphate and dolomite is very appropriate to get the nutrients needed and can improve the quality of oil palm fruit and the quantity of fresh fruit bunches of oil palm. The effect of Rock Phosphate and Dolomite fertilizers on the production of oil palm (Elaeis Guineensis Jacq) was carried out in the oil palm plantation of PT. Dwi Mitra Adhiusaha which is located in Natai Baru Village, North Mentaya Hilir District, East Kotawaringin Regency, Central Kalimantan. This activity was carried out by analyzing secondary data for both Rock Phosphate fertilizers from 2016 to 2020 and secondary production data from 2017 to 2021. This data analysis used the SPSS method and multiple linear regression which showed that fertilization had a positive correlation and regression towards achievement of oil palm fresh fruit bunches production at PT. Dwi Mitra Adiusaha.

The effect of lignocellulolytic bacteria consortium on composting empty oil palm fruit bunches

Oil palm empty fruit bunches (OPEFB) are waste produced by palm oil mills from processing fresh fruit bunches into oil. For every 1 tonne of fresh fruit bunch (FFB) processing, 21–23% EFB will be produced. EFB can be used as compost. OPEFB compost has considerable potential because it contains complex nutrients (macro and micro). The OPEFB composting process has problems because of the lignin content which causes the decomposition process to take a long time so that microorganisms are needed that can accelerate the OPEFB decomposition rate. This study aimed to test the ability of lignolytic bacteria from larvae of Oryctes rhinoceros L. plus cellulolytic bacteria from organic waste that have the potential to decompose OPEFB. This research was conducted experimentally using a non-factorial Completely Randomized Design (CRD) consisting of eight treatments. The results showed that the administration of cellulolytic bacterial isolates had a significant effect on water content, compost weight loss, pH, C-Organic, C/N ratio and P nutrient content, but had no significant effect on N and K nutrient levels. Treatment of lignocellulolytic bacteria ORL9 and ORL6 and a consortium of cellulolytic bacteria showed good compost quality, which could be seen from the parameters of weight loss of compost, pH, N nutrient content and reduced C/N ratio.

UTILIZATION OF AGRICULTURAL WASTE AS A SUBSTRATE FOR PRODUCING CELLULASE ENZYME BY ASPERGILLUS NIGER

Fresh Fruit Bunches (FFB) of oil palm, bran, straw, and bagasse are agricultural wastes whose availability is very abundant in Indonesia. The agricultural waste is lignocellulosic waste which still has economic value if further processing is carried out, namely as a substrate in the production of cellulase enzymes. Cellulase enzymes are commonly used in various industries such as food biotechnology, textiles, animal feed, paper, and agriculture to degrade cellulose with its main products, namely glucose, cellobiose, and cellooligosaccharides. In producing cellulase enzymes, it is necessary to have microorganisms that have a high ability to produce enzymes, one of which is Aspergillus niger. The purpose of this study was to determine the activity of crude cellulase enzyme, protein content, and specific activity of cellulase enzyme from agricultural waste which includes FFB, bran, straw, and bagasse. The research methods included preparation of Aspergillus niger culture, delignification, basal medium preparation, cellulase enzyme production, enzyme extraction, crude cellulase enzyme activity test (CMC-ase), lowry method protein content test, and determination of cellulase enzyme specific activity. The study showed that the highest crude cellulase enzyme activity in bran was 26.83 U/ml, the highest protein content in bagasse was 63.42 g/ml, and the highest specific activity of cellulase enzyme in straw was 0.9818 U/ml. The high enzyme activity is influenced by the cellulose content in the material, type of substrate, media, substrate concentration, pH, and temperature.

Application of Empty Fruit Bunches of Oil Palm and Indigofera zollingeriana for Conservation of Oil Palm Plantation

Oil palm empty fruit bunches are materials used as organic fertilizers that can be applied to oil palm plantations, thereby reducing the use of inorganic fertilizers. Indigofera zollingeriana is an appropriate alternative as an interplant because of its high branch and leaf development. Functions as a ground cover and a supplier of carbon stocks naturally plays a role in water and soil conservation. This study aims to determine the effect of oil palm empty fruit bunches and I. zollingeriana on land improvement to support oil palm growth and production. Variables observed included changes in soil water content, soil microorganism activity, and carbon stock. The results showed that the soil planted with I. zollingeriana and given the empty fruit bunches of oil palm had a higher soil moisture content. The highest soil carbon stock, oil palm carbon stock, and vegetation carbon stock were 81.6 t ha-1, 36.60 t ha-1, and 1.89 t ha-1, respectively. The population and activity of microorganisms varies. The highest total microorganisms were treated with I. zollingeriana and oil palm EFB 105 (10⁵CFU g-1), while the lowest was 60 (10⁵CFU g-1). Planting I. zollingeriana and providing oil palm empty fruit bunches increased groundwater reserves by 36.71%.

Bioethanol Manufacturing from α-Cellulose Waste of Empty Palm Oil Frugs (Elaeis guineensis jack) with Hydrolysis Concetration Variations HCl and Cellulase Enzyme

This study uses raw materials containing lignocellulose, namely empty fruit bunches of oil palm. Oil palm empty fruit bunches were isolated to produce cellulose, hydrolyzed into simple sugars, fermented, and distilled. From the isolation of cellulose obtained α-cellulose of 19.9612 grams (26.6149%). Then it was hydrolyzed using HCl with a concentration variation of 15%; 20%; 25%; 30%; and enzymatically hydrolyzed using cellulase to produce simple sugars which were tested qualitatively with Benedict's reagent and Tollens reagent, then quantitatively tested by the Luff Schroll method. The higher the concentration of acid used, the higher the sugar will be. The best bioethanol obtained from acid hydrolysis is using 30% HCl with ethanol content of 6.54% and enzymatic 7.32%.

Marketing Channel Analysis of Oil Palm Fresh Fruit Bunches in Lubuk Barumun District, Padang Lawas Regency

The purpose of the research is to find out marketing channel analysis of oil palm fresh fruit bunches in Lubuk Barumun District, Padang Lawas Regency. The research was conducted in Lubuk Barumun District in Padang Lawas Regency, North Sumatra Province with the consideration that Padang Lawas Regency has potential in developing oil palm plantation areas. The research was carried out from January to February 2021. The sample collection of producer farmers was carried out by purposive sampling with the sample criteria being independent oil palm farmers. From the population of oil palm farmers in Padang Lawas Regency as many as 297 people, a sample of 10 percent was taken, namely 30 farmer respondents. Quantitative analysis is used to determine the Hirschman Herfindahl index on market structure, market behavior based on the price relationship between two markets at the same level and the magnitude of market performance based on marketing margin analysis, profit margin ratio, farmer's share, cost share, and profit share. The results showed that, the number of oil palm farmers is large while the number of sellers or intermediaries is only a few so that the marketing system for fresh fruit bunches of oil palm tends to be imperfect competition because there are many sellers but few buyers (oligopsony). Analysis of the Hirschman Herfindahl index, it is known that the market structure of oil palm fresh fruit bunches in Lubuk Barumun District, Padang Lawas Regency tends to lead to an imperfect competition market (oligopsony) which causes the bargaining position of oil palm fresh fruit bunches farmers to be in poor condition weak, namely as a price taker. The efficiency of an already efficient marketing channel is the one that shows the smallest value of marketing efficiency, namely in channel III (Ep < 5% efficient). Marketing channels I and II have not been efficient (Ep > 5% inefficient). Keywords: Marketing Channel, Oil Palm, Fresh Fruit Bunches .

The Effect of Service Quality on Delivery Order (DO) System on Farmer Satisfaction with Fresh Fruit Bunches (FFBs) of Palm Oil in CV. Satria Abadi in Tanjung Jabung Timur, Jambi Province, Indonesia

The Effect of Service Quality on Delivery Order (DO) System on Farmer Satisfaction with Fresh Fruit Bunches (FFBs) of Palm Oil in CV. Satria Abadi in Tanjung Jabung Timur, Jambi Province, Indonesia

PENGARUH RESIDU BOKASHI KOTORAN SAPI DAN TANDAN KOSONG KELAPA SAWIT TERHADAP PERUBAHAN SIFAT KIMIA TANAH DAN KANDUNGAN N. P, K DAN Mg TANAMAN SAWIT SETELAH DUA TAHUN PENERAPAN

The aim of this study was to examine the effect of bokashi residue from a mixture of cow dung and Oil Palm Empty Fruit Bunches (TKKS) whose raw materials were taken from the Cattle-Palm Integration System on changes in soil chemical properties and content of N. P, K and Mg palm plants. This study used a Completely Randomized Block Design (RAK) with one factor and 6 treatments, namely : F0 = Control (N,P,K,Mg), F1 = Cow dung only, F2 = 1/3 part of cow dung + 2/3 part of TKKS waste, F3 = 1/2 part of cow dung + 1/2 part of TKKS waste, F4 = 2/3 part of cow dung + 1/3 part of TKKS waste, and F5 = Only TKKS waste. The results showed that the bokashi residue of a mixture of cow dung and oil palm empty fruit bunches had a very significant effect on changes in soil pH, and no significant effect on changes in soil Al-dd, nutrient content of N, P, K, and Mg of immature oil palm plantations. The control treatment (F0), namely the use of chemical fertilizers NPK and Mg showed the smallest change in soil pH and was significantly different from other treatments in all tested formulas. Changes in NPK and Mg elements did not show any effect of giving bokashi but there was a tendency to add nutrients to the bokashi treatment which showed that the residue of bokashi mixture of cow dung and empty oil palm fruit bunches was able to last up to 24 months after application. It is recommended to re-apply bokashi a mixture of cow dung and oil palm empty fruit bunches on immature oil palm plants every 2 years.

ANALISIS RENDEMEN TANDAN BUAH SAWIT BERDASARKAN TAHUN TANAM DAN VARIETAS DI PROVINSI RIAU

Palm oil (CPO) is extracted from loose palm fruit which is released from the oil palm fruit bunches, either naturally or by boiling. Several factors affect the yield of palm oil in the oil extraction process, including the year of planting and the variety planted. This study aims to look at the yield levels of oil palm fruit based on the variety year of planting so that the actual value is known and the effect of the year of planting on the yield value of FFB can be identified. The method used in this study refers to MPOB (Malaysia Palm Oil Board) and NRCOP (National Research Center of Oil Palm) standards which consist of 6 (six) stages, namely FFB sampling, initial calculation of FFB, seeds, and mesocarp, measuring moisture content, mesocarp oil extraction, calculating the percentage of kernels and shells, and calculating the value of the FFB material balance. Based on the results of the TB material balance analysis, it is known that the young planting year does not fully produce a low yield of palm oil, this is because many influencing factors cannot be controlled and are variables that cannot be locked/determined. The results of the average material balance for all planting years for the dry extraction method showed a CPO yield value of 22.97%, testing showed the highest yield was in the 2002 planted year with 27% content and the lowest was in the 2015 planted year with 19.68%.

Manufacturing and Testing of Mulch Sheet from Agricultural Waste Raw Materials

This study aims to make sheet organic mulch from several agricultural wastes and determine the best type of material for making sheet organic mulch. This research was carried out at the Greenhouse of the Faculty of Agriculture and the Laboratory of Agrotechnology, Faculty of Agriculture, Samudra University, Langsa City, Aceh Province which took place from February to April 2021.This study used a non-factorial completely randomized design (CRD) with four replications and used several agricultural waste materials consisting of bagasse, water hyacinth, rice straw, corn husks, banana fronds, coconut fiber and empty fruit bunches of oil palm. The raw materials used are agricultural waste 2.4 Kg and NaOH 0.168 Kg. The parameters observed in this study were water absorption, mulch moisture content and mulch yield.The results showed that the type of agricultural waste had a very significant effect on the sheet mulch produced. For water absorption parameters, raw material from bagasse (M1) is the best treatment. As for the water content parameter, the best treatment was found in Coconut Coir (M6) while the best treatment for the mulch yield parameter was found in Rice Straw (M3) agricultural waste.Based on the results of the study, to produce the best sheet mulch, it is recommended to use agricultural waste material from rice straw (M3).  

Design and Simulation of Oil Palm FFB Loading Machine

The process of loading the fresh fruit bunches of oil palm to the truck requires a lot of manpower if it is done manually. In fact, either the palm oil plantation or the smallholder palm oil farmer still performs this task manually, so that it can lead to fatigue and can result in injuries for the worker due to heavy workload. The purpose of this research is to design and simulate a machine for lifting the fresh fruit bunches to the truck, so that the activities of lifting the fresh fruit bunches to the truck become easier and can have a bigger working capacity. This research was conducted using a functional and structural design approach consisting of several stages, including: problem identification, design concept formulation, engineering analysis, engineering drawings, material strength analysis, kinematics simulation, power consumption simulation, and digital scale simulation. A simple structure of electric motor-driven bucket elevator was designed to load the fresh fruit bunches on to the truck tailgate. Based on the simulation results, the fresh fruit bunches can be lifted up satisfactorily from the bottom to the top with an elevator mechanism. This elevator is designed with lightweight for easy installation and kept at the tailgate of the truck. The maximum electric power consumption for lifting the fresh fruit bunches was found to be 1466.24 watts with designed loading capacity 23 ton/hour.

Production of Fuel pellet From Agricultural And Plantation Estate Crops Biomass

Biomass contains energy used as solid fuel so that biomass will have high added value. Directly combustion of biomass has caused environmental pollution problems. Agricultural and plant estate plantation biomass waste that is widely spread in Indonesia needs to be utilized. The research was aimed at designing and producing biomass pellets for a pilot-scale capacity of 200 kg/hour. The biomass used consisted of empty oil palm fruit bunches (OPEFB), oil palm shells (OPS), cocopeat, corn cobs, and sugar cane bagasse. Pellets are formed by pressing biomass powder with high pressure using a 10 hp pelletizer. The quality of pellets produced was tested based on the standard DIN 53731. The performance test of pelletizing machinery showed that such types of machinery could be produced for 150-200 kg/hour. The test results showed that almost all quality parameters of biomass pellet (moisture content, calorific value, ash content, density, length, and diameter) met the requirements. Synthetic gas produced from burning biomass pellets in the gasifier and stove is able to use for drying and heating for 80 minutes. Pelletizing can enhance the volumetric and calorific value, reduce the transport and storage costs, reduce the moisture content, and improve the handling characteristics of biomass.

POTENSI PAJAK PENGHASILAN PEDAGANG PENGUMPUL TANDAN BUAH SEGAR (TBS) KELAPA SAWIT (STUDI DI KPP ABC)

Palm oil collector traders are entities or individuals whose business activities are collecting oil palm plantation products in the form of oil palm fresh fruit bunches (FFB) and selling them to industrial business entities or exporters engaged in the plantation sector. The purpose of the study was to determine the potential income tax, the steps that have been taken and the obstacles, the realization of tax revenue for the collectors of Fresh Fruit Bunches (FFB) of oil palm at the Tax Service Office (KPP) ABC. The research method used is descriptive qualitative. The results of the study show that the potential taxes of palm oil collectors are PPh Article 21, PPh Article 22, PPh Article 23, PPh Article 25/29, Final PPh Article 4 paragraph (2) including the MSME taxation provisions. Steps that have been taken are socialization and appeals to taxpayers. The obstacles are geography, human resources, and awareness of taxpayers. Meanwhile, the realization of tax revenue is quite good and shows an increase, especially in Article 22 Income Tax.

INNOVATION OF BIODEGRADABLE MEMBRANE NANOFILTER MASK BASED ON CELLULOSE EMPTY PALM OIL BUNCHES AS A FUTURE MASK

Background: Covid-19 has become a public health emergency of international concern that is transmitted through respiratory droplets. Prevention is a very important things to maintain public health, one of which is by using masks. This raises new problems related to mask waste which is non-biodegradable. There needs to be a solution in the form of environmentally friendly masks that are easily biodegradable, one of which is by utilizing the cellulose content in empty palm oil bunches. The purpose of this study was to determine the process of making environmentally friendly masks from empty oil palm fruit bunches, to determine the thickness and biodegradation results of masks. Method: The method used in this research is experimental. In this study, the manufacture of nanofilters, thickness testing, and biodegradation tests were carried out. The process of making environmentally friendly masks from oil palm empty fruit bunches goes through four main stages, namely extraction of cellulose from the waste of oil palm empty fruit bunches, synthesis of cellulose acetate, manufacture of biodegradable nanofilter membranes, and finishing. Result: The results showed that the masks had a thickness of 0.79-0.97 mm and the results of biodegradation tests showed 2.7-7.03% results. These results show a very good indication that it has the potential to be used as an air mask that is feasible to use and environmentally friendly because it is easily biodegradable. Conclusion: The process of making environmentally friendly masks from oil palm empty fruit bunches goes through four main stages, namely extraction of cellulose from the waste of oil palm empty fruit bunches, synthesis of cellulose acetate, manufacture of biodegradable nanofilter membranes, and finishing. Thickness test results yield 0.79-0.97 mm and biodegradation test results show 2.7-7.03% results. Keywords: Biodegradation, Mask, Palm Oil Bunches

Soil Organisms Activities in Red Onion Cultivation with Application of Plant Extract Suspension and Compost

Agro-industrial waste such as banana weevil, pineapple rhizome, and empty fruit bunches of oil palm has not been utilized properly, even though the waste can be processed into liquid organic fertilizer after extracting the beneficial microorganisms contained in it. This research aimed to observe and study soil organisms’ activity after applying plant extract suspensions and compost types. The research was conducted at the Integrated Field Laboratory and Soil Science Laboratory, Faculty of Agriculture, University of Lampung. The treatments were designed in a 3 × 3 factorial design in a Randomized Block Design with three replications. The first factor was the plant suspension extracts derived from banana weevil, pineapple rhizome, and oil palm empty fruit bunches, while the second factor was the compost in the form of solid compost and liquid compost. The results showed the activity of soil organisms in the form of respiration, soil microbial carbon biomass, soil microbial population, and mesofauna population, which was applied to a suspension of plant extracts from pineapple rhizome, given the highest yield. Furthermore, the bacterial phosphate dissolution index and the diversity of soil mesofauna applied to liquid compost were higher than those of solid compost or without compost. There was no interaction between the application of plant extract suspension and the compost types on the soil organism’s activity.

Preliminary study of molecular sieve materials to alleviate problems faced by tropical peatland

Zeolites are crystalline aluminosilicates usable for numerous applications, including in the separation or purification gas processes, catalysts, ion exchanger and adsorbent. These benefits are due to their molecular sieve property. One of the appropriate technologies for the peat management related to C sequestration and potential peat fire suppressor is molecular sieve material, i.e., zeolite-clinoptilolites and other gas adsorbent material taken from empty fruit bunches of oil palm (EFBOP) obtained through the pyrolysis process (biochar). This study assessed the physicochemical and morphological characterization of natural zeolite-clinoptilolite type, originated from Bayah, Banten, Indonesia, and biochar as gas adsorbent to minimize greenhouse gas emissions and C sequestration. Physicochemical characteristics of 60-80;80-100, 100-150 particles mesh size of zeolite and biochar were measured according to standard analytical procedures based on Kepmentan 261/KPTS/SR.310/M/4/2019. Mineralogical characteristics and the capacity to absorb greenhouse gasses (CO2 and N2) were determined using SEM-EDS and Brunauer-Emmet-Teller analysis, respectively. The result indicated that 100- 150 mesh zeolite had a higher CEC value (126.45 cmol(+) kg−1), CO2 (1.0586 mmol g−1) and N2 adsorption capacity (75.6 cm3 g−1), compared to biochar originated from EFBOP 26.9 cmol(+) kg−1; 0.071 mmol g−1; and 1.66 cm3 g−1, respectively. Biochar observed in this research yielded a higher pH and organic carbon content, with larger pore space. Combining zeolite and biochar provided an optimal result to deplete greenhouse gas emission i.e., 0.3662 mmol g−1, and improved water retention as indicated by water holding capacity percentage.

PENGEMBANGAN LAHAN BASAH SUB-OPTIMAL : PERTUMBUHAN Moringa Oleifera (L) PADA TANAH SULFAT MASAM YANG DIBERI BAHAN AMELIORAN

Moringa is a plant that has a myriad of benefits, either to fulfill human nutrition or as an ingredient used for animal feed. Information to the public is still very minimal about the benefits of this Moringa plant, and it also requires a large area of land to cultivate it. Acid sulphate land is a land that is underutilized as agricultural crop cultivation because it has a serious limiting factor, but has the potential to cultivate Moringa plants, because Moringa plants are tolerant of high soil acidity. This high soil acidity can be overcome by the addition of ameliorant materials in the form of husk ash and empty oil palm fruit bunches (OPEFB). Besides being able to improve the physical and chemical properties of the soil, ameliorant is expected to improve soil fertility in acid sulfate soils. This research was carried out by taking soil in the Barito Kuala area, precisely in the Tabukan sub-district as a polybag scale planting medium, this study used a factorial completely randomized completely randomized design method. The results of soil sample analysis showed that the characteristics of acid sulfate soils were very low, and had very high levels of toxic elements such as Fe and Al. While the results of the analysis of OPEFB compost the chemical element values ranged from high to very high so it was very good for application to acid sulfate fields. The treatment of OPEFB compost and husk ash affected the growth of the number of Moringa plant shoots with the best treatment being 20 ton.ha-1 and husk ash 10 ton.ha-1.

ANALYSIS OF SOIL CHEMICAL CHARACTERISTICS IN PABATU SERDANG BEDAGAI UNIT OIL PALM PLANTATIONS

Soil is a natural medium that is one aspect of supporting the life of all living things, including plants. Soil chemical properties greatly affect the growth process of oil palm plants, especially in the production process of oil palm fruit bunches. The purpose of this study was to determine the soil's chemical properties in oil palm plantations. The method used in this study is a descriptive method by conducting surveys and laboratory analysis. Soil samples were taken randomly at a depth of 0-20cm at four points of plantation land. Several parameters have been analyzed, such as pH, total N, CEC and exchangeable Al (Al-dd). Soil samples were analyzed at the Laboratory of Soil Research Indonesian Oil Palm Research Institute (PPKS) Medan. Determination of the criteria for assessing soil chemical properties based on the soil fertility standards issued by the Soil Research Center (BPT) Bogor (2009). The results of the analysis showed that the soil pH was slightly acidic, total N was low, CEC was low and Al-dd was very low.

HUBUNGAN KELERENGAN LAHAN TERHADAP PRODUKSI TANDAN BUAH SEGAR KELAPA SAWIT DI PERKEBUNAN PT. BINA PRATAMA SAKATO JAYA KABUPATEN SIJUNJUNG

Palm oil production in Indonesia must be optimized to meet world market demands. The steeper the slope of the land, the more erosion and weed growth will occur. This can result in disrupted oil palm growth due to erratic competition, air, and light between oil palm and weeds around the plant. This study aims to determine the relationship between the slope of the land with the production level of Fresh Fruit Bunches of oil palm in the PT. Bina Pratama Sakato Jaya Unit Kiliran Jao Sijunjung Regency. The research is in the form of a survey with a purposive random sampling method. Observation parameters consisted of the weight of fresh fruit bunches, the diameter of stem circumference, and plant height. Data processing using a simple linear regression method. The plantation area of ​​PT. Bina Pratama Sakato Jaya is currently 4,678.79 Ha. Slope significantly affects the production of oil palm Fresh Fruit Bunches (FFB). The highest average production was obtained on flat (0-3%) and gentle slopes (3-8%), and the lowest average production on slopes (15-30%) and very steep (30-45%)