Analysis Of Several Soil Physical Properties In The Third Generation Of Oil Palm Plants At PT. Sinar Pandawa Labuhanbatu

. The physical properties of the soil that need to be considered are the problems of degradation and soil structure due to management functions. In addition, on cultivated land that is not eroded, organic material is lost quickly.This research was carried out through 2 stages of activities, namely field activities and analysis activities. Stages of field activities were carried out at the Kebun Sinar Pandawa Palm Oil Plantation PT. Sinar Pandawa, Labuhanabtu, North Sumatra Province with a height of 28 meters. The method used in this research is a free grid measurement method at a semi-detailed survey level (observation frequency of 1 sample per 500 meters). Carrying out soil sampling at up to 5 sampling points with a distance of 100 meters in the field using a random method, spread over a predetermined area based on the base map. Land Use Research Results withSoil texture at PT. Sinar Pandawa, Labuhanbatu Regency, Sandy Clay, The Bulk Density value shows low, soil porosity is still high, the soil color looks relatively dark, and the soil water content is still relatively normal.


INTRODUCTION
Oil palm plantations are a commodity that plays an important role in the economy so that its productivity is high over a long production period and is resistant to pests and diseases [1].The need for oil palm plants will continue to increase in line with the high demand for oil among society, both nationally and globally [2].Palm Oil (Elaeis Guinensis Jacq) is a mainstay commodity that can be expected to increase the income and dignity of plantation farmers and Indonesian transmigrants [3].Palm oil has apparently succeeded in becoming a commodity that can penetrate areas such as Kalimantan, North Sumatra and Lampung [4].According to [5], the physical properties of soil that need to be considered are the problem of soil structure degradation due to management functions.In addition, in cultivated land that is not eroded, organic matter is lost quickly [6].It was found at the Missouri Agricultural Experiment Station that as a result of cultivation for more than 60 years, in soil that is not eroded, organic matter is lost by a third, the loss is more greater at the beginning of cultivation compared to subsequent cultivation [7].Cultivated plants such as oil palm plants have different canopy areas and land cover when compared to densely growing forest plants [8].Meanwhile, to protect the soil from the effects of erosion, cover crops are planted [9].
Cover crops can actually protect the soil from the threat of soil damage due to erosion and can also improve the physical, chemical and biological properties of the soil through the breakdown of organic material originating from weathering or decomposition of the vegetation itself [10].This can also maintain the nutrient cycle in the soil so that nutrient loss due to the erosion process is not too large [11].Soil management in several plantation land uses, such as fertilization, land clearing, burning, and the use of heavy equipment will affect the soil properties in that land use.Research result [12]in [13],stated that several cases in the field show that soil characteristics can change within a narrow time span.The physical characteristics of the land are an important factor in cultivating oil palm plants.According to [14].in[15],There is a change in the physical properties of the soil due to the planting of oil palm in plantations as the age of the plant increases.Based on the statement above, it is necessary to carry out this research by examining several conditions of the physical properties of the soil for each different planting year in the oil palm plantation area inPT.Pandava Raysto provide information regarding the growth and development as well as the optimal potential of oil palm plants

II. METHODS
This research was carried out through 2 stages of activities, namely field activities and analysis activities.Stages of field activities were carried out at the Kebun Sinar Pandawa Palm Oil Plantation PT.Sinar Pandawa, Labuhanabtu, North Sumatra Province with a height of 28 meters above sea level in Figure 1.Stages of laboratory activities, namely soil sample analysis, were carried out at the Applied Science Laboratory, Faculty of Science and Technology, Labuhanbatu University, North Sumatra, Medan.The research was carried out in March-November 2023.

Fig 1. Research Location
The tools used include digital cameras, calculators, sieves, tarpaulins, polybags, sample rings, hoes used for digging soil, machetes, rulers, ovens, Erlenmeyer.The materials used in this research are Ultisol soil samples, biochar., polybag, water.The method used in this research is a free grid measurement method at a semi-detailed survey level (observation frequency of 1 sample per 500 meters).Take soil samples from up to 5 sampling points with a distance of 100 meters in the field using a random method, spread over a predetermined area based on the base map as shown in Figure 3 [4].Sampling was carried out using a random sampling method at predetermined points in each block, sampling was carried out from two depths, namely from a depth of 0-30 cm and from a depth of 30-60 cm, 5 samples each at the same two depths for chemical content examination.explore the properties of the soil with certain predetermined criteria, Porosity (%) obtained by the bulk weight of the soil has been determined.Another data that must be known is the specific gravity of the particles, namely 2.65 g/cm3.Analyzing soil porosity Porosity is calculated using the equation: c.
Permeability measurement using the Constant Head Test method.

d.
Analyzing available water Available water can be calculated by calculating the difference between pF 2.54 (field capacity) and pF 4.2 (permanent wilting point) using the pressure plate method at the Palm Oil Research Center Laboratory (PPKS).

RESULTS AND DISCUSSION
Identify the physical characteristics of planting oil palm plantations at PT. Sinar Pandawa, Labuhanabatu Regency, namely bulk density, porosity, water content, soil texture are presented in Table 2 Research Results on Oil Palm Plants able to reduce the highest soil bulk density, namely reaching 1.32g/cm3,then followed and the lowest at the second location was 0.97g/cm3.This is in accordance with research conducted by [16],which states that bulk density at a location can reduce the density of mineral soil contents because it increases the surface area of the soil, thereby increasing the pore space in the soil.According to [17], at the location of the Oil Palm Plantation, the soil density decreases as a resultbiocharwhich hasits porous nature increases the pore space in the soil.When applied to soil, it causes a significant effect on reducing bulk density and increasing soil pore volume.From the results of the analysis it was found that oil palm plants in the fourth location had an impact on soil porosity.An increase in porosity is in line with a decrease in soil bulk density, so that the amount of soil mass in a volume of soil can determine the amount of pore space in the soil.[18], states that porosity is the ratio between the density of the soil mass and the density of soil particles, therefore it can be said that a soil volume consists of soil mass and soil pore space.
Thus, soil with low mass density means the soil has a lot of pore space, and vice versa.So the existence of pore space in the soil greatly determines the size of the mass density of a soil [19].The highest porosity occurred at the second location at 64% followed by the first location at 45%.This is in accordance with research [21], that the influence caused by the location of oil palm plants is not all the same, but varies based on each type of soil.Based on the results of the analysis, it can be seen that the highest available water is at the location of oil palm plantations, which is one of the factors that influences the availability of water in the soil is soil texture.Soil texture greatly influences the soil's ability to retain water [22].Galang ultisol soil has a sandy loam texture, where the soil has a dominant sand content so that the soil's ability to hold water is low.This situation causes the availability of ultisol soil.Apart from that, the availability of water in the soil is also influenced by the distribution of pore sizes in the soil.Coarse-textured soil is rich in macropores which have free drainage so the ability to store moisture is low.Fine-textured soils have more micropores that are able to hold water against free drainage [23].

IV. CONCLUSION
Based on the physical properties of the soil, the results of the research and the discussion description, it can be concluded that the soil texture at PT. Sinar Pandawa, Labuhanbatu Regency, Sandy Clay, The Bulk Density value shows low, soil porosity is still high, the soil color looks relatively dark, and the soil water content is still relatively normal.

Fig 1 .
Fig 1.Taking soil sample points in the field Observed Parameters a.Bulk Density Measurement of soil density (bulk density) is carried out on samples taken from the soil.Whole soil samples were taken using a ring sample.Analyzing Soil density is calculated using the equation: Soil Weight (g) / Soil Volume (cm3) Bulk Density: Soil Weight (g) Soil Volume (cm3)

Table 2 .
. Parameters of Soil Physical Properties inpalm oil plantation PT.Pandava Rays