Effect of application of arbuscular mycorrhizal fungi on growth and yield of soybean in different agroecosystems

Soybean is a legume that can be cultivated in various types of agroecosystems such as lowlands, dry land, and swamps with various types of soil. This research aims to analyze the effect of mycorrhizal application on the growth and yield of soybeans planted in various agroecosystems. The research was designed with a two-factor randomized block design. Location of soybean planting as the first factor consists of four soybean development locations in Takalar Regency, South Sulawesi, namely: soybean cultivation in dry land, lowland in Galesong subdistrict, soybean cultivation in dryland, and lowland in South Galesong subdistrict. Application of mycorrhizal is the second factor which consists of two levels: no application, and mycorrhizae application. The results showed that the location of planting had a significant effect on soybean production, where soybean cultivation in lowlands resulted in significantly higher soybean production. The mycorrhizal application treatment obtained significantly higher soybean growth and production. The results of the analysis of soil chemical properties show that the total N content of soil in lowland land is moderate, P-available has low status, and low C-organic status. Galesong dry land showed a high total N content of 0.59%, but available P and organic C are very low.


Introduction
Soybeans (Glycine max L. Merill) are used as food and feed ingredients for their protein content and protein composition [1].In Indonesia, soybeans are widely processed for various foods, such as bean sprouts, soy milk, tofu, beancurd, soy sauce, oncom, tauco, tempeh, ice cream, cooking oil, and soybean flour.Soybeans are also used as animal feed, and as industrial raw materials and refreshments.The protein contained in soybeans has complete amino acids compared to other cereal grains, which is the main reason why soybeans are increasingly being used in the pet food industry [2].In addition, other qualities of soy protein are associated with cholesterol-lowering ability and anti-cancer activity [3].
Along with the increase in population and the increase in people's welfare, the demand for soybean commodities continues to increase from year to year.The need for soybeans in 2021 will reach 2.98 million tons, whereas soybean output will only reach 215,000 tons [4] so soybeans brought in from other regions will continue.Therefore, the government continues to strive to increase soybean production, both through intensification and extensification programs in dry and rainfed land as well as developing location-specific technologies.
Soybeans, classified as a food crop, can be grown in different agroecosystems, including rainfed lowland, dry land, and swampland with various types of soil, soil fertility statuses, climatic differences, and cropping systems [5,6].Utilization of rainfed lowland and dry land is one strategy to increase soybean production [7,8].In rainfed lowlands, soybeans are developed after rice harvest [9].The main obstacle to soybean cultivation is the uncertain climatic conditions because soybeans are very sensitive to high rainfall and prolonged drought [10].Meanwhile, the development of soybean plants has enormous potential considering the vast potential of dryland and green-fed rice fields.
The development of soybean plants on dry land and in rainfed rice fields after rice harvest is faced with the problem of low soil fertility and limited water availability [11].Therefore, efforts are needed to improve soil fertility and increase plant resistance to drought.This effort can be achieved by applying arbuscular mycorrhizal fungi (AMF).AMF is an organism from the fungus group that lives in the soil and is associated with plants [12].Plants associated with mycorrhiza have the ability to absorb water and nutrients more optimally, due to the presence of hyphal threads from mycorrhiza, so that the root coverage is wider [13].
Mycorrhizae are symbiotic with almost all types of plants [14].Mycorrhizae infect plant roots and then produce an intensive network of hyphae.The external hyphae of mycorrhizae are able to absorb nutrients, thereby increasing nutrient availability for plants [12], mycorrhizae also increase plant resistance to drought [15] and soil salinity [16], and have the potential to act as biological control agents against various soil-borne pathogens [17].
There were also findings on mycorrhiza positively influencing plant growth by [18,19] which where AMF was proven to be effective in increasing the growth and yield of soybean plants as well as increasing the efficiency of phosphate fertilizer utilization.Therefore, it is necessary to conduct research to analyze the effect of mycorrhizal application on the growth and production of soybeans planted in various agroecosystems.

Materials and methods
This research was implemented using an experimental design at two different agroecosystems, namely in dryland, and rainfed lowland rice fields, Galesong sub-district, and South Galesong sub-district, Takalar District, South Sulawesi.
The experiment was designed in a two-factor randomized block design.The first factor is the location of soybean planting which consists of four soybean development locations in Takalar District, South Sulawesi, namely: L1= Soybean planting on dryland in Galesong Sub-District L2 = Soybean cultivation in rainfed lowland in Galesong Sub-District L3 = Soybean planting in the dryland, South Galesong Sub-District L4 = Soybean planting in rainfed lowland in South Galesong Sub-District As the second factor is the application of mycorrhizal which consists of two levels, namely: M0 = without the application of mycorrhizal M1 = mycorrhizal application 10 grams/plant This resulted in a total of 24 experimental units, with each of the 8 treatment combinations replicated three times.

Mycorrhizal preparations
The mycorrhiza used was obtained from the results of multiplication carried out in the microbiology laboratory of the Research and Development Center for Environment and Forestry and was in the form of mycorrhizal biological fertilizer.

The experimental procedures
The land in each research location was organized into six plots, further divided into two sets-those subjected to mycorrhizal application and those without mycorrhizal treatment-each replicated three times.The distance between experimental plots was 1 m and the distance between replications (groups) was also 1 m.Soybean seeds were planted individually with 40 cm x 20 cm.The mycorrhizal application was carried out at the same time as planting at a dose of 10 grams per plant.SP-36 fertilization at a dose of 100 kg ha -1 , urea fertilization at a dose of 100 kg ha -1 , and KCl fertilization at a dose of 150 kg ha -1 .

Observed parameters
The parameters observed in this research include soybean plant height, number of leaves, weight of pods per plant, dry seed weight per plot, and ha.Parameters of soil chemical properties observed included levels of N-total, C-organic, organic matter, P-total, and P-available.

Statistical analysis
Observation data were analyzed using variance analysis of variance based on Randomized Block Design with a significance of 0.05.If the results of the data analysis are significant, then continue by testing the differences between treatments with the LSD test of 0.05.

Plant height
Results of analysis of soybean plant height growth 8 weeks after planting showed that the AMF application treatment had a real effect, while the treatment for differences in planting locations was not significant.The average plant height in Table 1 shows that the mycorrhizal application treatment obtained the tallest plant, namely 42.58 cm, and was significantly different from the plant height obtained in the treatment without mycorrhizal application, namely a plant height of 35.58 cm.Note: -The average value followed by the same letter is not significantly different based on the LSD test at the 0.05 level ; G: Galesong Sub-District ; GS: South Galesong Sub-District

Number of leaves
The number of leaves on soybean plants aged 8 weeks after planting showed that plants treated with mycorrhiza had a greater number of leaves, namely 23.92 leaves compared to the number of leaves obtained on plants no mycorrhiza treatment (Table 2).Tables 1 and 2 show that giving mycorrhiza has a good effect on plant growth, indicated by the plants being much taller and having more leaves than without giving mycorrhiza.The results of this study are similar to the findings of [20] which found that the application of mycorrhiza had an influence on the growth of soybean plants.Arbuscular mycorrhiza infects the root system of the host plant by producing an intensive network of hyphae, so that plants in symbiosis with mycorrhiza are able to increase their capacity to absorb nutrients and water.This condition allows plants that are in symbiosis with mycorrhiza to grow better than plants that are not in symbiosis with mycorrhiza.[21] further stated that root infection by AMF causes changes in plant root activity with the formation of external hyphae which cause increased nutrient and water uptake.

Pod weight
The average pod weight per plant is influenced by differences in planting location and mycorrhiza application.Table 3 shows that soybean plants planted in rainfed rice fields in Galesong and South Galesong Districts produce pods that are much heavier, namely 27.52 g -30.18 g/plant compared to those planted in dry land.The results of the analysis also showed that the application of mycorrhiza resulted in a weight of soybean pods that was significantly heavier than the weight of soybean pods no application of mycorrhizae.Note: -The average value followed by the same letter in the same row and the same column are not significantly different based on the LSD test at the 0.05 level ; G: Galesong Sub-District ; GS: South Galesong Sub-District

Dry seed weight per plot
The dry weight of seeds per plot is influenced by differences in planting agroecosystems.Table 4 shows that planting in rainfed rice fields in the Galesong area resulted in a significantly heavier seed weight, namely 195.21 grams compared to the seed weight obtained in dry land in both Galesong and South Galesong.The mycorrhizal application treatment showed that plants that were applied mycorrhizae produced significantly more seeds, namely 166.71 g/plot compared to those without mycorrhizal application.Note:-The average value followed by the same letter in the same row and the same column are not significantly different based on the LSD test at the 0.05 level ; G: Galesong Sub-District ; GS: South Galesong Sub-District Tables 3 and 4 show that soybean cultivation is influenced by the location of the agroecosystem used, where soybean plants planted in rainfed lowlands show greater pod weight and seed weight.These findings are similar to those reported by [22] who stated that there were differences in the growth of soybean varieties planted in rainfed rice fields and dry fields.Likewise, the results of research [23] found differences in the growth and production of chilies planted in various locations in the highlands of West Java.Differences in plant growth and production from the two different agroecosystems are caused by differences in environmental factors which will influence metabolic activity and ultimately affect plant appearance.Therefore, the development of soybean cultivation is directed at suitability to growing environmental factors.The high production of soybeans in rainfed lowland is also caused by differences in soil fertility as seen in Table 6, where the total N-nutrient content of soil in rainfed lowland areas includes moderate nutrient status, available P content is 12.83-13.55ppm or status low, as well as low C-organic status.Meanwhile, dry land, especially the Galesong dry land, shows a high total N content, namely 0.59%, but the available organic P and C levels are very low.This means that there is no balance of nutrients in the soil, especially the balance between nitrogen and phosphorus.High N nutrient status without being balanced with P nutrient levels will stimulate dominant vegetative growth and inhibit the plant production phase [24].Likewise, research conducted by [25] found that soybean growth and production were greatly influenced by the balance between nitrogen dan phosphour.

Dry seed weight per hectare
The average dry seed weight per hectare in Table 5 shows that planting soybeans in rainfed rice fields in both Galesong and South Galesong produces heavier dry seeds, namely 2.15-2.40t/ha, and this is significantly different from the weight seed.obtained from plants in dry land.Likewise, the application of mycorrhizal fungi gave a much higher yield, namely 2.11 t/ha compared to without mycorrhizal application which only produced 1.73 t/ha of seeds.This means that the application of mycorrhiza increases soybean yields up to 22% higher than without the application of mycorrhiza.The real influence of AMF on plant growth and production is caused by the ability of mycorrhiza to increase root surface area so that nutrient absorption can be maximized (26).Increasing the availability of nutrients and water needed by plants allows maximum plant growth and ultimately high production will be obtained.[27] reported that increased faba bean crop production was associated with increased nutrient availability due to biofertilizer inoculation.The results of this research also show that soybean production in dry IOP Publishing doi:10.1088/1755-1315/1302/1/0120396 land is lower than soybean production in rainfed rice fields.The low production of soybeans in dry land compared to rainfed rice fields is due to the fact that soybean cultivation in dry land is faced with various biophysical constraints such as limited water availability, nutrient poor, and low soil organic matter content.As research conducted by [28] concluded that the low production of soybeans in dry land was due to soybean plants often experiencing drought during the pod formation and seed filling phases.Note: -The average value followed by the same letter in the same row and the same column are not significantly different based on the LSD test at the 0.05 level ; G: Galesong Sub-District ; GS: South Galesong Sub-District

Soil chemical properties
The results of the analysis of soil chemical properties presented in Table 6 show that the N-total nutrient content of the soil in rainfed lowland is 0.24-0.29%or medium nutrient status.levels of available Pavailable 12.83-13.55ppm or low status, and levels of C-organic with low status.Meanwhile, on dryland, especially on dryland, Galesong showed a high total N content of 0.59%, but the levels of available P and available organic C were very low.

Conclusions
Soybean cultivation in rainfed lowland areas results in higher soybean production than in dryland.Mycorrhizal application resulted in higher soybean growth and production of 2.11 tons/ha or 22% higher than without mycorrhizal application.

Table 1 .
The average of soybean plant height (cm) at 8 week after planting at various of planting location and mycorrhizae application.

Table 2 .
Average number of leaves of soybean plants with mycorrhiza application at various planting locations.The average value followed by the same letter is not significantly different based on the LSD test at the 0.05 level ; G: Galesong Sub-District ; GS: South Galesong Sub-District

Table 3 .
The average of soybean pod weight (g/plant) at various planting locations and mycorrhizae applications.

Table 4 .
The average dry soybean seed weight per plot (g/plot) at various planting locations with mycorrhizal application.

Table 5 .
Average weight of dry soybean seeds per ha (tons/ha) at various planting locations and mycorrhiza applications.

Table 6 .
Soil chemical properties in several research sites.