Soybean Cultivation Technology Innovation and Environmentally Friendly Pest Control in Paddy Fields in South Sulawesi, Indonesia

2.1.1 Land preparation in paddy fields whose solids are harvested manually, using human power

Planting soybeans in paddy fields harvested by paddy using a manual scythe, the rice stems are cut off at the base of the rice stems so that they do not separate the rice stalks that stand on the paddy fields making it easier to grow soybeans (Figure 1a). In a non-tillage system to kill grass in paddy fields, farmers use herbicides both contact and systemic. Contact herbicides that are widely used by farmers are herbicides with active ingredients of paraquat dichloride. This herbicide is a full-grown herbicide to control weeds in rainfed lowland fields, while a systemic herbicide that is widely used by farmers is an active ingredient of isopropyl amine glyphosate (Roundup Max 660 SL). Herbicide spraying was carried out on paddy fields.

Rice that has been harvested and straw stumps are cut about 20–30 cm from the ground which aims to prevent the growth of new shoots and facilitate the planting of soybeans. In addition, it also functions to block the seeds of pea fly pests from laying eggs on pieces of seeds so that the dead and attacked plants become reduced. Because soybeans are not resistant to drought and waterlogging, a drainage canal is needed before planting with a distance of 3–5 m and a depth of 20–30 cm. This channel beside flowing water so that it is not flooded also functions for irrigation if the plants experience drought, especially if irrigation water is available. The straw which is still present in paddy fields should be spread over the surface of the land (Figure 1b). The results of research in Indonesia show that soybean yields that are planted after paddy fields without tillage are better than those with perfectly cultivated soil because perfectly treated soils can cause evaporation so groundwater supplies are not sufficient for plant growth. In addition, perfect soil processing can cause delays in planting time so that the plants will experience drought in the stage of development and filling of seeds, especially in the dry season. Planting soybeans immediately after harvesting rice, at which time the rainfall has been reduced but still enough for soybean growth [6].

The harvesting system uses Combine Harvester to separate pieces of straw which are about 50–75 cm high so that when planted directly soybeans will be disrupted. In rice fields that are still high in the hay, farmers use two ways to prepare soybeans, namely, some farmers cut back the straw to the base of the stem and some farmers do not cut the straw again but immediately sprayed the herbicide 2–3 times until the straws die and dry like Figure 2a. The advantages of soybean plants that are planted between rice stalks are not attacked by peanut fly pests. This is probably caused by the imago of the bean fly being blocked by rice stems when they want to lay their eggs on soybean cotyledons. Another advantage of soybean plants planted between rice straws is straw stems that have been extracted and then immersed in the soil so that the soil becomes fertile and the soybean grows fertile as shown in Figure 2b and c.

The way farmers grow soybeans in paddy fields with this system can create an environmentally friendly organic farming system because all the remaining rice straw stems are immersed in organic fertilizer. This makes farmers not use chemical fertilizers in their farming systems, moreover, the land used for planting is still fertile because it contains a lot of fertilizer from residues during fertilization in the rice planting period.

Soybean cultivation techniques that are appropriate after paddy is without tillage (TOT), also known as “zero tillage”. This technology is appropriately developed in anticipation of the limited workforce in South Sulawesi and at the same time utilizes the remaining availability of groundwater at the time of rice harvesting, especially in areas with simple irrigation or rainfed rice fields. Components of growth and seed yield in soybeans grown with a system without tillage are better than those with perfect tillage systems (Table 1). Components of growth such as plant height, number of branches, number of pods, and seed yields were significantly different between systems without tillage with tillage systems. Weaknesses in a perfect tillage system will result in a delay in planting time, so that in areas with a short period of rain it will cause plants to lack water, the plants will experience drought, and seed yield will decrease.

2.1.2 Land preparation using perfect tillage carried out by farmers

The process of harvesting rice in paddy fields using combine generally compacts the soil, making it difficult to plant soybeans using the zero tillage method. To fertilize their land, some farmers use tractors. The use of 4-wheel tractors for tillage is only carried out by farmers who have a lot of farming costs. This is because the cost of cultivating the land using a 4-wheel tractor costs Rp. 1,350,000 per hectare. Meanwhile, planting soybeans using the zero tillage method only costs around IDR 450,000–600,000 per hectare.

2.4.1 Application of organic fertilizer from straw fermentation

Composting straw increases the levels of macro and micronutrients, especially Phosphorus (P2O5) and Potassium (K2O), as well as Magnesium (Mg) and Potassium (K) (Table 1). The main nutrient elements that need to be added to fertilizing cocoa plants include Nitrogen, Phosphorus, Potassium, and Magnesium [8] (Figure 6).

The results of soil analysis after immersion of rice straw into the soil and fertilization showed an increase in the percentage of clay mass in the soil. After most of the material has decomposed in the composting process, the temperature will gradually decrease, and at this time advanced compost maturation occurs, namely the formation of a humus clay complex [9].

2.4.2 Application of liquid organic fertilizer from cow urine (Biourin)

This ceremony uses the means of plant destruction as a vegetable pesticide. However, this is forgotten by subak member farmers in Bali [10]. Biourine is a liquid organic fertilizer derived from the urine of fermented livestock. Fermentation technology is used in processing cow urine into bio urine. This process can cause changes in the properties of materials into simpler molecules so that they are easily absorbed by plants. Based on research conducted by Sutari [11], there was an increase in macronutrient content, micronutrients, and pH in the urine of cattle that had been fermented into bio urine. Cow bio urine can improve plant growth because, cow urine contains elements of N (0.36%), P2O5 (5.589 mg/l), K2O (975.0 mg/l), Ca (25.5 mg/l). and C-organic (0.706%) [12]. Besides that, cow bio urine can improve the physical properties of the soil because beef bio urine is fermented using Azotobacter and Bacillus sp. Biourine contains the hormone Indo Acetate Acid (IAA) of 1197.6 mg/l, while the urine of fresh cattle containing IAA is only 704.26 mg/l. IAA hormone functions as the main auxin in plants [11].

MOL (local micro-organisms) can function as decomposers and also as liquid organic fertilizer. According to Septiana et al. [13], plant residues such as kale, spinach, mustard greens, cabbage, and bamboo shoots can be made into liquid organic fertilizer by adding a biocatalyst. The addition of 60 ml of the biocatalyst is very good for increasing the phosphorus content to 79.26 ppm in the manufacture of liquid organic fertilizer from mustard greens and spinach waste. Baharuddin [14], agricultural waste such as municipal waste, straw, corn waste, sugarcane waste, and livestock manure can be processed using biotechnology to produce liquid organic fertilizer/MOL and biopesticides. The results of research by Suhera et al. [15], microbes as a type of MOL are quite effective for increasing the weathering process in plant residues. Giving Microbat 20% can inhibit Phytophthora palmivora by about 50%. Furthermore, it was said that giving Microbat 10% could accelerate weathering (92%) compared to using EM-4 10% (75%). Giving 10 cc/l of Microbat water can increase potato production 30–45% (Figure 7).

According to Widhiastuti et al. [16], some other agricultural wastes are good enough to make liquid organic fertilizers such as palm oil mill waste as soil biodiversity fertilizer. The waste can function as organic fertilizer by increasing the physical, chemical, and biodiversity properties of the soil, and increasing the total soil bacteria.

2.5.1 Spodoptera litura armyworm pest

The pests that attack soybeans in the districts of Maros, Pangkep, Wajo, and Soppeng are armyworms with varying intensities. The intensity of each variety is different. The highest attack intensity of armyworm attacks was found in Detam-2 (16.24%) and Gema (16.29%) varieties in Wajo District and the lowest in Grobogan (10.38%) and Argomulyo (11.25%) varieties, while in The highest attack rate of armyworm pests in Maros was the Burangrang variety (15.26%) and the lowest was the Grobogan variety (9.87%) (Figure 8) [17].

Spodoptera litura is an important pest that damages soybean leaves compared to other leaf-damaging pests [18]. Yield losses due to Spodoptera litura pest attacks can reach 80%, even puso if not controlled [19]. The rate of yield loss depends on the variety used, the growth phase, and the time of attack [18]. Spodoptera litura is known as a polyphagous pest and migratory insect which causes serious damage to soybean crops (Table 2) [20].

2.6.1 Use of botanical insecticides

Botanical pesticides are pesticides that are produced from plant parts. Several types of plants can be used as vegetable pesticides: Srikaya seeds (annonacin) which are stomach poison and contact to control aphids, jicama (pchyrrhizid) to control (Plutella zinckenella), tuba roots (Derris), Lantana cedar (salira), Fragrant Lemongrass (Andopogon), Patchouli (Pogostemon cabilin), Clove (Euginia sygium), Neem (Azadirachta indica), tobacco leaves and pork nuts (Kphrosia candida). Of all these vegetable ingredients, pork and neem nuts have the highest ability and are almost comparable to carbaryl insecticides in controlling weevil pests [22].

Neem extract should be sprayed at an early stage of insect development, sprayed on the leaves, and sprinkled on the roots so that it can be absorbed by plants and control insects in the soil [23]. Furthermore, it was said that 50 g of neem seed extract was dissolved in 1 liter of water and added 0.5 ml/l grading agent effectively suppressed mite populations on sweet potatoes with a mortality of 70%. neem 50 g/l water can reduce yield loss of Maruca testulalis by 13–45%. The results of research by Sukorini [24], the application of vegetable pesticides from amethyst leaves gives the lowest attack intensity (0.53–0.89%) and the highest on butrowali plants (1.02–1.94%) in cabbage plants clove leaves contain eugenol between 70 and 95% which can kill microorganisms such as Bacillus subtillis, Staphylococcus aureus, and Escherichia coli. In addition, eugenol can also kill or suppress the development of plant pathogens such as Fusarium oxyspora, Phytopthora capsici, Rhizoctonia solani, and Sclerotium rolfii [25].

Based on their origin, biopesticides are divided into two: Botanical pesticides, which are extracts from certain parts of plants, including leaves, fruit, seeds, and roots, which have toxic properties against certain pests and diseases. Botanical pesticides are generally used to control pests (insecticides) and diseases (bactericidal or fungicide). Several types of plants are capable of controlling pests such as the Meliaceae family (Neem) and the Anonaeceae family (Srikaya seeds and Soursop seeds). The results Indiati, S.W. dan Marwoto [26] that the use of castor seed extract (Ricinus communis) as a vegetable antifertility ingredient in field rats with 2 ml/100 g of rat body weight/day given for 5 days, causes infertility in female field rats and has the effect of reducing 64.2–90.70% active sperm temperature in male rats compared to controls. The results of Balitsa Lembang research [27], several types of plants that can be used as vegetable pesticides: sugar apple seeds (annonain) which are stomach and contact poisons for controlling aphis, yam seeds (pchyrrhizid) for controlling (P. zinckenella), tuba roots (Derris), Cypress lantana (salira), Fragrant citronella (Andopogon), patchouli (Pogostemon cabilin), cloves (Euginia sygium), neem (Azadirachta indica), tobacco leaves and pork nuts (Kphrosia candida). Of all these vegetable ingredients, pig beans and neem have the highest ability and are almost comparable to carbaryl insecticides in controlling weevils [27].

According to Thamrin et al. [28], extract from the bark of kapayang (Pangium edule) can kill the puith stem borer (Scipopaga innotata) around 80% after application, while controls using synthetic insecticides (BPMC) have a mortality of around 100%. Furthermore, it is said that rose, papaya, jengkol, lemongrass, noni, pepper, and gadung plants can kill caterpillars (Plutella xylostella) around 65–100%. The use of kedondong leaf extract can kill Plusia sp. larvae around 26.7% at 36 hours after infestation (jsi), 66.7% at 48 hrs, and 77.0% at 72 hrs, while the control (chlorpyrifos (control) kills 83, 3% at 36 jsi, 100% at 48 isi. Similarly, Luwa leaf extract (Ficus glomerata) can kill plutella caterpillar plants (Plutella sp) by about 70%, parang red beans, green severe beans, and soursop are quite effective in killing pariah fruit caterpillars by about 75–80%. Betel leaf contains saponins, flavonoids, and polyphenols, while galangal rhizome contains benzyl benzoate, −methoxycinamal and xanthorhizal which can be used to control neck disease in rice (Pyricularia oryzae), and leaf spot disease in peanuts.

Neem (Azadirachta indica) contains the active compounds azadirachtin, meliantriol, and salanin. It is in the form of powder from leaves or liquid oil from seeds/fruit. Effectively prevents eating (antifeedant) for insects and prevents insects from approaching plants (repellent) and is systemic. Neem can make insects sterile because it can interfere with hormone production and insect growth. Neem has a spectrum effective for controlling soft-bodied insects (200 species), including grasshoppers, thrips, caterpillars, white butterflies, etc. Besides that, it can also be used to control fungi (fungicides) at a preventive stage, causing fungal spores to fail to germinate. Controlled fungi include powdery mildew, rot, leaf smallpox/scab, leaf rust, and leaf spot. And prevent bacteria in powdery mildew (powdery mildew). Neem extract should be sprayed at an early stage of insect development, sprayed on the leaves, and sprinkled on the roots so that it can be absorbed by plants and control insects in the soil.

Tuba root (Deris eliptica) is a compound that has been found, including rotenon. Rotenone can be extracted using ether/acetone to produce 2–4% rotenone resin, made into water concentrate. Rotenon works as a very strong cell poison (insecticide) and as an antifeedant that causes insects to stop eating. Insect death occurs several hours to several days after rotenone exposure. Rotenone can be mixed with pyrethrin/sulfur. Rotenone is a broad-spectrum (non-systemic) contact poison and a stomach poison. Rotenone can be used as a molluscicide (for mollusks), insecticide (for insects), and acaricide (for mites).

Rotenone can be used as a molluscicide (for mollusks), insecticide (for insects), and acaricide (for mites).

The compound tobacco contains is nicotine. It turns out that nicotine is not only toxic to humans but can also be used to poison insects. Dry tobacco leaves contain 2–8% nicotine. Nicotine is a fast-acting nerve poison. Nicotine acts as a contact poison for insects such as caterpillars that destroy leaves, aphids, triphs, and control fungi (fungicides).

In addition to being able to kill plant-disturbing insects, vegetable insecticides can also function as (1) Reference, which repels the presence of insects mainly due to their smell or the substances they contain, (2) Antifidants, causing insects to dislike plants, for example, because they taste bad, (3) Preventing insects from laying eggs and inhibiting the process of hatching eggs, (4) Poisons that can interfere with the nervous system and insect hormones, and (5) Attractants, as attractants for the presence of insects that can be used as a trap plant. Natural ingredients that contain bioactive compounds can be classified into three, namely (1) natural ingredients containing anti-phytopathogenic compounds (agricultural antibiotics), (2) natural ingredients containing compounds that are phytotoxins and plant growth regulators (phytotoxins, plant hormones, and the like) and natural ingredients containing compounds that are active against insects (insect hormones, pheromones, anti-oxidants, repellents, attractants, and insecticides that poison plants) (Figure 9).

2.6.2 Use of pathogens

SlNPV propagation was carried out by taking several armyworms instars 4 and 5 which died naturally due to virus infection in soybean plantations with the characteristics of the caterpillars being elongated/expanding, not shrinking when massaged emitting a foul-smelling liquid, and sometimes hanging on the lower surface of the leaves. The armyworm then made an emulsion using sterile aqua dest. The armyworm NPV emulsion was then diluted with sterile aqua dest and rubbed on the surface of the mulberry leaves. The caterpillars were kept until they died. After death, the armyworms were collected, extracted, mixed with distilled water, and then filtered using nylon gauze to obtain a pure coarse polyhedra suspension. According to Bedjo [29], the use of SLNPV (Spodoptera liture Nuclear Polyhedrosis Virus) 150–200 g/ha can kill around 80–100% of the S liture armyworm. S LNPV multiplies in its host’s cells, so the transmission is through food. Symptoms of SLNPV transmission in armyworms appear 1–3 days after application. Instar-1 caterpillars infected with SLNPV will look milky white. Symptoms in instar caterpillars 3 and 4 will appear brownish white on the abdomen (abdomen), while on the back it is blackish milk brown. If the 5th and 6th instar caterpillars are infected with SLNPV, then at the pupal stage they will rot. In caterpillars that are infected with the SLNPV virus, their feeding activity is reduced, movement is slow, and the body swells due to the replication or multiplication of SLNPV virus particles. The caterpillar’s integument usually becomes soft and brittle and easily torn. If the body of the caterpillar is broken, it will emit a very pungent odor. The death of caterpillars infected with this virus in the field is characterized by symptoms of the bodies of the larvae hanging or clinging to leaves or twigs of plants. Armyworm death usually occurs 3–7 days after contracting the virus. Furthermore, Sanjaya et al. [30], stated that a dose of 438 PIB/ml SINPV is sufficient. Effective for killing Instar-5 larvae in armyworms.

Biological pesticides are formulations that contain certain microbes in the form of bacteria, fungi, or viruses that are antagonistic to other microbes (causing plant diseases) or produce certain compounds that are toxic to both insects and nematodes. Some examples of biological insecticides include: (1) Nuclear polyhedrosis virus (NPV), (2) Beuveria bassiana (sunflower isolate) which is capable of controlling noncong beetles, the main pest of orchids and ticks on chrysanthemum plants, (3) Bio-PF contains Pf to control wilt, (4) Bio-GL contains (Gliodadium spp) to control soil-borne diseases, and (5) Prima—BAPF contains Bacillus spp. to control root swelling, wilt disease and root rot [31]. To distinguish between armyworms that die due to virus infection and pesticide poisoning in the field, it can be seen the characteristics and differences that arise, namely the death of caterpillars affected by the virus, they tend to elongate or not shrink, whereas if they die from pesticides, they tend to shrink. Larvae that die from the virus, when they are massaged or pricked, tear easily and secrete mucus like pus which smells bad, while caterpillars that are exposed to pesticides do not smell bad [32].

The results of laboratory experiments show that NPV has a high biotic potential, indicated by its level of pathogenicity which is expressed by the LC50 value (the concentration that kills 50% of the population). The LC50SlNPV for the armyworm was 5.4 × 103 polyhedra inclusion bodies (PIBs)/ml [33], while for the pod-eating caterpillar, it was 6 × 103 PIBs/ml [34]. The NPV infection process begins with the ingestion of the polyhedra by the caterpillar with the feed. In the digestive tract, which is alkaline (pH 9.0–10.5), the polyhedra coat dissolves, freeing the virions. Virions penetrate the wall of the digestive tract to enter the body cavity, then infect susceptible cells. Virion replication occurs in the cell nucleus. Within 1–2 days after the polyhedra are ingested, the hemolymph which was originally clear turns cloudy. The caterpillar looks greasy, accompanied by swollen integumentary membranes and changes in body color to pale-reddish, especially on the stomach. Its ability to eat decreases, so its growth is slow. The caterpillar tends to crawl to the top of the plant and then dies hanging upside down with the pseudo limbs at the end of the plant. The integument of the dead caterpillar undergoes lysis and disintegration, making it very fragile. Polyhedra. Young caterpillars (instars l-lll) die within 2 days, while old caterpillars (instars IV-VI) in 4–9 days after the polyhedra are ingested [35].

Considering that it is susceptible to sun exposure, especially ultra-violet rays, and the behavior of caterpillars that are active in the evening and at night [36].

The Nuclear Polyhedrosis Virus (NPV) bioinsecticide is one type of pathogenic virus that has the potential as a biological agent in controlling armyworms because it is specific, selective, effective for pests that are resistant to insecticides, and safe for the environment. NPV has been developed in vivo in the Balitkabi laboratory, for biological control of Lepidoptera pests. As a bioinsecticide, the virus can control target insect pests precisely because it is specific, has a fairly high killing ability, is relatively inexpensive, and does not pollute the environment. The results of NPV engineering with carrier materials can maintain NPV virulence so that it can suppress armyworm populations on soybean plants in the field by up to 90% [29] (Figure 10).

To distinguish between armyworms that die due to virus infection and pesticide poisoning in the field, it can be seen the characteristics and differences that arise, namely the death of caterpillars affected by the virus, they tend to elongate or not shrink, whereas if they die from pesticides, they tend to shrink. Larvae that die from the virus, when they are massaged or pricked, tear easily and secrete mucus like pus which smells really bad, while caterpillars that are exposed to pesticides do not smell bad [32]. NPV application should be done in the afternoon or evening under favorable weather conditions, considering that it is susceptible to sun exposure, especially ultra-violet rays, and the behavior of caterpillars that are active in the evening and at night [36]. The results of other studies regarding the use of NPV to control armyworms in rice can cause 53% mortality at 3 days after inoculation and 95% at 9 days after inoculation [37].