**1. Introduction**

South Sulawesi is one of the soybean development centers with a land potential of around 586,492 ha. The average soybean production achieved in South Sulawesi ranges from 1.10 to 1.50 t/ha [1]. This production is still much lower than the potential that is often achieved from research results of 2.0–3.0 t/ha [2]. The low production was due, among other things, to high pest attacks and the use of fertilizers that had not been optimal.

In the cultivation of soybeans in paddy fields after rice, the timeliness of planting greatly determines the success of farming because of the limited time for land preparation. Soybean planting is immediately carried out 2–4 days after rice harvesting with a no-tillage system (zero tillage) because it is associated with soil moisture conditions, in addition to saving energy and production costs. To produce well, soybean crops need to be irrigated 3–4 times, water can come from irrigation networks and groundwater with a pumping system.

According to the Report of the Indonesian Horticultural and Food Crop Protection Agency [3], the area of attack by pod borers, pod suckers, and armyworms for 5 years ranging from 7182 ha. The main pest attack rate on soybeans in 2008 was around 15–35% [4]. Furthermore, the results of research by Fattah and Hamka [5], conducted in Panincong Village (soybean development center in South Sulawesi), the intensity of pod borer attacks (9.59–13.16%), the intensity of pod suckers (6.17–22.55%), and armyworm intensity (8.61–17.26%). Control efforts carried out by farmers generally use insecticides with high doses and a spraying frequency of 1–2 per week. The use of these chemical pesticides has impacts including (1) polluting the environment including pesticide residues, (2) poisoning humans and animals, (3) killing natural enemies and other useful organisms such as bees which are plant pollinators, (4) creating new pests strains that are resistant to pesticides, (5) causing pest resurgence or an increase in pest populations after excessive application of pesticides. To avoid the negative effects of the use of chemical pesticides, the main soybean pest control is directed to the use of bio-pesticides or insecticides.

Biopesticides or insecticides from plant materials are not something new but have been used by farmers for a long time, even at the same time as agriculture itself was born. Farmers in Indonesia are already using vegetable materials as pesticides, including using soursop leaves to control locust pests and rice stem borers. Meanwhile, farmers in India use neem seeds as an insecticide to control insect pests. In addition to vegetable materials which are widely used by farmers as vegetable insecticides, the use of biopesticides is also used, such as the use of NVP from armyworms.

This book is structured to provide information on environmentally friendly soybean cultivation technologies including the use of crop residues such as straw as organic fertilizers and also to provide information about the importance of using natural ingredients in pest control and the use of biopesticides in soybean farming systems carried out by farmers in South Sulawesi.

### **2. Technology of soybean cultivation at the farmer level**

#### **2.1 How to process land**

Farmers in South Sulawesi generally plant soybeans in rainfed lowland areas with no-tillage systems. Planting soybeans after rice in rainfed lowlands with a notillage system (TOT) has several advantages such as; saving costs, energy, and time. Conversely, if the rainfed lowland paddy field is perfectly processed (OTS), it will be less profitable due to a delay in planting time, in addition to the land losing water because the soil surface is open. Other benefits obtained from soybean planting with a non-tillage system in paddy fields can break the pest cycle, use the remaining fertilizer that is still left in the soil, and make the remaining soybean plants green fertilizers [6].

*Soybean Cultivation Technology Innovation and Environmentally Friendly Pest Control in Paddy… DOI: http://dx.doi.org/10.5772/intechopen.109897*

Rice field preparation is crucial so that soybeans grow and produce well. There are two kinds of rice harvesting models, namely those that harvest rice manually (human labor) and those using a Combine Harvester. The two methods of harvesting cause differences in straw residue in paddy fields.

### *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

#### **Figure 1.**

*Rice field that has been cut with straw: (a) spraying herbicides, (b) making canals with a hoe, and (c) making canals using a hand tractor.*

**Figure 2.**

*Former rice plantations were then planted with soybeans: (a) straw stalks, (b) soybean plants mixed with rice stalks, and (c) soybean growth after the rice stalks were removed.*

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.


#### **Table 1.**

*Growth and yield of soybean seeds in the complete tillage and zero tillage systems in South Sulawesi. Indonesia. 2015.*

*Soybean Cultivation Technology Innovation and Environmentally Friendly Pest Control in Paddy… DOI: http://dx.doi.org/10.5772/intechopen.109897*
