INTRODUCTION
Soybean [Glycine max (L.) Merrill] is one of the most important oilseed crops in the world. It contains 18 to 22 percent oil and is highly desirable in the diet and have 40 to 42 percent of good quality protein. Therefore, it is the best source of protein and oil and truly claim the title of the meat/oil that grows on plants. Generally, it is used in the food industry for flour, oil, margarine, cookies, biscuit, candy, milk, vegetable cheese, lecithin and many other products. At present, the United States of America has the largest area under its cultivation. Soybean is also grown in other parts of the world including Brazil, Peoples Republic of China, Argentina, Indonesia, Korea and Japan. In Pakistan, soybean has suffered a setback and has therefore, not been able to attain a respectable position among the oilseed crops. Its cultivation remained limited to a very small acreage and showed a declining trend.
Potential Areas:
Expansion of the area of soybean in those parts of the region which are idle or not used at certain seasons of the year could produce soybean in the country. Thus, there is a large scope to increase the area under this crop
– Dobari lands in Sindh and the area of Punjab which often lie idle between two summer crops of rice from September/October to May every year for one or the other reason.
– Cotton fallow areas where no crop is grown between two crops of cotton from December to May.
– Riverine lands which are flooded during summer from June to September but are dry during the winter from November to May.
– Dry land (barani) areas which are available in part of summer during the monsoon when moisture is abundant and most of the land is left fallow for wheat sowing in November. This land is available from June to October.
– Area under fall (septemberber) and spring (March) planted sugarcane is available for intercropping of soybean because short season soybean grow without affecting slow growing sugarcane plants.
Proposed Cropping Pattern:
Soybean has a vast potential as Spring (Zaid Rabi) and Autumn (Kharif) crop cultivation. Throughout the country cotton and rice 8.4 and 2.10 million hectares, respectively and 30 percent of this area remains fallow after each crop which could be brought under soybean plantation. The results of past research revealed that soybean can give reasonable yield in Punjab, Sindh and high yield in the foothill areas of NWFP. In addition, soybean also improve the soil status for ensuring crops of cotton and rice in the irrigated areas of Punjab and Sindh. Soybean is a very successful crop both in irrigated and rainfed areas without clashing any major crop like rice, cotton and wheat. Thus, the area which remains fallow can be utilized effectively.
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Rice Soybean Rice
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Cotton Soybean Cotton
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Wheat Soybean Wheat
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Wheat-Sorghum / Millet-Fallow-Soybean-Wheat
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Intercropping soybeans with corn, sorghum, cotton, or sugarcane
PRODUCTION TECHNOLOGY:
For obtaining potential yield of soybean following recommendations have been made on the basis of results of experiments conducted by NARC scientists.
CLIMATIC REQUIREMENTS
Temperature: Soybean can be grown successfully under a wide range of temperatures. The minimum and maximum soil temperatures for germination of soybean seeds are approximately 5 oC and 40 oC. Irrigations (depending upon rains).oC, respectively. The optimum temperature for rapid vegetative growth rate is about 30oC whereas, temperature above 40oC has adverse effect on flower initiation and pod retention.
Moisture: Moisture availability is particularly critical during two periods of soybean germination and pod filling. However, availability of adequate moisture during the pod filling period is critical. Water stress during floral initiation, pollination, and seed development may greatly reduce the seed yield significantly.
Photoperiod: Latitude and time of year (sun declination) are the determents of photoperiod and temperature. Soybean is short day plant (SDP) where flowering is promoted by day length shorter than a critical maximum varies among varieties. Actual controlling factor is the length of uninterrupted darkness or nyctoperiod. Photo periodically sensitive varieties of soybean are adapted to a narrow latitude range (200-250 km).
SOIL AND FERTILIZER REQUIREMENTS:
Soil: Soybean can be grown on almost all well-drained soils, however, crop is more productive on fertile loam soils. Soybean is not sensitive to acidic soils as many other legumes. Soil with pH 6-7 is suitable for crop growth. In this pH range, adequate calcium and magnesium are normally available. For efficient production, soil must be managed properly to allow optimum uptake of water and nutrients.
Fertilizer: Fertilizer application is important in the soybean production and has great effect on yield. Usually 25:50:50 (NPK) kg ha-1 at the time of sowing gives higher yields. Fertilizers are usually broadcasted during seed-bed preparation. Under conditions fertilizer dose may vary according to the soil fertility and status. Soybean in rotation with other crops (i.e. cotton, rice and wheat) often provide some nitrogen for the following crops and may reduce the need for pesticides by limiting certain disease or insect problems.
Adding N fertilizer to soybeans usually decreases nodulation and results in smaller amounts of N being symbiotically fixed. Therefore, nitrogen is recommended only when adequate nodulation is not achieved. However, supplemental N should not be applied within 30 days of emergence but should be applied before flowering, which is usually early March to spring crop and late July to autumn crop depending on maturity group of a variety.
Seed-bed Preparation: Two to three ploughings followed by plankings are sufficient to get proper tilth. This will improve moisture conservation of the soil which is required for soil-seed interaction, good seed germination, emergence, growth and development.
Seed Inoculum: The nitrogen fixing bacteria (Rhizobia) that lives on soybean roots in nodules are not native to most soils. The best way to introduce this bacteria is to inoculate the seed. Once, introduced, the rhizobia population remains active in the soil for a long time. In the presence of the appropriate inoculant ofRhizobium japonicum, more nodules are formed on roots of soybean plant which can fix atmospheric nitrogen from the air that is almost as effective as nitrogen applied as fertilizer to promote growth and development of the plant.
Method of Inoculation: Inoculum is a black powder containing nitrogen fixing bacteria which are mixed with ground peat or some similar carrier and applied on seed just before planting time. Seeds are moistened with concentrated sugar solution, inoculant is applied @ 1250 gm per 100 kg seeds and then mixed thoroughly to have a uniform coating of inoculum on the seeds. This process should be done in shady place. The use of fungicide in case of seed treatment, may interfere with inoculated seed and with symbioses of Rhizobium-soybean system. Thus, compatible fungicides (i.e. Benlate and Dithane Z-78 (Zineb) with no toxicity to Rhizobia should be used. Treat seed immediately before planting and use inoculum dose little higher than recommended.
Varieties: Different soybean varieties of American origin were selected afterconducting a large number of trials. These varieties are NARC-1, NARC-2, Ajmeri, FS-85, Malakand-96, Swat-84 and Kharif-93 have been developed by the scientists of Oilseed Programme, NARC, Islamabad and their provincial counter parts.
Planting Time: Variation in yield loss due to delay in the planting is the result of variation in weather and its influence on disease, plant height, flower abortion, amount of vegetative growth, etc. Therefore, planting date is considered to be the one of the important factor for maximum crop yield. Late planting may result in significant decrease in seed yield. The optimum planting time for different areas along with suitable varieties is presented below.
Time of planting and suitable soybean varieties for different areas during autumn and spring seasons
| Province | Time of planting | Suitable Varieties |
| (Autumn Crop) | ||
| PUNJAB | ||
| RainfedArea | 1st week of July |
NARC-1, NARC-2,Williams-82, FS-85 |
| Irrigated Area | Mid July to Mid Aug | NARC-1, NARC-2,Williams-82 |
| Sindh | ||
| South | June | NARC-1, NARC-2, Williams-82 |
| North | Mid June to Mid July | |
| May to June | Malakand-96, Ajmeri and Kharif-93 | |
| NWFP | ||
| (Spring Crop) | ||
| PUNJAB | ||
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Irrigated Area |
Last week of January to 1st week of Feb. | NARC-1, NARC-2, FS-85, Williams-82 |
| SINDH | Mid January to 1stweek of February | NARC-1, NARC-2,Williams-82 |
| NWFP | 1st week of Marchto mid March | NARC-1, NARC-2, Swat-84,Williams-82 |
Seed Rate: Seed @ 40 kg acre-1 planted at a depth of 3 to 5 cm with 30 to 45 cm row spacing gives optimum population of 120,000 to 130,000 plants per acre. As much as 20 to 24 plants per meter of row are generally satisfactory. However, within a wide range of plant populations for a particular row spacing, soybean yield do not vary significantly. However, low populations result in low poding height and excessive branches but good lodging resistance. Conversely, high plant populations result in increased lodging, high poding height and less branching. Generally, soybeans in narrow rows are higher yielding because they capture more of the sun’s energy which drives photosynthetic machinery of the plant. However, wide rows are used if the varieties are tall and bushy type.
Method of Sowing: The method of sowing should meet three objectives i) adequate and uniform depth of seed placement, ii) adequate seed numbers and uniform distribution, iii) sufficient soil-seed contact for germination. Under, existing conditions, soybean must be planted with single row cotton drill or tractor drill because of their consistency in producing good stands.
Irrigation: Number of irrigations varies with climatic conditions, management practices and length of growing season. Moisture stress during flowering, pod filling and seed development stages reduces yield. Usually 6-7 irrigations are required for spring soybean and 2-3 irrigations for autumn crop depending upon the rains. Therefore, irrigation must be given at the following stages:
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Three weeks after germination
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Initiation of flowering
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Pod filling stage
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Seed development stage
Weed Management: Weeds complete with soybeans for nutrient’s, moisture and light and thus, reduce yield. The most effective measure for developing weed control in soybean vary; depending on types of weeds, degree of weed infestation, soil type, weather patterns, crop rotation, tillage methods, row spacing and equipments available. A good weed control program should includes combination of preventive, cultural, mechanical and chemical practices.
Preventive Measures: All these measures taken to prevent the introduction and spread of weeds include the use of weed free crop seed.
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Weed free soil, seed and farm yard manure
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Plant certified seed
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Clean planting/harvesting equipments
Cultural Control
Crop Rotation: Crop rotation reduce the weeds populations of certain weeds common to a particular crop. It results in improved crop yield, quality, improved soil conditions, and reduces the chance of plant disease and insect infestation.
Tillage Practices: Deep and dry ploughing gives a substantial control of perennial weeds. By tillage method, weeds are buried with soil, thrown over and with disruption of the ultimate relationship between the weed, crop and soil.
Mechanical (Physical) Control: Hand weeding is the most common practice and used employed by the farmers, two weedings are recommenced during the growing period. Mechanical weeding by rotary weeder control the annual weeds effectively and economically.
Chemical Control: The experimental results have shown that proper use of pre-emergence herbicides i.e. Pendimethalin 8(Stomp), Trifluralin (Treflan) and Oxadiazon (Ronstar) can be applied after planting before the germination of soybean. These have been found very effective in controlling a wide range of grasses and broad leaf weeds.
Herbicides, their doses and time of application
| S.No. | Common name | Trade name | Rate |
| 1. | Pendimethalin | Stomp | 4.5 lit ha-1 |
| 2. | Trifluralin | Treflan-R | 990-1480 ml ha-1 |
| 3. | Oxadiazen | Ronstar | 3.2-3.7 lit ha-1 |
Integrated Weed Control : This involves the use of two or more above mentioned weed control techniques. The combined use of more than one weed control technique is advantageous, because one technique rarely achieves complete eradication of weeds.
Diseases: About 35 diseases of economic importance are known to affect soybean throughout the world. Diseases can reduce yield from 10 to 30 percent, depending upon the severity, pathogen and weather conditions. In Pakistan only 6 major diseases have been observed and these are anthracnose, charcoal rot, purple seed stain, pod and stem blight and bacterial blight/pustule. Careful diagnosis is very important for the disease control strategies, because more than one pathogen or a complex may be responsible for final loss in yield and seed quality. Thus, the collection of samples is essential throughout the growing season.
Disease management programme should include the following methods:
Preventive Measures
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Plant quality and healthy seed, free of mechanical damage.
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Harvest seed soybeans as soon as they are mature.
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Avoid planting in wet and poorly drained soils to reduce chances of the development of soil borne diseases (Root rot).
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Keep the crop free from weeds because they may be the hosts to any diseases.
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Seeds should be stored at 8 to 10 percent moisture at 15oC temperature to have more seed viability.
Cultural Control
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Plough down crop residues
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Crop rotation with non-leguminous crop.
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Plant early before the soil temperature rises.
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Reduce plant population, increase row width and avoid high fertility to prevent a closed canopy, improve aeration and increase drying in the canopy.
Chemical Control
i) Seed Treatment: To protect from soil born diseases, seed should be treated before planting with one of the available fungicides; Captan, Dithane M-45, Benlate and Tecto @ 1.5-2 gms per 1 kg seed.
ii) Foliar Spray: At the appearance of disease symptoms, after field survey foliar spray with one of the systemic fungicides, Dithane M-45 @ 1 kg ha-1, Benlate and Tecto @ 120-150 gm ha-1 dissolved in 250 litre of water should be done after 10 to 15 days interval. This process should be repeated 2-3 times depending upon the severity of disease.
Integrated Disease Control
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Use multi-race resistance varieties or least susceptible cultivars and avoid tall, viney cultivars that may lodge.
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Use integrated control; combines high tolerate cultivar, good drainage, complete tillage, seed treatment and rotation with cereals.
Insects and their control
Major insects damage soybean crops are stem fly, white fly, green stink bug, cut worm and larvae. Insects attack on all parts of the soybean plant and feed throughout the growing season. Certain insect can also provide access for disease organism and or transmit them directly to plants. Therefore, understanding the relationships between the insect and the crop will enable farmers to manage pests much better. A new practice to control insect attack is based on knowledge of the economic injury levels of the consequential insects. The economic injury levels is the population of insects that is capable of producing an amount of economic damage which is at least equal to the cost of controlling the insects. Wise monitoring of major insects is required in order to effectively make decision relative to insecticide application.
Bio Control
Many insect predators, parasites and pathogens occur in soybean fields that help in keeping population of pest species below economic levels. However, experience has shown us that beneficial insects and pathogens do not do a complete job, and that chemical control becomes necessary.
Cultural Control
Early planted soybeans tend to receive the majority of the overwhelming adult of flies and bugs, while late planted will alleviate some of the problems with these two insects and cutworm. Therefore, it is still more economical to plant early for high yields and control any potential insect problems with insecticides than it is to plant late for insect control.
Chemical Control
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For cutworm and termite apply powder of BHC @ 7 kg per hectare or Dieldrin 20 EC @ 5-7 litres ha-1 mixed with irrigation water.
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For other insects especially flies, thrips and larvae spray; Dimecron 100% @ 600 ml ha-1 or Methyl-Parathion 50 percent @ 800 to 1200 ml ha-1 Somicidin 20 EC @ 400 to 600 ml ha-1 dissolved in 250 litre of water, if attack is severe spray two times with an interval of 8-10 days.
Harvesting and Threshing: Soybean matures in 92 to 120 days depending upon growing season and the variety that was planted. Senescence is the decline in chemical activity associated with aging of plants and maturation is only loss of water from plants or seeds which are physiologically mature. Seeds are physiologically mature when they are no longer synthesizing food. Physiological loss of chlorophyll and acceleration of senescence is characteristics of dry, dehisent fruits (soybean pods). Ethylene and abscisic acid play an important role in abscission and dehiscence of pod and often capsule dry fruits (soybean). Oil and storage protein have reached their maximum dry weight. At this stage seed moisture is 45 to 55 percent, pods and stems are yellow, and leaves are yellow or have dropped. Delay in harvesting not only reduces seed quality but it also reduces harvesting efficiency and increases shattering losses. As soon as the pods are dry enough to open easily, harvest it, thresh after drying within 7-10 days and threshed seed must be cleaned before storage or marketing.
Yield: Number of pods per plant is a function of spacing and intercepted light while leaf N is a principal factor in determining soybean seed yield. The average farmers yield ranges from 1500 to 2500 kg ha-1. At Agricultural Research Institutes under high level management practices the yields range from 2500 to 3500 kg ha-1.
Storage: Well dried seed should be stored at about 8 to 10 percent moisture content and 15o C in tropical regions. To maintain dried seed at a low moisture level, two practices are feasible. these are:
i) To grow soybean for seed in an area where relative humidity is low.
ii) To use moisture proof containers for seed storage.
For long-term benefit and effectiveness, air conditioned storage in tropical and subtropical areas are more suitable. Adequately air-conditioned storage should be maintained at a temperature of 20oC to 22oC or less and a relative humidity of 60 percent or less when the storage period is of eight-nine months duration. Poor quality soybeans seeds will deteriorate quickly in storage than high quality seeds. In addition, the practice of “Carrying over” soybean seeds should be discouraged because this crop does not store well and the quality of seed quickly diminishes during the second over wintering period.
Availabilty of seed: A good quality soybean seed is available with the following agencies:
1. Oilseed Program, National Agric. Res. Centre, Islamabad.
2. Pakistan Oilseed Development Board, Islamabad.
3. Punjab Seed Corporation, Sahiwal and Khanewal.
4. Agricultural Development Authority, Peshawar.
5. Sindh Agricultural Supply and Services Organization, Hyderabad
Marketing: Beside Government Agencies (PSC, SASSO and ADA) private agencies like National Feeds and Wali Oil Mills, Sheikhupura has been directed to procure the entire produce from the farmers @ Rs.410 per 40 kg.
Advantages of soybean plantation
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Has short duration season and farmer could utilize rice, cotton, and rainfed fallow areas.
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Well fit in the existing cropping system without clashing with major crops.
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Economics often dictates crop sequence, but where choices are available, soybeans should follow crops other than soybean like cereals that make better use of the nitrogen provided by legume crops.
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Soybean also provides good quality protein which is high in one of the limiting amino acids lysine, and is useful as a supplement to other cereals.
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Soybean oil consists of 85 percent unsaturated fatty acid from which two essential fatty acids, linoleic and linolenic acids, not synthesized by the human are provided, therefore, soya oil is good for better health and heart patients.
QUICK TIPS TO OBTAIN MAXIMUM YIELD
| Seed bed preparation | 3-4 ploughings with two planking. |
| Time of planting | |
| Autumn (Kharif crop) | |
| Punjab | Mid-July to end July |
| Sind | Mid-June to Mid-July |
| N.W.F.P | May to June |
| Spring (Zaid Rabi Crop) | |
| Sind | Mid-January to 1st week of February |
| Punjab | Last week of Jan. to 1st week of Feb |
| N.W.F.P | 1st and 2nd week of March |
| Seed rate | 100-120 kg ha-1 |
| Planting method | Planting with seed drill.Row to row distance spring 30 cm, kharif 45 cm,Plant to plant distance 3-5 cm |
| Fertilizer | 25:25:50 (NPK) kg ha-1at the time of planting. |
| Irrigation | 6 to 7 irrigations for spring and 3 to 4 irrigations for autumn crop (depending upon the rains).
Irrigations must be applied at the following stages
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| Weed control |
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| Harvesting and Storage |
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| Improved Varieties | NARC-1, NARC-2, Williams-82, Ajmeri, Malakand-96, Kharif-93, Swat-84 and FS-85 |
| Crop rotation | Rice-Soybean-Rice, Cotton-Soybean-Cotton ( irrigated), Wheat -Soybean-Wheat (rainfed) |