Garlic-Ginger Intercropping Brings Good Returns: A Full Analysis of the Planting Advantages

In the history of Zhucheng City, Shandong Province, ginger was mostly grown as a sole crop. Trials and demonstrations of garlic-ginger intercropping began in the 1980s and achieved relatively good economic returns. However, because the intercropping techniques were not fully matched, for example no intercropping rows were left, the intercropped ginger bulbs became smaller, and some even failed to meet export standards, which dampened ginger growers' enthusiasm for intercropping. In order to explore the cultivation techniques for garlic-ginger intercropping, the author carried out multiple trials and survey analyses from 1992 to 1995 in Chengguan Town, Lubiao Township and other places, and summarized a matched set of techniques suitable for local garlic-ginger intercropping. After extension, a double harvest of both garlic and ginger was achieved. The details are introduced below.

Key Points of Garlic-Ginger Intercropping Cultivation Techniques

Apply sufficient base fertilizer and prepare the beds carefully. Choose a fertile medium loam plot with irrigation and drainage conditions where ginger has not been grown for 3 years. Spread 5000 kg of farmyard manure and 50 kg of superphosphate per 667 sq m, plow deeply to 30 cm, harrow fine and level, and open beds in an east-west direction, 120 cm wide, of which the bed ridge is 20 cm wide and the bed surface is 100 cm. Apply 100 kg of NPK compound fertilizer or 50 kg of soybean cake in bands.

Select fine seed and treat the seed ginger bulbs. When planting garlic in autumn, choose Cangshan garlic with large cloves and no disease as seed, and discard split cloves and rotten cloves. When interplanting ginger in spring, choose ginger bulbs that are disease-free, not rotten, not shriveled and not damaged for sprouting, and strictly discard thin and weak bulbs, and bulbs with brown flesh or watery and soft bulbs. Around Qingming Festival, choose a windless sunny day and arrange the selected seed ginger in a single layer on dry ground that is sheltered from the wind and facing the sun. Dry them in the sun from 9:00 in the morning to 3:00 in the afternoon, and bring them back indoors after 3:00. Pile them for 2-3 d (days) and then dry them again, repeating 3 times, with the whole process taking 10-15 d (days). Then sprout them on a heated kang. According to the amount of seed ginger, build a 50 cm high wall on the kang with bricks or adobe, spread a 10 cm thick layer of dry wheat straw inside, then spread a layer of newspaper, and place the ginger bulbs tightly upright on the heated kang, generally in 5 layers. Then light a fire to raise the temperature. In the early stage, keep the temperature at 20-22°C. After 15 d (days), the ginger buds begin to sprout, and the temperature is raised to 25-28°C. When the ginger buds grow to 1 cm, lower the temperature to 22-25°C and maintain a relative humidity of 70%-80%. This alternating temperature sprouting can make the ginger buds plump and strong without excessive growth.

Sow at the proper time and plant at a reasonable density. In mid-October, sow garlic seed with plastic film mulching, in an east-west direction, with a bed width of 120 cm, planting 6 rows, with a plant spacing of 10 cm, and 37,000 plants per 667 sq m. On the bed surface, plant 3 rows of garlic and leave 1 intercropping row 30 cm wide (Figure 1). Garlic sowing can be done by punching holes after mulching, or by opening furrows, sowing, and then mulching. After seedlings emerge, break the film to let the seedlings out and seal the openings with soil. Ginger is planted by hand in holes from April 25 to May 5, with a row spacing of 60 cm and a plant spacing of 20 cm, 5500 plants per 667 sq m. Try to keep the depth and plant spacing consistent to facilitate management.

Apply fertilizer by stages and in formulated proportions. With sufficient base fertilizer applied, garlic basically needs no topdressing after sowing. After harvesting the garlic scapes the following year, apply 10 kg of urea per 667 sq m together with watering, serving both purposes with one fertilizer application. When ginger grows to 2 branches, apply 15-20 kg of compound fertilizer, and in the vigorous growth period apply another 35-50 kg of compound fertilizer, so as to meet ginger's fertilizer needs.

Strengthen watering and drainage management. Ginger needs a large amount of water in the late growth stage, and the ground should be kept moist but not dry. Ginger and garlic are afraid of both drought and waterlogging, so attention should also be paid to drainage to prevent ginger from rotting. In addition, earth up in several rounds, and cultivate and weed.

Pay attention to pest and disease control. After garlic turns green in spring, spray 800-fold 90% trichlorfon solution to control garlic maggots, and spray once more before "Grain in Ear" to control ginger stem borers. For the control of ginger blast, on the premise of carrying out crop rotation for more than 3 a (years), select good seed, and when diseased plants are found, remove them promptly and spread quicklime in the diseased holes for disinfection. When ginger stem borers (borers) are found, use 500-600-fold 50% fenitrothion emulsion or 800-fold 80% dichlorvos emulsifiable concentrate, or spray 1500-fold decis or fenvalerate for control.

Harvest at the proper time. Garlic is harvested in early June within 17-20 d (days) after harvesting the garlic scapes. When harvesting, dig carefully and gently so as not to damage the ginger root system. Ginger should be completely harvested before "Frost's Descent" in mid-October. Three d (days) before harvest, water once first to make the soil moist, then gently dig out the ginger with a hoe, then from 2 cm above the base of the stem, cut off the aboveground stem with a knife, remove the fleshy roots, place them carefully and put them into the cellar in time. Dig and transport them all on the same day. Ginger bulbs must not be left in the open overnight, so as to prevent the bulbs from cold damage.

Garlic-Ginger Intercropping Increases Yield and Income

Garlic-ginger intercropping makes full use of land and conditions such as light, temperature, water and fertilizer, uses the ginger land idle in winter to grow garlic, changes one cropping per year into two croppings per year, raises the multiple cropping index, and significantly increases yield and returns. Generally, the yield of sole-cropped ginger is 2300 kg per 667 sq m; the yield of intercropped ginger is 2250 kg, with 1025 kg of garlic and 700 kg of garlic scapes. Intercropping increases net income by 3200 yuan compared with sole cropping.

In addition, ginger is a shade-tolerant plant and cannot tolerate strong light. In the early growth stage, it needs moderate light conditions. Garlic-ginger intercropping uses garlic seedlings for shading, which can save labor and materials. At the same time, garlic can volatilize a bactericidal substance, which can effectively prevent and reduce the occurrence of ginger blast. According to a survey in Chengguan Town, the disease incidence of intercropped ginger was significantly lower than that of sole-cropped ginger.