Bamboo Shoot Cultivation Methods and Key Points of Fertilizer and Water Management Techniques

Bamboo shoots have been regarded in China since ancient times as a “treasure among vegetables”. Bamboo shoots are a traditional Chinese delicacy, fragrant in taste and crisp in texture, with an extremely long history of use and cultivation. Bamboo shoots are the young shoots of plants in the grass family, subfamily Bambusoideae, such as bitter bamboo (Pleioblastus amarus), sweet bamboo (Phyllostachys dulcis), and moso bamboo (Phyllostachys edulis), also known as bamboo sprouts or bamboo buds. According to analysis, raw shoots contain protein, amino acids, fat, sugars, calcium, phosphorus, iron, carotene, and vitamin B1, vitamin B2, vitamin C, and other components.

Growth Habits of Bamboo Shoots

The underground stems of scattered-type bamboo species such as moso bamboo and early bamboo go relatively deep into the soil, and the bamboo rhizomes and shoot buds are protected by the soil layer, so they are less susceptible to freeze damage in winter, and the shooting period is mainly in spring. The underground stems of clumping-type bamboo species such as ma bamboo (Dendrocalamus latiflorus) and green bamboo (Bambusa oldhamii) go shallow into the soil, and the shoot buds often protrude above the soil surface, making them susceptible to freeze damage in winter, with the shooting period mainly in summer and autumn.

Bamboo originated in the tropics and subtropics and prefers warmth and fears cold, being mainly distributed in areas with annual rainfall of 1000-2000mm. The optimum temperature for moso bamboo growth is an annual average of 16-17°C, with a summer average below 30°C and a winter average of around 4°C. Ma bamboo and green bamboo require an annual average temperature of 18-20°C, with a January average temperature above 10°C. Therefore, bamboo forests are lush in southern China, while bamboo forests are sparse north of the Qinling Mountains-Huaihe River line. Bamboo requires deep soil that is loose, fertile, moist, and well-drained and aerated, with a soil pH of 4.5-7 being suitable.

Fertilizer and Water Management and Cultivation Methods for Bamboo Shoots

Fertilizer and water management:

(1) Fertilization: For newly planted bamboo forests, apply diluted human and livestock manure or urea in several applications around the bamboo plants between spring and summer to promote root group development and shoot emergence and new rhizome growth. In autumn, combine weeding and loosening of the soil with the application of barn manure or compost, turning it into the soil. After the forest is established, each year after spring shoot harvest is completed, apply about 1000 kg per mu of human and livestock manure into the holes left by digging shoots, and open holes in other locations to apply fertilizer so that fertilizer is evenly distributed throughout the forest. After applying fertilizer, cover it with soil. This fertilization is mainly to promote the growth of new bamboo and the development of new rhizomes, and to enable mother bamboo to quickly recover vigorous growth. In autumn, apply 1000-1500 kg per mu of barn manure or compost evenly by broadcasting and turn it into the soil to promote the development of shoot buds on the bamboo rhizomes. In winter, apply another 1000-1500 kg of barn manure or compost, or 2500-5000 kg of pond mud or river mud, spread on the soil surface, which not only supplies nutrients but also has a warming effect on the rhizomes and roots.

(2) Irrigation and drainage: In southern regions, during the plum rain period and between summer and autumn when there are typhoons, drainage work must be done well during heavy rains to prevent water accumulation in low-lying areas from rotting the rhizomes. In the event of autumn drought, timely irrigation is needed to prevent the soil from becoming too dry, which would hinder the formation and expansion of shoot buds and affect the next year's shoot yield. In areas with low rainfall, particular attention must be paid to irrigation, with emphasis during spring shooting or summer rhizome growth, and before the soil freezes in winter.

Cultivation:

(1) Weeding and loosening of soil: Newly established bamboo forests are prone to weeds before canopy closure, and weeding and soil loosening must be done twice each year. The first time is after the new bamboo branches and leaves have unfolded and before the plum rain arrives; the weeds cut at this time are tender and easily rot and die. Doing it too early is harmful to the new bamboo, and doing it too late easily damages the rhizomes; the second time is in August, when most weed seeds are not yet mature, so the weeds will not spread and proliferate after being removed. After the bamboo forest has closed its canopy, weed once a year between July and August. When loosening the soil near new bamboo, stay 33 cm away from the plants to avoid injuring and breaking the roots of the new bamboo.

Soil loosening should be relatively deep to thicken the arable soil layer, which benefits the development of rhizomes and roots, allows more rainwater to be stored, and reduces drought damage. During soil loosening, dig out and remove dark brown old rhizomes, bamboo stumps left after cutting, as well as tree stumps and stones, so that bamboo rhizomes and root groups can extend smoothly.

(2) Burying rhizomes and covering with soil: Because new rhizomes are mostly distributed in the soil layer above the old rhizomes, if left to nature, the soil layer where the bamboo rhizomes are located becomes shallower year by year, so that the range over which rhizomes and roots absorb soil nutrients and water shrinks, affecting the growth of the rhizomes and the entire plant. Therefore, during soil loosening, aging rhizomes and shallow rhizomes should be dug out and removed to induce new rhizomes to develop into deeper soil layers, and soil should also be spread to thicken the arable soil layer. If thick, strong rhizomes are found extending into shallow soil layers or exposed above the soil surface, immediately dig a ditch more than 30 cm deep beneath them and bury them, and apply fertilizer in the ditch. For bamboo forests built into terraces, scrape off a layer of soil from the terrace wall each year and spread it onto the terrace surface below. On gently sloping land without terraces, because soil moves downslope with rainwater, when covering with soil, take soil from the lower slope and carry it to the upper slope.

(3) Tip hooking: Between October and November of the year when new bamboo grows, cutting off the top tip of the bamboo culm is called tip hooking. This measure can reduce damage from wind and snow, inhibit the apical dominance of the bamboo culm, and promote rhizome growth and shoot emergence. Therefore, shoot-production forests place special emphasis on tip hooking. In order to give the bamboo forest a reasonable leaf area, about 15-17 tiers of branches and leaves should be retained when hooking the tip.

(4) Selection, retention, and renewal of mother bamboo: In newly established bamboo forests, during the first 5-6 years, select and retain as many thick, strong spring shoots in suitable positions as possible during the peak shooting period, letting them grow into the forest so that standing bamboo is evenly distributed throughout the forest. Shoots that emerge early are mostly produced from shallow rhizomes, and the bamboo that grows from them roots shallowly and grows weakly; shoots that emerge late often become degraded shoots due to insufficient nutrient supply, and even if they grow, they cannot become good bamboo.

For moso bamboo shoot-production forests, retain 100-150 mother bamboo per mu, and after the quota is full, retain 20-30 new bamboo per mu each spring that are robust in growth and in suitable positions. In the winter of that year, cut down the same number of old bamboo so that the standing bamboo in the forest maintains a certain density at all times, with robust-aged bamboo making up the majority. The age of standing moso bamboo can be identified by the color of the culm: before three years of age it is green, at four to five years it is yellow-green, at six to seven years it is greenish-yellow with a relatively thick grayish-white waxy layer, and after eight years it gradually turns bronze-colored and the waxy layer gradually falls off. Generally, after seven years of age, bamboo growth vigor weakens and it can be cut. Old bamboo to be cut should be selected from those whose leaf color is turning yellow and which will soon change leaves the following year; do not cut the “shoot-incubating bamboo” with deep green leaves. When cutting old bamboo, also cut the dense ones and leave the sparse ones, so that standing bamboo is evenly distributed throughout the forest and the utilization rate of sunlight is improved.