The flavor foundation of a good cup of coffee was laid the moment the seed touched the soil. This article systematically lays out the complete technical chain of coffee from seedling propagation to plantation management: seed collection and washing in seed propagation, nursery establishment, germination and transplanting of seedlings, and seedling-stage care; the key points of cutting and grafting in vegetative propagation; and then extends to coffee plantation site selection and planning, land clearing and field planting, shade tree arrangement, single-stem and multi-stem training and pruning techniques, as well as soil management measures such as weeding and mulching, deep plowing and soil improvement, and irrigation and fertilization. For enthusiasts who wish to gain a deeper understanding of the logic of coffee cultivation and build a systematic awareness from origin to cup, this is a solid technical reference. The variety terminology and operational standards covered in the article can also mutually corroborate the origin-processing philosophy that Front Street Coffee emphasizes in bean selection and roasting.
(1) Seedling Propagation
Coffee seedling propagation falls into two major categories: one is sexual reproduction through seeds, and the other does not go through seeds and uses vegetative propagation.
1. Seed Propagation
(1) Seed collection, seed washing, and seed storage
Seed collection should be carried out during the full-ripe stage when the coffee fruit is fully mature—on Hainan Island, the full-ripe period for Robusta is concentrated in February to March, while for Arabica it falls in September to November. Select healthy, high-yielding mother trees and pick fully ripe fruit as the seed source. After the fruit is picked, it needs to be peeled and washed as soon as possible: the fruit can be spread on rough, hard ground and the skin broken with bricks, or the skin can be removed with a pulper, after which the seeds are floated in water to remove the skin and then taken out. Next, mix in stove ash, then rinse repeatedly with water to thoroughly remove the mucilage attached to the seed surface. During the operation, be sure to avoid cracking the parchment, otherwise germination performance will suffer—seeds without parchment protection have only a 54% germination rate, while seeds that retain the parchment can exceed 80%. Washed seeds should be dried in the shade in a ventilated place and must never be exposed to the sun, because once sun exposure reduces moisture content to 15%, the germination rate drops markedly. Dried seeds are not suitable for long-term storage: Robusta coffee completely loses its germination capacity after more than three months of storage; because Arabica coffee is harvested from September to November and immediately enters the low-temperature winter, its seeds can be stored until sowing in February to March of the following year, but they must be kept in a ventilated, cool, dry place and checked regularly to prevent mold.
① Selection of nursery site: loam or sandy loam close to a water source, with good drainage, fertile soil, and a deep, loose soil layer should be chosen as the nursery.
② Land preparation and base fertilizer application: the nursery soil must be fully plowed and harrowed until fine, with deep plowing of 20 to 25 centimeters, stones, grass roots, and debris removed, and then beds made. The bed surface width is 1 meter, and the path between beds is 50 centimeters wide. On flat land, beds should preferably run east-west. Apply 5,000 to 10,000 jin of fully decomposed organic fertilizer per bed, together with 50 to 100 jin of superphosphate, and mix the fertilizer thoroughly and evenly with the soil.
③ Erecting shade frames: coffee seedlings fear strong light, so shade facilities are indispensable. Shade frames are divided into two specifications, large and small. Large shade frames are 180 to 200 centimeters high, and the area can range from a few fen of land to several mu; small shade frames are 80 to 100 centimeters high, covering one bed each. Large shade frames are easier to manage and provide more uniform light transmission, but the materials for building them are harder to obtain; shade netting can also be used instead. Small shade frames are relatively inconvenient to manage, and the seedlings do not receive sufficiently uniform light, but the materials are easier to source. Each location can choose the erection method according to actual conditions. If plastic-bag seedling raising is used, it is best to pair it with large shade frames so that land can be used more fully.
④ Sowing and germination promotion: coffee seeds take a long time from sowing to emergence. If sown directly, it is not only labor-intensive, but germination is also uneven and the seedlings grow unevenly. The recommended method is germination followed by transplanting: first sow the seeds densely in a sand bed, and then move them into the nursery before the seedlings grow true leaves. The specific operation is: after preparing the land and making beds, spread about 1 cun of fine sand on the bed surface to make a sand bed. The sand bed needs a shade frame and should maintain 80% to 90% shade, then the seeds are evenly broadcast on the sand bed. The sowing rate is about 1 jin of seeds per 1.5 square meters, with a seed spacing of about 1 centimeter. Press lightly with a wooden board so the seeds make close contact with the sand, then cover with another layer of sand, just enough that the seeds are no longer visible, and finally cover with a thin layer of grass and water thoroughly. After that, water once a day to keep it moist, and the seedlings will emerge after 40 to 60 days. When a few seedlings break through the surface, the covering must be removed promptly so the seedlings can grow smoothly.-------
⑤ Transplanting: the best time for transplanting is after the seeds have emerged, when the cotyledons have already flattened but true leaves have not yet grown. At this stage the seedlings have begun to develop the first to second rounds of lateral roots, and they recover and grow relatively quickly after transplanting. Before transplanting, first water the sand bed thoroughly. When lifting the seedlings, protect the root system as much as possible, transplant immediately after lifting, and keep the seedling roots moist. Spacing is determined according to variety and seedling age: Arabica coffee can use 20×20 centimeters; for Robusta coffee, the spacing for seedlings used in the same year is 20×20 centimeters, while for seedlings used the following year it is 25×25 centimeters or 25×30 centimeters. When transplanting, the main root must not be bent, and any overly long part may be appropriately shortened. Backfill soil should be pressed firmly in layers so the root system fits closely against the soil, and after planting, water thoroughly to settle the roots.
If plastic bags are used for seedling raising, arrange 2 to 3 plants per row, with a 25 to 30 centimeter path between rows, to facilitate watering and also give the seedlings enough space to grow without becoming leggy. The specifications of seedling bags are 14×22 or 15×24 centimeters. Smaller bags may be chosen for seedlings used in the same year, while larger bags are chosen for seedlings used the following year. The nutrient soil for seedling bags can refer to the fertilization standard for the transplant bed, combined with a certain amount of organic fertilizer and superphosphate.
Points to note when transplanting:
Grade and plant separately according to seedling size.
The transplanting depth should be consistent with that of the original germination bed, and must not be too deep, so as not to hinder seedling growth.
Do not bend the main root.
After transplanting, water thoroughly to settle the roots.
⑥ Nursery management: in terms of watering and fertilization, sufficient water and fertilizer are the key to rapid seedling growth. After transplanting, water once a day to keep the soil moist. After true leaves emerge, the frequency of watering can be reduced according to soil moisture conditions. At the same time, carry out the first fertilization, and afterward fertilize once every 10 to 15 days. The fertilizer can be fully decomposed liquid manure made from fermented pigpen manure and green manure. During the seedling stage, fertilizer concentration should not be too high, and the concentration should gradually increase as the seedlings grow. When applying chemical fertilizer, it can first be dissolved in water and then applied, but the concentration must be well controlled, and chemical fertilizer must not touch the leaves; if dry application is adopted, extra care is needed. One month before the seedlings are planted out, watering and fertilization should be stopped, and the shade facilities should be removed so the seedlings can be hardened off.
Weeding and loosening the soil: because of frequent watering and fertilization, the soil tends to become compacted and weeds also flourish, so weeding and soil loosening must be done often.
Mulching: where conditions permit, dead mulch is best. It can keep the soil moist, prevent compaction, and reduce the workload of loosening soil and weeding, and after the mulch decomposes it is also a high-quality organic fertilizer.
Adjusting shade: the light requirement of seedlings increases as they grow. Before 3 pairs of true leaves emerge, shade should be controlled at 70% to 80%; at 3 to 6 pairs of true leaves, it can be reduced to 50% to 60%; by the time the first pair of branches grows or before field planting, it can be further reduced to 20% to 30%, so that the seedlings are fully hardened off before planting out.
2. Vegetative Propagation
Robusta coffee is a cross-pollinated crop, and seedling progeny vary greatly, with very significant yield differences among individual plants in the same plantation. Therefore, using vegetative propagation to cultivate seedlings from superior mother trees can increase the yield of the progeny, maintain fruiting capacity, make coffee fruit and bean quality more uniform, and avoid degeneration of superior varieties. Most coffee-producing countries in the world have adopted vegetative propagation methods, mainly applied to Robusta.
Vegetative propagation can be divided into two types: cuttings and budding.
(1) Propagation by cuttings
① Establishment of a multiplication nursery: coffee vegetative propagation requires large numbers of orthotropic shoots and bud patches as material for cuttings and budding. To accelerate propagation speed, a multiplication nursery needs to be established. The planting density of the multiplication nursery is 1.5 meters × 1 meter, planted in separate rows according to different clones.
② Preparation of cutting material: use orthotropic shoots for cutting material, not primary branches, because new plants grown from primary branch cuttings can only grow prostrate and cannot develop into upright coffee trees. For cuttings, choose the 2nd to 3rd segment below the healthy orthotropic terminal bud, green and not yet lignified, with fully mature leaves; do not use semi-lignified or already lignified orthotropic shoots. Leave the leaves on the cutting about four fingers wide (about 6 to 8 centimeters). Each cutting segment is 4 to 6 centimeters long. Split the cutting lengthwise into two strips, each with one leaf, and cut the incision diagonally and smoothly.
③ Preparation of the cutting bed: the cutting bed is generally a sand bed, 40 to 50 centimeters thick, with coarse sand in the lower part and medium-fine sand in the upper part. The cutting bed needs 80% to 90% shade. Before use, wash the sand clean, and it can also be mixed with 1/2 coconut coir. Using misting equipment can increase the rooting rate of cuttings, but the equipment purchase cost is relatively high.
④ Cutting method: cuttings can be inserted obliquely or straight, with the insertion depth reaching the leaf node. The spacing between rows is 10 to 15 centimeters, judged by whether the leaves shade one another. After insertion, water thoroughly so the cuttings make close contact with the sand. After cutting, cover the cutting bed with plastic film to reduce water evaporation and increase the rooting rate. When covering with film, bend iron wire or bamboo strips into arches and insert them at the edges of the sand bed, then place the film over them and press it tight to maintain humidity inside the bed. If misting equipment is used, there is no need to cover with film.
⑤ Management after cutting: mainly watering and disease prevention, requiring relatively high air humidity and relatively low temperature inside the cutting bed. Do not water too much, to avoid rotting or disease in the cuttings. To prevent disease, immediately after cutting spray carbendazim at 1:1000, and if disease occurs afterward, spray another 1 to 2 times.
⑥ Transplanting of rooted cuttings: about 60 days after cutting, new roots grow to 3 to 4 centimeters. Although transplanting at this time is relatively convenient, it is best to wait until the cutting root system has grown the second round of lateral roots (about 90 days after cutting) before transplanting, for a higher survival rate. Transplanting requires careful operation because the root system is very tender and easily broken.
Cuttings that have not yet rooted remain in the sand bed and are transplanted after rooting. After transplanting, or after bagging, cutting-propagated seedlings are managed the same as seed-propagated seedlings. When cultivated in the nursery until they have 5 to 7 pairs of leaves, they will grow the first pair of branches, and at that point they can leave the nursery for field planting.
(2) Grafting: grafting methods can use budding and cleft grafting.
① Budding method: select one-year-old seedlings, wipe the soil clean from the base of the stem, then open a bud insertion site 2.5 to 3.5 centimeters long. From a superior mother tree or multiplication nursery, select plump, well-developed nodes, cut off a bud patch with a small amount of xylem, place it into the bud insertion site, and tie it tightly with tying tape. After 20 days, open the bud point; after 30 to 40 days the bud union has healed, and all tying is removed. Five days later, surviving seedlings can have the rootstock cut off, while those that did not survive are budded again.
② Cleft grafting method: use one-year-old seedlings as rootstock. For cleft grafting, cut off the rootstock 10 to 15 centimeters above the ground, and make a vertical cut 3 to 5 centimeters long in the middle of the cut surface. Select an orthotropic shoot matching the size of the rootstock, cut it off 3 to 4 centimeters below a node, whittle the base of the scion into a wedge shape, insert it into the rootstock cut, taking care to align the cambium, and tie it tightly with tying tape. To improve the survival rate, the scion can be wrapped well with tying tape, expose the bud point after 20 days, and remove all tying after 30 to 40 days.
③ Management of grafted seedlings: after successful grafting, the seedlings need to be cultivated in the nursery until they meet the standard for field planting before they can leave the nursery. In addition to the same management as seed-propagated seedlings, grafted seedlings also require special attention to protecting new buds and promptly removing shoots sprouting from the rootstock.
Before grafting, the seedlings should be watered thoroughly; after grafting, water carefully and do not wet the graft union.
(2) Establishment of the Coffee Plantation
1. Site selection, planning, and land clearing
Environmental conditions are closely related to coffee growth and development, and the plantation site should be determined according to coffee's growth habits and environmental requirements. Try to avoid lowlands where cold air easily accumulates and frost forms; coffee roots need air, so choose well-drained, loose soil; coffee needs a wind-still environment, so in areas without primary forest, windbreak planning should be considered. The size of the coffee plantation is mainly planned according to the severity of local wind damage, generally 10 to 15 mu is suitable.
During land clearing, take care to preserve the wind-still environment of the original woodland. Large trees that need to be retained as shade should be marked and preserved, while the remaining trees are first cut down and then cleared away.
Soil and water conservation on the plantation site is a very important task. On gentle slopes below 10 degrees, contour cultivation can be used; on slopes above 10 degrees, contour terraces should be built.
Digging planting holes can be done in conjunction with terrace construction. Planting holes generally use the specification of 60 (length) × 60 (width) × 50 (depth) centimeters. When digging holes, topsoil and subsoil should be placed separately so that topsoil can be returned to the holes. Before field planting, planting holes should be given sufficient base fertilizer. Generally, decomposed cattle pen manure, pig pen manure, or compost may be used, applying 30 to 50 jin per hole, mixed with half a jin of superphosphate. After applying the base fertilizer, return topsoil and mix evenly. If close planting is used, horizontal trenches may be dug. Planting holes should be dug 2 to 3 months before field planting so they can fully weather.
2. Planting density. Planting density mainly depends on variety, pruning system, soil type, local rainfall, and management level, such as fertilization, irrigation, and shade.
For Robusta coffee with multi-stem training, the spacing is generally 2.5×3 meters; with single-stem training, it is generally 2×2.5 meters.
For Arabica coffee with multi-stem training, the spacing is generally 2×3 meters or 2.5×3 meters; with single-stem training, it is generally 1.5×2 meters or 2×2 meters.
For Liberica coffee, the plants are tall and large, and the spacing is generally 4×5 meters.
Generally speaking, where the soil is fertile, annual rainfall is high, and management level is high, planting can be sparser.
In recent years, coffee has been intercropped with coconut, areca palm, rubber, or other crops, and the spacing can be determined according to the requirements of intercropping.
(3) Field planting period and field planting methods. Field planting is generally done when the rainy season arrives each year. On Hainan Island, the best planting period is August to September; where there is spring rain, planting in February is also acceptable. Healthy seedlings 10 to 11 months old that have already grown 2 to 3 pairs of branches should be selected for planting. It is best to lift seedlings on cloudy days or in the afternoon of clear days. Planting with soil or bare-root planting are both acceptable. For bare-root planting, water thoroughly the day before lifting the seedlings, and after the seedlings are lifted, cut off 1/2 of the leaves.
It is best to plant seedlings immediately after lifting them. If they must be transported far or cannot be planted immediately, coat the roots with mud slurry and place them in a cool place. For plastic-bag seedlings, cut open the plastic bag and place the seedling into the planting hole, taking care not to let the soil in the bag crumble, so as not to damage the roots. The planting depth should be the same as the seedling's original depth, lateral roots should be allowed to spread naturally, backfill soil and press firmly, and after planting, water immediately and cover with grass. To cultivate a multi-stem tree shape, oblique planting or stem cutting can also be used at planting.
3. Shade
---- The purpose of shade is to create an environment suited to coffee growth and development, so as to ensure high and stable yields after field planting through comprehensive agricultural technical measures. The degree of shade should vary according to different cultivation environments and different varieties: in tropical high-altitude areas and valleys or basins with high mountains on the east and west sides or all around, shade can be slight or unnecessary; on west-facing slopes with low humidity, strong prevailing winds, a long dry season, and strong light, shade should be appropriately greater. Robusta generally requires 30% shade; Arabica requires 25% to 30% shade; mature Liberica trees generally do not need shade.
----- As shade tree species, they should have conditions such as fast growth, evergreen habit, sparse branches and leaves, deep main roots, few lateral roots, and strong wind resistance. According to current production experience, Taiwan acacia is a relatively good shade tree, but its drawback is root disease; Leucaena leucocephala from El Salvador grows quickly, but its crown is not large.
----- The planting density of shade trees should be determined according to the size of their crowns. If Taiwan acacia is chosen as the shade tree, one Taiwan acacia can be planted every 2 to 3 rows between coffee rows and every 4 to 5 plants within the row.
----- It is best to plant shade trees in advance, and plant coffee trees only after they can provide shade. If this cannot be done, temporary shade crops should be planted between coffee rows, such as pigeon pea, tephrosia, leucaena, and Tephrosia purpurea, and cut down once the permanent shade trees become effective.
Temporary shade trees should be thinned year by year according to the different growth stages of coffee, and branches below 2 meters on permanent shade trees should be pruned away so as not to affect normal coffee tree growth. When the trees enter the fruiting stage, a relatively low shade level of about 25% to 30% should be retained, and excess shade trees should be cut down, leaving about 10 to 15 trees per mu.
4. Training and pruning
Reasonable training and pruning is the guarantee for achieving rapid growth and high yield in coffee. Training before the coffee tree enters the fruiting stage shapes a strong framework tree form and lays the foundation for high yield; pruning, on the basis of training, regulates the relationship between growth and fruiting. The main training methods for coffee trees are single-stem training and multi-stem training.
(1) Single-stem training and pruning
Single-stem training is a training method that cultivates one main stem, uses primary branches as framework branches, and uses secondary and tertiary branches as the main fruiting branches. In single-stem training, to promote robust branch development, topping is usually adopted. According to the requirement for controlling main stem height, the terminal bud is removed to suppress apical dominance and promote branch growth, thereby achieving the purpose of single-stem training.
Topping methods can be divided into one-time topping and multiple topping.
① One-time topping method: when the coffee tree is 1.5 to 1.7 meters tall, cut off the terminal bud. Some also top only when the tree is 1.8 to 2.2 meters tall.
② Multiple topping method is mostly applied to Arabica, with two or three toppings. Two-time topping: carry out the first topping when the tree is 1 to 1.2 meters tall. After the first branches have developed fully (about half a year under good management), select and retain one robust orthotropic shoot as the continuing main stem. When it grows to 80 to 90 centimeters tall, carry out the second topping. After topping, no more orthotropic shoots are retained, and the tree height is maintained at about 1.7 to 1.8 meters.
If three toppings are used, the first topping height is 0.8 to 1 meter, the second topping height is 1.2 to 1.5 meters, and the third topping height is 1.6 to 2 meters. After each topping, the retained continuing main stem should be opposite in direction to the previous retained continuing main stem, to keep the crown balanced.
The time and position of topping should be around May of the second or third year after field planting. When topping, retain the 3 to 4 pairs of primary branches that grew from the beginning of the year to May, because the primary branches that grow at this time are mainly vegetative, develop well after topping, and produce secondary branches earlier, which is favorable for forming framework branches. With good management, a compact crown can be formed in the same year.
If topping is done after June, most of the axillary buds of the retained primary branches have already formed flower buds and few secondary branches will emerge. Even if some emerge, they grow farther from the main stem and are weaker, which affects crown formation and fails to achieve the purpose of topping.
Management of topped trees: after topping, promptly remove orthotropic shoots sprouting from the main stem (especially the top), and prune the secondary and tertiary branches that emerge. The following types of branches should be cut off: branches growing within 15 centimeters of the stem on the first primary branch; branches growing upward, inward, or downward with improper orientation; aged, drooping, and weak branches; branches with pests or diseases; and excessive branches growing on the same branch and the same node. How many secondary branches should be retained on each primary branch mainly depends on the level of agricultural management; generally 7 to 8 are retained, interlaced with each other and evenly arranged. After secondary branches emerge, the primary branch has aged and can no longer bear fruit, so the primary branch should be shortened at the point where the secondary branch grows at its tip.
(2) Multi-stem training. Multi-stem training is a training method that uses primary branches as the main fruiting branches. The purpose of training is to cultivate multiple main stems and grow large numbers of robust primary branches. Multi-stem trees are not topped; when yield declines after 3 to 5 years of fruiting, the main stems are replaced with new ones.
① Methods of cultivating multiple stems
---- Oblique planting method: at field planting, plant the seedling obliquely, generally at an angle of 30 to 60 degrees to the ground (preferably 45 degrees). Oblique planting can suppress terminal growth of the main stem and promote sprouting of orthotropic shoots at the base. Take care to select and retain 3 to 4 robust orthotropic shoots with a certain spacing to cultivate as new stems. Once the new stems have grown, cut off the old stem.
---- Stem bending method: plant upright at field planting. When the seedling has grown to about 1 meter tall, bend the main stem over and fix it with rope or wooden hooks. Take care to select and retain 3 to 4 robust orthotropic shoots with a certain spacing to cultivate as new stems. The original stem is cut off after fruiting for 2 to 3 years. This method is more labor-intensive than oblique planting and requires materials to fix the main stem.
----- 1. Bend and fix the main stem. 2. Cut off the original stem after 2 to 3 years of fruiting. 3. The cultivated new stems.
---- Stem cutting method: this method is mainly suitable for seedlings more than 2 years old. Cut the stem about 25 centimeters above the ground, then plant it in the field, and use the multiple orthotropic shoots that grow after stem cutting to cultivate new stems.
No matter which method is used to cultivate multiple stems, after the new main stems have been retained, always pay attention to cutting off orthotropic shoots sprouting from the new and old stems, so as to avoid disrupting the tree shape and consuming nutrients.
② Replacement of main stems in mature trees
For coffee trees under multi-stem training, after 3 to 5 years of fruiting, because the main stems continue to grow, the fruiting position gradually rises and the growth increment of the old stems decreases year by year, so the main stems must be replaced in time. There are mainly two forms, namely one-time replacement and gradual replacement.
One-time replacement: after harvesting the fruit, saw off all the main stems at once from a point 25 to 30 centimeters above the ground. The saw cut should be slightly slanted and smooth. When large numbers of orthotropic shoots sprout below the cut, appropriately select and retain 3 to 4 robust orthotropic shoots with a certain spacing as new stems, and remove the rest. The advantages of this method are: one-time stem cutting, convenient management, and the new main stems receive uniform light and grow robustly, and will not become leggy due to excessive shade.
Gradual replacement: that is, replace 1 to 2 main stems each year and cultivate 1 to 2 new stems. Before replacing the main stems, cultivate 1 to 2 orthotropic shoots in advance. At the time of stem cutting, saw off the stem above where the orthotropic shoot sprouted. Its disadvantages are that the growth of the new stems is affected by the old stems, and they become leggy due to insufficient sunlight and are prone to bending or falling in strong wind and rain.
(3) Rejuvenation of old trees
Rejuvenation of old trees uses one-time stem cutting, and a small harvest can be obtained one year after stem cutting. Carry out stem cutting after fruit harvest, sawing the old stem from top to bottom at an angle of 30 to 45 degrees at 30 centimeters above the ground, and the saw cut should be smooth. After stem cutting, combine with deep plowing of the soil, prune part of the root system, and strengthen fertilization to promote growth. Remove excess buds in time.
(4) Rehabilitation of dead-tip trees and weak trees. Dead-tip trees are caused by branches once bearing a large amount of fruit, consuming too many nutrients themselves and then dying off in large numbers, creating a hollow phenomenon in the middle of the crown. Young trees after field planting or mature trees that, due to neglect of management, have weak and aged main stems, poor plant vigor, and bear very little fruit are called weak trees.
The rehabilitation method can, according to the condition of dead tips in the coffee tree, adopt mid-stem cutting or main-stem bending to cultivate new stems and rebuild the crown. However, water and fertilizer management must be strengthened for results to be achieved.
(5) Coffee rejuvenation by budding and variety replacement
After coffee seedling trees have fruited for many years, yield gradually declines. To increase coffee yield, the method of stem-cutting rejuvenation combined with budding and variety replacement can be used. The bud sticks used for budding are selected from high-yielding Robusta clone multiplication nurseries or mother tree gardens. The coffee tree is cut back once after fruit harvest, leaving 3 to 4 orthotropic shoots as rootstocks for budding and variety replacement. When the orthotropic shoots grow to 50 to 60 centimeters and the base has not yet lignified, field budding is carried out. (The budding method is the same as above.) This is a fast and good way to increase the yield of low-yielding coffee plantations.
5. Soil management and fertilization
(1) Weeding and mulching. Weeds easily grow in young coffee plantations, especially in the rainy season, so weeding should be done once a month. If labor is sufficient, first clear the weeds in the ring around the plant. In mature coffee plantations, weeding can be done once every 2 to 3 months. If herbicides are used, take care not to spray them on coffee branches and leaves, and use them even more cautiously in young coffee plantations.
Coffee roots are shallow, and are easily affected by adverse climatic conditions such as high temperature and drought, so mulching within the coffee plantation or within the root ring should be done well. According to experience from various places, mulching with grass in coffee plantations can increase yield by 60% to 80%; dead mulch can increase soil organic matter, promote soil microbial activity, and in hot, dry seasons can also lower soil temperature and increase soil moisture content. Mulching materials can be adapted to local conditions and sourced locally; citronella residue, rice straw, fallen leaves, and weeds can all be used. The appropriate mulching thickness is 10 to 15 centimeters, and the width depends on the material. If materials are sufficient, mulching can extend to between the rows.
(2) Deep plowing and soil improvement. This can improve soil physical and chemical properties, especially in relatively poor soil, where deep plowing and fertilization are even more important. Under general soil conditions, after deep plowing and soil improvement, lateral root growth is 3 to 4 times greater than without deep plowing, and aboveground growth also increases correspondingly. The deep plowing depth is 40 to 50 centimeters, length 60 to 80 centimeters, and width 40 to 50 centimeters, carried out once a year. It is best to press 20 to 30 jin of green manure into the bottom layer of the deep plowing hole, in two layers, and apply 4 liang of superphosphate on the green manure. In the upper layer of the hole, apply another 20 to 30 jin of compost or pig or cattle pen manure, and finally cover with soil.
(3) Irrigation. Coffee-growing areas in China all have distinct rainy and dry seasons. Irrigating in the dry season, especially when drought occurs during flowering, can ensure normal growth and flowering of coffee plants, increase the fruit-setting rate, and thereby achieve high yield.
(4) Fertilization. Fertilization is one of the key measures for obtaining high yield in coffee cultivation. According to data, for every 1 jin of dry beans harvested, the coffee tree must absorb 35 grams of nitrogen from the soil (equivalent to 6 liang of ammonium sulfate), 7 grams of phosphorus (equivalent to 1.1 liang of superphosphate), and 38 grams of potassium (equivalent to 2 to 3 liang of potassium chloride). Research by the Spice and Beverage Research Institute shows that for every 5 kilograms of fresh fruit produced, Robusta coffee requires 200 to 210 grams of ammonium sulfate, 50 grams of superphosphate, and 120 to 130 grams of potassium sulfate each year. In terms of the amount of fertilizer needed, this is not much, but coffee trees also grow large amounts of branches, leaves, stems, and roots each year, all of which consume large amounts of nutrients. In addition, shade trees absorb nutrients, and soil fixation and soil erosion also consume part of the fertilizer. Therefore, fertilization of coffee is very important.
① Within 1 to 2 years after field planting, fertilize in combination with training. Fertilization of young coffee trees is mainly nitrogen fertilizer, with appropriate application of phosphorus and potassium fertilizers, to accelerate crown formation and promote root development. Human and livestock manure and urine and green-leaf compost also have good effects on the growth of young coffee trees.
The first fertilization can be carried out two months after the coffee seedlings are planted, and afterward fertilize once every 1 to 2 months. If human and livestock manure and urine are applied, they should be fermented and decomposed, diluted with water at a ratio of 1:3 before use, applying 10 jin per plant. Liquid manure is best applied in the dry season. Ammonium sulfate can be added to the fermented manure and applied together; each carrying pole of fermented manure can be mixed with 3 to 5 liang of ammonium sulfate. Chemical fertilizers (nitrogen and potassium fertilizers) can also be applied after rain in shallow trenches dug 15 centimeters outside the crown spread, applying 15 to 25 grams per plant. Fertilization of young coffee should follow the principle of frequent application and light application.
② Fertilization of coffee trees at the fruiting stage
Under relatively good management, coffee begins to fruit in the third year after field planting. According to analysis, in addition to nitrogen, coffee fruit development also requires relatively large amounts of potassium. Therefore, fertilization of mature fruiting coffee trees should be mainly nitrogen and potassium fertilizers, with appropriate combination of phosphorus fertilizer and other elements. Applying potassium fertilizer during fruit development has a very significant effect. According to measurements, for Arabica coffee, applying potassium fertilizer in July to August has the best effect; the dry matter increase of Robusta coffee fruit has three peak periods, namely July to September, October to December, and January to February of the following year, so potassium fertilizer can be applied in 3 split applications.
Fruiting trees are generally fertilized 5 times a year, respectively in February to March (flowering stage), April to May (young fruit stage), July to September (stage when the fruit begins to fill out), October to November, and December to January of the following year. The annual application is 15 to 20 kilograms of organic fertilizer or compost, 250 to 500 grams of urea, 150 to 500 grams of superphosphate, and 150 to 200 grams of potassium chloride.
Note: "Arabica," "Robusta," and "Liberica" are the terms used in China for (Yunnan) Arabica coffee, Robusta coffee, and Liberica coffee. These terms are not necessarily scientific. Yunnan coffee is mostly "Catimor" and a small amount of "Typica" under the Arabica line, while subspecies, mutants, and hybrids under the Arabica line are as numerous as hairs on an ox.
The above content is compiled by CoffeeHunters, a coffee news website.
