How to Grow Cotton? A Detailed Guide to Cultivation Techniques and Field Management Key Points

Cotton is one of the world's most important crops. Its high yield and low production cost keep cotton products relatively inexpensive. It can be made into fabrics of many specifications, from lightweight, transparent voile to heavy canvas and thick velveteen, suitable for making all kinds of clothing, household fabrics and industrial fabrics. It is also an important nectar-source plant. Let's take a look at cotton cultivation techniques together below!

Growing Conditions

Cotton is a light-loving crop, suited to growing under relatively ample light conditions, with both a high light compensation point and a high light saturation point. The physiological water requirements differ at each growth stage. From sowing to emergence, a water content of 70-80% of field capacity in the 0-20 cm soil layer is ideal; at the seedling stage, a water content of 60-70% of field capacity in the 0-40 cm soil layer is ideal; at the early bud stage, a water content of 65-75% of field capacity in the 0-60 cm soil layer is ideal; after the full bud stage, a water content of 70-80% of field capacity in the 0-80 cm soil layer is ideal; and at the boll-opening stage, maintaining a relative soil water content of 55-70% is ideal. Cotton growth and development require water and nutrients, which are mainly obtained from the soil through the root system. The temperature and air it needs are partly drawn from the soil, and it also needs the mechanical support of the soil in order to grow.

Apply Sufficient Base Fertilizer

Cotton has a long growth period, and its root system is deep and extensive. It requires not only abundant mineral nutrients in the surface soil, but also relatively high fertility in the deeper plow layer that can slowly release nutrients. Base fertilizer is applied to the soil by plowing before cotton sowing, which can meet this requirement. Base fertilizer is mainly farmyard manure, and it can be applied to the soil in autumn and winter together with deep plowing and turning, or applied during land preparation in spring. Generally, apply 3000-4000 kg of high-quality farmyard manure per mu and 30-50 kg of Stanley compound fertilizer, along with 1-2 kg each of zinc and boron fertilizer as a base application per mu.

Sow at the Right Time

1. Timing: In production, the suitable sowing period is generally when the 5 cm soil temperature stabilizes above 12-14°C, or when the air temperature stabilizes above 16°C. Sowing at the right time allows cotton plants to grow steadily, promotes earlier budding and flowering, extends the boll-setting period, and is conducive to early maturity, high yield and good quality. Sowing too early, when soil temperature is low, easily causes seed rot and missing seedlings. Sowing too late delays each growth stage, leading to late maturity, reduced yield and lower fiber quality.

2. Seeding rate: The seeding rate should be determined according to the sowing method, seed quality, retained plant density, soil and climate conditions, and so on. Too little makes it hard to ensure the proper number of plants and affects yield. Too much wastes cotton seed and causes crowding of cotton seedlings, easily producing tall, spindly seedlings and increasing the labor for thinning. When the seed germination rate is low, soil moisture is poor, the soil is clayey or saline-alkaline, or underground pests are severe, the seeding rate should be increased as appropriate.

3. Depth: Cotton cotyledons are thick and large, and their ability to push through the soil is poor. Sowing depth is closely related to the time of emergence, the completeness of the cotton seedlings, and their vigor. If sown too deep, the temperature is low, pushing through the soil is difficult, emergence is slow, more nutrients are consumed, the seedlings are thin and weak, and it may even cause seed rot and sprout rot, resulting in missing plants. If sown too shallow, it easily dries out, causing missing plants and broken rows. Sowing depth should be determined according to soil texture and moisture. In principle, the sowing depth should be 3-4 cm. For soil with good moisture and a relatively clayey texture, sow shallower; for soil with poor moisture and a relatively sandy texture, sow appropriately deeper.

Pruning and Topping

1. Removing leaf branches: After the first fruiting branch appears, promptly remove the leaf branches below the first fruiting branch, keeping the main-stem leaves to provide organic nutrients to the root system. This is called removing leaf branches, or wiping off the oil shoots. Removing leaf branches is one of the means of controlling excessive cotton growth to achieve high yield. For weak seedlings and cotton plants in gaps, the leaf branches may be left until they elongate and then the side tips are tipped. Removing leaf branches is done in the early bud stage. Generally, medium-maturing varieties with a loose plant type need leaf branches removed, while early-maturing varieties with a compact plant type may skip this work.

2. Topping the growing tip: Topping can eliminate apical dominance, regulate the balanced distribution of photosynthetic products among organs, increase the proportion of nutrients allocated to the lower fruiting organs, strengthen the transport of assimilates to the root system, enhance root vigor and nutrient uptake capacity, and thereby increase the boll-setting rate.

3. Tipping side branches: Tipping side branches means removing the growing tips of the fruiting branches. This can control the lateral growth of fruiting branches, improve field ventilation and light penetration, help increase the boll-setting rate, increase boll weight, and promote early maturity. In production, for cotton fields with sufficient fertilizer and water, vigorous growth and relatively high density, during the middle and late stages of field management, remove the cluster tips in stages from bottom to top. Combined with the boll-setting situation, leave 2-3 fruiting nodes on the lower part, 3-4 fruiting nodes in the middle, and for the upper part, tip according to the timing of the local first frost.

Rational Topdressing

1. Light application of seedling fertilizer: Topdressing seedling fertilizer can promote root development and cultivate strong seedlings. Seedling fertilizer is generally mainly nitrogen fertilizer and can be determined according to seedling condition, soil fertility, base fertilizer, and so on. For cotton fields with poor soil fertility, insufficient base fertilizer and weak growth, apply 5-10 kg of urea or high-nitrogen compound fertilizer per mu in furrows, then cover with soil. For cotton fields with high fertility and sufficient base fertilizer, seedling fertilizer may be omitted.

2. Steady application of bud fertilizer: After cotton budding, the demand for nutrients gradually increases. Rational topdressing at the bud stage can meet the needs of cotton plant development, coordinate the relationship between vegetative growth and reproductive growth, and promote steady plant growth. Generally, in the early bud stage of cotton, apply 15-20 kg of Stanley compound fertilizer per mu. The topdressing method is preferably deep application in furrows, kept at an appropriate distance from the cotton plants to avoid root damage and effects on normal growth.

3. Applying flowering and boll fertilizer: The flowering and boll stage is the period when cotton needs the most fertilizer. Heavily applying flowering and boll fertilizer plays a significant role in securing the "three bolls." Generally, apply 20-30 kg of urea and Stanley compound fertilizer per mu. For cotton fields with poor soil fertility, little base fertilizer and weak growth, it may be applied appropriately earlier, when more than 80% of the cotton plants have flowered and 1-2 young bolls have set. The topdressing method is preferably band application.

4. Applying top-covering fertilizer: Supplementary application of top-covering fertilizer mainly prevents nutrient deficiency and premature aging in the late stage of cotton, promotes steady plant growth, enhances resistance to disease, pests and premature aging, and helps set more autumn bolls and increase boll weight. Generally, foliar topdressing is carried out around topping. For cotton fields deficient in nitrogen or prone to premature aging, spray 50-75 kg of 1% urea solution per mu, once every 5-7 days, for 2-3 consecutive sprays. For cotton fields deficient in phosphorus or potassium, or growing excessively and staying green and late-maturing, spray 0.2% potassium dihydrogen phosphate solution once every 7-10 days, for 2-3 consecutive sprays, so as to achieve the goals of no yellowing leaves, no leaf drop, no premature aging, high yield and good quality in the late stage.

High-Yield Cultivation Techniques and Field Management Key Points for Mung Bean

Mung bean is an annual erect herbaceous plant of the genus Vigna in the Fabaceae family. It is widely grown in various East Asian countries, with small amounts also grown in Africa, Europe and the United States. Because of its short growth period, strong adaptability and fast seedling growth, it is suitable for intercropping and relay intercropping with various dryland crops in hilly areas, and can also be intercropped or mixed with tall crops such as corn and sorghum. Let's take a look at high-yield mung bean cultivation techniques together below!

Land Selection and Preparation

1. Land selection and crop rotation: Mung bean is extremely adaptable. Generally, sandy soil, thin hillside land, black soil and clay soil can all support its growth. It is often intercropped with corn, sorghum, cotton, sweet potato, sesame, millet and other crops, and can also be planted on field ridges and in gaps. Continuous cropping is avoided, because continuous cropping leads to many pests and diseases, poor quality, and harmful microorganisms that multiply and inhibit the development of rhizobia. At the same time, mung bean is also an important soil-enriching crop and an excellent preceding crop for cereals. Therefore, when planting mung bean, land should be arranged reasonably and rotation should be practiced. It is best to rotate with cereal crops such as corn, sorghum and wheat. Chinese cabbage should not be used as the preceding crop. Generally, an interval of 2-3 years is best.

2. Land preparation and moisture conservation: Mung bean is a dicotyledonous crop. Its cotyledons emerge from the soil, and the seedlings have weak ability to push through the soil. If the soil is compacted or there are too many clods, it easily causes missing plants, broken rows or uneven emergence. Therefore, before sowing, deep plowing and fine harrowing are required, with careful land preparation, harrowing the clods level, making the soil loose, storing water and conserving moisture, preventing soil compaction, keeping the top loose and the bottom firm, so as to facilitate emergence and practice rotation.

Sow at the Right Time

1. Selecting good varieties: Select varieties with large grains, thin seed coats, low hard-seed rate, easy cooking and softening, good taste and good yield performance. The main varieties include Bailü 522, Bailü No. 6 and Bailü No. 8. The Asian Vegetable Research and Development Center's Zhonglü No. 1 and Zhonglü No. 2, and Jilin's Jilü 9346, Gonglü No. 1 and Gonglü No. 2. These varieties generally yield more than 40% higher than farm varieties.

2. Sowing at the right time: Mung bean can be sown in spring and summer. Spring sowing is from late April to early and mid-May. Summer sowing is in mid-to-late June, and early sowing should be strived for. Mung bean likes warmth. The suitable emergence and growth temperature is 15 to 18°C, and it needs relatively high temperatures during the growth period. It begins to germinate at 8 to 12°C. During flowering and pod formation, the most suitable temperature is generally 18 to 20°C. If the temperature is too high, stems and leaves grow excessively, which affects flowering and pod formation. Mung bean is not tolerant of frost in the late growth stage. When the temperature drops below 0°C, the plants freeze to death, and the seed germination rate is also low. Therefore, for summer and autumn sowing of mung bean, attention must be paid to sowing early at the right time so that it can mature normally before low temperatures and early frost arrive. The seeding rate per mu is generally 1.5-2.0 kg, and the sowing depth is preferably 3.0-5.0 cm.

3. Rational close planting: The planting density of mung bean should be determined according to variety characteristics and soil fertility. Generally, the principles are: early-maturing varieties dense, late-maturing varieties sparse; erect types dense, semi-vining types sparse, vining types even sparser; fertile land sparse, poor land dense; early sowing sparse, late sowing dense. For mung bean, generally for early-maturing varieties on low-water and low-fertility plots, the suitable density is 180,000-200,000 plants, retaining 11-15 plants per meter of row; for medium-maturing varieties under medium water and fertility conditions, the suitable density is 150,000-170,000 plants, retaining 8-10 plants per meter of row; for late-maturing varieties under high water and fertility conditions, the suitable density should be 120,000-140,000 plants, retaining 7-8 plants per meter of row.

Field Management

1. Compacting and replanting: After sowing, for plots with poor sowing moisture, compact the soil promptly, compacting as you sow, so that the seeds make close contact with the soil, increasing surface moisture, promoting seed germination and development, and achieving early and complete emergence. After mung bean emerges, if missing plants or broken rows are found, replanting should be completed within 7 days.

2. Thinning and fixing seedlings: To ensure good individual seedling development, thin and fix the seedlings. When mung bean seedlings reach the two-leaf-one-heart stage, remove clustered seedlings. At the 4-leaf stage, fix the seedlings, with a plant spacing of 13-16 cm, and a row spacing of about 40 cm for sole cropping. According to the set density, remove weak, diseased, small and mixed seedlings and weeds, and keep strong seedlings. Retain one plant per position to facilitate robust plant growth.

3. Cultivation and weeding: This not only eliminates weeds, but also breaks soil compaction, loosens the soil, reduces evaporation, raises soil temperature, and promotes nodule activity. It is a measure for increasing mung bean yield. Generally, after the first compound leaf of mung bean unfolds, the first shallow hoeing is done together with thinning; after the second compound leaf unfolds, seedling fixing begins and the second cultivation is carried out; at the branching stage, the third deep cultivation is carried out, along with root covering and earthing up. Cultivation should continue until the rows close. The cultivation depth should follow the principle of shallow-deep-shallow.

4. Irrigation and waterlogging prevention: Mung bean is a crop that needs relatively more water but is not tolerant of waterlogging and fears flooding. Mung bean seedlings have strong drought resistance and need less water, while the flowering and pod stage is the peak water demand period. At this time, if drought occurs, irrigate promptly. But mung bean also fears waterlogging and flooding. If there is too much water at the seedling stage, root diseases will worsen, causing root rot and seedling death. If waterlogging occurs in the late stage, plants grow poorly, show premature aging, flowers and pods drop, and yield declines. Therefore, mung bean should be drained to prevent waterlogging during the rainy season.

Rational Fertilization

1. The fertilization principle for mung bean should be mainly organic fertilizer, supplemented by inorganic fertilizer, with organic fertilizer and inorganic fertilizer used in combination, applying sufficient base fertilizer and appropriate topdressing. Mung bean has a short growth period and strong tolerance to poor soil, and its root system also has symbiotic nitrogen fixation capacity, so in production it is often not fertilized. However, to increase mung bean yield on medium- and low-yield plots, fertilizer should be added. Generally, apply about 10 kg per mu of seed fertilizer such as diammonium phosphate or nitrogen-phosphorus-potassium compound fertilizer. Mung bean topdressing is best done at the flowering stage together with row closing. Per hectare, 40-60 kg of nitrogen fertilizer such as ammonium nitrate or urea, and 100-120 kg of potassium sulfate can be topdressed.

2. For relatively poor plots, foliar topdressing can be carried out at the pod-setting stage, spraying plant growth agents such as potassium dihydrogen phosphate, Fu'er 655, Lüfeng 95 and Bang'er Yibianfeng on the leaves, with relatively obvious yield-increasing effects. On plots with higher fertility, the seedling stage should focus on control, and further topdressing is not suitable. Too much nitrogen fertilizer will lead to excessive vegetative growth, rampant stems and leaves, field shading, plant lodging, severe flower and pod drop, and reduced mung bean yield.

3. Although mung bean rhizobia have nitrogen fixation capacity, adding farmyard manure and phosphorus and potassium fertilizers has obvious yield-increasing effects. Farmyard manure can be applied all at once before sowing, then plowed into the soil. If there is no time to apply base fertilizer, a certain amount of nitrogen and phosphorus fertilizer should be applied in the early growth stage, that is, at branching and early flowering, to enhance rhizobial nitrogen fixation capacity and increase flower bud differentiation. Increasing organic fertilizer, inoculating rhizobia, improving fertilization methods and raising the utilization rate of chemical fertilizers: according to relevant reports, the nitrogen supplied by mung bean rhizobia can reach 50-70% of the total nitrogen required by mung bean. Therefore, rhizobia inoculation is one of the very economical and effective yield-increasing measures.

Timely Harvest

1. Generally, when 70-80% of the pods on the plant have matured, harvest at the right time on a sunny day.

2. For large-area mung bean plots, manual picking is difficult, so mung bean varieties with uniform maturity and non-shattering pods at maturity, such as Yulü No. 3, should be selected. After 70-80% of the beans have matured, harvest in the morning or evening.

3. It is best to harvest when more than two-thirds of the pods have turned black.

4. Because pods in different positions mature unevenly, varieties prone to pod shattering should be harvested in batches. For non-shattering varieties, when more than 2/3 of the pods in the whole field have turned black, harvest all at once.

How to Mulch Cotton with Plastic Film? Key Cultivation Techniques for Film-Mulched Cotton

Cotton is an important cash crop. As an important raw material for the textile industry as well as the light industry, chemical industry, pharmaceutical industry and national defense industry, developing cotton cultivation is of great significance. In the cotton cultivation process, plastic film mulching is a common cultivation method. It has effects such as preserving and raising temperature, conserving and lifting soil moisture, and protecting soil structure, and is of great significance for promoting stable and high yields in cotton cultivation. So, how do you mulch cotton with plastic film? Below is an introduction to the key cultivation techniques for film-mulched cotton. Let's take a look.

I. Pre-Sowing Preparation

1. Land selection and preparation:Choose a field with deep soil, medium or higher fertility, and flat terrain. The ground surface is required to be level, with no clods and no stubble, loose on top and firm below, with sufficient subsoil moisture and good surface moisture.

2. Increasing base fertilizer:After plastic film mulching, organic matter decomposes quickly, and the root system absorbs more fertilizer from the soil and absorbs it earlier, so the amount of base fertilizer should be increased. Generally, the base fertilizer application amount accounts for about 45% of the total; for cotton fields with relatively sandy soil, the base fertilizer should account for about 30% of the total.

Image: Cotton cultivation

II. Mulching Methods

1. Sow first, then cover:The advantages are that it can maintain soil moisture and soil structure at sowing. The heat preservation effect before emergence is good, which is beneficial to emergence, beneficial to mechanical sowing, convenient for improving sowing quality and speed, and saves labor. The disadvantages are that if the film is not broken in time to release seedlings, cotton seedlings are easily scorched by high temperatures; after the film is broken, cotton seedlings are easily damaged by low temperatures; and because the temperature and humidity differ greatly inside and outside the film, cotton seedlings have poor stress resistance after emergence and are susceptible to disease and death.

2. Cover first, then sow:After land preparation, first cover with plastic film, and at sowing time punch holes in the film according to the required plant spacing and sow through the film. The advantages are that when moisture is good, the film can be applied in time, which is beneficial to moisture conservation; when the film is broken, the holes are small, and the effects of heat preservation, moisture conservation and weed control are all relatively good; after cotton emergence, there is no need to release seedlings, and the seedlings can adapt to external environmental conditions, with strong stress resistance and relatively robust growth. The disadvantages are that manual hole punching and spot sowing require more labor, the sowing depth and amount of covering soil are not easy to keep consistent, and emergence is uneven; if rain occurs after sowing, the soil surface compacts, and breaking the crust takes more labor.

III. Sowing at the Right Time

In film-mulched cotton fields, soil temperature, moisture and other conditions are better, so the sowing period is 5-7 days earlier than open-field cotton. In the Yellow River basin cotton region, the suitable sowing period is, in principle, sowing before the last frost and emergence after the last frost; generally sowing in mid-April, with about 6-8 days needed from sowing to emergence, and after emergence the seedlings can avoid damage from the last frost.

Image: Cotton cultivation

IV. Field Management

1. Breaking the film to release seedlings:If the method of sowing first and then covering is used, when 60%-70% of cotton seedlings have emerged and most cotton seedling cotyledons have turned green, promptly punch holes in the film to release the seedlings. Generally, break the film to release seedlings twice, with the second release after full stand. The diameter of the film holes should preferably be 3-4 cm; too large a diameter will dissipate moisture and lower temperature. After the water accumulated on the leaves above the emergence holes has evaporated, immediately seal the openings with soil to prevent soil moisture loss or the film being lifted by strong wind.

2. Water and fertilizer management:Although plastic film mulching has moisture-conserving and moisture-lifting effects, after cotton flowering, transpiration is vigorous and water consumption is greater than that of open-field cotton, so timely irrigation is needed when drought occurs. At the bud stage, when the field capacity of the soil is below 55%, generally irrigate 20-30 m3 per mu; at the flowering and boll stage, when the field capacity of the soil is below 60%, irrigate 30-40 m3 per mu. Film-mulched cotton grows quickly in the early stage and flowers and sets bolls early, and is prone to premature aging in the late stage. Therefore, it needs fertilizer early and in large amounts. It requires sufficient base fertilizer and heavy application of flowering and boll fertilizer. Change the conventional single heavy application of flowering and boll fertilizer to two applications, that is, apply organic fertilizer and part of the quick-acting fertilizer when the film is removed at early flowering, and then heavily apply quick-acting nitrogen fertilizer once more when the cotton plant has set 1-2 large bolls. Combine fertilization with irrigation to give full play to fertilizer efficiency. In cotton fields of medium fertility, apply about 15 kg of pure nitrogen per mu, of which 1/3 is used as base fertilizer or seed fertilizer, with attention to combining appropriate phosphorus and potassium fertilizer, and 2/3 is topdressed at the flowering and boll stage.

3. Regulating plant type:Film-mulched cotton grows relatively vigorously at the full bud and early flowering stages. Chemical regulation should be carried out 2-3 times depending on seedling condition. The first time at the bud stage (8-10 leaves on the main stem), with mepiquat chloride or chlormequat at 30-50 mg/kg; the second time around the early flowering stage (about 15 main-stem leaves), at 50-100 mg/kg; the third time after topping, at 100-150 mg/kg. The spray volume should be such that the entire leaf surface of the whole plant is fully wet but not dripping.

4. Removing the film:In general cotton regions, it is best to remove the film around the full bud stage or early flowering. This is because around the full bud stage or early flowering, the warming effect of plastic film mulching gradually disappears, and removing the film at this time also facilitates timely field management such as fertilization and cultivation with earthing up. However, in extra-early-maturing cotton regions and hilly cotton regions, the film may not be removed, so as to give full play to the warming and moisture-conserving effects of the film.

[Editor's Conclusion]Using plastic film mulching cultivation techniques to grow cotton is one of the important measures for promoting high-quality and high-yield cotton, and it is of great significance. The above has introduced the key cultivation techniques for film-mulched cotton, hoping it can help everyone!