What are the requirements of cotton for growing conditions and its growing environment?
Cotton is the seed fiber of plants in the genus Gossypium of the mallow family, native to the subtropics. The flowers the plant produces are milky white or pink. What people normally call cotton is the fiber inside the fruit that grows after flowering, which bursts open and turns outward when the fruit ripens. It likes heat, loves light, tolerates drought, and dislikes waterlogging, and is suitable for planting in loose, deep soil. Let us take a look below at the growing conditions for cotton!
Light conditions
Cotton is a light-loving crop, suitable for growing under relatively ample light conditions. Both its light compensation point and light saturation point are high. According to measurements, the light compensation point of a single cotton leaf is 750-1000 lux, and the light saturation point is 70,000-80,000 lux. Under normal circumstances, the suitable range of light intensity for cotton leaves is 8000-70000 lux, and within this range the photosynthetic intensity increases as light intensity rises.
Moisture conditions
Cotton growth requires absorbing water from the soil, and the physiological water requirements differ at each growth stage. From sowing to emergence, the water content of the 0-20 cm soil layer should preferably be 70-80% of field capacity; at the seedling stage, the water content of the 0-40 cm soil layer should preferably be 60-70% of field capacity; at the early bud stage, the water content of the 0-60 cm soil layer should preferably be 65-75% of field capacity; after the full bud stage, the water content of the 0-80 cm soil layer should preferably be 70-80% of field capacity, and must not fall below 60-65%; at the boll-opening stage, the relative soil water content should preferably remain at 55-70%. According to relevant research, over the entire growth period a cotton field consumes about 2/3 of its water through transpiration and 1/3 through soil evaporation.
Soil conditions
Cotton growth and development require water and nutrients, which are mainly obtained from the soil through the root system. The needed temperature and air are partly drawn from the soil, and at the same time the soil's mechanical support is required for growth. The physical, chemical and biological properties of cotton field soil largely constrain cotton yield and quality. Soil moisture, nutrients, temperature, air, salt and alkali content, and texture all have a major influence on cotton growth.
Heat conditions
The two stages of early and late cotton growth are the most sensitive to heat conditions. Sowing to emergence mostly takes 7-20 days and requires an active accumulated temperature of 160-320°C. When the air temperature remains above 20°C after sowing, seedlings can emerge in just 7-8 days. If the temperature is unstable after sowing, although it averages 15-17°C, it takes about 20 days for seedlings to emerge. The lower the daily average temperature, the more accumulated temperature is needed from sowing to emergence. The heat conditions from flowering to boll opening not only affect cotton yield but also seriously affect cotton quality. In years when the interval from flowering to boll opening is noticeably extended for the same region and the same variety, the accumulated temperature in this stage is on the high side, and cotton yield and quality decline noticeably.
How is cotton planted? Key points of cotton cultivation techniques and field management
Cotton is one of the most important crops in the world, with large yields and low production costs, which makes cotton products relatively inexpensive. It can be made into fabrics of many specifications, from light and transparent voile to thick canvas and thick velveteen, suitable for making all kinds of clothing, furnishing fabrics and industrial fabrics. It is also an important nectar plant. Let us take a look below at cotton cultivation techniques!
Growing conditions
Cotton is a light-loving crop, suitable for growing under relatively ample light conditions, and both its light compensation point and light saturation point are high. The physiological water requirements differ at each growth stage. From sowing to emergence, the water content of the 0-20 cm soil layer should preferably be 70-80% of field capacity; at the seedling stage, the water content of the 0-40 cm soil layer should preferably be 60-70% of field capacity; at the early bud stage, the water content of the 0-60 cm soil layer should preferably be 65-75% of field capacity; after the full bud stage, the water content of the 0-80 cm soil layer should preferably be 70-80% of field capacity; at the boll-opening stage, the relative soil water content should preferably remain at 55-70%. Cotton growth and development require water and nutrients, which are mainly obtained from the soil through the root system. The needed temperature and air are partly drawn from the soil, and at the same time the soil's mechanical support is required for growth.
Apply sufficient base fertilizer
Cotton has a long growth period and a deep and extensive root distribution, so it requires not only abundant mineral nutrients in the surface soil but also relatively high fertility in the deeper plow layer that can release nutrients slowly. Base fertilizer is applied by plowing into the soil before cotton sowing, which can meet this requirement. Base fertilizer is mainly farmyard manure, and it can be applied in autumn and winter together with deep plowing and deep turning, or it can be applied when preparing the land in spring. Generally, apply 3000-4000 kg of high-quality farmyard manure per mu and 30-50 kg of Stanley compound fertilizer, and at the same time apply 1-2 kg each of zinc and boron fertilizer per mu as a base application.
Sow at the right time
1. Time: 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, to set buds and flower earlier, and to extend the boll-setting time, which is conducive to early maturity, high yield and good quality. Sowing too early with low soil temperature easily causes seed rot and missing plants. Sowing too late delays each growth stage, leading to late maturity, reduced yield and lower fiber quality.
2. Seed quantity: The sowing rate should be determined according to the sowing method, seed quality, retained plant density, and soil and climate conditions. Too little makes it difficult to guarantee the proper number of plants and affects yield. Too much wastes cotton seed and also causes crowding of cotton seedlings, easily forming tall and 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 sowing rate should be increased as appropriate.
3. Depth: Cotton cotyledons are thick and have poor soil-penetrating ability, so sowing depth is closely related to how early seedlings emerge, how complete the stand is, and how strong or weak the seedlings are. If sown too deep, the temperature is low, it is difficult for seedlings to push through the soil, emergence is slow, more nutrients are consumed, seedlings are thin and weak, and it may even cause seed rot and bud rot leading to missing plants. If sown too shallow, it easily dries out, causing missing plants and gaps in the rows. Sowing depth should be determined according to soil texture and moisture. In principle, the sowing depth should be controlled at 3-4 cm. For soil with good moisture and a somewhat clayey texture, sow shallow; for soil with poor moisture and a somewhat sandy texture, sow appropriately deeper.
Pruning branches 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 fat sprouts. Removing leaf branches is one of the means of controlling excessive cotton growth to obtain high yields. For weak seedlings and cotton plants at gaps, the leaf branches may be left, and once they elongate, the tips are then pinched off. Removing leaf branches is done in the early bud stage. Generally, medium-maturing varieties with a loose plant type need leaf branch removal, while early-maturing varieties with a compact plant type may skip this work.
2. Topping the main stem: Topping can eliminate apical dominance, regulate the balanced distribution of photosynthates among the various organs, increase the proportion of nutrients allocated to the lower fruiting organs, strengthen the transport of assimilates to the root system, and enhance root vigor and the ability to absorb nutrients, thereby raising the boll-setting rate.
3. Pinching the side tips: Pinching the side tips means removing the tips of the fruiting branches. This can control the lateral growth of fruiting branches, improve field ventilation and light penetration, help raise the boll-setting rate, increase boll weight, and promote early maturity. In production, for cotton fields with ample fertilizer and water, vigorous growth and higher density, in the middle and late stages of field management, the group tips are pinched off in stages from bottom to top. Combined with the boll-setting situation, 2-3 fruiting nodes are kept on the lower part and 3-4 fruiting nodes in the middle, while the upper part can be pinched according to the timing of the local first frost.
Reasonable 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 and base fertilizer. 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, applied in furrows and covered with soil afterward. For cotton fields with high fertility and sufficient base fertilizer, seedling fertilizer may be omitted.
2. Steady application of bud fertilizer: After cotton sets buds, its demand for nutrients gradually increases. Reasonable topdressing at the bud stage can meet the needs of cotton plants for growing larger, 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, and at an appropriate distance from the cotton plants to avoid damaging the roots and affecting normal growth.
3. Applying flower and boll fertilizer: The flower and boll stage is the period when cotton needs the most fertilizer. Heavy application of flower and boll fertilizer has a notable effect on 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 somewhat earlier, when the cotton plants have flowered over 80% and have set 1-2 young bolls, and the topdressing method is preferably band application.
4. Applying topping fertilizer: Supplementary application of topping fertilizer mainly prevents nutrient deficiency and premature senescence in the late stage of cotton, promotes steady plant growth, enhances resistance to disease, pests and premature senescence, and helps set more autumn bolls and increase boll weight. Generally, foliar topdressing is carried out around topping. For cotton fields lacking nitrogen or showing premature senescence, spray 50-75 kg per mu of 1% urea solution, once every 5-7 days, for 2-3 consecutive sprays. For cotton fields lacking phosphorus or potassium, or growing vigorously and staying green late, spray a 0.2% potassium dihydrogen phosphate solution once every 7-10 days, for 2-3 consecutive sprays, so as to achieve the goal of no yellowing leaves, no leaf drop, no premature senescence, and high yield with good quality in the late stage.
**Advantages of cotton and its growing conditions
Cotton is a plant of the genus Gossypium. People are familiar with it because of the cotton quilts made from processed cotton, and cotton quilts are almost a daily bedding item that every one of us has used. In our country, when it comes to cotton, the cotton of ** is regarded as having the finest texture, mainly because the climate of the ** region is relatively suitable for growing this plant. Below we will learn about the advantages and prices of ** cotton.
**Advantages of cotton
** has uniquely favorable natural conditions, with alkaline soil, large temperature differences in summer, abundant sunshine, full photosynthesis, and a long growth period, which cause the cotton grown in ** to show more outstanding characteristics. The cotton of ** is soft in texture, comfortable to the touch, bright in color and good at absorbing water, and its quality is far superior to other ordinary cotton.
**Price of cotton
The price of ** cotton mainly changes with changes in supply, and the supply of ** cotton is mainly affected by the weather. Based on past situations, the price of ** cotton is around 12800 yuan per ton, with the fluctuation range generally within 300 yuan.
**Growing conditions for cotton
I. Light conditions for cotton growth
** cotton is mostly of early-medium-maturing, early-maturing and extra-early-maturing varieties, and is not sensitive to light length. It is a light-loving crop, suitable for growing under relatively ample light conditions. Both the light compensation point and light saturation point of cotton are high. According to measurements, the light compensation point of a single cotton leaf is 750-1000 lx, and the light saturation point is 70,000-80,000 lx. Under normal circumstances, the suitable range of light intensity for cotton leaves is 8000-70000 lx , and within this range, the photosynthetic intensity increases as light intensity rises.
II. Moisture conditions for cotton growth
Water is an important component of the cotton plant body, and cotton growth requires absorbing water from the soil. The physiological water requirements of cotton at each growth stage are: from sowing to emergence, the water content of the 0-20 cm soil layer should preferably be 70-80% of field capacity; at the seedling stage, the water content of the 0-40 cm soil layer should preferably be 60 - 70% of field capacity; at the early bud stage, the water content of the 0-60 cm soil layer should preferably be 65-75% of field capacity; after the full bud stage, the water content of the 0-80 cm soil layer should preferably be 70-80% of field capacity, and must not fall below 60-65%; at the boll-opening stage, the relative soil water content should preferably remain at 55-70%. According to relevant research, over the entire growth period a cotton field consumes about 2/3 of its water through transpiration and 1/3 through soil evaporation.
When planting cotton, what needs the most attention is the closing of the furrows for cotton. Closing the furrows for cotton is a field management measure for cotton. Cotton treated by closing the furrows will not lodge, and closing the furrows can also effectively solve the problem of field weeds.