After planting wheat for three days, the temperature dropped by about five degrees below zero. Can wheat germinate? Will it freeze?
How to plant wheat seeds
1, select improved varieties.
Selecting improved varieties with good quality, high productivity per plant, strong stress resistance, high economic coefficient and no premature aging is conducive to achieving the yield target of 1000 kg or more.
2. Fine soil preparation and balanced fertilization
2. 1 fine soil preparation
In order to improve the soil structure and enhance the ability of soil water storage and moisture conservation, intensive cultivation, ploughing 23~25 cm before sowing, and returning orange stalks to the field, not only enhance soil fertility, but also break the plow bottom, reaching the standard of depth, fineness, permeability, flatness, solidity and sufficiency (water), that is, the tillage layer should be deep (dry land 20~25cm, rice stubble land 65438).
2.2 Trenching on the boundary
Build a ridge, establish supporting facilities for irrigation and drainage in wheat fields, and dig "three ditches" (wet ditch, waist ditch and underground ditch). After the spring, dredge the "three ditches" in time and connect the ditches to meet the requirements of irrigation and drainage.
2.3 Balanced fertilization
According to the comprehensive fertility of soil, the fertilization scheme is formulated, with organic fertilizer as the main component and combined application of organic fertilizer and inorganic fertilizer to improve the organic matter content of soil and achieve the purpose of balanced fertilization. In order to reduce the winter snow and spring rain, we should apply sufficient base fertilizer at the same time, including organic fertilizer 30~45 t/ ha, pure N 225.0kg/ ha, P2O5 90.0 ~112.5 kg/ha, K2075.0 ~112.5.
3. Sow in time.
3. 1 seed treatment
Before sowing, the seeds should be coated with chemicals, or the coated seeds should be directly selected.
3.2 Suitable sowing date
In order to cultivate strong seedlings, form a wheat production group with developed roots and many tillers, make full use of heat resources and sow in time, thus laying the foundation for high yield of wheat. Generally, when the water content of wheat in the field is 70%~80%, it is most beneficial to seedling emergence. Therefore, when the sowing date conflicts with the soil water content, it is necessary to sow with suitable water content, which can be 3~5 days later, so that the wheat can be fully planted. Generally speaking, the best sowing temperature is 16~ 17 and 650℃ before the daily average temperature and winter ≥0℃, and 6 pieces 1 core seedlings can be formed during the overwintering period.
3.3 sowing amount
According to the characteristics of wheat varieties and sowing dates, the sowing amount of wheat is determined. General semi-winter varieties and weak winter varieties were sown in the early, middle and late September of 10 respectively, and the sowing amount was 90~ 105 kg/ha. The middle and late June of 65438+1October and the late June to early October of 65438+1October are suitable for sowing weak spring varieties and spring varieties respectively. The sowing amount is120 ~150kg/ha, and the sowing amount will increase appropriately with the delay of sowing date. In high-yield fields over 7,500 kg/ha, the basic seedlings can be controlled at 6.5438+0.8 million ~ 2.25 million plants/ha, and the sowing at the end of September1early October can be reduced to 6.5438+0.5 million ~ 6.5438+0.8 million plants/ha. For large panicle varieties with few tillers and few panicles, it is suitable for basic seedlings 1.95 million ~ 2.7 million plants/hectare.
4. Scientific on-site management
4. 1 Scientific fertilization and weeding
In order to prevent the phenomenon of lack of seedlings and broken ridges and ensure the safe winter of wheat, irrigation should be carried out in time to form a strong root system of wheat. In order to make the weeding effect better, 65438+ can carry out chemical weeding from mid-October to late February in/kloc-0. From mid-February to the end of February, and in the middle and late March, 75~ 120,120 ~150kg/ha were applied topdressing, respectively, to promote the greening and jointing of wheat and improve the tillering rate of wheat. Watering green water in early March, topdressing and watering wheat fields with moderate fertility, small population but high fertility and suitable population or large population before, early and late jointing stage respectively.
4.2 Chemical Control and Lodging Prevention
Wheat lodging can be divided into root lodging and stem lodging. Generally, the main reason is stem lodging, mainly because of the large amount of nitrogen fertilizer applied in the early stage, which leads to too large wheat population, closed field, poor ventilation and light transmission, long basal internodes, and easy lodging in windy weather in the later stage. Therefore, scientific fertilization and watering should be carried out according to soil fertility in wheat production.
4.3 Heading and filling maturity
In the heading and flowering period of wheat (middle and late April), in order to control wheat aphids, midges, armyworms, rust, powdery mildew, red blight and so on. To prolong the growth period of wheat and increase the yield, pesticide/kloc-0 can be sprayed continuously for 2 times. Irrigate 1~2 times at the same time, and irrigate 1 at heading and flowering stage, so as to protect flowers, increase grains and promote filling, achieve the purpose of big grains and heavy grains, and prevent premature root senescence; Irrigation with wheat yellow water for the second time to supplement water and make preliminary preparations for the second crop.
5, timely harvest
Generally, in the first half of June, the wheat is basically mature, and two-thirds of the wheat ears in the whole wheat field are harvested in Huang Shi. The end of wheat wax ripening is the best harvesting time. But wheat should not be over-ripe, so as not to lose seeds and reduce the harvest. Wheat should be harvested, dried and stored separately according to varieties, so as to avoid mixed varieties and reduce the commodity and economic value of wheat.
What is the optimum temperature for wheat seed germination?
Wheat seeds can germinate at 4 ~ 37℃, the fastest germination temperature is 20 ~ 25℃, and the optimum sowing time is 16 ~ 18℃. The lowest temperature of wheat germination is 0℃, and the highest temperature is 30 ~ 35℃.
According to the actual investigation and field experiment, the agro-meteorological indexes of suitable sowing date of wheat were determined. Usually, the accumulated temperature of the main stem is 70 ~ 90℃ for each additional leaf age before winter (low-fertilizer land and drought time need more accumulated temperature), and the accumulated temperature from sowing to emergence needs 80 ~ 100℃, so the accumulated temperature from sowing to tillering (three-leaf spreading) needs about 340℃. Generally, wheat seedlings grow 6 ~ 7 leaves and 3 ~ 5 strong seedlings before winter.
The accumulated temperature before winter or after sowing is 450 ~ 700℃, including 450 ~ 600℃ for spring varieties and 500 ~ 700℃ for winter varieties.
Due to the inter-annual instability of suitable sowing date of wheat, the determination of sowing date in a specific year must be based on the comprehensive analysis of climatic and ecological adaptability of varieties, weather forecast and agricultural conditions of that year. For example, the suitable sowing date of winter wheat in Beijing is 5 ~ 6 days earlier than normal, and it can be delayed by about 5 days in autumn and warm years.
The suitable sowing date of autumn sowing wheat in plain areas of China is mainly determined by temperature. Generally speaking, for every latitude increase of 65438 0 degrees, the sowing date will be advanced by 4 days. In the same area, for every elevation increase of 100 meters, the sowing date will be advanced by about 4 days. The suitable sowing date of northern wheat in northern winter wheat area is from mid-September to early October of 10, from late September to early October of 10 in Huanghuai Plain, and from 1 165438 in the middle and lower reaches of the Yangtze River.
The suitable sowing date of spring wheat is when the average temperature is stable at about 0 ~ 2℃ and the topsoil is frozen for 6 ~ 7 cm. It is best to freeze in the midnight snack during the day and sow around noon. The northeast spring wheat area is generally from mid-March to mid-April, early in the south and late in the north; The spring wheat area of Qinghai-Tibet Plateau is around the middle and late March. From mid-March to mid-April in the northwest spring wheat area, it is late in northern Xinjiang and early in southern Xinjiang. In the same area, it is generally better to sow low-lying land first and then highland.