How many times can peanuts be planted in Guangdong a year?

Guangdong peanut and climate peanut are important oil crops, and the oil content of seeds can reach 48-60%. It accounts for more than 95% of the total edible vegetable oil in Guangdong Province. Peanuts are full of treasures. Its nuts are rich in oil, protein, various minerals and vitamins, and the peanut cake after oil pressing is superior feed and farmland organic fertilizer; Peanut shells can also be used as feed after being crushed, and many industrial products can be processed. The kernel, seed coat, shell and peanut oil of peanut can be used as medicine, the root nodules of peanut can fix nitrogen in the air, and peanut vines can be used as green manure, so planting peanuts has many benefits. Guangdong is one of the major peanut producing provinces in China, with the planting area and total output second only to Shandong and Henan, ranking third in the country. 1992, the peanut area in the whole province was 3 14.58 thousand hectares, the output was 19 17 kg, and the total output was 603,000 tons. 1. Relationship between climatic conditions and peanut production. Requirements of climatic conditions at different growth stages Peanut is an annual leguminous crop in tropical hilly areas, which is warm-loving, drought-tolerant and waterlogging-resistant. Temperature, light, moisture, gas and other climatic factors during peanut growth have great influence on peanut growth and yield formation. From sowing to harvesting, peanuts go through seed germination, seedling stage, flowering and fruiting stage, pod development stage and seed maturity stage. 1. Germination and seedling stage: Peanuts can only start to emerge after sowing in the soil and absorbing about 50% of their own weight of water. When the soil moisture content is 60-70% of the field capacity, the germination rate is the highest; When it is less than 50%, the seedlings are uneven. If it is less than 40%, the seeds can hardly germinate and emerge. However, the soil moisture content reached more than 80-90% of the field capacity, which led to difficulty in breathing and decreased germination rate. When peanut seeds germinate and emerge, the optimum temperature is 15-35℃. The lowest germination temperature of pearl bean and multi-grain varieties is 65438 02℃, and that of common and dragon varieties is 65438 05℃. Therefore, the soil temperature must be above 12- 15℃ before sowing. Low temperature will prolong the germination and emergence time, consume a lot of seed nutrients, affect the emergence rate, and even lead to lack of seedlings and broken ridges. Too high a temperature is also unfavorable. When the temperature is 40℃, the germination rate decreases, and it cannot germinate when it exceeds 48℃. In the sowing season of spring peanuts, the temperature is low, so the seedling stage often lasts more than 10 days. The temperature is high in summer and autumn, and it only takes 7- 1 1 day from sowing to emergence. In addition, when peanuts germinate, the soil should be well ventilated, otherwise it will affect the germination of seeds and the emergence of seedlings. Therefore, it is most suitable to choose loose and breathable sandy loam to grow peanuts. 2. Seedling stage: The suitable temperature for seedling stage is 20-27℃, when the plants are short and dense; When the temperature is lower than 15℃, the growth of seedlings is slow, and chilling injury will occur if the temperature is lower than 8℃ continuously. At 0-4℃, he died after 6 days. When the temperature exceeds 27℃, although the growth of seedlings is accelerated, it is easy to form weak seedlings. Drought tolerance at seedling stage, and soil water content is 50-60% of field water capacity. Even if the field water capacity is less than 50%, it has little effect on seedling growth. Local drought in soil is beneficial for peanut to take root and sprout in Miao Zhuang. When the soil moisture exceeds 70% of the field capacity, it is rainy, which often causes wet damage, making the root system of peanut plants weak and the seedlings yellow. Of course, too dry soil is not good for seedling growth, which leads to poor plant growth and inhibition of flower bud differentiation. Adequate light at seedling stage can shorten plant internodes, increase branches, advance flowering period and increase flowers. So there are many sunny days during the seedling growth period, which can make the seedlings grow healthily. 3. Flowering and needle dropping period: During this period, the stems and leaves of peanuts grow rapidly, and a large number of flowers and needles are released at the same time. The number of flowering needles is closely related to meteorological conditions, and the optimum temperature is 23-28℃. In this range, the higher the temperature, the more needles fall during flowering. When the average temperature of the day is lower than 2 1℃ or higher than 30℃, the number of flowers is obviously reduced, and when the temperature is lower than 19℃, fruit needles cannot be formed. A large amount of water is needed in flowering period, and the suitable soil water content is 60-70% of the field capacity. Soil drought not only affects flowering, but even interrupts flowering. However, when the soil moisture content exceeds 80% of the field capacity, it will lead to long stems and leaves, fewer flowers and fewer needles. Adequate sunshine promotes early flowering, more flowers and orderly flowers. The weather is rainy, the light is weak, the main stem of peanut grows fast, the branches are few, the plants are thin, the full flowering period is delayed, and the invalid flowers are increased. Therefore, it is necessary to keep the rows ventilated and breathable after sealing the line, so as to bloom more and put more needles. 4. Pod development period: During this period, the soil should be moist, and the soil water content should reach 60% of the field water capacity. When the soil is short of water, the ovary stops growing and the fruit is formed, but too much water in the soil leads to poor ventilation, lack of oxygen in the soil, premature root senescence, and an increase in empty fruit, fruit and rotten fruit. The optimum temperature for pod development is 25-33℃, when pod develops rapidly and gains weight. When the temperature of big peanut is lower than 15℃ and small peanut is lower than 12℃, the pod will gradually stop growing and bear fruit easily. 5. Seed maturity: The suitable soil temperature in this period is 25-30℃. When the soil temperature is higher than 40℃, the vegetative growth of plants declines too early and too fast, the dry matter accumulation is less, and the weight gain of nuts is not great; When the temperature is lower than 20℃, plants are greedy, dry matter accumulation is less, and nuts gain little weight. This period requires soil moisture, which is beneficial to pod expansion and grain oil accumulation; If the soil is dry, it will affect the plumpness of nuts and the oil content will drop obviously; The soil is too wet, which leads to the futile growth of plants and even the germination and rot of nuts. This period needs sunny and warm weather, which is beneficial to pod fullness and grain weight gain under sufficient sunlight. 2. Analysis of peanut yield and climatic conditions. The main climatic factors affecting peanut yield are: (1) temperature from March to May. Peanut needs a certain accumulated temperature throughout its growth period. In years with high temperature, the days required for growth period are shortened correspondingly, and the accumulation of nutrients is reduced, which is not conducive to high yield. On the contrary, when the temperature is moderately low, the number of days required for the growth period is correspondingly prolonged, more nutrients are accumulated, and the yield is higher. According to statistics, there is a significant negative correlation between the total accumulated temperature from March to May and peanut yield, indicating that the temperature in March to May is appropriately low, which is beneficial to high peanut yield. (2) Rainfall 20-40 days after flowering. 20-40 days after peanut flowering is the period from the formation of peanut underground pods to the expansion and maturity, which requires moderate precipitation. If there is too much precipitation, too high soil humidity, or even floods, and the soil air is less, it will affect the normal absorption function of the root system, leading to premature aging of peanuts, rotten roots and pods, or mildew and germination, leading to yield reduction. According to statistics, the precipitation 20-40 days after peanut flowering is negatively correlated with peanut yield. (3) Sunshine at flowering. Sunshine has an effect on the formation of peanut yield, especially in the flowering and fruiting period. If there is enough sunshine in this period, the number of peanut blossoms will increase obviously, and the flowering period will be relatively concentrated, which is beneficial to the formation and increase of the first and second effective pods and easy to achieve stable and high yield. On the contrary, during this period, there was less sunshine and more rainy days, the branches and leaves of peanuts were too lush, the flowering period was not concentrated, the flower potential was weak, and the number of effective pods in the first and second batches was small, so it was difficult to obtain high yield. According to statistics, there is a significant positive correlation between sunshine hours and yield in 20-40 days after peanut flowering. Therefore, in the production, long-term sunshine should be arranged at the flowering stage of peanuts to improve the photosynthesis intensity of peanuts and thus increase the yield of peanuts. (4) According to the research, when the average temperature of the day is ≤ 65438 02℃, the pod stops developing; When the average temperature of the day was 65438 05℃, ovarian development stopped. Therefore, the daily average temperature of peanut during the growing period should be above 65438 05℃. Peanuts can mature in places where the daily average temperature is ≥ 15℃ and the accumulated temperature is above 2600℃. The areas with average daily temperature ≥ 15℃ and accumulated temperature above 3500℃ are most suitable for peanut planting. Because of the high temperature in the early stage, the vegetative growth period is shortened and the nutrient accumulation is less, it is difficult to obtain high yield of autumn peanut. The flowering needle stage and pod development stage are also in the process of little rain and obvious cooling in our province, especially in northern Guangdong, which leads to the obvious extension of flowering maturity compared with spring sowing, and often stops development because the temperature is lower than the lower limit temperature required for pods, resulting in a large number of cracked or semi-full fruits. (5) In some years, sowing is late or low temperature comes early, resulting in insufficient heat in the late growth stage of autumn peanuts, resulting in insufficient pod setting and reduced production. Three. Main agricultural climate problems and countermeasures in peanut production. Low temperature and rainy weather in early spring: low temperature and rainy weather often occurs in Guangdong from February to March in early spring. It affects the timely sowing and emergence of spring peanuts, leads to rotten seeds and dead seedlings, and affects the yield. For example, in 1976, severe cold weather occurred in our province, and rotten seeds and dead seedlings generally appeared in spring peanuts, which seriously affected the yield of that year. Defensive measures: (1) sow in time. (2) Choose "cold tail and warm head" to sow in sunny days, which is beneficial to seed germination and ensure the whole seedling. (3) Cultivate cold-resistant and high-yield varieties and adopt autumn seeds. The cold resistance of autumn sowing seeds is obviously stronger than that of spring sowing seeds, and autumn sowing seeds emerge quickly, neatly and with high emergence rate. (4) Early sowing peanut fields should choose fields with high terrain and no water accumulation, and pay attention to field drainage. (5) Seed selection before sowing and pest control during sowing. 2. Rain and waterlogging: The influence of rain and waterlogging on peanuts mostly occurs in the concentrated period of heavy rain in the first flood season in central and northern China. Around June, it is the mature stage of peanut pods in spring, and it is also the rainstorm-prone period in the north-central part of our province. Frequent floods and waterlogging in the soil lead to slow ripening of peanut pods and more fruits. Mature pods are easy to fall off and germinate, and often cause rust, which leads to a decline in yield. Defense measures: mainly do a good job in irrigation and drainage system, adopt ridge planting and dig irrigation and drainage ditches to ensure that there is no water in the field after rain, and the furrow will dry up after rain, so as to reduce the groundwater level and soil water accumulation. 3. Drought: mainly spring drought in southwestern Guangdong and autumn drought in northern Guangdong. In the year of severe spring drought, it is difficult for peanuts to germinate and emerge, and there are many seedlings missing, which directly affects the yield. Autumn drought mainly affects the development and maturity of autumn peanut pods, thus affecting yield and reducing seed quality. Defensive measures: (1) sow in time. In areas prone to autumn drought, autumn peanuts should be sown early in time; Drought-resistant sowing should be adopted in areas prone to spring drought. (2) irrigation. (3) Add deep ploughing layer to improve water holding capacity. Practice has proved that deep tillage has a good effect on increasing soil water storage and resisting the threat of drought. 2. Analysis of climatic characteristics of peanut planting areas According to the climatic conditions affecting peanut growth and the present situation of peanut planting, peanut planting areas in our province can be divided into three areas: southwest Guangdong, central Guangdong and northern Guangdong. Compared with climatic conditions, the growth, development and yield formation of peanuts are equivalent to the most suitable area in southwest Guangdong, the most suitable area in central Guangdong and the less suitable area in northern Guangdong. 1. Peanut area in southwest Guangdong: including all areas from the south of Yangjiang City to the south of Yunkai Mountain, it is the most important peanut producing area in our province. This area is characterized by low latitude and abundant heat, belonging to the northern tropical monsoon climate. The annual average temperature is 22-24℃, the highest average temperature in Leng Yue is 15- 17℃, and the accumulated temperature is ≥ 10℃8000-8500℃. Peanuts can be planted in spring, summer and autumn, and in winter in Leizhou Peninsula. The rainfall in this area varies greatly, with more rainfall in the north than in the south, more in summer and autumn, and less in winter and spring. The rainy season generally begins in mid-April, with low temperature and more light rain in spring, and the spring drought in Leizhou Peninsula is more prominent, which affects the planting of peanuts in spring. In addition, typhoons and rainstorms in summer and autumn bring floods, which have a certain impact on the growth of autumn peanuts in the middle and late stages. Cooling in late autumn is beneficial to the growth and yield formation of autumn peanuts. (2) Peanut area in central Guangdong: the south includes the northern boundary of peanut area in southwest Guangdong, and the north includes all areas south of Fengkai, Deqing, Qingcheng, Fogang, Longmen, Zijin, Meixian and Tai Po lines. It basically belongs to the subtropical monsoon climate, with an annual average temperature of 20.0-22.5℃, the most Leng Yue average temperature of 10.0- 14.5℃, and the accumulated temperature of ≥ 10℃ of 6500-8000℃, with slight freezing damage. The rainy season begins in early April and ends in the middle of 10. The temporal and spatial distribution of precipitation is uneven. There are three rainfall centers in this area, which are located near Enping, Puning and Fogang. The annual rainfall of each center is more than 2000 mm, of which Enping is as high as 2600 mm, and the areas with less annual rainfall in this area are Luoding and Yunan. Xingmei basin; The average annual rainfall in Nanwo, Raoping, Chenghai and southern Leizhou Peninsula is below 1500mm. It belongs to the summer rain area, and the rainfall from April to September accounts for more than 80% of the annual precipitation, while the winter rain only accounts for 8- 10%. There is more precipitation in the first flood season, which has certain influence on pod setting and maturity of spring peanuts. 3. Peanut area in northern Guangdong: including all areas from the northern boundary of peanut area in central Guangdong to the south of the northern boundary of this province. It basically belongs to the subtropical monsoon climate, with an annual average temperature of 19-2 1℃ and an average temperature of 7- 10℃ in Leng Yue. >; = 10℃ Accumulated temperature 5900-6600℃. The heat condition in this area is a little poor, and the low temperature and rainy weather are serious every spring, which affects the whole spring peanut seedling. The temperature drops early in autumn, and peanuts planted in autumn feel insufficient heat in the later stage of growth, with more rain in spring and summer and less rain in autumn and winter. The rainy season generally begins in the middle and late March and ends in late September. The rainfall in the flood season before April to June is more than that in the flood season after July to September. There is a little more rain in winter than in the south, accounting for more than 10% of the annual rainfall. Drought and waterlogging are common, especially in autumn, which is not conducive to the late growth and yield formation of autumn peanuts. It is advisable to choose waterlogging-resistant and drought-resistant varieties and sow them early in time. Peanut cultivation techniques for stable and high yield (1) should be sown in time to strive for the whole seedling. Whole seedling is an important link for stable and high yield of peanut. Spring peanuts are sown too early, often due to the influence of low temperature, resulting in serious seedling shortage; Sowing too late will delay the peanut production season. Therefore, we should sow in time according to the climate law. Generally speaking, it is more appropriate to plant seeds around the rain in southern Guangdong, from the rain to the shock in central Guangdong and from the shock to the vernal equinox in northern Guangdong. The suitable sowing date of autumn peanut mainly considers that it is not affected by low temperature (the daily average temperature is lower than 15℃) in the late pod setting period to ensure the normal development and maturity of pods. That is, the end point is the date when the daily average temperature stably passes 15℃ and the all-day guarantee rate reaches 80%. According to the growth days of different varieties, it is determined by backward calculation in summer. Then the northern part of the province should not be later than "beginning of autumn", the central part should not be later than "Summer" and Leizhou Peninsula should not be later than "Bailu". (2) Promote local excellent peanut varieties. At present, the peanut varieties planted in our province are: Guangdong Oil 1 16, Shanyou 27, Shanyou 7 1, Shanyou 523 and Guangdong Oil 256. These varieties are ideal in yield, disease resistance and maturity, and are suitable for planting all over the province. Among them, Shanyou 7 1 has strong fertilizer tolerance, lodging resistance and disease resistance, and its plants are short, so it is suitable for planting in coastal windy areas. Shanyou 523 is fertilizer-tolerant, with large pods and high yield, but its plants are tall and lodging-resistant, so it is suitable for planting in inland calm areas. (3) Promote autumn planting reasonably. Autumn peanut seeds have high protein content and good quality. After sowing, it has strong tolerance to bad environment such as low temperature, drought and waterlogging, and is not easy to be infected by germs. After sowing, they can easily get complete seedlings, which is an effective and feasible measure to increase production. In areas where there are no conditions for planting autumn peanuts, it is necessary to do a good job in collecting, drying and storing spring peanuts. (4) Deep ploughing and soil improvement, fine soil preparation and continuous border planting. Peanut is an underground fruit crop, and soil environmental conditions have great influence on pod development. Good soil conditions are the basis for the normal development of pods, which requires deep, loose and moist soil environmental conditions. If the soil is hardened and the air permeability is poor, it will affect the growth of pods. Deep ploughing and soil improvement can not only play the role of heat preservation and water conservation, but also increase the oxygen in the soil, improve the soil environment for peanut growth, increase the number of fruits per plant and increase peanut yield. In addition, the ridge should not be too big and too wide, so as to give full play to the advantages of peanuts. It is necessary to open holes to plant peanuts, implement reasonable close planting, do a good job in field irrigation and drainage ditches, and avoid and alleviate the impact of drought and flood on peanuts. (5) Do a good job in crop rotation and improve the soil climate. If crops are planted continuously for a long time or it is not suitable to arrange previous crops, soil fertility will be reduced, physical and chemical properties of fertile soil will be destroyed, good soil climate and environmental conditions will be lost, and pests and diseases will be more serious. Because all kinds of peanut Fusarium wilt are common, solanaceae crops should be banned from making peanut stubble. Popularizing peanut-rice rotation is beneficial to high yield and high yield again; Rotation of peanut with corn, sugarcane and sweet potato in dryland can increase soil organic matter and improve soil physical and chemical properties. On the other hand, it can prevent peanut wilt and promote stable and high yield of peanut and rotation crops. Therefore, rational crop rotation is a measure to make rational use of land resources, increase the output of grain and oil, and improve economic benefits. Six, the appropriate promotion of plastic film planting peanuts. Plastic film cultivation is a new technology in peanut production in recent years. According to experiments in various places, cultivating peanuts with plastic film can not only prevent cold and keep warm, but also sow in early spring, which can not only make spring peanut seedlings fully robust, but also appropriately extend the vegetative growth period, increase the effective flower and fruit setting rate, reduce weeding labor, harvest early, and increase production and income. In particular, the cultivation of peanuts with plastic film can overcome the shortcomings that spring peanuts often encounter rainy weather, and the rain directly washes the soil after sowing, thus keeping the soil loose and preventing the loss of water and fertilizer. In case of dry weather, it can also protect water and prevent drought, thus achieving the purpose of increasing production. (seven) pay attention to the prevention and control of peanut rust, leaf spot, bacterial wilt and various Fusarium wilt in the whole growth process.