1. What are the links of pollution-free lotus root cultivation techniques? In lotus root cultivation, there are five cultivation methods: shallow water lotus root, deep water lotus root, pond lotus root, plastic film lotus root and protected lotus root. But in essence, pond lotus root, plastic film lotus root and protective lotus root all belong to the category of shallow water lotus root. Therefore, the cultivation techniques of shallow water lotus are mainly introduced here. Specifically, the cultivation techniques of pollution-free lotus root include soil preparation, seedling raising, field planting, water and fertilizer management, field weeding, facility management, pest control and product harvesting. 2. Soil preparation in pollution-free lotus root cultivation. Soil preparation is to select suitable plots and do a good job of ploughing and applying base fertilizer under standard environmental conditions. The suitable soil pH for pollution-free lotus root cultivation is 5.6 ~ 7.5, and the salt content is below 0.2%. It is required that the water source is sufficient, the terrain is flat, the irrigation and drainage are convenient, the water depth can be kept in the range of 5 ~ 30 cm all the year round, and the deepest water depth does not exceed 1 m. Generally, about 15 days before field planting, the suitable tillage depth is 25 ~ 30 cm. Weeds should be removed during soil preparation, so that the mud surface is smooth and the mud layer is soft. Base fertilizer should be applied again in lotus root cultivation. It is suggested that 3000 kg of decomposed organic fertilizer, 60 kg of diammonium phosphate and compound microbial fertilizer 180 kg should be applied per mu of base fertilizer. 25 kg of compound fertilizer, 50 kg of decomposed cake fertilizer and 20 kg of urea can also be applied per mu. In the land where lotus roots are planted in the first year, or in the land where lotus roots have been planted for more than three years, 50 ~ 100 kg of quicklime can be applied per mu. 3. The content of lotus root seedling includes lotus root seedling, also called seed lotus root seedling, including two aspects, namely the quality and quantity of seed lotus root. The first is the quality of lotus root, which has five aspects. (1) Variety purity. Generally, the purity of varieties used for production should be no less than 95%. (2) Seedling size. You can remember a "1, 2,3 requirement", that is, a single lotus branch is required to have no less than 1 terminal buds, no less than 2 complete nodes and no less than 3 nodes. (3) freshness. Generally speaking, it is best not to exceed 10 days from digging to planting, and it is best to dig and plant at any time. Short-term storage, you can soak in water, or you can water it to keep it moist and shade it in the sun. (4) intact. Require no pests and diseases, no dangerous pests and diseases, and lotus seeds should be selected in areas without serious pests and diseases. No big mechanical damage, fresh and not wilting. Lotus seeds and lotus roots can normally carry about 15% mud, which plays a protective role. (5) disinfection. It can be disinfected by soaking in 800 times solution of 50% carbendazim wettable powder, and the soaking time is generally 30 minutes. Secondly, the requirement of lotus seed quantity, which is the second content of lotus seed preparation, is to determine the appropriate seed quantity. In general, the amount of seed lotus root per mu for early-maturing cultivation is 250 ~ 300 kg, and that for middle-late-maturing cultivation is 250 kg. 4. Lotus root "micro-seed lotus root" technology has been widely applied. The amount of seeds used for lotus root per mu is 250 ~ 300 kg, referring to the conventional amount of lotus root. The extensive use of lotus seeds undoubtedly increases the transportation cost and introduction difficulty, increases the possibility of mixed varieties, and greatly limits the development of lotus root industry. "Miniature lotus root" is not a new variety, but a new seedling form. It uses tissue culture technology to cultivate "test tube lotus root" indoors, and then further cultivates "test tube lotus root" into "miniature seed lotus root" for production and utilization. The single weight of "mini-seed lotus root" is only 0. 15 ~ 0.2kg, which is 3 ~ 4 times. The seed consumption per mu of "mini-seed lotus root" is 120 ~ 150, and its total weight is only 20 ~ 30kg, which is less than 10% of the conventional seed consumption. So it is very suitable for long-distance introduction and transportation. In addition, "miniature lotus root" can reduce the harm of pests and diseases and reduce the use of pesticides because it does not carry germs. Many years' production practice shows that there is no difference between the yield per mu of "miniature seed lotus root" and that of conventional seed lotus root cultivation. 5. Problems needing attention in lotus root field planting, that is, how to plant lotus root, including planting time and method. As far as planting time is concerned, it is gradually delayed from south to north. Fujian, Guangdong, Guangxi, Yunnan, Hainan and other places are generally planted in early March to early April, the Yangtze River basin is generally planted in late March to mid-April, and the Huanghuai basin is generally planted in mid-April. If plastic greenhouse is used for covering cultivation, the planting period can be advanced by about 15 ~ 20 days. As far as planting methods are concerned, it is required to plant evenly, with appropriate depth and inward lotus root buds. Generally, the row spacing is 1.2 ~ 1.5m, and the hole spacing is1~1.2m; The row spacing and hole spacing of early-maturing cultivation are 2 ~ 2.5m and1.5 ~ 2m respectively. Greenhouse cultivation belongs to the category of early-maturing cultivation. The optimum planting depth is 5 ~ 10 cm, and the showerhead is inserted into the mud at an angle of about 20. For the planting holes around the field, it is required that the shower heads of all lotus branches face the field. 6. The farmer's proverb says, "If there is no water, there will be no harvest, but if there is more fertilizer, there will be less harvest". How to manage water and fertilizer well in producing pollution-free lotus root. As far as the water level depth of lotus root field is concerned, lotus root should maintain a certain depth throughout the growing season, but the requirements are different in different periods. General water depth 10 ~ 30 cm is ok. When the early temperature is low, the water depth should be shallow. In summer and hot season, the water depth should be appropriate. In places with low temperature in winter, when lotus roots stay underground for the winter, deep water irrigation should be used appropriately to prevent freezing injury. As far as fertilizer is concerned, lotus root cultivation emphasizes the re-application of base fertilizer, which we have already introduced when we talked about soil preparation. What is said here is topdressing. Generally, it is required to apply the first and second topdressing on the 25th-30th day and 50th-60th day after planting, with 65,438 0.500kg of decomposed manure or 20kg of compound fertilizer and 65,438 0.5kg of urea applied each time. In order to harvest the aged lotus root, the third topdressing was carried out on the 75th-80th day after planting, and 65438 00 kg of urea and 65438 kg of potassium sulfate were applied per mu. Even in the process of fertilization in the lotus field, we should try to avoid spreading fertilizer on the leaves, and water and rinse the fertilizer scattered on the leaves in time to avoid damage to the leaves. 7. Weed control in lotus field. In pollution-free lotus root cultivation, weed control should start from the land preparation stage. Before planting, combine soil preparation and ploughing, do a good job in rural cleaning and remove weeds in the field. It is suggested to manually pull out weeds in time before closing the line after planting. After the closure of the lotus field, the harm of weeds was naturally suppressed. Focus on prevention and control of Spirogyra. When spirogyra occurs, it can be taken with copper sulfate solution in sunny days, every 7 days 1 time, * * * 2 ~ 3 times. The dosage of copper sulfate depends on the water depth, and the dosage per mu of field is calculated according to the dosage of 0.5 kg copper sulfate per 10 cm of water depth. Problems in using herbicides in lotus root field. Here, according to our understanding, farmers are advised to be cautious when using herbicides in lotus fields. There are two specific requirements: first, strictly follow the requirements of the instruction manual; The second is to try it out in a small area and observe it for 3 ~ 5 days before deciding whether to use it in a large area. 8. Key points of facility management The purpose of lotus root facility cultivation is mainly early maturity cultivation. For facility management, the emphasis is on temperature regulation. At the beginning, the temperature in the facility should be kept at 20 ~ 30℃ and should not be lower than 65438 05℃. When the temperature in the facility is above 30℃, the film should be uncovered for ventilation during the day, and the daily film uncovering ventilation time should be gradually increased with the increase of temperature. When the daily average temperature is above 20℃, the film at both ends of the facility should be uncovered day and night to keep ventilation; When the daily average temperature is above 23℃, the covering film should be completely removed (the skeleton of the small arch shed should be removed at the same time). 9. In the process of planting and production of pollution-free agricultural products, pest control technology is often the key factor affecting the quality and safety of products. So, how to control pests and diseases in pollution-free lotus root production? Pest control technology, especially pesticide application technology, is often the decisive factor of the quality and safety level of pollution-free agricultural products. Therefore, we should master the principle of pest control of pollution-free agricultural products, that is, adhere to the policy of "prevention first, comprehensive management", focusing on "agricultural control, physical control, biological control" and combining chemical control measures. 10. Measures to be taken in the process of lotus root pest control In the process of pollution-free lotus root pest control, the priority measures to be taken include "agricultural control, physical control and biological control". Agricultural control is to choose disease-resistant varieties and plant disease-free lotus roots; Adopt paddy-upland rotation and freeze in winter; Clean the countryside, strengthen weeding and reduce the source of pests and diseases. For example, removing weeds such as POTAMOGETON POTAMOGETON and Hedyotis diffusa in the field can reduce the harm of root-eating golden flower insects. Using 20 kilograms of tea seed cake per mu, mashing it, soaking it for 24 hours, and pouring the residue juice has a good effect on preventing and controlling rice root-eating golden flower worms and snails. Physical prevention and control includes trapping and killing adults with black light or frequency vibration insecticidal lamp, and trapping and killing adults with sweet and sour liquid (6 parts of sugar, 3 parts of vinegar, 0 part of liquor/kloc-0, 0 part of water/kloc-0, 90% trichlorfon 1 part); Set yellow boards in the field to trap and kill winged aphids; People kill lobsters and snails. Manually remove the egg mass of Spodoptera litura or concentrate on killing it before the larvae disperse. Biological control includes stocking Monopterus albus and loach in the field to control rice root worm, and using Bacillus thuringiensis to control Spodoptera litura. If 50-75g of Bacillus thuringiensis (Bt) wettable powder per mu 16000 unit (iu/mg) is mixed with 50 kg of water, it can control Spodoptera litura. 1 1. Application technology of chemical pesticides in pollution-free lotus root pest control. First, it is required to ban the use of chemical pesticides that have been explicitly banned by the state; Second, it is necessary to prohibit the use of highly toxic, highly toxic and highly residual pesticides; Third, we must strictly control the amount of pesticides, methods of use and safe intervals. 12. Specifically, how to control the main diseases and insect pests of lotus root? The main diseases and pests of lotus root are lotus root rot, brown spot, Spodoptera litura, aphids (also known as lotus root aphids), lobsters (also known as crayfish), rice-eating golden worms (also known as root maggots, ground maggots, rice-root golden worms) and snails. (1) Lotus root rot: the leaves withered and curled, and the underground rhizome center rotted and blackened, which seriously reduced the yield by more than 50%. Soak lotus seeds with 800 times solution of 50% carbendazim wettable powder for 65438 0 minutes before planting. After colonization, the diseased plants were removed in time. (2) Lotus root brown spot disease: leaf disease. 75g of 50% carbendazim wettable powder mixed with 60kg of water per mu, or 77% kocide wettable powder 130g mixed with 60kg of water at the initial stage of the disease, with a safe interval of 20 days. (3) Spodoptera litura, also known as the night thief moth, is one of the main pests, mainly with larval leaves. Select the larvae that are damaged by transfer for treatment, and spray 60 ml of 2.5% deltamethrin emulsifiable concentrate with 60 kg of water per mu at a safe interval of 7 days. (4) Aphids: one of the main pests. Spraying 75g of 40% dimethoate emulsifiable concentrate and 90kg of water per mu; Or spray 20 grams of 50% pirimicarb wettable powder with 60 kilograms of water per mu, with a safe interval of 10 day. (5) Lobster: also known as crayfish, the professional name is Procambarus clarkii. It mainly harms the new stems and leaves in the early stage. Seven days before sowing, 50 ml of 2.5% deltamethrin EC was mixed with water per mu, and then evenly poured 1 time, and the water depth in the field was kept 3 cm. (6) Rice root-eating golden flower worm: also known as ground maggots and root maggots, the larvae are similar to fly maggots. Edible lotus root system, underground rhizome and lotus root products will affect the appearance of lotus root products. Add 3 kg of 5% phoxim granules per mu into 50 kg of fine soil and mix well, and apply it to the rhizosphere of lotus root plants. (7) Ampullaria gigas: also known as Ampullaria gigas, mainly occurs in the southern region. Concentrated spawning, massive, red, easy to identify. Spraying 0.5 kg of 6% Mida granules, or 70 g of Bailuo 45% triphenyltin acetate wettable powder or 50% spirodiclofen ethanolamine salt wettable powder, or 1 kg of 6% tetraacetaldehyde granules per mu, with a safe interval of 70 days. 13. Collection standard of lotus root. When the main lotus root forms 3 ~ 4 swollen internodes, it is appropriate to start harvesting the green lotus root, and the time is 100 ~ 1 10 days after planting. When the leaves (lotus leaves) begin to turn into Huang Shi, harvest the old lotus roots. When harvesting, lotus branches should be kept intact without obvious scars. The products of early-maturing varieties and late-maturing varieties can be stored in the field and harvested in stages until April of the following year.