Full process fertilization plan for sunflowers

Sunflowers are one of the five major oil crops, with an oil yield of 28% -36%. At the same time, it is also the main snack for people's leisure and an auxiliary ingredient for processed foods. In recent years, with the continuous adjustment and gradual optimization of agricultural planting institutions, the cultivation area and planting area of sunflowers have shown a continuous expansion trend, which has played a positive role in promoting agricultural efficiency and increasing farmers' income.

Fertilization characteristics of sunflowers

Sunflowers are a crop that requires a lot of fertilizer. The period from flower disc formation to flowering is the peak fertilizer requirement for sunflowers. During the period from emergence to disc formation, more phosphorus is needed, while during the period from disc formation to the end of flowering, more nitrogen is needed. During the period from disc formation to wax ripening, the most potassium is absorbed. Therefore, when fertilizing sunflowers, phosphorus is the main fertilizer in the early stage, and nitrogen and potassium are the main fertilizers in the middle and late stages. For every 100kg of sunflower seeds produced, 4.59-6kg of nitrogen (N), 2.6-3.04kg of phosphorus (P2O5), and 18.6-30kg of potassium (K2O) need to be absorbed from the soil. Phosphorus and potassium fertilizers are mostly applied as base or seed fertilizers, while nitrogen fertilizer is used as topdressing or 1/3 is used as base fertilizer, and 2/3 is used as topdressing.

Key fertilization techniques for sunflowers

To achieve high yield of sunflowers, it is necessary to consider the nutrient absorption patterns and characteristics of sunflowers under the premise of heavy application of organic fertilizers, determine the appropriate fertilization period and amount, in order to fully exert the yield increasing effect of fertilizers. Fertilization must be based on the principle of equal emphasis on base fertilizer, seed fertilizer, and topdressing, and the combination of organic fertilizer and chemical fertilizer, in order to fully exert the yield increasing effect of fertilizers.

1. Basal fertilizer

Type. Organic fertilizer combined with chemical fertilizer application. Applying base fertilizer in combination with autumn plowing is more conducive to fertilizer conservation and can increase seedling emergence rate compared to spring plowing. Fertilization method, combined with mechanical operation, adopts spraying, raking evenly before plowing. Fertilizer dosage: 1000-2000 kilograms of organic fertilizer per mu, combined with balanced or high nitrogen compound fertilizers such as San'an 18-18-18, 22-16-16, etc., should be applied at a depth of less than 15 centimeters, with a weight of 40-60 kilograms per mu, depending on local conditions.

2. Seed fertilizer

The application of seed fertilizer mainly focuses on phosphorus to achieve the goal of strengthening seedlings. Apply San'an 18-22-14 high phosphorus compound fertilizer or 16-24-14 high phosphorus compound fertilizer, combined with sowing, and apply the fertilizer 2-3 centimeters below the seeds or 3-4 centimeters next to the seeds.

3. Topdressing

The fertilizer applied after the emergence of sunflowers is called topdressing. Sunflowers are a crop that requires a lot of fertilizer. Relying solely on base fertilizer and seed fertilizer cannot fully meet the nutritional and reproductive growth needs of sunflowers in the late stage of flowering and growth, as well as their nutrient needs. Therefore, topdressing is particularly important. Top dressing should be applied with high nitrogen and potassium compound fertilizers, in addition to some trace elements such as zinc, molybdenum, manganese, and copper. Recommend the fourth element 17-6-25 or 20-6-20 high nitrogen and high potassium compound fertilizer. The added activated humic acid can improve soil, fertilize soil fertility, stimulate crop growth, and improve product quality. Especially adding trace elements can increase the nutrient utilization efficiency of N, P, and K, and increase crop yield and quality.

Special attention should also be paid to the timing of fertilization. The period from budding to flowering of sunflowers is a vigorous production stage where both nutritional and reproductive growth occur simultaneously, requiring abundant and concentrated nutrients. Therefore, topdressing should be arranged before this period. Usually, a small pit is dug 10-15 centimeters away from the base of the sunflower root and stem for fertilization, and then covered with soil. Fertilizers should be applied deeply to allow them to come into contact with moist soil, making it easy to exert their fertilizer effects in a timely manner. When using intercropping and early fertilization, the first intercropping can be combined, with a depth of 8-10 centimeters and a distance of about 15 centimeters from the seedlings. In the late stage of fertilization, it can be combined with the last intercropping, and the fertilizer can be applied between rows, with a depth of 8-10 centimeters. In short, when fertilizing, it is important to pay attention to the depth and apply it to the moist soil layer, but not to damage the plant roots due to deep application. It is also important to ensure that the fertilizer is not too close to the plant and does not burn the roots.

Notes on Sunflower Fertilization

Sunflowers are crops that consume more potassium. Its fertilizer absorption ratio is N: P2O5: K2O=1:0.3:2.3, and its potassium absorption exceeds the sum of nitrogen and phosphorus absorption. Its potassium absorption is 5-8 times that of cereal crops, so potassium fertilizer should be applied again; Sunflowers are crops that prefer zinc and boron. According to experimental data, the application of nitrogen and phosphorus fertilizer combined with a small amount of boron and zinc can increase yield by 9.9% to 11% per mu. For sunflowers, soil available boron levels below 0.25 milligrams per kilogram of soil are considered severe boron deficiency, 0.25-0.5 milligrams per kilogram of soil is moderate boron deficiency, and 0.8-1.0 milligrams per kilogram of soil is moderate. The soil for planting sunflowers is often moderately boron deficient, and applying a small amount of boron fertilizer to this soil can achieve a significant increase in yield. Boron fertilizer increases yield by increasing thousand grain weight and seed setting rate; Zinc can promote the synthesis of auxin in plants, as well as promote the transportation of nitrogen, phosphorus, potassium, and various nutrients to flower organs and seeds, participating in the formation of flower organs and the maturation of seeds. Sunflowers lack zinc, their flower discs become smaller and deformed, their seeds are not full, and they have many empty shells. Various flower spots will appear on the upper leaves of the stem. The common ones are potential zinc deficiency, poor ripening of seeds, affecting yield, reducing quality, and not being detected. The application of fourth element compound fertilizer with added trace elements can effectively prevent the occurrence of nutrient deficiency.