Wheat is an important food crop in China. Its sown area and total output are second only to rice. Wheat cultivation ranges from Hainan Island in the south, to Heilongjiang in the north, from Xinjiang in the west, and to the plain high mountains in the coastal provinces in the east. China has both winter wheat and spring wheat.
1. Winter wheat fertilizer use technology
The fertilization of winter wheat in the vegetative growth stage (emergence, tillering, wintering, returning green, getting up, jointing) is mainly aimed at promoting tillering and increasing panicles, while at the reproductive growth stage (preparation, heading, flowering, filling, maturing), it is increased. Granule weight gain is dominant.
Due to the differences in climate, soil, cultivation practices, and varietal characteristics, the amount of nitrogen, phosphorus, and potassium absorbed by wheat plants throughout their lives and their distribution in different parts of the plant also vary. Taken together, it is generally believed that for every 100 kilograms of wheat produced, about 2.8-3.2 kilograms of pure nitrogen, about 1-1.5 kilograms of phosphorus, and 2-4 kilograms of potassium, and about 1:0.4:1 of nitrogen, phosphorus, and potassium are needed. . Among them, nitrogen and phosphorus were mainly concentrated in sub-plots, which accounted for 76% and 82.4% of the total content of the whole plant. Potassium was mainly concentrated on the stems and leaves, with a total content of 77.6% of the whole plant.
The amount of N, P and K nutrients absorbed by winter wheat during various growth and development stages is: before and after returning to the green stage, the absorbed nutrients and accumulated dry matter are less; the absorption rate increases after turning green, and the nutrients are absorbed from jointing to heading. The fastest period of accumulated dry matter; after flowering, the absorption rate of nutrients gradually decreased. The absorption of nitrogen by winter wheat has two peaks: one is from tillering to winter, the other is from jointing to booting, and the latter peak is much larger than the previous peak. The analysis results of winter wheat plants with a yield of 6188 kg/ha by the Soil and Fertilizer Institute of the Chinese Academy of Agricultural Sciences showed that the nitrogen absorbed during the vegetative growth stage accounted for 40% of the total growth period, phosphorus accounted for 20%, and potassium accounted for 20%; from jointing to flowering, it was wheat. The peak period of absorption of nutrients was about 48% of nitrogen absorption, 67% of phosphorus, and 65% of potassium. After the grain formation, the absorption of nutrients decreased significantly. Therefore, there should be sufficient nitrogen and adequate phosphorus and potassium nutrition in the wheat seedling stage. According to the fertility law and nutritional characteristics of wheat, base fertilizer should be re-used and topdressing should be applied early. The amount of basal fertilizer should generally account for 60% to 80% of the total amount of fertilizer, and top dressing should account for 40% to 20%.
(1) Basal fertilizers for wheat basal should be farmyard fertilizers, with the application of chemical fertilizers. Applying basal fertilizer to cultivate strong seedlings and promote effective tillering and grain development plays an important role. The amount of topdressing fertilizer varies greatly from place to place. Generally, on the basis of 30-75 tons of farmland manure per hectare, a certain amount of nitrogen and phosphate fertilizer is applied in the north, and nitrogen is applied in the southern winter wheat area. Potassium or nitrogen, phosphorus, potassium fertilizers. Generally in the soil with high fertility, 1/3 nitrogen fertilizer can be used as base fertilizer. Apply 75-150 kg of urea or 225-300 kg of ammonium bicarbonate per hectare. If the fertility of the soil is high, the amount of manure used by the farm is large, and the base fertilizer may not be applied with nitrogen fertilizer. The nitrogen fertilizer is used as a forced fertilizer. For medium-sized plots, 1/2 of the nitrogen fertilizer can be used as a base fertilizer, applying 112.5-225 kg of urea or 375-600 kg of ammonium bicarbonate per hectare. For a plot with low fertility, 2/3 of nitrogen fertilizer is used as a base fertilizer, and 150-255 kg of urea or 450-750 kg of ammonium bicarbonate is applied per hectare. In plots with low fertility and no irrigation water, nitrogen fertilizers are generally used as base fertilizers. Generally, phosphorus fertilizers should be applied to wheat fields with soil available phosphorus below 20 mg/kg. Apply 450-750 kg calcium phosphate or calcium magnesium phosphate fertilizer per hectare. Basal fertilizer, it is better to use Phosphate and farmyard fertilizers after mixing or stacking, which can reduce the contact between phosphorus fertilizer and soil, prevent the fixation of water-soluble phosphorus, and use the absorption of wheat. When the soil available potassium is lower than 50 mg/kg, potassium fertilizer should be added, and 75-150 kg of potassium chloride per hectare. Saline-alkali land is best applied potassium sulfate, when the effective zinc in the soil is less than 0.5 mg/kg, zinc fertilizer can be applied every year, and about 15 kg of zinc sulfate per hectare.
(2) Seeding Fertilizer When wheat is sown, a small amount of fertilizer can also be used as a seed fertilizer to ensure that wheat can be absorbed into nutrients in time after emergence, which has a good effect on increasing the growth of winter wheat tiller and secondary roots. The application of wheat seed fertilizer in insufficient basal fertilizer or poorly-fertilized soil and late-seeding wheat field has a more significant effect on yield increase. Fertilizer can use urea 30-45 kilograms per hectare, or ammonium sulfate 75 kilograms per hectare and superphosphate 75-150 kilograms. Seeds and fertilizers are best broadcast separately. Ammonium bicarbonate should not be used as a fertilizer.
(3) Topdressing According to the needs of each growth and development stage of wheat, the top-dressing is an important measure to obtain high yield. Are described separately as follows:
1 seed dressing fertilizer: seed dressing fertilizer referred to as "miao fertilizer", usually in the early stages of emergence of the tiller, per hectare topdressing ammonium bicarbonate 75-150 kg or urea 45-75 kg or a small amount of human waste. Its role is to promote uniform seedlings and increase the number of tillers before winter, especially for the lack of basic seedlings or late sowing of wheat. In low-yielding soils, such as muddy fields and wet fields where the hilly dry land and nutrients are decomposed slowly, the effect of drought and fertilizer application is good. However, for wheat fields with adequate basal and seed fertilizers, it is not necessary to top-dress the seedlings at the seedling stage.
2 Over-winter fertilizer: also known as "paraffin fertilizer", the southern and the Yangtze River have a heavy application of wax fertilizer habits. The wax fertilizer is based on the application of semi-efficient and slow-lasting man-made fertilizers. For the three types of seedlings, the main fertilizers should be quick-acting fertilizers to promote long-rooted tillering and grow into strong seedlings, prompting rapid transformation and upgrading of the three types of seedlings. For northern winter wheat areas, sowing seedlings that are later in the day, individuals growing poorly, and having fewer tillers, and no fertilizers at the early part of the tillering stage, are generally required to adopt spring fertilizer winterization measures and combine top dressing with frozen water to apply nitrogen fertilizer before and after the light snowfall. , Ammonium bicarbonate 75-150 kg or 45-75 kg urea per hectare, for the application of Miao Fei can not apply "flue fertilizer."
3 return to the green fertilizer: poor fertility, insufficient base fertilizer, late planting, less tillering before winter, wheat fields growing weaker, should be early recovery or regain green manure. Ammonium bicarbonate 225-300 kg or urea 45-75 kg per hectare, should be applied more than 6 cm deep is appropriate. For the basal fertilizer is sufficient, and the winter wheat field is not suitable to go back to green manure.
4 Top dressing fertilizer during jointing stage: The jointing fertilizer is applied after the peak of winter wheat tiller, promotes the formation of panicle into big panicle, raises the rate of succession of panicles, promotes the differentiation of floret, and strives to obtain large panicles and grains. The growth of the jointing wheat seedlings is usually divided into three types, and the corresponding top dressing and management measures are adopted.
Wang Miao: leaf shaped like pig ears, dark green leaves, leaves wide and soft, down drape, a lot of childbirth, there are phenomena. Nitrogen fertilizers should not be applied to such seedlings, and watering should be controlled.
Strong seedlings: leaves shaped like donkey ears, leaves are longer and the color is green and blue, and the tips of the leaves are slightly slanted, and the tillers are moderate. For this kind of wheat seedlings, a small amount of nitrogen fertilizer can be applied, and 150-225 kg of ammonium bicarbonate or 45-75 kg of urea can be applied per hectare, with the application of phosphorus and potassium fertilizer, 75-150 kg of calcium phosphate and 45-75 kg of potassium chloride per hectare. And with watering.
Weak seedlings: Leaves shaped like horse ears, yellow-green leaves, small leaves upright, few tillers, showing lack of fertilizer. For this type of wheat seedlings, more available nitrogen fertilizer should be applied, and 300-600 kg of ammonium bicarbonate or 150-225 kg of urea should be applied per hectare.
5 Fertilizers at the booting stage: The main nitrogen fertilizer during the booting stage is less. Generally 75-150 kg of ammonium sulfate or 45-75 kg of urea is applied per hectare.
6 late fertilization: After the heading of wheat still need some of the elements of nitrogen, phosphorus, potassium. At this time, the root system of wheat is aging and its absorption capacity is weakened. Therefore, the method of top dressing is generally adopted. From earing to milk ripening, such as yellow wheat leaves, there is a phenomenon of premature aging of deferred fertilizer, can be sprayed with 1% ~ 2% concentration of urea, spraying solution per hectare about 750 liters. For wheat fields with a dark-green leaf color and a late-maturing trend of glutinous green, 750 liters of a 0.2% potassium dihydrogen phosphate solution can be sprayed per hectare. In recent years, in production practice, spraying growth regulators and trace elements such as fulvic acid, nucleotides, amino acids, etc. in the later stage of wheat growth have played a role in increasing wheat yield.
2. Spring wheat fertilizer use technology
Spring wheat and winter wheat are very different from each other in terms of their growth and development. They are characterized by early spring sowing and a short growing period, which is only 100-120 days from sowing to maturity. Spring wheat is mainly distributed in the northeast and northwest. According to the information provided by the Soil and Fertilizer Institute of Qinghai Academy of Agriculture and Forestry Sciences, which integrates 7500 kg/ha of spring wheat production in the province, approximately 2.5-3.0 kg of nitrogen, 0.78-1.17 kg of phosphorus, and 1.9-4.2 kg of potassium are required for every 100 kg of grain produced. The ratio of nitrogen, phosphorus and potassium is 2.8:1:3.15. According to the Ningxia Academy of Agricultural Sciences, the yield of nitrogen, phosphorus, and potassium has two peaks in the field of 6195 kg/ha. The first one is from jointing to booting, and the second is from flowering to milking. The former is slightly higher than the former. The latter is high. The rate of absorption of phosphorus has been rising from emergence to milk-cooking, from the sharp increase in jointing to the highest value in milk-cooking. According to the reproductive rules and nutritional characteristics of spring wheat, basic fertilizer should be re-used and fertilizer applied early.
(1) Basal fertilizer Because the spring wheat in the early spring soil is frozen and frozen at 5-7 centimeters, the top seedling is sown and the ground temperature is very low. Base fertilizer applies 30-60 tons of farmyard manure, 375-600 kg of ammonium bicarbonate, and 450-600 kg of superphosphate per hectare. According to the investigation of the Heilongjiang Academy of Agricultural Sciences, the spring basal fertilization has the best fertilization effect in autumn and spring, and the basal fertilization in the autumn is the next best. The fertilization before the spring flood is the worst.
(2) Seed Fertilizer Because the fertilizer is concentrated in the vicinity of the seed, the wheat can be used after germinating and long rooting. The specific method is to open the ditch at a predetermined spacing and then spread fertilizer and sowing in the ditch after the land is leveled and made into hoe before planting. , cover soil, repression. If the land is dry, it can be planted first, then practical, and then sprinkled, covered with soil, and suppressed. Generally, 150 kg of ammonium bicarbonate and 225-375 kg of superphosphate are applied per hectare, mixed with 1500 kg of high-quality farmyard fertilizer, or 150-300 kg of binary nitrogen-phosphorus compound fertilizer.
In recent years, spring wheat production areas use a single fertilization method, and all fertilizers are used as base fertilizer and seed fertilizer. In general, on the basis of sufficient farmyard fertilizer, apply 600-750 kg of ammonium water or 600 kg of ammonium bicarbonate per hectare and apply 750 kg of calcium phosphate. When sowing, combined with a small amount of fertilizer, diammonium phosphate 75-120 kilograms per hectare, after no top dressing. This method is suitable for drylands.
(3) Top-dressing spring wheat is a “tire rich†crop, which was developed earlier. Most varieties begin to grow in cone elongation and cob differentiation at the 3-leaf stage. At the 4th leaf stage, young panicle differentiation begins and requires more nutrients. Therefore, the first topdressing should be done at the 3-leaf stage or 3-leaf 1 center stage. This time the fertilizer is called a tiller fertilizer and it needs to be re-applied, accounting for about 2/3 of the amount of fertilizer. Applying urea 225-300 kg per hectare is mainly to increase the percentage of tillers and spikes, and to promote the early growth of seedlings, which lays the foundation for large grains and spikes. The second top dressing during the jointing stage is called jointing fertilizer, which is generally applied lightly, which accounts for about 1/3 of the amount of topdressing, and applies 105-150 kg of urea per hectare. In the plots that are not covered with over-fertilizers, they should be applied early and reused. In the booting stage, it is appropriate to apply fertilizer to increase grain fertilizer. After most of the applied joint fertilizers were applied, they were no longer fertilized, and the main application of foliar fertilizer was the same as that of winter wheat.
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