What wheat varieties are good to plant in each region? How to plant for high yield? 2018-2019 Technical Guidance for Wheat Autumn and Winter Planting
Since this summer, there has been more rainfall in the main winter wheat producing areas, and the soil subsoil moisture is generally sufficient. The growth and development progress of autumn-maturing crops is close to the same period of a normal year, and the maturity period is expected to be similar to a normal year. In most areas, winter wheat is expected to be sown at the appropriate time. Wheat seed supply is sufficient and can meet production needs. However, during this year's autumn planting period, there is uncertainty in weather conditions and soil moisture. All regions should prepare early, effectively improve the sowing quality of winter wheat, cultivate strong and full seedlings before winter, and lay a solid foundation for next year's summer grain harvest. The following 2018—2019 Technical Guidance for Wheat Autumn and Winter Planting is proposed for four major planting regions for reference by all regions.
1. How to plant for high yield in the Huang-Huai and Northern Winter Wheat Region?
The Huang-Huai Winter Wheat Region includes Shandong, Henan (except Xinyang), central and southern Hebei, northern Jiangsu, northern Anhui, southwestern Shanxi, and the Guanzhong area of Shaanxi. The Northern Winter Wheat Region includes central and northern Hebei, central and southeastern Shanxi, and Weibei in Shaanxi. The Huang-Huai and Northern Winter Wheat Region is the largest winter wheat production area in China and also the main production area for high-quality strong-gluten and medium-strong-gluten wheat in China. This region has relatively good production conditions, relatively abundant light and heat resources, and annual precipitation of 400—900 mm, with more precipitation in the south and less in the north. The terrain is flat and the soil is fertile. The cropping system is mainly a one-year two-crop rotation of wheat and maize. Wheat sowing begins in early to mid-October and harvest occurs from late May to early to mid-June of the following year. The key aspects of wheat autumn sowing and pre-winter management in this region include the following:
(1) Pre-sowing preparation
1. Variety selection. Varieties should be selected according to local climate, soil, soil fertility, cropping system, yield level, and pests and diseases, with the goals of high yield, high quality, and high efficiency, and with emphasis on disaster reduction and avoidance and stable high yield. Ensure that seeds used for production are of high quality, with seed purity not less than 99%, cleanliness not less than 99%, and germination rate (normal seedling rate) above 85%. First, select varieties according to quality requirements. According to enterprise processing needs, appropriately expand the planting area of high-quality wheat. Strong-gluten wheat suitable planting areas may choose strong-gluten varieties with excellent quality and good yield potential, while medium-gluten and medium-strong-gluten wheat should balance yield potential, stress resistance, and quality. Second, select winter or semi-winter varieties according to temperature conditions in different ecological regions. Strictly use winter varieties in the Northern Winter Wheat Region, use winter or semi-winter varieties in the Huang-Huai Winter Wheat Region, and weakly spring varieties may be appropriately used in some areas of the southern Huang-Huai region or late-sown wheat fields. Cross-region planting and the use of unapproved varieties are strictly prohibited. Third, select varieties according to the cropping system. Wheat-cotton intercropping requires wheat varieties suitable for late sowing and early maturity to shorten the symbiotic period of wheat and cotton, while also requiring shorter plants and a compact plant type with strong border-row advantage, so as to fully utilize light energy and improve photosynthetic efficiency. Fourth, select varieties according to soil conditions. High-yield fields with good fertilizer and water conditions should use fertilizer-tolerant and lodging-resistant varieties with high yield potential; water-deficient areas should use drought-tolerant, water-saving, and stable-yield varieties; dry and barren land should use drought-resistant and barren-tolerant varieties; and dry fertile land with relatively high fertility should use drought-resistant and fertilizer-tolerant varieties. Fifth, select varieties according to disasters prone to occur in the region. Areas with severe dry hot wind should use varieties that are appropriately early-maturing, resistant to premature senescence, and resistant to premature wilting; areas prone to late frost damage should choose varieties with steady early spring growth and strong frost resistance; southern areas with relatively more precipitation and severe waterlogging should use varieties tolerant to moisture, resistant (tolerant) to Fusarium head blight, and with a long seed dormancy period; areas with relatively severe rust infection should use rust-resistant (tolerant) varieties. Sixth, strictly manage introduction and replacement of seeds. Replace varieties in a timely manner according to changes in production conditions, and prevent large-scale introduction, seed transfer, and frequent replacement of improved varieties without experimentation. While planting main recommended varieties, actively introduce new varieties for trials and demonstrations, do a good job in seed breeding, and determine “successor” varieties.
2. Seed treatment. Strengthen wheat seed treatment, effectively carry out seed coating or chemical seed dressing, reduce autumn seedling disease, lower overwintering inoculum sources, and control damage from underground pests at the seedling stage, which can delay the onset time of wheat stripe rust, powdery mildew, sheath blight, and other diseases. According to the disease resistance of wheat varieties in each area, disease incidence, climatic conditions, and cultivation methods, rationally select chemicals. Strictly control the amount of chemical used for seed dressing, and prohibit excessive use; sow immediately after seed dressing, use while freshly mixed, and finish sowing the same day. Appropriately increase the seed rate after chemical seed dressing. When coating and dressing seeds, use chemicals according to pesticide label instructions.
3. Straw return. Maize straw return should achieve “chopping, even spreading, deep burying, and compacting.” Straw crushing and return requires a length of ≤7 cm, evenly spread on the soil surface, and deeply buried by plowing. If subsoiling technology is used, rotary tillage must be done first to cut the straw into the soil layer, with a rotary tillage depth of more than 15 cm. After straw return, irrigate and firm the soil; if moisture is suitable, harrow and press in a timely manner.
4. Deep plowing (subsoiling) and harrowing-pressing. Focus on high-quality, standardized land preparation technology with deep plowing (subsoiling) and compaction as the main contents, comprehensively improve land preparation quality, and lay a good foundation for wheat sowing. Deep plow 23—25 cm and then harrow and press, or subsoil 30—35 cm and then rotary till, harrow, and press. Deep plowing or subsoiling can break the plow pan, promote wheat root penetration, and enhance drought resistance; harrowing and pressing can break clods, settle the soil, prevent air leakage and moisture loss, preserve full and strong seedlings, and ensure safe overwintering. The effect of deep plowing or subsoiling can last for 2 years, so it is possible to deep plow or subsoil for 1 year and use rotary tillage for 2 years. For one-crop-per-year dryland wheat fields, deep plowing and subsoiling should be carried out in early July to facilitate rainwater storage and moisture conservation, and timely harrowing to retain moisture. Some drylands may adopt minimum or no-tillage technology mainly based on subsoiling, or promote machinery that integrates rotary tillage, fertilization, sowing, and compaction. At the same time, strengthen pre-operation training for agricultural machinery operators so that they truly master land preparation quality standards and technical essentials, and improve field land preparation operation quality.
5. Application of base fertilizer. Emphasize soil testing and formulated fertilization, combine nitrogen, phosphorus, and potassium fertilizers, and supplement trace element fertilizers. High-yield fields should adopt the nitrogen fertilizer postponement technique, with 50% of nitrogen fertilizer applied as base fertilizer and 50% as topdressing, while all other fertilizers are applied as base fertilizer. According to scientific experiments and practical experience, the suitable fertilization rates for different fertility levels are as follows: for a yield of 300—400 kg per mu, apply 10—12 kg pure nitrogen, 4—6 kg phosphorus pentoxide, and 4—6 kg potassium oxide per mu; 70% of nitrogen fertilizer as base fertilizer and 30% as topdressing at the green-up stage, with all phosphorus and potassium fertilizers applied as base fertilizer. For a yield of 400—500 kg per mu, apply 12—14 kg pure nitrogen, 6—7 kg phosphorus pentoxide, and 5—6 kg potassium oxide per mu; 60% of nitrogen fertilizer as base fertilizer and 40% as topdressing at the green-up or jointing stage, with all phosphorus and potassium fertilizers applied as base fertilizer. For a yield of 500—600 kg per mu, apply 14—16 kg pure nitrogen, 7—8 kg phosphorus pentoxide, and 6—8 kg potassium oxide per mu; 50% of nitrogen fertilizer as base fertilizer and 50% as topdressing at the jointing stage, with all phosphorus and potassium fertilizers applied as base fertilizer.
6. Irrigation to create moisture. Adhere to sowing with sufficient moisture to ensure full emergence after sowing. Wheat fields with insufficient moisture (when the relative water content of the 0—40 cm soil layer is below 70%) should have moisture created before sowing. For wheat fields that cannot be moisture-created in time and are irrigated after sowing with overhead watering, loosen the soil in a timely manner to ensure timely wheat emergence, prevent soil crusting, and reduce soil moisture loss. Pay attention to draining field water in low-lying wheat fields in the south and sow after the moisture has drained; drylands should sow while taking advantage of moisture.
(2) Sowing
7. Suitable sowing date. Generally, the average daily temperature for suitable sowing of winter varieties is 16—18°C, and for semi-winter varieties it is 14—16°C. To cultivate strong seedlings before winter, winter and semi-winter varieties should ensure an effective accumulated temperature before winter of 550—600°C and form strong seedlings before winter with 5—6 leaves on the main stem, 3—5 tillers per plant, and 3—5 secondary roots. At the same time, weather conditions, fertility level, pests and diseases, and safe overwintering should also be considered. Generally, the suitable sowing period is late September to early October in the Northern Winter Wheat Region, October 5—15 in the northern and central Huang-Huai Winter Wheat Region, and October 10—20 in the southern Huang-Huai Winter Wheat Region.
8. Reasonable sowing rate. A reasonable sowing rate and suitable basic seedling number are the starting point for establishing a high-quality population and are important measures for building a reasonable population structure and coordinating the relationship between population and individuals and between wheat growth and development and environmental conditions. Within the suitable sowing period, the appropriate sowing rate should be determined according to location, variety, and time. First, variety characteristics. Varieties with strong tillering ability and high earing rate should have the sowing rate appropriately reduced. Second, sowing time. For early sowing, the sowing rate should be appropriately reduced; for late sowing, the sowing rate should be appropriately increased. Third, fertility level. In fields with better soil fertilizer and water conditions, the basic seedling number should be sparse and the sowing rate should be lower; in wheat fields with poor water and fertilizer conditions, the sowing rate should be appropriately increased. Generally, the basic seedling number per mu is 200,000—300,000 in the Northern Winter Wheat Region, 150,000—250,000 in the northern and central Huang-Huai Winter Wheat Region, and 150,000—180,000 in the southern Huang-Huai region. After the average daily temperature at sowing is below 15°C, for each day sowing is delayed, the basic seedling number increases by 10,000, but it should generally not exceed 350,000.
9. Fine sowing. Sow with a wheat seeder that meets requirements and is of qualified quality. On the premise of high-quality land preparation, promote sowing methods such as wide-width uniform sowing, wide-narrow row sowing, and equal-row spacing reduced-spacing uniform sowing; in dryland farming areas, demonstrate and promote mechanical furrow sowing and integrated land preparation and sowing; in rice stubble wheat areas, promote mechanical drilling. Each region should determine the suitable sowing row spacing according to local actual conditions, ensuring consistent row spacing, accurate sowing rate, and consistent depth, with a sowing depth of 3—5 cm, without missed sowing or repeated sowing.
10. Compaction after sowing. Sowing compaction is an important measure for drought resistance, freeze prevention, improving emergence quality, and cultivating strong seedlings before winter. Seeders with compacting devices should compact as they sow; seeders without compacting devices should be compacted with a compactor after sowing. Ensure compaction strength and quality, make the soil firm, reduce soil air leakage and moisture loss, promote wheat seedling growth, and cultivate strong seedlings before winter.
11. Check seedlings and reseed. After wheat emergence, check seedlings in a timely manner. Areas with missing seedlings or missed sowing should be reseeded as early as possible with germinated seeds of the same variety to prevent missing seedlings and broken rows from affecting full and uniform seedlings and population quality.
(3) Pre-winter management
12. Irrigate overwintering water. For wheat fields lacking moisture and fields with straw return, rotary tillage sowing, and hollow, unsettled soil, irrigate overwintering water in a timely manner to preserve seedlings for safe overwintering. Overwintering water is generally applied from late November to early December, when the average daily temperature is stable at around 3°C and water can infiltrate in time, and completed when it is “frozen at night and thawed during the day.” Promote water-saving irrigation and prohibit flood irrigation. After irrigation, loosen the soil in a timely manner to conserve moisture, prevent surface cracking, and avoid air leakage that damages roots and kills seedlings. In early December, if soil moisture is suitable (the average relative water content of the 0—40 cm soil layer in wheat fields reaches or exceeds 70%), and the field has high land preparation quality, sufficient base fertilizer, normal growth, and a suitable population, overwintering water may be omitted before winter. For wheat fields without irrigation conditions, loosen the soil in a timely manner after each rainfall to conserve moisture.
13. Chemical weeding. Before winter is a favorable time for chemical weeding in wheat fields. Generally from mid-November to early December (average daily temperature above 10°C), at the 3—4 leaf stage of wheat and the 2-leaf-1-heart to 3-leaf stage of weeds, select suitable chemicals to control weeds in wheat fields.
14. Control underground pests. For wheat fields with relatively severe damage from underground pests such as white grubs and wireworms, use suitable chemicals per mu, mix with water and fine soil, and apply into the soil along with hoeing. Use the chemical amount according to pesticide label instructions.
15. Strictly prohibit grazing on green wheat. Strengthen pre-winter wheat field management and protection, manage livestock and poultry well, eliminate grazing by livestock and poultry on green wheat, and ensure normal growth and safe overwintering of wheat seedlings.
2. How to plant for high yield in the Middle and Lower Yangtze Winter Wheat Region?
This region includes the area south of the Huai River in Jiangsu and Anhui provinces, most of Hubei, and Xinyang in Henan, and is one of the main winter wheat producing areas in China. This region has a humid climate and good heat conditions, with annual precipitation of 800—1400 mm; the terrain is low and flat, and the soil is mainly paddy soil. The cropping system is mainly a one-year two-crop rotation of rice and wheat. Wheat is mostly sown from late October to mid-November and harvested from late May to early June of the following year. The central and northern parts of this region are important medium-gluten wheat producing areas in China, while the southern riverside and coastal areas are high-quality weak-gluten wheat producing areas. The key aspects of wheat autumn sowing and pre-winter management in this region include the following:
(1) Pre-sowing preparation
1. Variety selection. Select varieties with high yield, high quality, and strong resistance to moisture, freezing, lodging, and disease (mainly resistance to Fusarium head blight, powdery mildew, and sheath blight) and resistance to pre-harvest sprouting. In the north, semi-winter varieties may be selected, and in the south, spring varieties may be selected, appropriately expanding the planting area of high-quality weak-gluten wheat. At the same time, promote the establishment of special wheat production bases, strengthen coordination with flour processing enterprises and food processing enterprises, and achieve high-quality, special-purpose, and efficient production.
2. Seed treatment. In areas where diseases such as sheath blight and smut occur, suitable chemicals may be used for seed dressing (coating). Strictly master the chemical amount and concentration used for seed treatment agents, and do not increase or decrease the amount or concentration at will; ensure that the seed coating agent (seed dressing agent) evenly covers the seed surface and improve the coating (dressing) effect; vigorously promote specialized equipment for seed dressing (coating) to improve seed treatment quality; use while freshly mixed (coated), and finish sowing the same day.
3. Straw return. For rice, control the time of the final irrigation well, cut off water 7—10 days before harvest to create good moisture conditions for wheat sowing, and harvest in a timely manner after maturity to prevent excessive “aging of the rice.” Rice harvesting machinery should be equipped with chopping and even spreading devices, with chopped straw length controlled at about 5 cm and stubble height below 10 cm, and evenly spread. If rice straw is not evenly spread, it must be spread manually; if the chopped straw length is too long or the rice stubble height at harvest is too high, a specialized straw crusher should be used after harvest for crushing. The straw crusher should travel at a constant speed, and the crushing blades should be close to the ground to ensure thorough crushing of stubble and straw and even distribution. Use large and medium-sized tractors of more than 90 horsepower for rotary tillage to bury weeds and return straw. The depth of rotary tillage for burying straw should reach 12—15 cm to prevent rice straw from accumulating in the sowing layer.
4. Application of base fertilizer. For weak-gluten wheat with a yield of 300—400 kg per mu, generally apply 12—14 kg pure nitrogen per mu, with base fertilizer accounting for 70% and jointing fertilizer accounting for 30%. For medium-gluten wheat with a yield of 400—500 kg per mu, apply 14—15 kg pure nitrogen per mu, with base fertilizer accounting for 60% and jointing fertilizer accounting for 40%. High-yield fields are recommended to use 60% base fertilizer, 20% jointing fertilizer, and 20% booting fertilizer (applied when half of the flag leaf has emerged). According to the basic soil fertility level, the nitrogen-phosphorus-potassium ratio for medium-gluten and weak-gluten wheat is 1:(0.4—0.6):(0.4—0.6), and a phosphorus and potassium ratio of 5:5 between base fertilizer and jointing fertilizer is more suitable. Generally, base fertilizer may use 5—10 kg urea (containing 46% nitrogen) and 15—25 kg 45% compound fertilizer (nitrogen, phosphorus pentoxide, and potassium oxide content each 15%).
(2) Sowing
5. Suitable sowing date. From sowing to the beginning of overwintering requires an accumulated temperature above 0°C of 500—550°C. To ensure that wheat seedlings form age-appropriate strong seedlings at the beginning of overwintering (5—6 leaves on the main stem, 2—3 tillers per plant, and 3—5 secondary roots), the suitable sowing period in this region is late October to early November.
6. Reasonable sowing rate. In this region, precise and semi-precise sowing is used at the suitable sowing time, with the basic seedling number per mu controlled between 120,000—160,000; if later than the suitable sowing period, the sowing rate should be appropriately increased, with an increase of 5,000 basic seedlings for each day of delay, and generally not exceeding 80% of the expected ear number. Attention should be paid to appropriately adjusting the sowing rate according to moisture, straw return, land preparation and sowing quality, and other factors affecting emergence.
7. Fine sowing. For wheat fields where rice is harvested earlier, stubble is cleared in time, moisture is suitable (soil water content below 80% of field capacity), and soil tillage condition is good, a 2BG-6A type and other minimum (no) tillage drills may be used to complete shallow rotary tillage, trenching, sowing, soil covering, and compaction in one operation. The sowing depth is 2—3 cm, row spacing is 20—25 cm, and travel at medium speed to ensure even seed drop. The joint between two passes should match well to avoid repeated sowing or widened row spacing, and avoid stopping in the field to form seed piles. Leave empty strips at both ends of the field first to facilitate turning of the machine body, and finally reseed the empty strips at both ends. For dead corners that the machine cannot reach, reseed manually or transplant densely grown seedlings to sparse areas after emergence. When soil water content reaches more than 80% of field capacity, a newly improved banded drill should be used for sowing to prevent blockage of the seed outlet and missing seedlings or broken rows. The general requirements for sowing quality are suitable sowing depth, consistent depth, reasonable seedling number, and uniform emergence.
8. Compaction after sowing. Seeders with compacting devices should compact as they sow; seeders without compacting devices should be compacted in a timely manner with a compactor after sowing to ensure compaction quality.
9. Mechanical ditching. After sowing, carry out mechanical ditching in a timely manner. Dig one vertical ditch every 2.5—3 m, with a ditch width of 20 cm and a depth of 25—30 cm. Dig one horizontal ditch 2—3 m from the horizontal ridges at both ends of the field. For longer fields, add one waist ditch every 50 m, with a ditch width of 20 cm and a depth of 35—40 cm. The outlet ditch at the field head should be 25 cm wide and 40—50 cm deep. Ensure that the internal and external three ditches are connected. Pay attention to evenly spreading ditch soil to cover wheat rows, reduce exposed seeds, and prevent freezing and preserve seedlings.
(3) Pre-winter management
10. Early supplementary seedling fertilizer. For fields with relatively few basic seedlings and insufficient base fertilizer application, supplementary seedling fertilizer should be applied in a timely manner at the 2-leaf stage. For wheat fields where the total leaf number of the main stem is 11 or fewer, when both base fertilizer and seedling fertilizer are insufficient, tillering fertilizer should be applied at the 3—4 leaf stage of the main stem. Before winter and during overwintering, apply mud and miscellaneous ash fertilizer to cultivate soil around the roots, keep warm and prevent freezing, and enrich the soil. For wheat fields with a large amount of straw return, if wheat seedlings are severely yellowing, quickly apply quick-acting compound fertilizer or nitrogen fertilizer to transform the seedling condition.
11. Timely weeding. Weeding in wheat fields should mainly be done before winter, using chemicals at the appropriate time according to weed species, weed age, and moisture, with supplementary weeding in spring as a supplement. When moisture is suitable, carry out soil-closed chemical weeding before seedling emergence after sowing. For fields where closed chemical weeding was not carried out or the weeding effect is not ideal, spray chemicals in a timely manner before winter according to weed species and dominant weed species. For wheat fields mainly with grass weeds, control at the 2—4 leaf stage of weeds. For wheat fields mainly with broadleaf weeds, control after wheat reaches the 4—5 leaf stage and weeds have fully emerged. For wheat fields with mixed monocotyledonous and dicotyledonous weeds, suitable chemicals may be selected for control. Special attention should be paid to using chemicals according to label instructions or under the guidance of local agricultural technicians, and repeated application is not allowed. Apply on sunny days at the end of a cold spell and the beginning of a warm one, with an average daily temperature above 8°C, and avoid applying chemicals during low-temperature cold wave weather to prevent freezing chemical damage.
12. Reduce waterlogging and resist drought. Clear ditches and manage moisture in a timely manner, dredge irrigation and drainage systems, and prevent waterlogging damage. If moisture is insufficient after sowing, irrigate for full emergence to promote timely emergence. Note that flood irrigation should not be used, to prevent bud rot and bud suffocation. When subsoil moisture is insufficient or there is autumn-winter drought, and the relative water content of the cultivated layer is below 60%, irrigate in winter. Note that thin land and weak seedlings should be irrigated early, while fertile land and vigorous seedlings should be irrigated later. Winter irrigation is generally carried out when the average daily temperature is 3—4°C. Winter irrigation should preferably use methods such as furrow irrigation, so that there is no standing water in the field, to avoid soil crusting. Flood irrigation must be avoided to prevent washing away topsoil.
13. Control excessive growth and promote strong growth. For wheat fields sown too early, with an overly large population, or excessively vigorous growth, intertillage or compaction may be adopted, and growth inhibitors may also be sprayed to control excessive growth and promote strong growth, and preserve seedlings for safe overwintering.