Technical Guidance on Autumn and Winter Planting of Wheat for 2015-2016 Issued

Huang-Huai and Northern Winter Wheat Region

(1) Pre-planting Preparation

1. Variety Selection

Select suitable varieties according to local climate, soil, soil fertility, cropping system, yield level, and pests and diseases. First, select varieties according to weather conditions. Choose winter and semi-winter varieties based on temperature conditions. Cross-region planting and the use of unapproved varieties are strictly prohibited. In the Northern Winter Wheat Region, strictly select winter varieties; in the Huang-Huai Winter Wheat Region, select winter and semi-winter varieties. Second, select varieties according to soil conditions. For high-yield fields with good water and fertilizer conditions, select varieties with high yield potential and resistance to lodging and fertilizer. For water-deficient areas, select drought-tolerant, water-saving, and stable-yield varieties. For dry and infertile land, select drought-tolerant and barren-tolerant varieties. For dry fertile land with thicker soil layers and higher fertility, select drought-tolerant and fertilizer-tolerant varieties. Third, select varieties according to cropping system. Wheat-cotton intercropping requires wheat varieties suitable for late sowing and early maturity to shorten the symbiotic period of wheat and cotton; at the same time, plants should be shorter with a compact plant type and strong edge-row advantage to fully utilize light energy and improve photosynthetic efficiency. Fourth, select varieties according to disaster conditions. Areas with severe dry hot winds should select varieties that are appropriately early-maturing, resistant to premature aging, and resistant to premature wilting, so as to avoid or reduce the harm of dry hot winds. Fifth, select varieties according to disease conditions. Areas with severe rust infection should select rust-resistant (tolerant) varieties; areas with excessive rainfall and severe waterlogging should select varieties that are moisture-tolerant, resistant (tolerant) to fusarium head blight, and have a long seed dormancy period. Sixth, select varieties according to quality. Select high-quality varieties with good nutritional quality, processing quality that meets the requirements of finished products, plump grains, and high test weight. Seventh, strictly manage variety introduction and replacement. Replace new varieties according to changes in production conditions and yield improvement, and prevent large-scale introduction, seed transfer, and frequent replacement of improved varieties without testing; while planting main recommended varieties, actively introduce new varieties for testing and demonstration, and do a good job in seed propagation to determine “successor” varieties and maintain the quality of seeds used in production.

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 underground pest damage at the seedling stage. This can delay the onset time of wheat stripe rust, powdery mildew, sheath blight, and other diseases. Reasonably select chemicals according to the disease resistance of wheat varieties in each region, disease incidence, climatic conditions, and cultivation methods. Strictly control the amount of chemical used for seed dressing, and prohibit excessive application; sow immediately after seed dressing, use while freshly mixed, and finish sowing the same day; appropriately increase the seeding rate after chemical seed dressing.

3. Straw Return

For corn straw crushing and return to the field, the length is required to be ≤7 cm and evenly spread on the soil surface. Plow the crushed straw into the ground. If subsoiling technology is used, rotary tillage must be carried out to cut the straw into the soil layer, with a rotary tillage depth of more than 15 cm. After straw return, irrigate and compact the soil; if soil moisture is suitable, harrow and press in time.

4. Deep Plowing (Subsoiling) and Harrowing-Pressing

Deep plow 23~25 cm and then harrow and press, or subsoil 30~35 cm and then rotary till and harrow-press, to break clods, settle the soil, facilitate root penetration, prevent air leakage and moisture loss, and ensure seedlings survive the winter safely. The effect of deep plowing or subsoiling can last for 2 years. With 1 year of deep plowing or subsoiling, rotary tillage land preparation is sufficient within 2~3 years. For one-crop-per-year dryland fallow wheat fields, deep plowing and subsoiling should be carried out in early July to facilitate rainwater storage and moisture conservation, combined with pre-sowing harrowing to conserve moisture.

5. Irrigation to Build Soil Moisture

Adhere to sowing with sufficient soil moisture to ensure full emergence after sowing. When the relative soil water content in the 0~40 cm soil layer is below 75%, build moisture first and then sow. For wheat fields that cannot be irrigated in time to build moisture and are irrigated after sowing with a head-wetting irrigation, loosen the soil in time to prevent cracks in the soil and reduce soil moisture loss.

6. Application of Base Fertilizer

Use soil testing and formulated fertilization, combine nitrogen, phosphorus, and potassium fertilizers, and supplement trace element fertilizers. For high-yield fields, adopt the nitrogen fertilizer postponement technique, with 50% of nitrogen fertilizer as base application and 50% as topdressing, and all other fertilizers applied as base fertilizer. According to production experience, the reference suitable fertilization rates for different fertility levels are: for low-yield fields with a yield of 200~300 kg per mu, apply 6~10 kg of pure nitrogen (N), 3~5 kg of phosphorus (P2O5), and 2~4 kg of potassium (K2O) per mu, with all nitrogen, phosphorus, and potassium fertilizers applied as base fertilizer; for medium-yield fields with a yield of 300~400 kg per mu, apply 10~12 kg of pure nitrogen (N), 4~6 kg of phosphorus (P2O5), and 4~6 kg of potassium (K2O) per mu, with 70% of nitrogen fertilizer as base application and 30% as topdressing at the green-up stage, and all phosphorus and potassium fertilizers applied as base fertilizer; for high-yield fields with a yield of 400~500 kg per mu, apply 12~14 kg of pure nitrogen (N), 6~7 kg of phosphorus (P2O5), and 5~6 kg of potassium (K2O) per mu, with 60% of nitrogen fertilizer as base application and 40% as topdressing at the green-up or jointing stage, and all phosphorus and potassium fertilizers applied as base fertilizer; for super-high-yield fields with a yield above 500 kg per mu, apply 14~16 kg of pure nitrogen (N), 7~8 kg of phosphorus (P2O5), and 6~8 kg of potassium (K2O) per mu, with 50% of nitrogen fertilizer as base application and 50% as topdressing at the jointing stage, and all phosphorus and potassium fertilizers applied as base fertilizer.

(2) Sowing

7. Suitable Sowing Period

Generally, the daily average temperature for suitable sowing of winter varieties is 16~18°C, and for semi-winter varieties is 14~16°C. To cultivate strong seedlings before winter, winter and semi-winter varieties must ensure that the effective accumulated temperature before winter reaches 550~600°C, while also considering weather conditions, fertility level, pests and diseases, and safe overwintering. 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 Seeding Rate

A reasonable seeding rate and suitable basic seedling number are the starting point for establishing a high-quality population, and are also 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. The principles to master are: first, variety characteristics; for varieties with strong tillering ability and high spike-forming rate, appropriately reduce the seeding rate. Second, sowing time; for early sowing, appropriately reduce the seeding rate, and for late sowing, appropriately increase the seeding rate. Third, soil fertility level; for soils with better water and fertilizer conditions, the basic seedling number should be sparser and the seeding rate should be lower. 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. When the daily average temperature at sowing is below 15°C, for each day of delayed sowing, increase the basic seedling number by about 10,000, but it should not exceed 350,000 at most. 9. Fine Sowing

Use a wheat seeder that meets requirements and is of qualified quality, and determine the suitable sowing row spacing according to local actual conditions, ensuring consistent row spacing, accurate seeding rate, and consistent depth. The sowing depth is 3~5 cm, with no missed sowing or repeated sowing.

10. Post-sowing Compaction

Seeders equipped with a compactor should compact while sowing; seeders without a compactor should be compacted with a compactor after sowing. Ensure compaction strength and quality, compact the soil, reduce field moisture loss, promote wheat seedling growth, cultivate strong seedlings before winter, and increase the proportion of strong seedlings.

(3) Pre-winter Management

11. Irrigation for Overwintering

For wheat fields lacking soil moisture and fields with straw return, rotary tillage sowing, and hollow, unsettled soil, irrigate for overwintering in time to ensure seedlings survive the winter safely. Winter irrigation is generally carried out when the daily average temperature stabilizes at 3~4°C and water can infiltrate in time, and should be completed before major freezing. Promote water-saving irrigation, prohibit flood irrigation, and loosen the soil in time after irrigation to preserve moisture, prevent surface cracking, and avoid air leakage that damages roots and kills seedlings. For wheat fields with suitable soil moisture, high land preparation quality, sufficient base fertilizer, normal growth, and suitable population, overwintering irrigation may be omitted before winter. For wheat fields without irrigation conditions, loosen the soil in time after each rainfall to preserve moisture.

12. Chemical Weed Control

In recent years, malignant grass weeds have shown a gradual development trend and have a great impact on wheat yield. It is necessary to focus on autumn treatment of spring grass and do a good job in autumn chemical weed control, generally from mid-November to early December, when wheat is at the 3~4 leaf stage and weeds are at the 2-leaf-1-heart to 3-leaf stage. To control grass weeds such as wild oat, jointed goatgrass, shortawn foxtail, and ryegrass, use 40~60 ml of 6.9% fenoxaprop-P-ethyl emulsifiable concentrate per mu plus 30 kg of water for foliar spraying. To control jointed goatgrass and brome, use 30 g of 3% mesosulfuron or 20 g of 3.6% mesosulfuron-iodosulfuron per mu, plus 30 kg of water for spraying. To control broadleaf weeds such as flixweed, shepherd's purse, and cleavers, use 1.0~1.8 g of 75% tribenuron-methyl dry suspension, or 10 g of 10% tribenuron-methyl wettable powder, or 50~60 ml of 20% fluroxypyr emulsifiable concentrate plus 30~40 kg of water, and spray evenly. To control alkaligrass and hard grass, after wheat emergence use 200~400 g of 25% isoproturon wettable powder per mu, plus 20 kg of water for spraying.

13. Pest and Disease Control

For wheat fields with severe damage by underground pests such as white grubs and wireworms, use 500 ml of 40% isofenphos-methyl emulsifiable concentrate or 50% phoxim emulsifiable concentrate per mu plus 750 kg of water, and irrigate along the rows; or use 250~300 ml of 50% phoxim emulsifiable concentrate or 48% chlorpyrifos emulsifiable concentrate, diluted 10 times with water, mixed with 40~50 kg of fine soil, and apply into the soil while hoeing. For wheat fields with severe occurrence of wheat leaf miner, use 80 ml of 40% omethoate per mu plus 30 ml of 4.5% beta-cypermethrin, plus 40~50 kg of water for spraying; or use 1% abamectin diluted 3000~4000 times for spraying, which also controls wheat aphids and red spiders. To control wheat sheath blight, use 20~30 g of 12.5% diniconazole wettable powder per mu, or 100 g of 15% triadimefon wettable powder, diluted with 50 kg of water and sprayed evenly. For fields with severe occurrence of wheat cyst nematode, use 3.7 kg of 5% nematode-killing granules per mu, broadcast along the rows at the seedling stage, and irrigate in time to improve control efficacy.

14. Grazing by Livestock Strictly Prohibited

Strengthen the management and protection of wheat fields before winter, manage livestock and poultry well, and eliminate grazing by livestock and poultry to ensure normal growth of wheat seedlings and safe overwintering.

Middle and Lower Yangtze Winter Wheat Region

(1) Pre-planting Preparation

1. Variety Selection

Select varieties with high yield, high quality, and strong resistance to moisture, lodging, and disease (mainly fusarium head blight, powdery mildew, and sheath blight). In the southern part of the Middle and Lower Yangtze Wheat Region, select spring varieties; in the northern part, select semi-winter varieties. 2. Seed Treatment

Use 2% tebuconazole suspension concentrate, with 15~20 g of pesticide per 10 kg of seeds, plus 0.5 kg of water for seed dressing, which can also control soil-borne and seed-borne diseases such as sheath blight and take-all. For wheat sown early at the suitable time, paclobutrazol and other chemical control agents can be used for seed dressing or seed soaking, which can dwarf plants, increase tillering, control vigorous growth, and promote strong growth. It is advisable to dress 1 kg of wheat seed with 1 g of 15% paclobutrazol powder or soak seeds with 100~150 mg/L paclobutrazol solution. When dressing seeds, pay attention to mixing evenly to prevent excessive local pesticide concentration from affecting wheat seedling growth.

3. Straw Return

For rice, control the final irrigation time well, cut off water 7~10 days before harvest to create good soil moisture conditions for wheat sowing, and harvest in time after maturity to prevent excessive “aging of the rice”. When harvesting rice, the stubble height should be below 10 cm, and rice straw should be chopped to about 5 cm and evenly spread. For full straw return, first perform deep rotary tillage (or deep plowing) to eliminate stubble before mechanical drilling, and the depth of rotary tillage for burying straw should be at least 12 cm or more (preferably 15 cm) to prevent rice straw from concentrating in the sowing layer.

4. Application of Base Fertilizer

For weak-gluten wheat, generally apply 12~14 kg of pure nitrogen (N) per mu, with the ratio of base fertilizer: balanced fertilizer (applied at the 3~4 leaf stage of the main stem): jointing fertilizer (applied at the 3rd leaf from the top) being 7:1:2. For medium-gluten wheat, generally apply 14~16 kg of pure nitrogen (N) per mu. In large-scale production, the ratio of base fertilizer: tillering-promoting fertilizer (or balanced fertilizer): jointing fertilizer is 5:1:4. For high-yield fields, the ratio of base fertilizer: tillering-promoting fertilizer (or balanced fertilizer, applied at the 3~4 leaf stage of the main stem): jointing fertilizer (applied at the 3rd leaf from the top): booting fertilizer (applied when half of the flag leaf has emerged) is 5:1:2:2. According to the basic soil fertility level, the nitrogen, phosphorus, and potassium ratio for medium-gluten and weak-gluten wheat is 1:(0.4~0.6):(0.4~0.6), and phosphorus and potassium are preferably applied as base fertilizer: jointing fertilizer at 5:5. Generally, the base fertilizer can use 5~10 kg of urea (containing 46% N) and 15~25 kg of 45% compound fertilizer (N, P2O5, and K2O contents all 15%).

(2) Sowing

5. Suitable Sowing Period

To ensure that wheat seedlings form age-appropriate strong seedlings at the beginning of overwintering (main stem 5~6 leaves, 2~3 tillers per plant, and 3~5 secondary roots), the accumulated temperature above 0°C from sowing to the beginning of overwintering needs to be 500~550°C. The suitable sowing period in this region is late October to early November.

6. Reasonable Seeding Rate

For wheat fields sown at the suitable time in this region, the basic seedling number per mu is 120,000~160,000. For sowing later than the suitable period, appropriately increase the seeding rate, increasing the basic seedling number by 5,000 for each day of delayed sowing, and not exceeding 80% of the expected spike number at most.

7. Fine Sowing

For wheat fields where rice is harvested earlier, stubble is cleared in time, soil moisture is suitable (soil water content below 80% of field capacity), and soil tillage condition is good, a 2BG~6A type and other reduced-tillage (no-tillage) drill can be used to complete shallow rotary tillage, trench opening, sowing, soil covering, and compaction in one operation. The sowing depth is 2~3 cm, row spacing is 25 cm, and driving at medium speed ensures even seed drop. The joints between the two passes should match to avoid repeated sowing or widened row spacing, and avoid stopping in the field to form seed piles. Leave empty widths at both ends of the field first to facilitate turning of the machine body, then replant the empty widths at both ends at the end. For dead corners that the machine cannot reach, manually replant or transplant dense seedlings to fill sparse areas after emergence. When soil water content reaches more than 80% of field capacity, use a newly improved band drill for sowing to prevent blockage of seed discharge ports and missing seedlings or broken rows.

8. Post-sowing Compaction

Seeders equipped with a compactor should compact while sowing; seeders without a compactor should be compacted with a compactor after sowing to ensure compaction quality.

9. Mechanical Ditching

Carry out mechanical ditching in time after sowing. 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 ridge 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 is required to 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 mud to cover wheat rows, reduce exposed seeds, and prevent freezing and protect seedlings.