What are the key points of cotton-stubble wheat cultivation techniques?

To address the problems of late sowing, low and unstable yields in cotton-stubble wheat, we have worked out a set of high-yield cultivation techniques for cotton-stubble wheat, which have greatly increased @#@245@#@ yields. In 1999, the planting area in the whole county was about 50,000 mu, with an average wheat yield of 350 kg per mu. The key technical points are:

(1) Irrigate enough to build up subsoil moisture and apply enough basal fertilizer. Build up moisture before October 15, then pull up the cotton plants, carry them out of the field, and let the late-autumn bolls open naturally on the cotton plants. Because cotton stubble depletes soil fertility considerably, the amount of basal fertilizer should be increased. However, cotton-stubble wheat is sown late and relies on the main stem for development, so before jointing, fertilizer and water management should be used to control tillering and regulate the population. Therefore, the proportion of urea used as basal fertilizer for cotton-stubble wheat should not be too large. Generally, apply 4,000 kg of high-quality farmyard manure, 25 kg of diammonium phosphate, and 15 kg of potassium chloride per mu. Nitrogen fertilizer should be concentrated as a topdressing at the wheat jointing stage.

(2) Select superior varieties and improve sowing quality. Cotton-stubble wheat has a short growth period and few tillers, so medium-spike, medium-grain wheat varieties that are high-yielding and early should be selected, such as Henong 321, 71-3, etc. Before sowing, select seeds carefully, sun the seeds, and treat them with chemicals. The sowing rate should be determined according to the sowing date. For sowing from October 15 to Frost's Descent, the basic seedlings per mu should reach 350,000-400,000; for sowing after Frost's Descent, the basic seedlings per mu should reach 400,000-430,000. To ensure sowing quality, prepare the soil finely, sow with a seeder, and sow at a depth of 3-4 cm. Seeding should be uniform and the sowing depth consistent.

(3) Winter management. (1) Overwintering with sufficient moisture: cotton-stubble wheat seedlings are weak and have few tillers, with poor resistance, and are prone to freeze damage during overwintering, so they must overwinter with sufficient moisture. If sufficient subsoil moisture was irrigated before sowing, it is best not to irrigate the freezing water, so as not to slow the rise of soil temperature in early spring and affect early wheat development. However, if autumn drought occurs, moisture is lost too quickly, or sowing was done by taking advantage of existing moisture without irrigating subsoil water, then freezing water should be applied judiciously, preferably early, and the soil should be hoed and raked promptly after irrigation to prevent soil crusting and cracking. (2) Winter pressing of wheat: winter pressing of wheat can not only close soil cracks, but also crush clods to reduce water evaporation, helping to protect against cold and preserve moisture for safe overwintering. After wheat stops growing, choose a sunny afternoon and use a stone roller to press the wheat. Generally, press lightly on soil with sufficient moisture and sandy soil; press appropriately harder where moisture is poor and the soil is clayey.

(4) Spring management. (1) Early spring management: when the surface soil begins to thaw in spring, use a bamboo rake along the rows to remove dead leaves and debris, then begin intertillage and hoeing, which can increase temperature, preserve moisture, and promote early seedling development. (2) Heavy fertilizer and water application at jointing: the first fertilizer and water application in spring should be postponed until the jointing stage, and fertilizer and water should be applied heavily, with 20 kg of urea topdressed per mu. This fertilizer and water application is the period of greatest benefit for wheat, and can increase the seed-setting rate, increase the number of grains per spike, and increase the 1,000-grain weight. In addition, it is also necessary to irrigate well at the booting and flowering-filling stages.

(5) Control of diseases, insects, and weeds. Before wheat jointing, use MCPA or tribenuron-methyl to control weeds, and for wheat aphids, use kuailing can be used. For wheat sheath blight, leaf blight, and powdery mildew, use wenmeiqing and fenxiuning for control. During the wheat filling stage, foliar fertilizers such as Penshibao and Huimanfeng can also be sprayed to prevent wheat dry-hot wind.