Start soil moisture preparation for cotton early and seize favorable opportunities

Although there is still one to two months before cotton seedling raising and sowing, the current situation of consecutive drought across autumn, winter and spring has already posed a great threat to cotton planting this year, and based on past years, there is also very little precipitation in our province in March-April. In view of the current situation, Dong Hezhong, deputy director and researcher of the Cotton Research Center of the Shandong Academy of Agricultural Sciences, suggests that cotton farmers: this year's cotton planting should start early and prepare early, seize the opportunity for soil moisture preparation according to weather conditions, actively prepare and conserve soil moisture, fight drought and protect seedlings, and strive for full seedlings from one sowing and early development of strong seedlings.

Select good seeds well and do a good job in pre-sowing preparation

Revitalizing agriculture through science and technology starts with good seeds. In ordinary years, problems such as no emergence or poor emergence caused by seed issues can still be remedied by reseeding or replanting seedlings, but this year, due to continuous drought and little rain, poor soil moisture, and relatively scarce water sources in various places, the innate conditions are insufficient, so the quality requirements for seeds are even higher. When choosing seeds, first choose seeds of approved and suitable cotton varieties, requiring good maturity and a high germination rate; second, be sure to buy seeds produced by formal enterprises with all three certificates complete, read the instructions carefully, and ask for a seed purchase invoice; third, 15 days before sowing, choose sunny days to sun the seeds for 2-3 days to break seed dormancy and promote germination and emergence.

Tap water sources and prepare and conserve soil moisture

The cotton-growing areas in our province are mainly distributed across three major regions: northern (eastern) Shandong, northwestern Shandong and southwestern Shandong. The southwestern Shandong region mostly uses seedling raising and transplanting, which does not require much water during the seedling period, while northern (eastern) Shandong and northwestern Shandong mostly have direct-seeded cotton fields, and there are also relatively many saline-alkali cotton fields, so soil moisture must be prepared and sowing must be done with sufficient moisture. Therefore, water sources must be fully tapped, and soil moisture preparation and conservation before sowing must be done well.

Where irrigation conditions are available, seize the opportunity to prepare soil moisture. Theoretical analysis shows that generally more than 20 days before cotton sowing is the best period for soil moisture preparation. Considering this year's continuous drought and little rain and relatively tight water sources, soil moisture should be prepared in a timely manner according to local water source conditions, and after preparation, harrow and level in time to conserve moisture.

Where there are no irrigation conditions, it is recommended to pre-cover with plastic film to raise moisture. About one month before sowing, after preparing the land while moisture is available, immediately carry out plastic film mulching, compact both sides of the film, and when the temperature is suitable, punch holes in the film for dibbling. This method can significantly reduce water loss through ground evaporation and maintain soil moisture, with notable effects for cotton planting in arid and saline-alkali areas, especially after local small-scale precipitation or timely film mulching after soil moisture preparation, the effect is even better and it is worth promoting.

Choose sowing methods according to local conditions

Water-seeded. When plastic film mulching is not used, this is the most effective drought-resistant sowing method. The method is: open a shallow furrow about 2.5 cm deep, water evenly, with the amount of water sufficient to connect to the subsoil moisture, wait for the water to infiltrate into the soil, and dibble cotton seeds; cover soil along the cotton rows and form a ridge, 3-5 cm above the ground; when more than 70% of the seeds have taken root, level it all at once.

Drought-resistant seedling raising. On the basis of sowing with sufficient moisture in the seedbed, appropriately reduce water supply to the seedbed and gradually carry out drought tolerance training for the seedlings. When the red stem of the seedlings reaches half, the hardening-off is successful, the drought adaptation ability is improved, and after transplanting they have a certain drought-resistant effect.

Furrow irrigation with film mulching. Before sowing, open furrows, water in the furrows, then sow and cover with soil, and then cover with plastic film. This method is suitable for protecting seedlings in dry land.

Flexibly determine the sowing date

At present, there are many types of cotton varieties, and the requirements for sowing date are relatively flexible. Generally, under conditions of plastic film mulching, April 10 to May 10 is a suitable period for cotton sowing. In previous years, cotton sowing mainly considered the temperature factor, and sowing began as long as the temperature was sufficient. This year, in addition to considering the temperature factor, more attention should be paid to soil moisture conditions. If the temperature is sufficient but the soil moisture is insufficient, it is recommended that cotton farmers wait a little longer; on the contrary, if the soil moisture is acceptable but the temperature is slightly lacking, sowing can also be considered, with an increased sowing rate.