What are the common problems in dryland rice cultivation?

1. How to grow enough rice seedlings under drought and water shortage conditions

The whole year's success lies in spring. This vividly and profoundly illustrates the importance of seedling raising in the whole year's production. Under this year's special conditions, growing enough seedlings is the key measure to win the battle against drought and secure a bumper harvest. To grow enough rice seedlings under drought and water shortage conditions, the first thing is to determine the seedling raising method according to local conditions, and the second is to implement the seedling raising technical measures. When determining the seedling raising method, there are three approaches to choose from for reference: first, in places where water can be obtained locally, promote dryland seedling raising; second, in places where no water can be obtained, coordinate through the township government to carry out off-site commercial seedling raising; third, farmers can contact off-site seedling raising for others through relatives and friends. In places with year-round drought and difficulty in raising seedlings, it is also necessary to seize the spring sowing opportunity and soil moisture to raise corn seedlings as a reserve for disasters, and in particular to raise as many sweet potato seedlings as possible. This is not only the last line of defense for disaster resistance in the main spring season, but can also serve as green feed for developing animal husbandry.

2. How to cultivate age-appropriate drought-resistant strong seedlings

As the saying goes, good seedlings mean half the grain. The quality of seedlings is the key to high rice yield. To cultivate age-appropriate drought-resistant strong seedlings, the following key technical links should be emphasized:

1) Select suitable varieties. Excellent varieties refer to those adapted to the local natural conditions, production level and cultivation techniques, not merely those with large panicles or good quality. Under drought-resistant seedling raising conditions, low-altitude areas should first consider whether rice can head and flower in mid-July, and should try to avoid the impact of the frequent high-temperature summer drought from late July to early August in our city on rice flowering and grain setting; middle and low mountain areas should consider avoiding the impact of low-temperature and continuous rain in autumn on rice flowering and grain setting, that is, under late sowing conditions, varieties with a relatively short growth period should be selected. Second, they should have strong resistance to drought and low temperature. Third, under disaster weather conditions, pests and diseases are more serious, so varieties with better disease resistance and that have undergone seed treatment should be selected. In areas and fields threatened by summer drought, where the sowing period is delayed due to lack of water, varieties with a growth period of more than 160 days must not be used.

2) Persist in timely early sowing. Timely early sowing can effectively prolong the vegetative growth period of rice, increase the effective accumulated temperature, raise the accumulation of photosynthetic dry matter, promote early maturity, effectively reduce the impact of high-temperature summer drought or autumn wind in the later growth stage of rice, and lay the foundation for increasing rice yield per unit area. Because most of the currently promoted varieties are large-panicle types with generally longer growth periods, in order to avoid the impact of the year's greatest disaster, summer drought, it is usually required that heading and flowering occur before July 15, so timely early sowing is required.

3) Prepare sufficient seedling bed land. Choose sandy loam land that is sheltered from the wind, sunny and convenient to manage, preferably vegetable garden land, as the rice dry-raised seedling bed land. After shallow plowing of the seedling land, promptly remove weeds and straw residues, especially crush the soil finely and level it. The seedling bed should undergo soil treatment before sowing. For each square meter of seedling land, use 2.5 g of 70% Dexon diluted in 2 kg of water and spray evenly, or mix evenly with fine mud and sand and spread evenly for disinfection and sterilization, or when sowing, mix seeds evenly with dry-raising nanny (each packet of dry-raising nanny 350 g mixed with 1-1.2 kg seeds) to disinfect and sterilize the seeds and improve the seeds' water retention and soil-fixing capacity. The bottom water of the seedbed should be watered thoroughly at one time, so that the seedbed soil layer is in a saturated water state and there is no visible water on the surface of the seedbed. Preparing sufficient seedbeds is an important measure for cultivating age-appropriate strong seedlings. Where water source conditions are relatively good and seedlings can be transplanted within 50 days of age, at sowing, each mu of paddy field (calculated at 1 kg of seeds) requires seedling land with a bed surface 1.5 m wide and 20 m long; where the transplanting seedling age is more than 60 days, at sowing, each mu of paddy field (calculated at 1 kg of seeds) requires seedling land with a bed surface 1.5 m wide and at least 30 m long.

4) Improve sowing quality. Do a good job in seed treatment, improve seed vigor, and ensure neat and consistent emergence. When the daily average temperature steadily passes 10°C, begin sowing at the end of a cold spell and the beginning of a warm one. After sowing, scatter a thin layer of fine soil to cover the seeds, with a soil cover of 1 cm. The seeds must be tightly covered, and arched film covering should be used for seedling raising. Vigorously advocate double-film covering, that is, cover the surface of the seedling land with a layer of old film first, then build a frame and cover a second layer of film, so as to facilitate heat and moisture retention and earlier emergence.

5) Strengthen seedbed management. From sowing to emergence, focus on heat and moisture retention. When the temperature inside the film exceeds 35°C, pay attention to ventilation and cooling. From emergence to the one-leaf-one-heart stage, focus on temperature regulation and moisture control, promote downward root growth, and keep the temperature inside the film within 25°C. At one leaf and one heart, for each square meter of seedling land, use 1 g of 70% Dexon, dilute to a 1000-fold solution and spray to prevent damping-off disease; if the bed soil is dry and turns white, appropriately supplement water. From one leaf and one heart to two leaves and one heart, gradually ventilate and harden the seedlings to reduce humidity, and keep the temperature inside the film at about 20°C. After two leaves and one heart, gradually open all the shed film. At the three-leaf-one-heart stage, apply weaning fertilizer. For each square meter, apply 5-10 g of urea, dilute 1000-fold with water and spray evenly, then spray clean water to wash the seedlings. Pay attention to preventing weeds in the seedbed: first, before three leaves and one heart, use Yangtian Yicijing (30% dichloroquinoline and benzyl wettable powder) at 30 g per mu diluted with water and spray. Second, before budding or 2-3 days after removing the film, use 17.2% Youhebao wettable powder at 200 g/mu and spray.