What are the technical measures for drought resistance and disaster mitigation in rice cultivation in Heilongjiang Province?

In response to the actual drought situation, the Rice Expert Guidance Group of the Ministry of Agriculture conducted in-depth research in drought-affected rice areas and proposed technical measures for scientific drought resistance and disaster mitigation to ensure increased rice production.

1. Strengthen the management and scheduling of irrigation water sources. Actively develop water sources, organize as much as possible the pumping of return flow and the use of water-lifting irrigation machinery to utilize rivers, lakes and groundwater, alleviating the contradiction of insufficient reservoir storage. For plots far from water sources, promptly dig supplemental water wells to ensure a safe water supply during severe drought seasons. Strengthen the management of existing water resources and the clearing, repair and film-mulching of main irrigation canals to prevent seepage and leakage. Scientifically allocate water sources and supply water in a planned manner, especially controlling the water supply for fields transplanted before May 15 that have already turned green, and directing limited water sources toward paddy field preparation and transplanted fields.

2. Promote water-saving cultivation techniques. Vigorously promote water-saving technical measures to effectively reduce the impact of drought on rice growth and development. First, implement mulching cultivation. For fields that have been prepared and transplanted but lack water for turning green, apply 250 kg of chopped rice straw per mu as mulch; for fields that have been prepared but not yet transplanted, adopt the film-mulching transplanting method in the main field, which can reduce water loss from the field surface, prevent weed occurrence, and achieve moist irrigation throughout the entire growth period. Second, implement seedling boarding measures. That is, for plots where land preparation and transplanting are relatively late, adopt the methods of seedling boarding in the seedling field and seedling boarding in the main field to increase leaf age flexibility, delay seedling aging, and achieve the goal of transplanting while waiting for water. Seedling boarding in the seedling field refers to removing the shed film early for seedbeds with seedlings less than 3 leaves and 1 heart, controlling watering with drought management as the main approach, combined with spraying paclobutrazol and rooting powder to promote well-developed root systems; for yellowing seedlings lacking fertilizer, apply 15 g of ammonium sulfate per square meter of seedbed and then water thoroughly once. This method can maintain seedling quality without major changes within one week. Seedling boarding in the main field mostly refers to selecting fields with water for boarding seedlings affected by severe bacterial wilt and damping-off, to alleviate further aggravation of the disease. Third, implement moist irrigation. For fields that have been transplanted and turned green, a water layer need not be established on the field surface; implement water-saving moist irrigation throughout the entire growth period, and irrigate a shallow water layer once water sources are sufficient. However, a water layer must be established at the booting stage to prevent drought and water shortage from causing massive spikelet sterility, which would affect yield and quality.

3. Scientifically prevent and control diseases, pests and weeds in drought-affected rice fields. Drought in rice fields easily aggravates the occurrence and damage of diseases, pests and weeds, so forecasting should be effectively strengthened and responsive technical measures adopted. First, prevent and control weeds. In fields without water after transplanting, the early chemical sealing effect is poor, and weeds will tend to worsen in the later period. At the 3-leaf 1-heart stage of barnyardgrass, spray 15 kg of propanil per hectare; for barnyardgrass at the 4-leaf stage or above, spray 300-400 g of 50% quinclorac diluted in water; for three-square bulrush and broadleaf weeds, spray 2 kg of 48% bentazone plus 0.75 kg of MCPA. Second, control insect pests. Insect pests often break out massively along with drought. For leaf miners, spray a small amount of dimethoate on the seedbed before transplanting and transplant with the pesticide; in the main field, evenly broadcast 3-3.5 liters of 18% bisultap per hectare, or spray 300-400 g of 10% imidacloprid-bisultap diluted in water. For adult rice leaf beetles, when 80% of adults are mating, dust 45 kg of 2.5% trichlorfon powder per hectare; when eggs have hatched, dust 22.5-30 kg of 5% trichlorfon powder per hectare or spray 225-495 ml of deltamethrin emulsifiable concentrate diluted in water. For the striped stem borer, when the rate of dead sheaths in the field reaches 1%, that is, in early July, spray 750-900 g of bisultap, or 375-525 g of cartap, or 600-900 g of cartap hydrochloride per hectare diluted in water. Third, prevent and control diseases. Pay attention to observing the occurrence and development trends of rice blast, sheath blight and rice false smut, adhere to the principle of prevention first and combining prevention with control, and keep diseases within the smallest possible range.

4. Rationally manage fertilizers to ensure safe maturity. Based on the actual irrigation water sources and population growth conditions, rationally manage fertilizers to promote and control population growth and ensure safe maturity of rice. For plots with normal growth, appropriately control the amount of nitrogen fertilizer and pay attention to increasing phosphorus and potassium fertilizer; especially for medium and late-maturing varieties, control nitrogen application, and according to variety type, weather changes, soil fertility and field growth conditions, skillfully apply regulating fertilizer, implementing the "eat less, eat more often" fertilization method to improve rice stress resistance and ensure safe maturity. For plots transplanted and turned green relatively late, where the growth period is delayed and premature aging is likely, persist in rational fertilizer management to promote early maturity; this can be done by spraying growth promoters such as rooting powder, or spraying foliar fertilizers such as monopotassium phosphate and Aifeng organic liquid fertilizer, to improve stress resistance, promote rice growth and ensure safe maturity of rice.