How to Grow Organic Rice: The Latest Cultivation Techniques and Methods Tutorial
Organic rice refers to rice grown without the use of chemically synthesized pesticides, chemical fertilizers, growth regulators and similar substances; instead, it follows natural laws and ecological principles and adopts a series of sustainable agricultural techniques to maintain a continuous and stable agricultural growth process. Growing organic rice brings significant ecological, economic and social benefits. It can reduce soil erosion, reduce pollution of the environment by pesticides and chemical fertilizers, protect the agricultural environment, and raise producers' incomes. It supplies society with natural, pollution-free, hazard-free rice. It meets people's needs and improves human health levels.
Conditions for Growing Organic Rice
1. Soil management
By adopting techniques such as returning straw to the field, applying organic fertilizer, biological bacterial fertilizer and deep and shallow plowing and turning in the field, the soil plow layer is activated, creating a favorable growing environment for organic rice.
2. Nutrient management
Fertilization is arranged according to the nutrient requirements of rice. Organic fertilizer and biological bacterial fertilizer can be used as base fertilizer, and attention should also be paid to applying seed fertilizer and carrying out foliar topdressing, so as to supplement nutrients in good time during the growth periods when they are needed.
3. Plant protection
Before sowing rice, the seeds can be soaked in organic biological preparations to prevent and control seedling-stage diseases. When diseases occur during the growing period, biological pesticides should be chosen for control, and foliar bacterial fertilizer can be applied at the same time to improve the resistance of the rice and prevent the further spread of diseases and insect pests.
Weeds in the paddy field can be controlled by manual weeding, and the use of chemical agents is strictly prohibited.
Organic Rice Cultivation Techniques
1. Plot selection
In the process of growing organic rice, plot selection is very critical. The soil environment of the selected plot must meet the national GB15618—1995 Grade I standard, the air conditions must meet the national Grade I quality standard, and the water quality must meet the GB5084—92 Grade III standard for surface water environment.
The plot for growing organic rice is generally chosen as one with good fertility, convenient irrigation and drainage, and natural isolation from other plots. Plots with pollution sources nearby are prohibited for growing organic rice.
2. Variety selection
In the cultivation process of organic rice, variety selection is very important. For organic rice production, varieties that are mid-season, strongly resistant, widely adaptable, and high and stable yielding should be chosen. The seeds must be screened: plump grains, uniform grain shape, no weed seeds, and no diseases or insect pests.
3. Seedling-raising techniques
Before sowing rice, the seeds must first be sun-dried and selected with salt water, then soaked in 1% quicklime to avoid seed-borne bacteria. The surface of the seedling bed should be plowed to a depth of more than 10cm to ensure the bed soil is level and finely crumbled. The bed width is generally 1.8-2.2m.
The base fertilizer for the seedling bed is generally high-quality organic fertilizer applied at 7.5-10kg/m2 to build soil fertility, mixed with the seedbed soil. Sowing and seedling raising begin when the temperature is 5℃.
The sowing rate varies with the sowing method. For conventional seedling raising, the seed rate is generally 1759 grains/m2. For plastic-film perforated seedling raising, it is 2509 grains/m2. For nutritional-pot seedling raising, it is 709 grains/tray.
4. Transplanting work
Before transplanting rice, preparatory work must be done well. First, the main field should be prepared in advance. It is best to irrigate the main field in advance to promote the germination and growth of weed seeds, then carry out mechanical harrowing to remove weeds that have already grown. After the main field is prepared, transplanting can begin once the temperature steadily exceeds 12℃.
Field planting of rice requires a reasonable density to ensure the quality of the seedlings. Transplanting requires shallow, straight, even, stable and sufficient placement.
5. Seedling field management
The focus of rice seedling field management is regulating temperature and controlling water, so that the seedlings grow slowly and robustly. The critical temperatures for seedling growth must be grasped: 12℃ for rice roots and 15℃ for rice leaves; below these temperatures growth stops.
The optimum temperature for seedling growth is generally 22-25℃, the temperature at which assimilation is vigorous. Within the optimum temperature range, at a lower temperature, especially with the stem growth point at a lower temperature, the seedlings grow robustly, have a high dry weight, and have a high plumpness (ratio of dry weight to plant height). If the temperature during the seedling stage is too high, often around 30℃, the seedlings will become leggy, thin and tall, with low dry weight, low plumpness and poor root development. If the temperature during the seedling stage is too low, often below 10℃, albino seedlings and bacterial wilt are likely to occur.
Rice seedlings grow and develop fastest between 0:00 and 7:00, and the seedbed temperature (15-28℃) must be ensured to promote seedling growth. Pay attention to the day-night temperature difference: it should not be too high during the day, and should be appropriately lowered at night, which helps the seedlings grow slowly and robustly. For dry seedling raising, moisture must be well controlled. With little soil moisture, the dry-grown root system develops well and aboveground growth is slow, producing age-appropriate strong seedlings with a dry-grown root system, a wide stem base, early overweight, standard plant height, and leaves that do not droop.
Field Management of Organic Rice
1. Soil fertilization
The soil can be fertilized through the technique of returning straw to the field: during mechanical harvesting in autumn, the straw and rice straw are fully chopped and evenly scattered in the main field, then deep plowing is carried out to mix the straw and rice straw evenly with the soil. Before rotary tillage, fully decomposed farmyard manure is applied as a base.
2. Weed control in the main field
Flooding the main field can be done by broad irrigation, which can float away weed seeds in the soil. Generally, about 15d before transplanting, the main field is plowed and flooded with a large amount of water to kill the old weeds in the field; then 2-3d before transplanting, the main field is plowed again to kill newly germinated weeds. If germinated weeds are found during the growth of the rice, they should be pulled out by hand in good time.
3. Water management
From young panicle differentiation to before heading, adopt a shallow-moist-dry intermittent irrigation technique; after heading, use shallow-water moist irrigation to promote root growth. In well-irrigation areas, adopt a warming irrigation technique and avoid letting well water enter the field directly. The weeds on the field ridges should be cut clean, and the barnyardgrass ears in the field should be removed completely; this can both prevent and control diseases and insect pests and ensure that sunlight shines directly on the water surface, raising the water temperature.
At the same time, water should be cut off early in good time to promote ripening. Generally, water can be stopped at the yellow-ripe stage (30d after heading); drain early in low-lying land, and drain appropriately later in leaky land.
4. Disease control
Common rice diseases include bakanae disease, rice blast, sheath blight and rice false smut. Methods such as cultivating strong seedlings, reasonable close planting, scientifically regulating fertilizer and water, timely field drying, and controlling peak seedling numbers can enhance the resistance of the plants and fundamentally control the occurrence of diseases.
5. Insect pest control
The common insect pests that harm rice mainly include rice weevil, rice thrips, rice planthopper and stem borers.
① Agricultural control: For insect pest control in organic rice, agricultural control is the first choice; by strengthening field management, the resistance of the rice is enhanced.
② Physical control: This refers to the insect pest control method of using frequency-vibration insect-killing lamps during rice cultivation to trap and kill phototactic pests.
③ Biological control: Use biological pesticides and botanical pesticides recognized by organic certification bodies to control the base number of insect pests in the field. Use existing natural enemies to control the population size of insect pests.