Fertilization Timing and Methods for Rice Seedling Raising and Fertilizer-Saving, Water-Saving, and Pesticide-Saving Cultivation Techniques

According to grain type, rice can be divided into indica and japonica rice, early rice and mid-to-late rice, and glutinous and non-glutinous rice. It is an annual plant of the grass family.So how should fertilizer be applied when raising rice seedlings? What is the specific timing? What are the fertilizer-saving, water-saving, and pesticide-saving cultivation techniques?

How should fertilizer be applied when raising rice seedlings?

Before planting rice, the soil in the paddy field must first be turned over to make it soft and loose. This process is divided into three stages: coarse plowing, fine plowing, and leveling. In the past, animal power and plows were used, mainly water buffaloes, to prepare the land and plow the fields, but now machines are mostly used for land preparation.

1. Seedling cultivation:

Farmers first cultivate seedlings in a certain field, which is often called a seedling field. After sowing the rice seeds, farmers usually spread a layer of rice husk ash on the soil; in modern times, specialized seedling centers mostly use seedling boxes to grow rice seedlings. Good rice seedlings are the key to successful rice cultivation. When the seedlings grow to about eight centimeters tall, they can be transplanted.

2. Transplanting:

The seedlings are carefully transplanted into the paddy field at orderly intervals. Traditional transplanting methods use seedling ropes, seedling markers, or transplanting wheels to make marks in the paddy field. When transplanting by hand, a seedling separator is worn on the thumb of the left hand to help the farmer separate the seedlings and insert them into the soil. The weather during transplanting is very important, as heavy rain can damage the seedlings. In modern times, transplanting machines are often used, but in paddy fields with large undulations and non-square shapes, manual transplanting is still needed. Seedlings are generally oriented in a north-south direction. There is also the more convenient method of seedling throwing.

3. Weeding and pest control:

While the seedlings are growing, they must be cared for constantly, and weeds must be pulled. Sometimes pesticides are also needed to kill pests (such as golden apple snails).

4. Fertilization:

When the seedlings shoot up and grow their first rice stem node, this is called the tillering stage. During this period, fertilizer is often needed to let the rice seedlings grow robustly and to promote fuller and more numerous grains at heading later.

5. Irrigation and drainage:

Rice relies relatively heavily on this procedure. For upland rice, it is a dry field, and the irrigation and drainage process is somewhat different, but generally after transplanting, when young panicles form, and during the heading and flowering stage, water irrigation must be strengthened.

What is the specific timing for fertilizing rice?

1. Generally, for main-field fertilization, the growth process of rice is divided into three periods: early, middle, and late. The early period refers to the time from transplanting to the end of tillering, which is the vegetative growth stage of rice. At this time, the goal is to promote effective tillering and strive for more panicles. The middle period refers to when rice growth has entered the reproductive growth stage (pollen formation period). At this time, the goal is to strengthen the stems and develop large panicles, but fertilizer must not be applied excessively. The late period refers to the time from heading to maturity. At this time, the focus is on more grains and filled grains, ensuring that fertilizer is not lacking while also avoiding excessive vegetative growth and late maturity.

2. The fertilization methods for the above three periods of rice actually refer to the principles, theory, and goals of fertilization. In real practice, they must also be determined according to specific conditions, that is, the amount of fertilizer applied must be determined according to different soils and different rice varieties, which means adapting measures to local conditions and applying them flexibly. Specifically, this means looking at whether the soil is fertile or poor and whether the soil texture is sandy or clayey. If the soil is both fertile and sandy, the amount of fertilizer applied should be reduced; if the soil is clayey and poor, the amount of fertilizer applied should be increased. This is called fertilizing according to the soil. In addition, attention must be paid to fertilizing according to the seedlings: apply less when the seedlings are strong and more when the seedlings are thin. This is why there is a range in the fertilizer application amounts below.

What are the fertilizer-saving, water-saving, and pesticide-saving cultivation techniques for rice?

1. Select improved varieties

Select seeds that have undergone quarantine to prevent diseases from spreading through seeds. The selected varieties should meet the following conditions: (1) approved by the relevant institutions; (2) suitable for planting under the climate and soil conditions of Dali City; (3) high quality and high yield, with good disease resistance and strong stress resistance. Varieties currently suitable for planting in our city include: Yunjing No. 37, Dianyou No. 35, Hexi 22-2, Fengdao No. 25, No. 26, No. 29, No. 30, etc.

Through the selection of new varieties, the goals of high quality and high yield are achieved, while reducing the amount of pesticides and chemical fertilizers used, lowering production costs, and controlling agricultural non-point source pollution.

2. Reduce seeding rate and sow sparsely to cultivate dry-raised seedlings with tillers

The seedling-raising season in Dali City is mid-to-late March. The optimal sowing rate is 50 kg per mu. Before sowing, soak the seeds in Shibaoke (2000-3000 solution) for 72 hours, and sow evenly and sparsely. The optimal seedling age is 45-50 days. Through the implementation of this technique, the goals of fertilizer-saving and water-saving cultivation are achieved, and agricultural non-point source pollution is controlled.

3. Adopt soil testing and formula fertilization technology to advance the action of reducing chemical fertilizers and pesticides

Apply 400-600 kg of refined organic fertilizer or 1500 kg of farmyard manure per mu as base fertilizer. Apply 60% of nitrogen fertilizer as basal and tillering fertilizer, and 20% as flower-promoting fertilizer. Apply at the four-leaf stage from the top. Apply 20% as flower-preserving fertilizer. Apply at the two-leaf stage from the top. Apply all phosphate fertilizer as base fertilizer. Apply potassium fertilizer as flower-promoting fertilizer 50-55 days after transplanting.

By implementing precise fertilization and using slow- and controlled-release fertilizers to replace part of the quick-acting chemical fertilizers as base fertilizer, the nutrient needs of rice at each growth stage are met, fertilizer use efficiency is improved, the amount of chemical fertilizer used is reduced, the maximum benefit of fertilizer is achieved, and disease occurrence is reduced, thereby achieving the goals of saving fertilizer, saving pesticides, and controlling pollution.

4. Scientifically save water in irrigation, regulate rice growth and development, and achieve high quality and high yield

During the seedling stage, water the seedbed sufficiently to ensure the emergence rate. During the seedling stage, control water to harden the seedlings, promote tillering, and cultivate dry-raised seedlings with tillers, laying the foundation for sparse planting and shallow transplanting.

During the tillering stage in the main field, use shallow-water irrigation, combined with light field drying, to promote tillering, promote robust rice growth, improve disease resistance, and dry the field in time once enough tillers have developed to create a high-yield population.

During the booting stage, use shallow-water irrigation to promote young panicle differentiation, form large panicles, and achieve high yield by increasing the number of filled grains per panicle.

During the grain-filling stage, use moist irrigation with alternating wet and dry conditions to improve root activity, prevent premature senescence, prevent lodging, promote full grains, form large grains, increase the head rice rate, improve rice quality, and advance the structural reform of the agricultural supply side.

Through the application of water-saving irrigation technology, the cycle of soil oxidation-reduction processes is promoted, the transformation and utilization of soil nutrients are promoted, fertilizer loss is reduced, fertilizer is retained in the soil, fertilizer use efficiency is improved, soil ecological balance is maintained, high quality and high yield of rice are promoted, and the treatment of agricultural non-point source pollution is further advanced.

5. Adopt green prevention and control technology to control diseases, insects, and weeds

Implement the policy of “prevention first, integrated control” and follow the principle of healthy cultivation and giving priority to agronomic measures. Strengthen field monitoring of diseases, insects, and weeds, carry out timely control, strictly follow the technical requirements of green prevention and control, use chemical control, reduce pesticide use to a minimum, control agricultural non-point source pollution, truly protect the agricultural ecological environment, and make rural areas a beautiful homeland where people can live and work in peace and contentment.