What are the precautions for spraying foliar fertilizer on rice?

Timing: Generally, spraying at the late booting, initial heading, grain-filling and full heading stages of early rice is most suitable, and spraying once per mu takes over an hour. If spraying fertilizer coincides with the heading and flowering stage, it should be done in the morning before the flowers open and after 4 p.m.

Preparing liquid fertilizer: Various quick-acting nitrogen, phosphorus and potassium fertilizers, monopotassium phosphate, triacontanol, borax, silkworm droppings and human and livestock urine can all be used as foliar fertilizer. The amount used per mu is small, but they must first be processed into liquid fertilizer. Quick-acting chemical fertilizers should be dissolved in 5-10 times their amount of water the day before spraying to prevent burning the rice leaves from over-spraying. Human and livestock urine should first be placed in a pit to decompose; for silkworm droppings, dissolve them in 10 times their amount of water, filter after 24 hours, then dilute to full volume with water before spraying; for borax, first crush it, stir it thoroughly with a small amount of water into a concentrated liquid, then dilute to full volume with water before spraying.

Spray fertilizer according to the growth of the rice plants to treat the specific condition. For fields with green leaf color and uniform heading, spray a mixed phosphorus and potassium fertilizer. Use 0.25 g of urea, 0.5 kg of superphosphate and 0.25 kg of potassium chloride per mu, add 60 kg of water and spray; or use 2.5-3.7 kg of decomposed cow urine and 1 kg of superphosphate per mu, mixed with 60 kg of water. For fields with yellow-green leaf color, uneven growth and thin soil, spray mainly nitrogen fertilizer, combined with phosphorus.