Since boron is the most easily transportable element in soil, the requirement of boron required by different crops is also different. Therefore, special attention should be paid to fertilization, which can cause toxicity to crops and environmental pollution if used improperly.
The following are common ways of applying borax fertilizer.
(1) Basic fertilizer
In the soil with moderate or severe boron deficiency, using borax fertilizer as the base fertilizer was better than spraying, and its fertilizer effect maintained longer. Application of borax: the planting area of farmland is 0.3~0.7 kg; Apply 20-30 g/tree borax to fruit trees and 100-200 g/tree borax to large trees, depending on the size of the crown. Because of its small amount, so difficult to uniform. Therefore, usually in chemical fertilizer, organic fertilizer or dry fine soil mixed with a small amount of borax fertilizer, after mixing, in the soil trenches or holes to avoid direct contact with seeds or seedlings, to avoid affecting germination or burning the root system. When the base fertilizer dosage of borax is greater than 1.0 kg per hectare, it will cause crop poisoning. So the use of borax fertilizer must be strictly controlled.
Borax cost is low, because of its low boron content, large usage, suitable for use as a basic fertilizer. It can be used with superphosphate or organic fertilizer under the condition of applying 15 kg/mu of boron mud in the field and 1.5-2.0 kg/plant of fruit trees. It must be applied evenly to avoid crop poisoning due to high local boron content.
Leaf spray irrigation can be performed when the soil is mildly boron deficient, potentially boron deficient, or boron deficient. Foliar spraying has the characteristics of saving labor, saving fertilizer, quick effect, and can be mixed with other similar properties of fertilizers, pesticides, growth regulators, etc. Water soluble borax fertilizer is recommended. Spray boron solution with borax solution 0.1%~0.2%, boric acid 0.05%~0.1%, spraying boron solution 30~100 kg/mu, make the plants fully and evenly wet; Because boron circulates poorly through the plant, spray it several times, usually 2 or 3 times. The optimum time of boron spraying was different for different crops, but it was carried out at seedling stage and heading stage for rape. Spray once at bud stage, first flowering stage and boll stage. Soybean, peanut and broad bean were treated with boron spraying in early stage and blooming stage respectively. Boron injection was performed at root tuber swelling stage and starch accumulation stage. Boron spraying should be carried out at booting stage, early flowering stage and filling stage. Trees should be sprayed once in late spring and before and after flowering, and again at young fruit in the case of severe boron deficiency. In full sun, preferably in the morning or in full sun, this can promote the absorption and use of boron crops. In dry, strong winds, spraying is the best option.
(3) Soaking and mixing
Soak the seeds in 0.2-0.05% borax solution, put the borax in warm water at 40℃, soak in borax for 4-6 hours, then remove and dry (do not expose to the sun).
When mixing seeds, use 0.5-1.0 g of borax per kilogram of seeds, that is, use hot water to mix borax with 3%-5% borax, and then spray on the seeds, and then stir well until all the solution has been absorbed. After drying, sow as soon as possible. In agricultural production, it is safer to use boron to impregnate seed than to mix seed, but soybean, peanut and other large particles of seed and crops grown on saline-alkali soil, it is not suitable to soak. In the process of seeding, we must pay attention to control the concentration of borax, the time of seeding and the proportion of borax to avoid damage to the seeds.
In the case of a severe boron deficiency in the soil, fertilization can be applied during the seedling period. In the case of mild boron deficiency, borax can be used at the beginning and seedling stage, 0.5-0.75 kg per hectare, and should be covered with soil and kept at a distance from plants.
The yield increase effect of borax fertilizer depends on soil boron supply capacity, crop type, application method, dosage, time and other factors. According to a report by Zhang Daoyong in the Journal of Practical Fertilizer Science in China, a survey of 342 varieties of rape found that the fertilization efficiency of the variety increased by an average of 38 percent. Especially in the case of severe boron deficiency, the amount of boron applied increases exponentially.