Characteristics of fertilizer requirement for sugarcane and fertilization techniques and time for optimum yield in China

Characteristics of fertilizer requirement for sugarcane in China and fertilization techniques and time for superior yield: sugarcane yield is high and fertilizer requirement is large. According to local measurements, the average absorption of nitrogen, phosphorus and potassium per 100 kg of raw cane is 1.7~2.1 kg, 0.4~0.6 kg and 2.0~2.7 kg, respectively. Because of the change of growth center, the quantity and proportion of nutrient uptake were different in different growth stages of sugarcane.

At the germination stage, the required nutrients mainly depended on the nutrients stored in the seedlings themselves, and did not need to absorb nutrients from the outside until the seedling stage, with the continuous emergence of new roots and leaves, they began to absorb a small amount of nutrients from the soil, and the absorbed nitrogen, phosphorus and potassium accounted for 3%, 1% and 3% of the total absorption, respectively. During the growing period, the absorption of nitrogen, phosphorus and potassium increased obviously with the rapid growth of sugarcane stems, and reached 55%, 65% and 65% of the total absorption respectively. At the mature stage, the growth of sugarcane slowed down or stopped, and the fertilizer requirement decreased, but the absorption of nitrogen, phosphorus and potassium still accounted for 30%, 25% and 15% of the total absorption, respectively, to meet the metabolic needs of each part of the plant and further accumulation of sucrose.

In order to meet the nutrient requirements of sugarcane, the fertilizer application measures can be adopted as follows:

① Base fertilizer. Sugarcane not only needs a large amount of fertilizer, but also has a relatively high fertilizer tolerance. Adequate base fertilizer can promote the development of sugarcane roots, germination and tillering, laying a good foundation for later growth. Basic fertilizer dosage is generally 2~3 tons of organic fertilizer, 3~5 kg of urea, 5~20 kg of calcium superphosphate, 5~8 kg of potassium fertilizer (potassium sulfate is good) per 667 meters. Conditional and then add 20~30 kg cake. Basal fertilizer should be applied in planting ditch when planting;

(2) seedling fertilizer and tillering fertilizer. In order to promote early tillering and rapid development of sugarcane, early application of seedling fertilizer and stable application of tillering fertilizer should be carried out. Fertilization for seedling raising should be applied when seedlings have 3~4 leaves, urea 3~4 kg per 667 square meters, phosphorus fertilizer 10 kg and plant ash 50~100 kg. Tillering fertilizer should be determined according to the actual situation and fertilizer frequency, if the base fertilizer, seedling fertilizer is sufficient, sugarcane seedlings thick, can be used in the tillering peak period, the amount should be reduced; on the contrary, the seedling is weak, it is appropriate to increase the amount of fertilizer, and divided into two people. Once applied at the beginning of tillering to promote tillering, called tiller fertilizer; once applied at the peak of tillering to protect strong tillers, called strong tiller fertilizer. General tillering fertilizer, 1.5 - 2 tons of human and livestock manure and 5-7 kilograms of urea per 667 square meters;

(3) Tapping stems and fertilizing. Sugarcane enters jointing and elongation stage, which is the fastest growing stage, the largest growth amount and the most fertilizer absorption stage in its life, so it must be reapplied. The amount of stem tapping fertilizer is about 2 tons of human and livestock manure, 5~8 kilograms of urea and 5 kilograms of potassium fertilizer per 667 square meters, which are applied in combination with intertillage and large cultivated soil;④ tail strengthening fertilizer. Sugarcane growth slowed down in the late growth period, but insufficient fertilizer supply would affect sugar accumulation and not conducive to the cultivation of lower sugarcane buds, so it could be supplemented with a strong tail fertilizer. Strong tail fertilizer is applied two months before maturity, 2~3 kg urea can be used per 667 square meters, and it is applied to water and combined with high soil cultivation. Strong tail fat should not be too late too much, so as not to greedy late ripening.

It should be pointed out here that sugarcane is a crop that needs more silicon. The silicon content in its leaves is as high as 4.5%. When the available silicon in the soil is lower than 100 mg/kg, the effect of silicon application is obvious. Silicon fertilizer is usually applied as base fertilizer, 450~650 kg of slag silicon fertilizer or 20 kg of high-efficiency silicon fertilizer (effective silicon dioxide is more than 50%) per 667 square meters, and the effect of combined application with organic fertilizer is better.