Nutritional characteristics of corn and fertilization methods

1. Nutritional characteristics of corn: (1) The test data show that for every 100 kg of corn kernels, the absorption ratio of nitrogen, phosphorus and potassium is about 1:0.3:1.5, and nitrogen (n) is required to be 3.5-4.0 kg, phosphorus ( P205) 1.2 to 1.4 kg, potassium (k20) 5 to 6 kg. (2) Absorption of three factors in corn: Generally, the nitrogen uptake in the corn seedling stage (before jointing) accounts for 2.2% of the total, the middle stage (from jointing to heading flowering) is 51.2%, and the late stage (after heading) accounts for 46.6%; For the absorption of phosphorus, the seedling stage accounted for 1.1% of the absorption, the intermediate period accounted for 63.9%, and the latter accounted for 35.0%; the absorption of potassium by corn increased rapidly after jointing, and reached the peak at the flowering stage, and the absorption rate was large, which easily led to the supply. Insufficient potassium, symptoms of potassium deficiency.
2. Fertilization technology According to the nutrient absorption law of corn growth period, the fertilization principle of corn is: applying enough base fertilizer, lightly applying seedling fertilizer, re-applying joint fertilizer and manure fertilizer, and applying granular fertilizer. (1) Base fertilizer: The base fertilizer is mainly composed of decomposed organic fertilizer, generally applying 1500-3000 kg of decomposed organic fertilizer per acre. According to the soil measurement, the phosphorus-deficient soil is applied with potassium phosphate 30-40 kg per mu, and the potassium-deficient soil is applied with potassium chloride or potassium sulfate 5-10 kg per mu. In the base fertilizer, the late-effect fertilizer accounts for about 80% of the total amount of base fertilizer, and the quick-acting fertilizer accounts for about 20%. The base fertilizer can be applied in full depth. If the amount of fertilizer is small, the method of ditch application or hole application can be used. (2) Topdressing: Topdressing is generally carried out by secondary topdressing. The first time is to raise the seedling fertilizer. The period is “small trumpet period. The quick-acting fertilizer ammonium bicarbonate is used, 30-50 kg per mu, and it can be combined with cultivating. Weeding and cultivating soil, the fertilizer is covered with soil after application. The second top dressing is the attacking panicle fertilizer, taking the attack of the pole and the attack (the key to corn fertilization), and selecting urea as the top dressing. The application period is “big bell mouth period”, generally per mu. Application of urea 30 ~ 50 kg, combined with cultivating and weeding soil application, urea after application, covered with soil, the specific method can be used deep drilling, for some zinc, iron, boron and other trace elements of arable land, spraying at the early jointing stage 0.3 The % ferrous sulfate ferrous or 0.2% borax solution has a significant yield increase effect.

Hot Rolled Steel Angles

Hot Rolled Steel Angles,Equal Angle Iron,Equal Angle Steel,Steel Lintel Angle

Steel Tubing,Stainless Pipe Co., Ltd. , http://www.czsteelpipes.com