Common types of fertilizers What are the main plant growth elements

There are 16 nutrients for plant growth, namely nitrogen, phosphorus, potassium, sulphur, calcium, magnesium, carbon, hydrogen, oxygen, boron, iron, molybdenum, copper, zinc, manganese and chlorine, of which nitrogen, phosphorus and potassium are massive elements and the rest are trace elements, although the plant's needs for these elements differ greatly, they play an equally important role in the growth and development of plants and are not interchangeable. There are many types of fertilisers, the main ones commonly used in production are the following.

1、Nitrogen fertiliser

Nitrogen is the main element of protein composition, protein is the basic material in the composition of cell protoplasm. Nitrogen fertilizer can promote the formation of protein and chlorophyll, so that the leaf colour is dark green, the leaf area increases, and promote the assimilation of carbon, which is conducive to increased yields and improved quality. Nitrogenous fertilisers often used in production are.

① Ammonium sulphate (ammonium sulphate): white or light brown crystals. It contains 20% to 21% nitrogen, is easily soluble in water, has little hygroscopicity and is easy to store and use. Ammonium sulphate is an acidic fertiliser and its long-term use will increase the acidity of the soil. It is best used as a chasing fertiliser, generally at a rate of 15-20kg per 667m2.

② Ammonium bicarbonate (ammonium carbonate): white fine crystals, containing 17% nitrogen, with a strong irritating odour, easily soluble in water, easily absorbed by crops, easily decomposed and volatile. It can be used as a base fertilizer or chasing fertilizer. When chasing fertilizer, it should be buried and mulched in time so as not to burn the seedlings with ammonia volatilization.

Urea: white, round, 46% nitrogen. Urea is not as fast as ammonium sulphate, and should be applied a few days earlier than ammonium sulphate when chasing fertiliser. Urea is the highest nitrogen content in solid nitrogen fertilisers, urea is a neutral fertiliser and does not contain secondary ingredients, so it does not damage the soil structure when applied year after year.

2. Phosphorus fertiliser

Phosphorus is an indispensable element for the formation of nucleoproteins and lecithin. Phosphorus can speed up cell division, promote root and above-ground growth, promote flower bud differentiation, early ripening and improve fruit quality. The following phosphorus fertilisers are commonly used in production.

Calcium superphosphate: an off-white or light grey powder, also available in granular form, containing 12% to 18% P2O5, is hygroscopic and corrosive, and is easily fixed by the soil after application to reduce fertiliser efficiency, and can be used as a base and chasing fertiliser. It can also be used as an extra-root fertiliser for direct absorption by the crop.

②Heavy calcium superphosphate (heavy calcium): contains about 45% P205 and is a highly effective phosphate fertiliser. The effective method of applying heavy calcium is the same as that of calcium superphosphate, which has a high active ingredient content and a relatively low dosage.

3. Potassium fertiliser

The nutritional efficacy of potassium can improve the intensity of photosynthesis, promote the formation of starch and sugar in the crop, enhance crop resistance and disease resistance, but also improve the absorption and use of nitrogen in the crop. The following potassium fertilisers are commonly used in production.

① Potassium chloride: a fast-acting potash fertiliser easily soluble in water, containing about 60% K20 and appearing as white, yellowish or purplish-red crystals. It has good physical properties and can be used as a base and chasing fertiliser. Potassium chloride should be used in combination with lime and organic fertilisers on acid soils.

② Potassium sulphate: white crystals, soluble in water, containing about 50% to 52% K20. In addition to being used as a base fertiliser and fertiliser, it can also be used as an extra-root fertiliser, with a concentration of 0.2%.

4, compound fertilizer: the previously mentioned chemical fertilizer generally contains only one nutrient element, a single element fertilizer. Compound fertilizers are chemical fertilizers that contain both nitrogen, phosphorus and potassium in the composition or only any two of these elements. It has the advantages of high nutrient content, few by-components, uniform nutrient release, stable and long fertilising effect, easy storage and application.

① Ammonium phosphate: is a phosphorus-based nitrogen and phosphorus compound fertilizer, containing 12% to 18% nitrogen, containing P205 46% a 56%, suitable for a variety of crops and a variety of soils, the most suitable for strip application as a base fertilizer, 667 square metres of 7-10 kg, scattered as a base fertilizer 667 square metres 25-30 kg. Among them, monoammonium phosphate is acidic, diammonium phosphate is alkaline, both are easily soluble in water, the water solution is neutral, there is a certain degree of moisture absorption.

②Nitrogen, phosphorus and potassium compound fertiliser: containing about 10% of each nitrogen, phosphorus and potassium, light brown granules. Nitrogen and potassium are water-soluble, with some phosphorus being water-soluble. It is mainly used as a base fertiliser, with a dosage of 25-30 kg for 667 m2.

③ Potassium dihydrogen phosphate: contains P205 24% and K20 21%, white and easily soluble in water, generally used for soilless seedling and soilless production of cucumbers. Due to its high price, it is mostly used as an extra-root fertiliser in large scale production.