In crop production, in addition to the three major elements—nitrogen, phosphorus, and potassium—micronutrients play an irreplaceable role and are crucial to crop quality and growth. Furthermore, with the dramatic increase in the use of chemical fertilizers, the demand for micronutrients has also gradually increased.
After years of agricultural practice, I have developed some personal insights into micronutrients. This article will explain the important role of micronutrient calcium fertilizers in crop production and introduce five calcium fertilizers on the market.
Micronutrients include calcium, magnesium, and sulfur, with calcium being the most widely used of the three. In the past, farmers often used lime, gypsum, bone meal, and wood ash to supplement crop calcium fertilizers, and this practice continues in some areas today.
A. Physiological Functions of Calcium
Calcium is a crucial component of cell walls. It exists between cells in the form of calcium pectate, enhancing cell stability.
Calcium is a component and activator of plant enzymes and plays a crucial role in promoting crop metabolism and nutrient accumulation.
Calcium combines with excess organic acids in crops to form calcium oxalate, mitigating or reducing the toxic effects of organic acids on crops.
Calcium strengthens cells and delays cell aging.
B. Effects of Calcium in Agriculture
Extends shelf life. Calcium enhances cell stability and resistance, making the peel and flesh relatively firm (calcium deficiency causes fruit to be softer, making it difficult to transport and store), thus reducing losses during transportation and on the shelf.
Prevents fruit cracking. Calcium pectate, formed by calcium, strengthens cell-cell connections, enhances the thickness and stability of the peel, and thus can prevent fruit cracking to a certain extent. Regular calcium supplementation in agricultural production is effective in preventing fruit cracking in crops such as grapes and tomatoes.
Beautifies fruit surface and increases marketability. Calcium fertilizers can enhance the appearance of fruit and improve its smoothness. It can also enhance resistance to sunburn, significantly reducing yield losses caused by sunburn and navel rot, and increasing commercial yield.
Promoting crop growth. In the presence of calcium deficiency, parts such as new roots, terminal buds, and fruit are vulnerable during periods of vigorous growth. High temperatures can easily cause growing points to wilt or die. Calcium supplementation can significantly reduce this incidence.
Increasing yield. Studies have shown that using a certain amount of calcium can significantly increase yield. For example, applying calcium to peanuts can reduce the hull rate by approximately 30%, and combining it with boron fertilizer has even greater yield-increasing effects.
The above analysis demonstrates that calcium plays an irreplaceable role in agricultural production. With some companies researching the role of secondary nutrients in agriculture and farmers emphasizing their importance in increasing yield and improving quality, the calcium fertilizer market has attracted significant attention. The wide variety of calcium fertilizers on the market can be overwhelming for growers, making it difficult to choose, and some even experience no effect at all. Below, I will provide an analysis of calcium fertilizers on the market for your reference.
Currently, there are five main types of calcium fertilizers on the market: traditional calcium fertilizers, nitrate-based calcium fertilizers, amino acid-based calcium fertilizers, EDTA-chelated calcium fertilizers, and sugar alcohol-based calcium fertilizers.
Traditional calcium fertilizers used to include superphosphate, calcium magnesium phosphate fertilizers, and quicklime. Now, some areas prefer calcined oyster shell powder (calcium oxide) for acidic soil conditioning, which is very affordable. These traditional calcium fertilizers are primarily applied by broadcast application. However, due to poor calcium mobility and absorption in the soil, they have little effect on crop growth and production, and are therefore primarily used for soil improvement.
Nitrate-based calcium fertilizers, represented by calcium nitrate, calcium ammonium nitrate, and calcium magnesium nitrate, are among the mainstream calcium fertilizers on the market. Broadcast application and flushing are the primary methods of application. Advantages: a. Low cost. The application rate is approximately 20 kg per mu, costing approximately 60 yuan per mu. b. Rapid results. Nitrate nitrogen is quickly absorbed and converted by crops, resulting in lush green leaves and vigorous growth. c. Prevents soil compaction. Nitrate-based calcium fertilizers are neutral fertilizers that won’t acidify the soil over time. Disadvantages: a. Calcium has poor mobility and must be evenly applied to calcium-deficient areas to be effective. b. It cannot be mixed with potassium dihydrogen phosphate or high-phosphorus aqueous solutions to prevent precipitation reactions and reduced fertilizer efficiency.
Amino acid calcium, also known as amino acid chelated calcium, is available in a wide variety of forms on the market. They primarily use amino acids as chelating agents, binding to calcium ions. They are typically applied as foliar sprays, with a very small percentage used as flushing. Calcium ion mobility is higher than that of nitrate-based calcium, but the cost is also relatively high. Using amino acid calcium can improve crop quality. In addition to the calcium ions, amino acids also play a significant role, enhancing flavor and promoting growth. It is widely used and accepted in the market, gaining recognition from many agricultural supply stores and farmers.
EDTA-chelated calcium (calcium disodium ethylenediaminetetraacetic acid) is currently the most efficient calcium fertilizer and exhibits high activity. Calcium can be transported up and down the plant body along with the flow of cellular sap, transporting calcium to all parts of the crop. EDTA-chelated calcium is also particularly stable and highly miscible. It does not precipitate with phosphate ions, boron fertilizers, or other fertilizers. However, it is relatively expensive, costing approximately 5 yuan per sprayer (15 kg of water).
Sugar alcohol calcium fertilizers use xylitol and mannitol as carriers. After binding to calcium ions, they migrate within the plant body as the sugar alcohols do. Sugar alcohols are primarily found in the phloem of crops, giving them a high affinity for calcium and allowing for rapid absorption and utilization. Sugar alcohol calcium fertilizers also have the highest absorption and utilization rate among crops, allowing for unimpeded transport up and down the plant body. They play a crucial role in increasing crop yield and improving quality.
The selection and application of calcium fertilizers are crucial in crop production and management. There are two main methods for applying calcium fertilizers: soil application and foliar spraying. However, the optimal effectiveness of calcium fertilizers depends on many factors. For example, acidic soil and sandy soil will reduce the absorption of calcium fertilizer, and excessive application of large element fertilizer will inhibit the root system’s absorption of calcium fertilizer, etc. Therefore, when buying calcium fertilizer, you must learn to adapt to local conditions, combine the soil conditions of your own field and the growth of crops, and use calcium fertilizer in an appropriate way.
