Fertilizer Selection Guide for Field Crops: Scientific Fertilization Boosts High Yields, Avoid These 3 Misconceptions!​

 For field crops such as wheat, corn, and rice, "choosing the right fertilizer" is a crucial step to achieve high yield and quality. Many farmers often fall into misunderstandings like "the more expensive, the better" or "more fertilizer leads to higher yield". This not only increases planting costs but also may cause soil compaction, excessive vegetative growth of crops, and aggravated diseases and pests. In fact, fertilizer selection for field crops must focus on three core factors: crop needs, soil conditions, and fertilization scenarios, while balancing effectiveness and economy, so that every unit of fertilizer can be converted into yield.​

First Understand the "Demand Logic": Select Fertilizers Based on Crop Growth Stages, Not Blindly Follow Trends​

A field crop goes through three key growth stages in its life: "seedling stage, vegetative stage, and reproductive stage". The demand for nutrients such as nitrogen, phosphorus, and potassium varies greatly in each stage, so fertilizer selection must be "demand-oriented".​

1.1 Seedling Stage: Focus on "Promoting Root Development and Strong Seedlings", Choose Low-Nitrogen and High-Phosphorus Fertilizers​

The seedling stage is critical for root development and seedling growth of crops. It is necessary to focus on supplementing phosphorus (to promote root growth) and a small amount of nitrogen (to keep seedlings green), while the demand for potassium is relatively low.​

Suitable Fertilizers: Diammonium phosphate (18% nitrogen, 46% phosphorus) and superphosphate (12%-18% phosphorus) combined with a small amount of urea (46% nitrogen, a common nitrogen fertilizer).​

1.2 Vegetative Stage: Focus on "Promoting Stem and Leaf Growth", Choose High-Nitrogen Fertilizers​

During the jointing stage of wheat, the trumpet stage of corn, and the tillering stage of rice, crops enter a rapid growth period. A large amount of nitrogen is needed to promote stem and leaf development, laying a foundation for subsequent flowering and fruiting, while a small amount of phosphorus and potassium should also be supplemented.​

1.3 Reproductive Stage: Focus on "Promoting Ear Development and Grain Retention", Choose High-Potassium Fertilizers​

During the booting stage of wheat, the filling stage of corn, and the flowering stage of rice, crop nutrients are transferred to the ears. Sufficient potassium (to promote the transportation of photosynthetic products) and phosphorus (to improve seed setting rate) are required, while nitrogen should be controlled (to prevent overgrowth and late maturity).​

Suitable Fertilizers: Potassium chloride (60% potassium, not suitable for chlorine-sensitive crops), potassium dihydrogen phosphate (22% phosphorus, 28% potassium, preferred for foliar spraying), and high-potassium compound fertilizers (15%-20% nitrogen, 15%-20% phosphorus, 25%-30% potassium).​

Must Check the "Soil Code": Select Fertilizers Based on Soil Characteristics to Improve Utilization Rate​

Different soils vary greatly in fertility, pH value, and water and fertilizer retention capacity. Fertilizer selection must be "targeted" to avoid nutrient loss or fixation.​

2.1 Check Soil Fertility: Supplement Nitrogen and Phosphorus for Poor Soils, Control Nitrogen and Increase Potassium for Fertile Soils​

Poor Soils (organic matter < 1.5%): The reserve of nitrogen and phosphorus in the soil is insufficient. During sowing, apply more organic fertilizers (2000-3000 kg per mu) combined with diammonium phosphate, and increase urea application during the vegetative stage to gradually improve soil fertility.​

Fertile Soils (organic matter > 2.5%): The soil has sufficient nitrogen, which easily leads to excessive vegetative growth of crops. Reduce urea dosage and increase potassium fertilizers (such as potassium chloride) to prevent lodging and diseases.​

2.2 Check Soil pH: Choose Alkaline Fertilizers for Acidic Soils, Acidic Fertilizers for Alkaline Soils​

Acidic Soils (pH < 5.5, such as red soil and yellow soil): Prone to lack of phosphorus, calcium, and magnesium. Prioritize alkaline fertilizers such as calcium magnesium phosphate fertilizer (12%-18% phosphorus, which also supplements calcium and magnesium) and ammonium bicarbonate (17% nitrogen, neutralizes acidity). Avoid acidic fertilizers like ammonium sulfate and ammonium chloride.​

Alkaline Soils (pH > 8.0, such as saline-alkali soil): Prone to lack of phosphorus, zinc, and iron. Prioritize acidic fertilizers such as superphosphate (12%-18% phosphorus) and ammonium sulfate (21% nitrogen). Combine with foliar spraying of chelated zinc and chelated iron to improve nutrient absorption.​

2.3 Check Soil Texture: Apply in Batches for Sandy Soils, Emphasize Base Fertilizer for Clay Soils​

Sandy Soils: Poor in water and fertilizer retention, and fertilizers are easily leached. Apply fertilizers in "small batches and multiple times" to avoid applying a large amount of chemical fertilizers at once. Combine with slow-release fertilizers (such as sulfur-coated urea) to extend fertilizer efficiency.​

Clay Soils: Strong in fertilizer retention but poor in air permeability. Emphasize base fertilizers (organic fertilizers + compound fertilizers); when top-dressing with quick-acting fertilizers (such as urea) during the vegetative stage, combine with intertillage and soil loosening to prevent nutrient fixation.​

Avoid "Fertilizer Selection Misconceptions": Be Alert to These 3 Common Mistakes​

3.1 Misconception 1: Only Focus on Price, Ignore Nutrient Content​

Some farmers think "cheap fertilizers are cost-effective", but they ignore nutrient content. For example, when buying 100 kg of fertilizer, 46% urea (containing 46 kg of nitrogen) has higher cost-effectiveness than 24% ammonium chloride (containing 24 kg of nitrogen) and has a wider application range (ammonium chloride is not suitable for chlorine-sensitive crops). When selecting fertilizers, calculate the "unit nutrient cost" (fertilizer price ÷ nutrient content) and prioritize regular products with high content and good reputation.​

3.2 Misconception 2: Prefer Chemical Fertilizers, Ignore Organic Fertilizers​

Long-term application of only chemical fertilizers will lead to soil compaction and reduced microorganisms. Field crops require a combination of "organic fertilizers + chemical fertilizers". Organic fertilizers (such as straw returning and decomposed manure) can improve soil structure and increase the utilization rate of chemical fertilizers.

3.3 Misconception 3: Blindly Top-Dress Nitrogen Fertilizers, Ignore Medium and Trace Elements​

Wheat "white ear disease", corn "bare tip", and rice "stunted seedling" are mostly related to the lack of phosphorus, potassium, zinc, etc. In addition to nitrogen, phosphorus, and potassium fertilizers, it is necessary to supplement medium and trace elements according to crop needs: supplement zinc for corn and rice (apply 1-2 kg of zinc sulfate per mu as base fertilizer), and supplement boron for wheat and rapeseed (spray 0.2% borax solution on leaves during the flowering stage) to improve seed setting rate.​

Summary: 3-Step Fertilizer Selection for Field Crops, Easy High Yields​

Step 1: Determine the Crop Growth Stage: Emphasize phosphorus in the seedling stage, nitrogen in the vegetative stage, and potassium in the reproductive stage; select fertilizers based on needs.​

Step 2: Test Soil Conditions: Select suitable fertilizer types according to fertility, pH value, and texture.​

Step 3: Calculate Cost-Effectiveness: Prioritize fertilizers with high content and easy absorption, and combine with organic fertilizers and medium/trace elements to avoid waste.​

Scientific fertilizer selection is not "following the trend to buy expensive products", but "targeted measures". Precise fertilization based on crop needs and soil characteristics can not only reduce planting costs but also achieve high yield and quality of field crops, allowing every inch of land to exert its maximum value!