No-filler fertilizer formulas generate more productive crops

Fertilizers are part of the fundamental investments of farmers and ranchers who plan productive and profitable crops each harvest. Studies show that soil fertility is responsible for around 60% of agricultural productivity and, for this reason, farmers must be careful when purchasing and be aware of what is actually being purchased.

The choice for balanced and technological formulations must be made carefully, which can increase or decrease the efficiency of delivering the element to the soil and crops. Another reason for rural producers to analyze the formulation purchased and received is the fact that many industries use fillers (fillers), that is, the addition of inert material to the fertilizer to adjust the formula, but without nutritional value to the plants.

The Ministry of Agriculture, Livestock and Supply (MAPA) establishes a maximum concentration of 10% filling in the ton of the final product of mineral fertilizers intended for agriculture. The normative instruction also presents specifications of the materials that can be used, such as grit, silicate, quartz, clay, peat and granulated limestone. The loophole to the industry is the fact that granulated limestone and calcium carbonate are the same material, and the trade name is inserted in advertisements, sales and packaging in an attempt to add value.

To understand the impact of this addition of filler, let's consider a traditional combination of nitrogen, phosphorus and potassium, the famous NPK and, depending on the formula, calcium, magnesium, sulfur and micronutrients. A common composition is 4-14-8 (4 parts nitrogen, 14 phosphorus and 8 potassium), especially for fruit and vegetable crops. This formulation can be obtained in different ways so as not to alter the final content of primary macronutrients.

The addition of filler to reach one ton, however, will affect the final levels of secondary macronutrients: the greater the amount of calcium carbonate filler, for example, the lower the sulfur concentration and the higher the calcium in the final product. This calcium, however, comes from grain, whose main characteristic is low solubility, that is, it does not perform any nutritional function for crops. Considering a formulation with 10% filling, when purchasing ten tons, for example, the farmer will pay for one ton of inert material, that is, without nutritional benefit for the crop. The damage will be noticed in the field: the soil will no longer receive a ton of nutrients that could generate high productivity and profitability.

On the other hand, there are options that add nutrients to the final product that will contribute to the good health of soils and crops, which will result in more vigorous, healthy and productive crops. The best way to find out whether or not the fertilizer has a filler is, before making the purchase, ask the supplier to open the formula to find out the composition of the raw materials. And it is the customer's right to know all the details of the formulation they are purchasing. For farmers who have already purchased fertilizers, the advice is to check the label and, if necessary, question the supplier.

In addition to macronutrients, it is pertinent to note micronutrients and the synergy of these components to ensure increasingly healthier soils. Another important characteristic to be observed is the particle size of the mixture: if the components have varying particle sizes, segregation may occur, resulting in irregular distribution of the fertilizer, which leads to crops with low productivity uniformity. The recommendation is to choose fertilizers with a granulated mixture, in which the nutrients are in an adequate composition in the same granule. For high productivity and profitability, the farmer's choice should always focus on multinutrient fertilizers, which combine macro and micronutrients in a balanced way to serve the most diverse crops.

With quality fertilizers, it is essential that rural producers follow agronomic practices for the rational and efficient use of the input. A detailed soil analysis and application of fertilizers following the concepts of the 4Cs of management [fertilization from the Right source, at the Right dose, in the Right place and at the Right time] are essential to guarantee the best possible results when reaching full productivity potential of plantations.

Fernando Guerra, Hortifrúti Crops Manager at Mosaic Fertilizers