Sana Boulabiar and Matias Navarro, Veolia Water Technologies, USA, discuss how crystalline water-soluble fertilizers are the most efficient way for delivering the nutrients that boost the quantity and quality of crops the world desperately needs while protecting its soil and water resources.
The rising pressures from population growth, coupled with changes towards protein-rich diets driven by a more affluent class of global consumers, are testing the limits of the Earth’s supply of land and water resources. These forces are not expected to diminish. The Food and Agriculture Organization (FAO) of the United Nations projects an approximate 50% increase in the demand for crops in 2050 from 2013 levels.
Over the course of recent history, no other modern agricultural practice has contributed more to solving the challenges of feeding more people than the application of mineral fertilizers. Fertilizers provide the three major essential nutrients: nitrogen (N), phosphorus (P) and potassium (K). Nitrogen is the most important determinant of plants’ growth, vigour, colour, and yield.
Phosphorus is essential to seed formation and photosynthesis, a vital process that converts sunlight to energy and is also critical to plant development and quality.
Potassium is a crucial ‘building block’ for plants, playing roles in water regulation, heat stress tolerance, and protein synthesis and enzyme activation.
These three vital macronutrients are essential but they arenot the only ones required to sustain healthy and productive
farms, as plants use 17 essential elements to thrive and survive.
That is the reason for the growing fertilizer market of NPK formulations that add secondary nutrients with ideal ratios to each other.
An industry with burning environmental issues
Given the constraints imposed by limited resources, further boosting agricultural productivity is essential.
Converting more land to agriculture translates into negative impacts such as reduced biodiversity, deforestation, and increasing emissions, as has been seen in the recent fires that have ravaged what is left of the Amazon rainforest – some of which were intentionally started to further expand the agricultural frontier. Additionally, climate change worsens the situation with erosion and loss of topsoil.
Furthermore, water shortages are putting pressure on the sector and agriculture is a centrepiece at both ends: as a contributor and as a casualty of water scarcity problems. For instance, entire fields have traditionally been irrigated using water in high quantities at long intervals, whether by sprinklers or by flood irrigation, resulting in significant losses and high fluctuations in soil-moisture content which affect plant growth and crop yields.
The responsible answer to optimal plant nutrition
The need to minimise water usage and increase irrigation efficiency drove the shift to more modern irrigation methods such as drip irrigation (or micro-irrigation), which consists in delivering water directly into the root zone of plants. Drip irrigation systems are able to supply small amounts of water at high-frequency intervals and therefore maintain optimal moisture range in the soil. This promotes water savings, as well as enhancing growth and production.
Just as advanced irrigation saves water and improves yields, the application of fertilizers also results in higher returns and more intensive use of the land, helping to preserve forests and avoid new acreage being converted to cropland.
In short, to gain efficiencies in resource use and improve environmental performance, the global agricultural industry needs to do more with less, which means more sustainable solutions that boost productivity and fertilizers’ efficiency with minimum water usage and more intense use of land. The market has adopted fertigation and foliar feeding techniques coupled with precision agriculture, a sensor-based technology assisted by drones and digital tools, to overcome these dual water and soil challenges.
Fertigation, a technique that distributes nutrients through irrigation systems, makes use of small and frequent applications of water and soluble fertilizers to enhance plant growth and increase yields. By feeding plants in exact amounts only when needed, fertigation increases the efficiency of nutrient uptake and minimises nutrient losses. In addition, selective wetting of the soil, as achieved by drip irrigation, allows for savings in both water and fertilizer.
Foliar feeding, another technique associated with higher yields and better crop quality, consists of spraying water-soluble fertilizers directly onto the plant leaves. It is a fast and effective solution when environmental conditions limit the uptake of nutrients by plants’ roots. Such conditions may include high or low soil pH, temperature stress, too low or too high soil moisture, root disease, presence of pests that affect nutrient uptake, nutrient imbalances in soil, etc.
Despite their many advantages, fertigation and foliar feeding cannot fully deliver these benefits through the use of conventional fertilizers. In other words, advanced farming techniques need advanced fertilizer products such as fully-soluble, crystalline products which have proven superiority over traditional crop nutrition. Other forms of granulated or powder-like grades are not as effective as crystalline water-soluble fertilizers. And when it comes to large-scale field operations, crystalline water-soluble fertilizers are even less expensive than commonly used liquid fertilizers.