The adoption of no-till is increasing due to the numerous benefits it offers, such as soil conservation, reduced erosion, and improved soil structure. However, these methods also present unique challenges, particularly regarding the efficient application of phosphorus fertilizers in the fall. Phosphorus is a critical nutrient for plant growth, but its efficiency can be compromised by several factors, including soil pH, soil type, and the presence of other minerals.
The phosphorus challenge and dealing with phosphorous deficiency encompasses several key issues. Firstly, fixation in the soil is a significant concern as phosphorus often reacts with other minerals in the soil, such as calcium, iron, and aluminum, forming insoluble compounds. This reaction hinders plants' ability to absorb phosphorus, consequently reducing its availability for plant uptake. A study by the International Plant Nutrition Institute revealed that in some soils, up to 80-90% of the applied phosphorus can be fixed and rendered unavailable to plants. Secondly, the risk of phosphorus runoff and leaching is heightened when phosphorus fertilizers are applied in the fall, especially in regions with heavy rainfall. This not only results in the loss of valuable nutrients but also contributes to water pollution.
Banked Phosphorus and Soil pH
It is important for growers to be aware that banked phosphorus does not always mean it is available for plant uptake. Fall-applied phosphorus in high pH soil can be fixed and become unavailable by springtime. The availability of banked phosphorous for plants in the soil is significantly influenced by the soil's pH level. While it is acceptable to have phosphorus banked in the soil, its availability can be compromised in soils with a high pH (7.5 or higher), causing the phosphorus to become tied up and unavailable to plants within a span of 3 to 4 months. Conversely, in soils with a neutral pH, phosphorus is more available, making it more effective to bank phosphorus in such soils.
This difference is due to the chemical reactions that occur in the soil at different pH levels. In high pH soils, phosphorus reacts with calcium to form insoluble compounds, making it unavailable for plant uptake. On the other hand, in neutral pH soils, there is a lower risk of phosphorus reacting with other minerals to form insoluble compounds, thereby making it more available for plant uptake and more effective to bank in the soil.
Innovations in Phosphorus Efficiency
To address the challenges associated with phosphorus efficiency, various innovative technologies have been developed, encompassing polymers, biological agents, and the incorporation of sulfur in phosphorus fertilizers. These technologies aim to prevent phosphorus fixation in the soil, improve nutrient availability and uptake by plants, and ultimately enhance the efficiency of phosphorus fertilizers.
AgroTech USA's patented technology found in NutriCharge and Ionize leverages patented chemistry to alter the soil's reactivity to phosphorus fertilizer, and construct a protective barrier around phosphorus particles. This inhibits their interaction with other soil minerals, preventing the formation of insoluble compounds. Independent testing has demonstrated that this technology can more than double the availability of phosphorus fertilizer in the soil. Additionally, AgroTech USA has developed a novel technology specifically designed for soils that test high in phosphorus. This solution extracts legacy phosphorus, converting it into a form that is readily available for crop uptake, eliminating the need for additional phosphorus fertilizer.
The efficient application of phosphorus fertilizers in strip-till and no-till farming systems is crucial for achieving optimal crop yields. However, several challenges are associated with fall-applied phosphorus, such as fixation in soil, runoff and leaching, soil pH, and the misconception that banked phosphorus is always available. Innovative additive technologies like NutriCharge and Ionize by AgroTech USA can help overcome these challenges and enhance the efficiency of phosphorus fertilizers. By adopting these kind of technologies and managing carryover phosphorus effectively, no-tillers can improve nutrient availability, reduce environmental impacts, and ultimately achieve better crop yields.