Every type of phosphorus and sulfur fertilizer is applied and handled differently. These general use recommendations for Smart Nutrition MAP+MST are based on optimal growing conditions. Your specific conditions and goals should be considered to achieve best results. Always ask your retailer for recommendations.
Proper nutrition is key for maximizing soybean yields. Both phosphorus and sulfur are essential macronutrients. Phosphorus is involved in many plant growth processes, from energy storage from photosynthesis and metabolism of carbohydrates to plant structure. Sulfur is required, in conjunction with nitrogen, to produce certain proteins derived from sulfur containing amino acids as well as other functions within the plant.
Since phosphorus is relatively immobile in soil, fall or early spring applications are both viable options under many soil conditions. Sulfur management can present application timing challenges with some sulfur fertilizers due to high potential of sulfate leaching in high rainfall environments and/or coarse textured soils. Season long uptake of sulfur requires sulfur availability to remain high to maximize yields. Sulfur applications are generally made in fall or early spring before the crop has reached maximum uptake levels. High precipitation events that occur after application of many salt sulfate fertilizer sources can result in significant loss from the rooting zone, leaving crops with limited nutrient availability. Smart Nutrition MAP+MST acts as a slow release sulfur fertilizer, allowing for fall or spring application with season long sulfur availability compared to conventional sources.
Sulfate leaching loss is a concern for soybean grown on coarse textured soils low in organic matter. A fertilizer source that contains elemental sulfur as Micronized Sulfur Technology (MST) – requiring oxidation to sulfate to become plant available and subject to leaching losses – may be a better option to protect against leaching losses.
Spring fertilizer applications can be difficult to manage considering wet weather patterns and the desire to get other field work accomplished (tillage and planting). Fall can present more opportunities for fertilizer applications because of generally drier conditions and labor/time availability. However, nutrients like sulfate can be subject to loss with high precipitation events during the fall and winter months. A fertilizer source that contains elemental sulfur may be a better option to protect against leaching losses and allow for flexibility of application timing.
