1 year ago



eturn to table of

eturn to table of contents INTRODUCTION TO THE ENCIRCA SM FERTILITY SERVICE by Andy Heggenstaller, Ph.D., Encirca Services - Commercial Unit Lead and Bob Gunzenhauser, Manager, Technical Services, Encirca Services SUMMARY • Tools that combine soil test and yield data with science-based recommendations for determining variable rate fertilizer and lime applications offer the greatest potential for reducing fertility input costs without sacrificing yield. • The Encirca SM Fertility service is a new offering from DuPont Pioneer designed to help growers maximize return on phosphorus, potassium, and lime investments. • The Encirca Fertility service incorporates grower data, Encirca Decision Zones, and university fertility recommendations to estimate nutrient needs and allocate fertilizer based upon potential return on fertilizer investment for each management zone in the field. • Because variable rate applications based on the Encirca Fertility service integrate the agronomic and economic factors that drive profitability, prescriptions can be generated that optimize nutrient application rates for any fertility budget. 68

Build return to table of contents SOIL FERTILITY IN THE CURRENT AG ECONOMY When crop production margins are narrow, many growers adjust their fertility program to reduce input costs. In these situations, nitrogen (N) is often prioritized over other fertility inputs. While this approach makes sense when phosphorus (P), potassium (K), and other nutrient levels are in the optimum range, it can result in lost yield and profit when other fertility factors limit the crop from making full use of applied N. It is possible to maintain yields with lower fertility expenses but only when input reductions are based on sound soil fertility fundamentals. SOIL FERTILITY FUNDAMENTALS Soil testing is the foundation of soil P, K, and lime management. Soil test levels provide an indication of the probability of a yield response to applied fertilizer based on university research. While the exact relationship between soil nutrient concentrations (in ppm) and soil test levels (low, optimum, high, etc.) varies by state, most fertility recommendation systems align to one degree or another with a “buildmaintain-drawdown” strategy (Figure 1). Following this strategy, fertilizer is applied to very low and low testing soils at relatively high rates to build fertility and increase yields. place with minimal risk of reduced yields in the short-term. Following a build-maintain-drawdown strategy, fertilizer can be withheld from higher testing field areas and redirected toward very low and low testing zones in a way that minimizes input costs while preserving most or all yield potential. Withholding fertilizer from optimum and high testing field areas is not a long-term strategy, however, as it will eventually result in depleted soil fertility and reduced yields. For this reason, frequent soil testing combined with variable rate application is the best approach for adapting fertility management to changing market conditions. THE ENCIRCA SM FERTILITY SERVICE The Encirca SM Fertility service is a new offering from DuPont Pioneer designed to help growers maximize return on their P, K, and lime investments under any market situation. At its core, the Encirca Fertility service combines yield and soil test data in order to allocate nutrients based upon the potential return on fertilizer investment for each management zone in a field. Using the service, growers can generate variable rate fertilizer prescriptions that best fit their budget based on zone-specific yield targets, yield history, soil test results, and their preferred state or custom recommendations. Key features of the Encirca Fertility service include: Driven by Grower Data The Encirca Fertility service starts with grower yield and soil data to establish the fertility needs in each field. Yield data can be transmitted seamlessly using most wireless data transfer services, including Encirca℠ Sync Pro. Similarly, soil data can be automatically imported from most major soil test laboratories. « Critical Level Fertilizer Need Maintain Drawdown Very Low Low Optimum High Very High 80% 65% 25% 5% < 1% Soil Test Level & Yield Response Probability Figure 1. Generalized relationship between soil test levels, yield response probability, fertilizer need, and recommended fertility management strategy. (Adapted from Mallarino et al., 2013 and Vitosh et al., 1995). Once soil test levels reach the critical level and are in the optimum range, fertilizer is applied at rates equal to crop removal at some frequency in order to maintain long-term soil fertility. Little or no fertilizer is applied to high and very high testing soils, where a drawdown of nutrients can take Figure 2. Yield and grid soil sample data for a field enrolled in the Encirca Fertility service. 69

Corn Work Shop Book - Pioneer
Central and Eastern Plains Production Handbook - Sorghum Checkoff
Field Crops - Practical Farmers of Iowa
Irrigated corn, Lincoln 2003 - Hybrid Maize
Sunflower Production - NDSU Agriculture - North Dakota State ...
Headline® Fungicide Plant Health Research Summary
Scientific Papers Series A. Agronomy
Soybean Yield Following a Rye Cover Crop
2011 Results - Brandt
Biotech Crops Reduce Pesticide Use - Conservation Technology ...
Phosphorus Management for Soybeans
Glyphosate Resistance and Other Issues with Round-up Ready Crops
Impact of Increased Corn Density On Specific Hybrids ...
The Current Status and Environmental Impacts of Glyphosate ...
Growing 100-Bushel Soybeans - iGrow