Adoption of Variable Rate Technology

Site Specific Management (SSM), which also variously referred to as Variable Rate Technology (VRT), is an emergingtechnology that enables producers to make more precise input application decisions based on soil and fieldcharacteristics. This study analyzes factors influencing the adoption of VRT for fertilizer application for cash grainproduction in Ohio. Results show that producer and field characteristics might influence the adoption decision onvarious SSM components differently. It also provides insight as to the sequence of adoption of SSM componenttechnologies and how this sequence might differ for producers of differing characteristics

An Economic Analysis of Variable Rate Technology

Variable Rate Technology (VRT) offers an opportunity to improve production efficiency by allowing input applicationsto fluctuate in response to spatial variations in soil characteristics and nutrient levels. Society may also benefit fromreduced negative externalities, such as surface and groundwater contamination, from input applications. Using adynamic spatial model, this study examines how the interaction among variability, spatial autocorrelation, and meanlevel of soil fertility affects optimal sampling density and the economic gains from VRT. VRT was found to beprofitable under selected conditions, and the optimal grid size will vary with these conditions. In the case wherevariability and mean fertility levels are significantly high associated with low spatial autocorrelation, VRT producesgreater net returns than Uniform Rate Technology (URT), even with the smallest grid size to base the input applicationdecisions. Results also demonstrate that optimal grid size increases with increased spatial autocorrelation

Cover crops, crop rotation, and gypsum, as conservation practices, impact Mehlich-3 extractable plant nutrients and trace metals

Conservation practices are encouraged to improve soil health and sustain agronomic crop production. Mehlich-3 is often used as a multi-nutrient extractant to determine soil fertility status. A study investigated the impacts of the conservation practices of gypsum, cover crops, and crop rotation on 28 Mehlich-3 extractable elements, of which 11 were considered plant nutrients, from soil at three midwestern US locations. Soil was collected from 0 to 15 and 15–30 cm depths 5 years after implementing the conservation practices. Treatments consisted of (1) with and without cereal rye (Secale cereale L.) winter cover, (2) continuous soybean [Glycine max (L.) Merr.] vs. soybean-corn (Zea mays L.) rotation, and (3) annual gypsum application (0, 1.1, and 2.2 Mg ha−1). Differences were observed by site, depth, and conservation practice depending on the element evaluated. Minimal interactive effects were observed among treatments. The most consistent effect was observed for crop rotation across sites. Gypsum only affected the site with the greatest clay content, where more Ca and S were retained, and Mg and Mn displaced. Cover crop only affected elements at this high clay site, where different elements were positively or negatively affected. Results suggest that not one practice fits all, and optimum conservation practices must be tailored for the site