Three essays on site -specific managemen

Site Specific Management (SSM) is an emerging technology that enables farmers to make more precise input application decisions based on soil and field characteristics. SSM not only offers substantial benefits of increased production efficiency for farmers, but also improved environmental quality for the society. In spite of its potential benefits, SSM is still early in the diffusion process. Like other new technologies, it will require an investment of time and resources to help it mature. This collection of essays investigates the adoption and economic values of SSM.;In the first essay, "Adoption of Variable Rate Technology: A Multinomial Logit Analysis," factors that may influence the adoption of SSM technology are examined. As a suite of technologies, various components of SSM may be adopted as a package. A multinomial logit analysis of a mailed survey of Ohio farmers revealed that farmer and farm characteristics might influence the adoption decision on various SSM components differently. The results also indicate that the sequence of adoption of SSM component technologies might differ for farmers of different characteristics.;In the second essay, "A Spatial Analysis of Yield Variability in Field Sized Units," a spatial regression model is presented to account for the spatial autocorrelation and structural instability in analyzing factors that may influence yield variations within a field. Results show that the size of grid sampling and spatial autocorrelation are key factors in analyzing yield variability. Spatial information obtained from different grid sizes may give different results. Also, failure to account for structural instability may mask the true results.;In the third essay, "Spatial Effects on the Economic Values of Variable Rate of Input Applications," a dynamic analysis along with a spatial approach is presented that studies the effects of variability and spatial autocorrelation associated with management zone size on the economic values of VRT. Simulation shows the reasonable size of management zone to base the input application decisions is significantly affected by the degree of variability, spatial autocorrelation, and mean fertility values. Altogether, they may influence the economic values of VRT.