Sequential adoption of site-specific technologies and its implications fornitrogen productivity: A double selectivity model

This paper analyzes the sequential decision to adopt two site-specific tech nologies, soil testing and variable rate technology, and the impact of adop tion on nitrogen productivity. The results indicate that while farm locatio n was a key variable influencing adoption of soil testing, farm size, human capital, and innovativeness of farmers had a significant impact on adoptio n of variable rate technology in four Midwestern states. A double selectivi ty model applied to correct for sample selection bias shows that adoption l eads to significant gains in nitrogen productivity for farms with below ave rage soil quality but statistically insignificant gains for farms with abov e average soil quality.