Un reencuentro con la productividad de agrosistemas: II,validez para adaptar tecnologia al maiz en MexicoRevisiting agrosystem productivity: II. Validity for adapting technology to maize in Mexico

摘要

The question of Agrosystem Productivity (AP) value for the stage of crop-technology-perfecting (CTP) was raised in the first of two papers (Torrent et al., 2005). This question is pertinent to Mexico, because several authors argue that modular, dynamic modeling of crop growth is an alternative, less expensive, and more powerful method for comprehensive fertilizer technology adaptation in CTP than the field method. It is well known that modular, dynamic modeling ignores factor interactions. Research was conducted in order to test contribution of factor interactions on hybrid maize yield variability. Two split plot, irrigated field experiments were conducted in a Chromic Haplusterts and a Chromic Kanhaplusterts in the fall-winter 1998-99 season in southeastern Mexico. The experiments involved six maize hybrids as split-plots and five rates of each N. P and K fertilizers, population density and planting date in a Rotatable, Central Composite Design as main-plots. Assessment of fitted quadratic equations and conditional maximum net income treatments show considerable genotype by management by location interaction. The lesson is that additive-dynamic-modeling of crop growth or any other additive approach that ignores interactions involving plant genotype would miss an important source of yield variability in adapting new technology to maize.