Testing the use of an analytical and mechanistic C3 - biomass accumulation model for precision fertilization

Abstract

A single and uniform fertilizer application may lead to ineffective crop nutrient uptake and use. In order to enhance nutrient use efficiency the application should be adjusted according to the need of the cultivated crop. This task is challenging because weather is unknown and unpredictable over the upcoming growing season. One solution is site-specific fertilizer application in several separate events throughout the season. Such a precision fertilization method requires information on the current crop state (e.g. the availability of water and nutrients in the soil) and a crop growth model that aims to assess current crop growth and near future needs. A field experiment with varying radiation, precipitation and nutrient conditions was established to test our crop growth model performance. Spring wheat (Triticum aestivum L.) was grown using three fertilization rates with three precipitation and two radiation treatments within each fertilization treatment. The observed crop biomass accumulation in the highest fertilization treatment was considered as the highest possible in the prevailing conditions. The simulated (maximal) biomass accumulation was in agreement with the highest observed biomass yield. The results were found promising for further use of the model in crop growth evaluation during the growing season.

On the Physics of High CAPE

“…where q g is the surface volumetric soil water content, and q fl is the field capacity. We relate field capacity to soil type following Rawls et al (1982) and Hakojärvi (2015).…”