Abstract

The management of nitrogen (N) crop fertilization should consider N application as a supplementary addition of mineral N to native soil mineralization and that need to synchronize with crop demand and to be localized where roots are (synlocation). This management could diminish losses mineral N from agricultural systems by leaching and denitrification. To achieve this, is important to understand the dynamics of N mineralization in an agroecosystem, the effect of the different pools of soil organic matter, soil moisture and temperature. Also, how mineral N is accumulated and maintained available in the profile and how in time and space achieve the synchrony between available N with the plant N demand. It should consider the exploration of the roots, which allows recover mineral N from depth at a particular moment during the growing time of crop. Hypothesis: the synchrony between roots exploration and availability of N mineral in the soil depends of the dynamic of N mineralization and the capacity of soil to give N available at a specific moment. These, will enable estimate the availability N in the soil during growing time of crop, proposing a synchrony factor between available mineral N of soil and demand N by wheat crop. The aim of this work is to determine and measure when and how the synchrony between N availability from a soil and N demand from a wheat crop is produced in a specific agroecosystem and how that can be manipulated to obtain a bigger N use crop efficiency. In order to fulfill this aim, during two wheat crop seasons, we shall conduct an experiment with 5 different N rates applied in three different times of crop season, to establish different mineral N supply in the soil, considering a control with no N application. Also, in parallel in a plot with no N application we would measure the N mineralization each week in all profile. Also, during each growing season we would measure the N uptake by the crop, collecting vegetal material 6 times during the crop season. The root soil exploration also will be measured to establish the rooting depth that participates in the N recovery by the crop