Assessment of nitrogen dynamics and cropping system sustainability in the Andean region of South America with a new tool available for computers and smartphones

Implementation of best soil and water conservation practices will be key to addressing challenges we will confront in the 21st century. With challenges such as climate change and continued population growth, there is a need for tools that can help us quickly assess how to maintain sustainability of cropping systems, which will be essential for maximizing agricultural production, especially in fragile soils of the Andean region of South America. Nitrogen (N) inputs are key for agricultural production, but because N is so mobile, high efficiency in the management and use of N input is necessary to reduce risk of N losses to the environment while maximizing production. One of the key crops in this region is the potato (Solanum tuberosum L.) crop. This crop leaves a small amount of crop residue after harvest, which increases the potential for a high rate of erosion, especially in the steep soils where the crop is cultivated in this region. A new Nitrogen Index with a Sustainability Index has been calibrated and validated for this region. The tool is available in the English and Spanish languages and can be run in metric or English units. It can be run on desktop and laptop computers (using the software written in the programming language Java™), or on a smartphone that has the Android™ system (via the “app”). The tool is very user friendly and can be used by conservationists, field agronomists, technical personnel, and others. It was found that the tool can accurately assess nitrogen dynamics and evaluate the crop uptake for crops grown in this region, such as corn (Zea mays L.) and potato (P