Nitrate leaching and soil water dynamics in cropping systems under no-till

• Grant number: 13/06801-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 01, 2013
• End date: December 31, 2013
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Ciro Antonio Rosolem
• Grantee: Gustavo Castoldi
• Supervisor: Tyson E. Ochsner
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: Oklahoma State University, United States
• Associated to the scholarship: 11/01955-9 - NITROGEN CYCLING IN CROPPING SYSTEMS UNDER NO-TILL, BP.DR

Abstract

The nitrogen dynamics in the soil-plant system is complex and involves several processes of losses, among which we can mention the leaching, which is directly dependent of the water flow and the content of nitrate (NO3--N) at the soil solution. Both of those factors are dependent, among other factors, of the plants cropped at the system. Our aim with this internship is acquire theoretical and practical knowledge, which includes new analysis tools to process the data obtained in Brazil and determine the soil water drainage and the loss of NO3--N by leaching, as well as the water dynamics and balance in soil and the relationship of these variables with the cropping systems. The cropping systems are composed by crop of Congo grass (Brachiaria ruziziensis), grain sorghum (Sorghum bicolor) and a mix of both during fall/winter. In the spring, pear millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor (L.) Moench) and indian hemp (Crotalaria juncea) are cropped in sub-plots. Soybean (Glycine max (L.) Merril) is the summer crop. Readings of soil moisture (in soil profile up to 1 m depth) and analysis of NO3--N content in soil solution (taken at 80 cm depth) have being held since sowing of fall / winter (May 2012) until the 2012/13 soybean harvest (Apr 2013). The percent of sand, silt, and clay, the field capacity and the permanent wilting point for each soil horizon still will be measured. The data will be processed and analyzed during the internship at the Oklahoma State University, under supervision/guidance of Prof. Tyson E. Ochsner. The beneficiary will receive training in theoretical physics soil and its applications, in programming MATLAB ®, will attend at the classes taught by Prof. Tyson E. Ochsner, as well as will assist in the studies developed by Prof. Ochsner. (AU)