Gas carbon emission from soil as affected by N fertilization and coffee husks

Abstract

Studies show that the joint application of crop residues and nitrogen fertilizer has promoted positive effects on carbon storage on soil, and improves the synchrony between nutrient release and uptake by plants. Therefore, this study intends to assess the balance of C on soil, by evaluating CO2 flux from it, after the combined application of different levels of nitrogen and coffee husk. The experiment will be conducted on a farm with high productivity in São Manuel (SP), where it will be applied 10 ton ha-1 coffee husk (from the coffee drying process) on the soil surface, under a canopy of coffee plants along 2.1 m². In order to speed up the coffee husk mineralization, it will be applied the equivalent of 0, 80, 160, 240, and 320 Kg ha-1 of N as urea form in the presence and absence of coffee husk. The CO2 flux will be determined at the 1st, 2nd, 3rd, 4th, 7th, 15th, 30th, 60th, 120th,150th, 180th and 210th day after coffee husk application with N levels. Will be collected soil samples from the area before setting up and at the end of the experiment (treatments mentioned), at depths 0-0,05; 0,05-0,1 e 0,1-0,2 m for the determination of the levels of C and MO. The C content on the coffee husk will be determined at the beginning and at end of the experiment. In this case, it will be collected the straw from each plot to determine the remaining C. The temperature and moisture content will be determined on measurement days of CO2 flow. The experiment will be conducted for 210 days and at this period it will be collected rainfall data through rain gauges installed in the experimental area.(AU)