Potencial de secuestro de carbono orgánico en quinua simulado con el modelo RothC-26.3

The present study was carried out in the INIFAP Experimental Field of Mexico Valley with the objective of estimating the potential sequestration of organic carbon from the soil (COS) in the quinoa varieties: Amarilla Marangani and Blanca with the use of the RothC-26.3 model. The simulations of COS dynamics with the RothC included: three time periods: 20, 60 and 100 years, the annual systems: monoculture of quinoa (MQ), monoculture of corn (MM) and rotation of quinoa-corn (RQM); and the use of three contributions of carbon (C) to the soil from crop residues (RV): 60, 70 and 80% of total dry matter (MST). Considering that about 80% of the MST remains on the cultivation land after the quinoa harvest, the carbon accumulation (C) was evaluated by plant structure in three fertilization treatments. Fertilization had no significant effect on MST production, attributed to the favorable level of soil fertility at the study site and the hardiness of the crop. The MST Amarilla Marangani was higher than Blanca. In both quinoas, the stems and inflorescences and the leaves and grain represented 76 to 84% and 11 to 23% of the MST, respectively. The changes in COS simulated by the RothC in both quinoa varieties indicated COS sequestration potential (Mg C ha-1 year-1) in a period of time greater than 20 years, only in the MQ system with RV= 80% MST.