Can higher CO2 concentrations affect yield and quality parameters in lettuce and sugar beet crops?

Pedro Alexander Velasquez-Vasconez,Maria Velasquez-Vasconez,Hugo Ruiz Eraso,Cristian Cardenas,Oyvin Nyheim Skarsgard

doi:10.18378/rvads.v16i1.8357

Abstract

It has been suggested that the increase in CO2 levels in the coming decades will have positive consequences on the nutritional content and yield of agricultural crops. However, the effects of the increase in CO2 concentrations remain little known in Andean region. This study evaluated the effect of increased CO2 on the protein content and growth of sugar beet and lettuce plants in the Andean region of Colombia. We used a Randomized Complete Block Design, strip 1 was open field, strip 2 was low tunnel with ambient CO2 and strip 3 was low tunnel with 1000 ppm CO2. The sugar beet experiment three harvest periods were evaluated. The results indicated that CO2 fertilization did not have a significant effect on the yield and head diameter of the lettuce. However, biomass production tended to increase in the first sugar beet harvest but decreased significantly in the last two harvests, probably due to a negative effect caused by acclimatization to CO2 enrichment. The protein content was not affected by the increase in CO2 levels in any of the crops. The results suggest the increase in atmospheric CO2 in the next years will not cause any benefit in lettuce or sugar beet grown in the Andean region.

Highlights

For the last 650,000 - 800,000 years CO2 concentrations in the atmosphere have not exceeded 280 ppm (LUTHI et al, 2008)
For sugar beet in low tunnel, CO2 fertilization led to a nonsignificant increase of 3,4% in the first harvest, while in the second and third harvest, yield decreased significantly by 12% (Fig. 1)
Considering all three harvests, the yield of the sugar beet plants grown in low tunnel was 8.6% lower when subject to CO2 fertilization

Summary

Introduction

For the last 650,000 - 800,000 years CO2 concentrations in the atmosphere have not exceeded 280 ppm (LUTHI et al, 2008). Rising CO2 levels is predicted to stimulate the yield of C3 crops by reducing stomatal conductance and by stimulating CO2 uptake (GRAY et al, 2016). Studies have shown that increasing CO2 concentrations improves productivity (FURLAN et al, 2001; PÉREZ-LÓPEZ et al, 2013). Several other factors influence the effects of elevated CO2 levels in crops, including genotype, exposure time and environmental conditions. The short timescale and many influencing factors make it hard to predict how plants will respond to higher CO2 levels based solely on the available scientific literature. Lee et al (2011) and Warren et al (2011) showed how the effect of CO2 fertilization on plants tends to decrease over time, eventually stabilizing at the same level of photoassimilate production as before CO2 fertilization

Methods

Results

Conclusion