Can N management affect the magnitude of yield loss due to heat waves in wheat and maize?

Abstract

Deleterious effects of heat on crop yields are well documented and the occurrence of heat stresses will likely be a major constraint to achieving increased yields of major crops. Thus, agronomic and genetic strategies for increased resilience to high temperatures will be necessary. Much of the work done on this area has been focused to identify genetic sources of increased resilience andmuch less has been done on the crop ecology side. Nitrogen (N) fertilization is within the most common management practices used in cereal production, however, there have been limited efforts to elucidate to what degree the level of soil fertility may affect the magnitude of the high temperature effect on crop yield. The likely interaction may be relevant for designing more appropriate fertilization strategies. We conducted different studies on maize (2009-2012) and wheat (2012-2013), always under field conditions, to determine whether the availability of N may be responsible for the magnitude of the yield penalty imposed by heat stress during reproductive phases (i.e. when heat waves are more likely). We concluded that sensitivity to heat stress increased with increasing N availability and speculated that moderate N stress might produce in the crop plants a sort of acclimation to reduce sensitivity to other stresses. Fertilisation recommendations in the future may need to balance the yielding benefits of high N availability with the detrimental effect of increasing sensitivity to heat stress.

We thank Drs M Elía (Univ. Lleida), RA Ordóñez (Iowa State Univ.), MC Cossani (South Australian Research and development Institute) and V Passarella (National Agricultural Research Institute) who worked in the past in our lab on different aspects of the interaction between N and heat that forms part of the core of this short review. Funding for the research in our lab compiled in this short review was provided by FONTAGRO (Regional Fund for Agricultural Technology, project 8031) and the Spanish Government (projects AGL2012-35300 and AGL2015-69595-R).