水が農業生産に与える影響に関する長年の謎を解明 Research solves long-standing mystery of how water impacts agricultural production
2022-9-19 ハーバード大学
その結果、土壌水分を用いたモデルは、降雨量に依存したモデルよりも、作物ごとの収量の年変動幅を30%から120%多く説明できることがわかった。
研究チームは、衛星による土壌水分の観測と統計的アプローチを用いて、気温と水の供給が収量に及ぼす個々の影響をより適切に分離し、理解することができた。
極端な暑さが作物収量に与える影響は、これまでのモデルによる推定値よりも小さいことがわかり、温暖化による被害予測が低くなった。しかし、干ばつや洪水に対する感度が高まっていることも分かった。
＜関連情報＞
- https://www.seas.harvard.edu/news/2022/09/better-understanding-crop-yields-under-climate-change
- https://www.nature.com/articles/s43016-022-00592-x
水の供給量をより正確に特定することで、世界の作物生産における重要性を示す More accurate specification of water supply shows its importance for global crop production
Jonathan Proctor,Angela Rigden,Duo Chan & Peter Huybers
Nature Food Published:19 September 2022
DOI:https://doi.org/10.1038/s43016-022-00592-x
Abstract
Warming temperatures tend to damage crop yields, yet the influence of water supply on global yields and its relation to temperature stress remains unclear. Here we use satellite-based measurements to provide empirical estimates of how root zone soil moisture and surface air temperature jointly influence the global productivity of maize, soybeans, millet and sorghum. Relative to empirical models using precipitation as a proxy for water supply, we find that models using soil moisture explain 30–120% more of the interannual yield variation across crops. Models using soil moisture also better separate water-supply stress from correlated heat stress and show that soil moisture and temperature contribute roughly equally to historical variations in yield. Globally, our models project yield damages of −9% to −32% across crops by end-of-century under Shared Socioeconomic Pathway 5-8.5 from changes in temperature and soil moisture. By contrast, projections using temperature and precipitation overestimate damages by 28% to 320% across crops both because they confound stresses from dryness and heat and because changes in soil moisture and temperature diverge from their historical association due to climate change. Our results demonstrate the importance of accurately representing water supply for predicting changes in global agricultural productivity and for designing effective adaptation strategies.
