Climate impact on US Potato yield, water demand and nutrient uptake

Potatoes are a main vegetable crop in the United States with an annual production of 4 million tons (dry tuber) grown on 0.4 million ha. Previous studies in the US have shown climate change might reduce US major grain crop productions, but less is known on US potatoes. Climate change impacts on potatoes in 32 main potatoes growing districts in the US were estimated with an ensemble of five process-based models (SIMPLE, CropSyst, LINTUL-POTATO-DSS, EPIC and DSSAT-Substor-Potato) and one statistical model under RCP8.5 scenario and five Global climate models. The crop models simulated the similar results to the historical observed yield data and field CO2 enhancement experiments. Ensemble median show that by 2030s or 2050s, climate change would reduce the potato yield in parts of Northwest and Mid-west, but increase yield in other areas.Adaptation with earlier planting date could offset the yield reductions in parts of in Northwest and Mid-west, and further increase potato yield in the places with the positive impact. CropSyst simulated Potato water demand would decrease by a spatial of 0~30% by 2030s/2050s, with more reductions in west regions than the east. The simulations indicate that climate changes by 2030s/2050s increase nutrient (nitrogen, phosphorus and potassium) uptake except the Northwest US, similar to the pattern of yield changes. For the whole US, the ensemble shows a 7.8% (10.0%) increase of potato yield by 2030s (2050s), with another 2.3%~4.9% of yield increase if earlier planting is implemented. Potato transpiration would decrease by 5%~15%, whereas the nutrients uptake would increase by 5%~10%.