CONTEXT

Climate models project higher temperatures and a substantial net water deficit during the summer months over Germany until the end of the 21st century. The agricultural sector is particularly vulnerable to changing weather and climate conditions.

OBJECTIVE

In this study, we examine the role of irrigation for potato yields as a climate change adaptation measure in Northeast Lower Saxony (Germany). The region represents the largest irrigated area in Germany and is one of the main growing areas of potatoes.

METHODS

We develop a statistical multivariate regression model to investigate whether regional climate and irrigation data at the monthly and county level are suitable to describe potato yield variability from 1978 to 2018. Irrigation is estimated based on the climatic water balance and crop water demand. These estimates are calibrated against irrigation data from local agencies to account for realistic monthly water withdrawals. We analyze future yield changes based on climate model projections for the 21st century and different irrigation scenarios.

RESULTS AND CONCLUSIONS

We find that the potato yield will decrease significantly by 18% on average until 2050 with climate projection uncertainty of ±6.4% under the high emission scenario RCP 8.5 and without irrigation. Irrigation at current levels could compensate for about 54% of these yield losses. Doubling the amount of irrigation minimizes yield losses by as much as 80%. Under the low (middle) emission scenario RCP 2.6 (RCP 4.5), potato yield are projected to decrease moderately by 4.5% ± 3.4% (5.4% ± 2.8%) with irrigation at current levels. We show that the yield losses mainly originate from higher temperatures during the summer. Our analysis indicates that the capacity of irrigation to minimize yield losses is limited. Strengthening climate change mitigation efforts may be more effective in preventing yield losses. However, the effect of elevated CO₂ might buffer the high yield losses, especially in RCP 8.5.

SIGNIFICANCE

The studies supports farmers and decision makers in assessing future risks in potato yields. It can guide policymakers in allocating economic resources to cope with climate change.

中文翻译：

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气候变化下德国防止马铃薯减产的灌溉潜力有限

语境

气候模型预测，到 21 世纪末，德国夏季月份的气温会更高，净水量将大幅减少。农业部门特别容易受到天气和气候条件变化的影响。

客观的

在这项研究中，我们研究了灌溉对马铃薯产量的作用，作为东北下萨克森州（德国）气候变化适应措施。该地区是德国最大的灌溉区，也是马铃薯的主要种植区之一。

方法

我们开发了一个统计多元回归模型，以调查每月和县级的区域气候和灌溉数据是否适合描述 1978 年至 2018 年马铃薯产量的变化。灌溉是根据气候水分平衡和作物需水量估算的。这些估计是根据当地机构的灌溉数据进行校准的，以考虑实际的每月取水量。我们根据 21 世纪的气候模型预测和不同的灌溉情景分析未来的产量变化。

结果和结论

我们发现，在高排放情景 RCP 8.5 和无灌溉的情况下，到 2050 年，马铃薯产量将平均显着下降 18%，气候预测不确定性为 ±6.4%。目前的灌溉水平可以弥补这些产量损失的大约 54%。将灌溉量加倍可将产量损失减少多达 80%。在低（中）排放情景 RCP 2.6（RCP 4.5）下，在目前的灌溉水平下，马铃薯产量预计将适度下降 4.5% ± 3.4%（5.4% ± 2.8%）。我们表明，产量损失主要源于夏季的高温。我们的分析表明，灌溉减少产量损失的能力是有限的。加强减缓气候变化的努力可能更有效地防止产量损失。然而，升高的影响CO ₂可能会缓冲高产量损失，尤其是在 RCP 8.5 中。

意义

这些研究支持农民和决策者评估马铃薯产量的未来风险。它可以指导决策者分配经济资源以应对气候变化。