CONTEXT

Farmers in the federal state of Mato Grosso contribute about one-third of national grain production in Brazil. Given their key role in providing food and feed for fast-growing world demand, major shocks on Mato Grosso's farm holdings can lead to devastating consequences for vulnerable consumers and producers inside and outside Brazil. Research has shown that rising temperature and water stress threaten the agricultural productivity of Mato Grosso's rain-fed farm production systems. Failure of current production systems on existing croplands may also foster agricultural expansion and increase pressure on the remaining native forest. Balancing agricultural production and environmental protection is of particular concern in Mato Grosso because more than half of its territory is in the Amazon Rainforest biome. The tight schedule of field activities within double-cropping systems reduces farmers' ability to adapt to climate change and manage shocks. The increasing uncertainty about climate change and price volatility further complicate farmers' decision-making.

OBJECTIVE

This study evaluates the impact of two climate change scenarios on the profitability of double-cropping systems, considering not only climate variability but also economic uncertainties faced at the farm level.

METHODS

Our modeling system combines future climate projections with biophysical and bioeconomic models. We used high-performance computing with many compute nodes and large shared memory to account for the large heterogeneity of possible management options and farm-gate prices.

RESULTS AND CONCLUSIONS

Simulation results indicate that farmers in Mato Grosso could be exposed to significantly lower economic returns, with a future gross margin reduction of 69% on average compared to current levels. Moreover, the number of profitable cropping alternatives could drop by 18% on average. According to our simulations, climate impacts on gross margins are likely to differ in Mato Grosso, with the Southeast macro-region being the most affected and the South Central region the least. The simulation results also revealed a higher risk of losses during the second cropping season. Double-cropping systems with cotton were the most impacted by changing climatic conditions, and sunflower the least.

SIGNIFICANCE

This study revealed that climate change might negatively affect double-cropping systems in the Southern Amazon due to reduced annual precipitation, a shortening of the rainy season, and shifts in the rainy season's onset and cessation dates. Our bioeconomic simulations further suggest that farmers in Mato Grosso could lose one of their most significant comparative advantages, namely the possibility of harvesting two crops in one cropping season.

中文翻译：

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在巴西的马托格罗索州，不再有双重作物种植吗？评估气候变化对农业系统盈利的潜在影响

语境

联邦州马托格罗索州的农民贡献了巴西全国谷物产量的三分之一。由于它们在为快速增长的世界需求提供食物和饲料方面起着关键作用，因此对马托格罗索州农场财产的重大冲击可能导致对巴西境内外脆弱的消费者和生产者造成毁灭性后果。研究表明，温度升高和水分胁迫威胁着马托格罗索州雨养农场生产系统的农业生产力。现有耕地上当前生产系统的故障还可能促进农业扩张并增加对剩余原生林的压力。在马托格罗索州，平衡农业生产和环境保护尤为重要，因为其一半以上的领土都在亚马逊雨林生物群落中。在双作系统中，田间活动的时间紧迫，降低了农民适应气候变化和管理冲击的能力。有关气候变化和价格波动的不确定性不断增加，使农民的决策更加复杂。

客观的

这项研究不仅考虑了气候变化性，而且还考虑了农场一级面临的经济不确定性，评估了两种气候变化情景对双作系统盈利能力的影响。

方法

我们的建模系统将未来的气候预测与生物物理和生物经济模型结合在一起。我们将高性能计算与许多计算节点和大共享内存结合使用，以解决可能的管理选项和农场价格的巨大差异。

结果与结论

模拟结果表明，马托格罗索州的农民可能面临明显较低的经济回报，与当前水平相比，未来的毛利率平均降低69％。此外，有利可图的种植替代品的数量平均可下降18％。根据我们的模拟，马托格罗索州的气候对毛利率的影响可能会有所不同，东南宏观地区受影响最大，而中南部地区最少。模拟结果还显示，第二个种植季节损失的风险更高。气候变化对棉花双作系统的影响最大，向日葵最少。

意义

这项研究表明，由于年降水量减少，雨季缩短以及雨季的开始和停止日期发生变化，气候变化可能会对南亚马逊地区的双作系统产生负面影响。我们的生物经济模拟进一步表明，马托格罗索州的农民可能会失去其最重要的比较优势之一，即在一个种植季节收获两种作物的可能性。