Assessment of climate change impact on double-cropping systems

Abstract

This study assessed potential impacts of climate on the dynamics of soybean-maize systems, a widespread cropping practice in Central Brazil, in regions of Mato Grosso state. Baseline (historical) and future climate scenarios in the mid and end of the twenty-first century were locally defined. Climate projections were input in a crop model, which was used to analyze their impact on first season's crop (soybean), and more emphasis was given on the second season's crop, maize development. In the climate projections, we observed a generalized increase in temperature for all scenarios, with variability of rainfall amount and pattern. Soybean growth showed a general enlargement of cycle length (average of up to 16%) and increase of yields (average of up to 34%) in future conditions. Soybean sowing dates and future climate contributed to the shortening of recommended maize sowing window and yield decreases. At most extreme scenarios of future climate, only soybean sown at the earliest dates would enable the latest maize sowing dates, bringing the greatest losses to the latter crop. Estimated maize yields showed relative average variations from baseline of − 22.5% and − 32.5% in RCP 4.5 in the mid and end of the century, while variations were of − 34% and − 55% in RCP 8.5 in the mid and end of the century, respectively. Timing of soybean sowing dates in a future climate will become more important in influencing the dynamics of subsequent maize's sowing dates and yields under a more extreme and unfavorable climate for its development.

Challenges to the Adaptation of Double Cropping Agricultural Systems in Brazil under Changes in Climate and Land Cover

“…The negative effects of climate change on maize yield do not extend to the southern part of the country and are concentrated on Central Brazil, close to the deforested area and where an increase in dry season duration is predicted [10,13,15,43]. The maize off-season yield losses simulated are close to those simulated by Andrea et al [21] for the RCP 8.5 scenario until the middle of the century. The maize off-season yield losses might reflect not only the effects of future climate change, but also For both scenarios, the impacts were greater in soybean than in maize gross revenue (Figures 6 and 7) due to a more intense climate change effect in the dry-to-wet season transition, when soybean was sowed, and when vegetation evapotranspiration provided most of the moisture to the atmosphere [43].…”

“…In fact, in places with intense deforestation in the Southern Amazon, dry spells higher than 15 days have been occurring at the onset (September, October) and the offset (March, April) of the rainy season [10]. Modeling estimates indicate that the shortening of the rainy season caused by both climate change and deforestation might intensify in the future and increasingly affect double cropping [4,21].…”

“…In addition to the effects on the individual crops, some studies evaluated the potential impacts of climate change and technological development in the soy-maize double cropping system in Mato Grosso state [20,21]. These studies estimate that soybean yield might slightly increase or nearly does not change while maize off-season yield might reduce in the same period.…”

The Effect of Best Crop Practices in the Pig and Poultry Production on Water Productivity in a Southern Brazilian Watershed

“…Among the analyzed production regions, the state of MT is the most threatened by the potential impacts of global warming [68,69]. In a business-as-usual scenario, the state's agricultural production would drop significantly causing a great increase in the water demand for products that depend on the state crops.…”

High-Throughput Phenotyping of Soybean Maturity Using Time Series UAV Imagery and Convolutional Neural Networks

“…Besides the actual costs, the cycle length is also associated with opportunity costs. The possibility of successful development of a second cash crop or a cover crop is increased when early maturity cultivars are used, which can be an important step towards the sustainable intensification of production [9]. The accurate measurement of maturity is also important in breeding trials.…”