Abstract
Sugarcane has emerged as the second largest source of biofuel, primarily as ethanol produced in Brazil. Dual row planting using asymmetric spacing of rows can decrease damage to plants and soil structure from harvest equipment though potentially can cause some loss of productivity due to increased shading. Can we assess this loss, without experimental testing of the thousands of potential permutations of planting design and cultivar canopy form? Here we develop a computational framework which couples 3D canopy architectural information, a ray-tracing algorithm, and a steady-state C4 photosynthesis model to study this question. We demonstrate the utility of the model by comparing evenly spaced rows at 100 cm to alternating row spacing of 45 and 155 cm. Asymmetric planting caused a 9% decrease in predicted net canopy carbon uptake over the growing season for a major current cultivar. The loss was greater at lower leaf area indices, when leaves were more vertical and when rows were oriented east-west, suggesting agronomic approaches to minimize loss. This study demonstrates the utility of this computational framework, which could also be used to aid breeding by identifying ideotypes for different environments and objectives, and to assess impacts of environmental change.
Highlights
Sugarcane has emerged as the second largest source of biofuel and it has the potential in Brazil alone to provide 15% of global liquid fuel use in transportation [1]
Assuming that ca. 40% of this photosynthate is lost in respiration for cell maintenance and metabolism to other plant constituents [5, 6], this would equate to a total dry matter productivity of about 82 mg ha−1 year−1 (243 kg ha−1 day−1) (Fig. 3, Supporting Information 1 Sections 5)
How does this compare to actual yields? The average yield of harvested stem in Brazil is about 80 mg ha−1 year−1 [23]
Summary
Sugarcane has emerged as the second largest source of biofuel and it has the potential in Brazil alone to provide 15% of global liquid fuel use in transportation [1]. For a perennial and high mass yielding crop such as sugarcane, this is important since the risk of plant and soil damage is high from the necessarily heavy harvesting and haulage equipment. Row spacing and equipment choices need to minimize this damage by keeping their impacts away from the rows. This damage has been recognized in regions where mechanization has been in place for many years [2]. This is a well-recognized issue for the world’s largest sugarcane
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
