Row Spacing and the Use of Plant-Available Water in Sugarcane Cultivation in Water-Abundant Louisiana

Abstract

Optimizing row spacing can potentially improve yields when resources such as light and water are limited. Sugarcane in Louisiana is principally grown on rows spaced 1.8 m apart, but interest in planting on 2.4 m rows is increasing. In this study, we hypothesized that wider row spacing would have greater water availability. Soil moisture sensors were placed at 15, 30, and 45 cm depths in treatments: 1.8 and 2.4 m row spacings, two varieties (L 01-299 and HoCP 04-838), and two planting dates. Soil moisture was monitored in 15-min intervals from 2017 to 2020. Mean volumetric water content was slightly greater in 2.4 m than 1.8 m row spacing at 15 and 45 cm, but the biggest difference was observed when soil water content reached its lowest levels where 2.4 m rows had 1.1, 3.1, and 9.8 times more water available at 15, 30, and 45 cm, respectively, compared to 1.8 m row spacing. However, in both row spacings, plant-available water was always present in the top 45 cm, even during periods of low rainfall. Potentially, high water availability provides an opportunity to increase photosynthesis in sugarcane varieties by selecting for greater photosynthetic capacity and CO2 uptake through increasesd stomatal conductance.

Gas exchange and time to reach maximum rate of photosynthetic rateand their relationship with whole-plant traits in sugarcane in water abundant Louisiana, USA

“…Incorporating improved photosynthetic traits in an excellent cultivar could lead to greater carbon inputs that can be converted to sugar production. Increasing substrate availability by greater gs has the additional consequence of increased water loss (Lawson and Vialet-Chabrand 2019), but despite that higher substrate availability is an important trait because sugarcane seldom lack sufficient water in water-abundant south Louisiana (Ellsworth and White Jr. 2022).…”

Improved Modeling of Gross Primary Production and Transpiration of Sugarcane Plantations with Time-Series Landsat and Sentinel-2 Images

“…Moreover, ref. [156] addressed the significance of row spacing, as it increases soil water content and provides more space for the sugarcane to grow, significantly increasing transpiration in periods of low rainfall, which could partially explain some of the abnormally high T VTM rates at the USA site in 2020 (driest year). In addition, some of the differences between the MSR and HSR transpiration estimates can be linked to the fact that the MSR pixel included multiple fields containing different varieties and, in some cases, different management practices.…”