Two‐Year Growth Cycle Sugarcane Crop Parameter Attributes and Their Application in Modeling

Abstract

Th e renewed interest in the use of sugarcane (Saccharin offi cinarum L.) for biofuel could provide a viable market for potential Hawaiian sugarcane feedstock producers. In Hawaii, sugarcane is grown as an irrigated 2-yr cycle crop. Th ere is however little information on crop parameter attributes of 2-yr cycle sugarcane. Th is fi eld study on Maui, Hawaii, analyzed the relationship between sugarcane biomass accumulation and specifi c crop parameters. Overall, the high dry biomass yield (80.20 Mg ha -1 ) was the result of a high leaf area index (LAI, 7.50) and radiation use effi ciency (RUE, 2.06 g MJ -1 . Th e crop growth rate was highly correlated to LAI (R 2 , 0.86), and a light extinction coeffi cient (k) of 0.53 was estimated. Stalk density was estimated at 18 stalks m -2 , with a maximum plant height of 3.6 m, and a rooting depth exceeding 2.0 m. When the crop parameters were incorporated into a biological model of Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) the model accurately simulated sugarcane yields across seven diff erent soil types and multiple management scenarios of applied irrigation water, N and P fertilizer inputs and various planting and harvest dates. Th e mean simulation percent (%) errors ranged from -6.4% to 1.8%, while the calculated Fisher's paired t test of 1.41 with 39 degrees of freedom, showed no signifi cant diff erences (P ≥ 0.05) between measured and simulated yields. Th e ALMANAC model should be useful as a decision support tool for evaluating sugarcane management alternatives that maximize yields while optimizing water, N and P inputs.

Crop Parameters for Modeling Sugarcane under Rainfed Conditions in Mexico

“…Other parameters are in Table 3. The resulting values for maximum leaf area index (7.5), leaf area decline rate index (0.30), and maximum root depth (2.0) were similar to those of Meki et al [36]. As for the biomass-energy ratio, which represents the potential (unstressed) growth rate (including roots), the value of 3.4 g MJ −1 m −2 [36] proved suitable for use with CP 72-2086.…”

“…The resulting values for maximum leaf area index (7.5), leaf area decline rate index (0.30), and maximum root depth (2.0) were similar to those of Meki et al [36]. As for the biomass-energy ratio, which represents the potential (unstressed) growth rate (including roots), the value of 3.4 g MJ −1 m −2 [36] proved suitable for use with CP 72-2086. For the dry matter decline rate index, which indicates reduction in the efficiency of conversion of intercepted photosynthetically active radiation to biomass due to production of high energy products like seeds and/or translocation of N from leaves to seeds [40], the default value of 0.1 in the ALMANAC model proved to be adequate in this study.…”

“…To define the range of values for these crop parameters, we first obtained the values for sugarcane within the database of the ALMANAC model, which are similar to those in the EPIC model [40]. The values from the model, which were for a one-year sugarcane crop growth cycle, were then compared with those reported by Meki et al [36] for a two-year cycle sugarcane. They were also compared with values reported by Inman-Bamber [13] for a cultivar with a variable cycle of one to two years and by Singels and van den Berg [21] for a wide range of ecotypes and cultivars.…”

“…Fourteen crop parameters based on the values for sugarcane contained in the ALMANAC database and those reported by Meki et al [36], Inman-Bamber [13], and Singels and van den Berg [21] were calibrated for the one-year cycle sugarcane cultivar CP 72-2086 under rainfed conditions. Table 3 shows the parameter values that had the best fit with the cultivar under study.…”

Dedicated Energy Crops and Crop Residues for Bioenergy Feedstocks in the Central and Eastern USA

“…Sugarcane has been grown in Hawaii as a sugar crop for over 100 years and is grown in a 2-year irrigation cycle with the bagasse considered a renewable feedstock. The ALMANAC model accurately determined biomass yields (R 2 = 0.77) from crop parameters with different soil types and under different irrigation, N and P applications [111]. The Soil and Water Assessment Tool (SWAT) model was used in Hawaii to simulate water stress and water use in sugarcane [112].…”