Soil Carbon and Nitrogen Stocks of Different Hawaiian Sugarcane Cultivars

Agronomy

Rebecca Tirado-Corbalá¹  Ray G. Anderson¹  Dong Wang¹  James E. Ayars¹ 

[1] USDA, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Water Management Research Unit, 9611 S. Riverbend Ave., Parlier, CA 93648-9757, USA; E-Mails:

关键词: Hawaii sugarcane;    cultivars;    soil carbon;    soil nitrogen;    carbon sequestration;    biofuel;   

DOI  :  10.3390/agronomy5020239

来源: mdpi

【 摘 要 】

Sugarcane has been widely used as a biofuel crop due to its high biological productivity, ease of conversion to ethanol, and its relatively high potential for greenhouse gas reduction and lower environmental impacts relative to other derived biofuels from traditional agronomic crops. In this investigation, we studied four sugarcane cultivars (H-65-7052, H-78-3567, H-86-3792 and H-87-4319) grown on a Hawaiian commercial sugarcane plantation to determine their ability to store and accumulate soil carbon (C) and nitrogen (N) across a 24-month growth cycle on contrasting soil types. The main study objective establish baseline parameters for biofuel production life cycle analyses; sub-objectives included (1) determining which of four main sugarcane cultivars sequestered the most soil C and (2) assessing how soil C sequestration varies among two common Hawaiian soil series (Pulehu-sandy clay loam and Molokai-clay). Soil samples were collected at 20 cm increments to depths of up to 120 cm using hand augers at the three main growth stages (tillering, grand growth, and maturity) from two experimental plots at to observe total carbon (TC), total nitrogen (TN), dissolved organic carbon (DOC) and nitrates (NO⁻³) using laboratory flash combustion for TC and TN and solution filtering and analysis for DOC and NO⁻³. Aboveground plant biomass was collected and subsampled to determine lignin and C and N content. This study determined that there was an increase of TC with the advancement of growing stages in the studied four sugarcane cultivars at both soil types (increase in TC of 15–35 kg·m²). Nitrogen accumulation was more variable, and NO⁻³ (<5 ppm) were insignificant. The C and N accumulation varies in the whole profile based on the ability of the sugarcane cultivar’s roots to explore and grow in the different soil types. For the purpose of storing C in the soil, cultivar H-65-7052 (TC accumulation of ~30 kg·m⁻²) and H-86-3792 (25 kg·m⁻²) rather H-78-3567 (15 kg·m⁻²) and H-87-4319 (20 kg·m⁻²) appeared to produce more accumulated carbon in both soil types.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.