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ARS Home » Southeast Area » Canal Point, Florida » Sugarcane Field Station » Research » Publications at this Location » Publication #305725
Title: Physiological and growth responses of sugarcane genotypes to nitrogen rate on a sand soil

Author
item Zhao, Duli
item Glaz, Barry
item Comstock, Jack

Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2014
Publication Date: 7/7/2014
Citation: Zhao, D., Glaz, B.S., Comstock, J.C. 2014. Physiological and growth responses of sugarcane genotypes to nitrogen rate on a sand soil. Journal of Agronomy and Crop Science. 200:290-301.

Interpretive Summary: Approximately 80% of sugarcane in Florida is grown on organic (muck) soils and 20% on sand soils. Although sugarcane yields are lower on sand soils than on muck soils in Florida, growers are interested in sugarcane expansion on sand soils for both sucrose and bio-energy production because of saturation of muck soil uses in the region. Nitrogen supply may limit sugarcane growth and yields on these sand soils. We conducted a 2-yr pot study using a sand soil at the USDA-ARS Sugarcane Field Station, canal Point. The objectives of this study were to determine the effect of varying N rates on leaf relative chlorophyll level, leaf photosynthesis, plant growth, dry matter accumulation and partitioning, and nitrogen use efficiency and to quantify variation among sugarcane genotypes in these physiological and growth traits on a sand soil in south Florida. Treatments included four N rates of 0, 75, 150, and 225 kg N ha-1 and three sugarcane genotypes of CP 80-1743, CP 01-2390, and TCP 87-3388. Nitrogen fertilizer was equally split and applied at about 55 and 125 d after planting for each treatment. During the experiment, the number of nodes and length of the primary stalks and tillers were recorded. Leaf relative chlorophyll measured by a Soil Plant Analysis Development (SPAD) meter and net photosynthetic rate were measured biweekly. All plants were harvested at 183 days after planting to measure green leaf area, shoot biomass accumulation and partitioning, and fertilizer nitrogen use efficiency. Genotypes differed significantly in leaf SPAD, photosynthesis, green leaf area, and shoot biomass accumulation and partitioning. CP 01-2390 had the highest leaf photosynthetic rate and shoot biomass and CP 80-1743 had the lowest green leaf area, shoot biomass, and nitrogen use efficiency among genotypes. Nitrogen rate affected leaf SPAD, green leaf area, shoot biomass, and fertilizer nitrogen use efficiency, but had much less effect on leaf photosynthetic rate. Green leaf area and biomass increased with increasing nitrogen rates. Our results suggest that selection of sugarcane genotypes with high nitrogen use efficiency while working to optimize nitrogen rates and delivery time can improve sugarcane yields on sand soils in Florida.

Technical Abstract: Yields of sugarcane (a complex hybrid of Saccharum spp.) in Florida, USA are lower on sand soils than on organic (muck) soils. Nitrogen (N) supply may limit sugarcane growth and yields on these sand soils. A 2-year pot study was conducted to determine sugarcane genotypic variation in response to N rate on a sand soil. Treatments included four N rates (0, 75, 150, and 225 kg ha-1) and three sugarcane genotypes (CP 80-1743, CP 01-2390, and TCP 87-3388). Nitrogen fertilizer was equally split and applied at about 55 and 125 days after planting (DAP) for each treatment. During the experiment, the number of nodes and length of the primary stalks and tillers were recorded. Leaf relative chlorophyll (SPAD) and net photosynthetic rate (Pn) were measured biweekly. All plants were harvested at 183 DAP to measure green leaf area (GLA), shoot biomass accumulation and partitioning, and fertilizer N use efficiency (NUE). Genotypes differed significantly in leaf SPAD, Pn, GLA, and shoot biomass accumulation and partitioning. CP 01-2390 had the highest leaf Pn and shoot biomass and CP 80-1743 had the lowest GLA, shoot biomass, and NUE among genotypes. Nitrogen rate affected leaf SPAD, GLA, shoot biomass, and NUE, but had much less effect on leaf Pn. Green leaf area and biomass increased with increasing N rates. Our results suggest that a two-pronged approach, selection of genotypes with high NUE while working to optimize N rates and delivery, can improve sugarcane yields on sand soils.