359-10 Effect of Organic Carbon and Nitrogen Rates On Table Grape Var Thompson Seedless.

See more from this Division: S04 Soil Fertility & Plant Nutrition
See more from this Session: Management Strategies to Improve Nutrient Use Efficiency: I
Wednesday, October 19, 2011: 10:35 AM
Henry Gonzalez Convention Center, Room 212A
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Rodrigo A. Ortega, Universidad Técnica Federico Santa Maria, Santiago, Chile and Mara M. Martnez, Universidad Tcnica Federico Santa Maria, Santiago, Chile
Table grape is one of the main exporting crops in Chile with over 60,000 ha planted.  In 2009 production reached a total of 850,000 ton, and the main varieties included, Crimson Seedless, Red Globe, Flame Seedless, Superior Seedless, Autumn Royal, and Thompson Seedless. Main productive problem is the duration of the root system, and therefore of the orchard, which has made producers to look for new ways to improve it. The application of organic carbon (OC) in the context of an integrated nutrient management, together with moderate nitrogen (N) rates, could be part of the solution. The present study had for objective to evaluate the effects of C and N on soil properties, plant characteristics, and yield and quality of table grape var. Thompson Seedless. A field experiment was established on a 2-year orchard planted on an inceptisol located in Limarí valley, and evaluated during two consecutive seasons. Soils have low organic matter content, alkaline pH and low P. A factorial experiment of 4 C rates (0, 100, 200, and 400 kg C/ha/season) and 4 N rates (0, 30, 60, and 120 kg N/ha/season), was evaluated. Carbon was applied as liquid humus through drip irrigation; Novatec TM, a fertilizer with nitrification inhibitor was used as nitrogen source. Soil evaluations included: N-NH4, N-NO3, C and N contents,  Olsen-P, pH, EC, and enzymatic activity (β-glucosidase, urease, acid and alkaline phosphatase). Plant evaluations included: leaf N-NH4, N-NO3, total N, SPAD, nitrate reductase (NR) activity, and chlorophyll content; grape yield and quality. Results indicated that C applications significantly affected soil enzymatic activity, particularly acid and alkaline phosphatases, and β-glucosidase. On the other hand, N applications affected available soil N, leaf chlorophyll content, and NR activity. During the second season a clear tendency was observed for a yield increase with C rate, reaching a maximum with the application of 300 kg C/ha. No significant effect was observed with N applications, meaning that the soil provided enough N to sustain an average yield of 21 ton/ha of grape, 70% of which was exportable.  Preliminary results confirm that integrated nutrient management would be a good approach to sustain yield and quality in table grapes.
See more from this Division: S04 Soil Fertility & Plant Nutrition
See more from this Session: Management Strategies to Improve Nutrient Use Efficiency: I