Sugarcane yield and development to different doses of vinasse injected with a subsurface drip irrigation system

Author(s)

Fabio Jordão Rocha

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2012-11-13

Examining board members

Marcos Vinicius Folegatti; Rubens Duarte Coelho; Vital Pedro da Silva Paz; Regina Celia de Matos Pires

• Advisor: Marcos Vinicius Folegatti; Rubens Duarte Coelho

Abstract

Vinasse is a by-product from ethanol production and reused in sugarcane fields providing nutrients to the plants, mainly potassium. Generated at a rate of 10-13 liters for every liter of ethanol, the vinasse represents an excellent alternative to chemical fertilizers and it also presents environmental and technical challenges for its applications on agricultural soils. Mismanagement of vinasse can cause environmental impacts and lower the quality of sugarcane production. This study had as aim to study the effect of application of different doses of vinasse by a subsurface drip irrigation system in sugarcane vegetative development, sugarcane yields, technological parameters, bio-products production, changes in pH and electrical conductivity (EC) of the soil, evaluation of potential to use of drip irrigation to apply vinasse. A completely randomized design with 6 treatments and 4 repetitions was conducted at experimental area of Bio systems Engineering Department of USP/ESALQ, placed in Piracicaba-SP. The treatment 1 was performed in dry land system with chemical fertilization at planting; treatment 2 was fertigated with chemical fertilizers (no vinasse); treatments from 3 to 6 received different levels of vinasse. Treatment 4 received the dose (DCETESB) calculated in according to criteria from technical standard P4.231/2005 of CETESB, and treatments 3, 5 and 6 received ½ DCETESB, 2xDCETESB and 3xDCETESB, respectively. Two cycles of sugarcane were evaluated, first year and firs ratoon. The monitoring of pH and EC of the soil, vegetative development, leaf nutrional analysis and drip irrigation performance were evaluated at first cycle. Biomass, sugar and ethanol production were evaluated at first and second cycles. The results showed that an increase of pH and EC occurred due to the vinasse application, however, was evident the need of a higher interval of time to see the differences. Treatments 4, 5 and 6 showed higher values of leaf area and plant height when compared to treatment 1, while the another biometric data did not show difference between the treatments. Leaf nutritional analysis showed that did not have effect of vinasse doses in nutritional status of the plants. Among technological parameters just as content was affected by the application of different doses of vinasse at two harvests, and the another parameters were not affected. Sugarcane yields showed difference between treatments just at first year when vinasse application resulted in production increasing. This increase caused an increase of second generation ethanol production (E2G), while the sugar, first generation ethanol (E1G) and total ethanol (E1G+E2G) did not show significance difference between treatments. (AU)

• FAPESP's process: 09/13655-0 - Application of vinasse by subsurface drip on fertirrigated sugarcane
• Grantee: Fábio Jordão Rocha
• Support Opportunities: Scholarships in Brazil - Doctorate