Intercropping of sugar cane and green manures for the substitution of mineral nitrogen fertilization and for the improvement of soil physical properties

• Grant number: 10/12554-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2010
• Effective date (End): October 31, 2011
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Miguel Cooper
• Grantee: Pedro Augusto Minighelle Selegato
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Sugarcane is among the most important crops in Brazilian agriculture, corresponding to 14 % of the farmed area in the country. Sugarcane crops are extremely dependent upon nitrogen (N) inputs for high yields. Most of the N requirements of sugarcane crop in Brazil is supplied by both mineral and organic fertilization. However, fertilization is not the only way of providing N to crops. Some crop systems are capable of providing significant N inputs to the soil, especially by the biological nitrogen fixation (BNF). In Brazil the benefits of crop rotation of sugarcane and cover crops capable of fixating atmosphere N is very well known by farmers and is often used. Although, most of the sugarcane harvested every year comes from the ratoon crops, and in such areas the benefits of BNF are not used yet. The objective of this work is to evaluate if the intercropping of Crotalaria breviflora in sugarcane ratoon crops is effective on providing the N required for satisfactory yields. Also it is expected that the technique will improve the soil physical properties, which may allow the use of the ratoon crop for more crops than without the intercropping. The experiment will be installed in randomized blocks with four replications. The C. breviflora will be sown in two rows for each inter-row of sugarcane. It will be evaluated different intervals between the sugarcane harvest and the sowing of C. breviflora, with or without its cutting at blooming. There will also be two control treatments with sugarcane alone, one with mineral N fertilizer application, and the other one without any N application. (AU)