Skip to main content
ARS Home » Southeast Area » Raleigh, North Carolina » Plant Science Research » Research » Publications at this Location » Publication #354204
Title: Nutrients released by Urochloa cover crop prior to soybean production

Author
item TANAKA, KATIUCA SUENKO - Sao Paulo State University (UNESP)
item CRUSCIOL, CARLOS - Sao Paulo State University (UNESP)
item SORATTO, ROGERIO - Sao Paulo State University (UNESP)
item MOMESSO, LETUSA - Sao Paulo State University (UNESP)
item MARTINS DE COSTA, CLAUDIO - Sao Paulo State University (UNESP)
item Franzluebbers, Alan
item JUNIOR, ADILSON - Sao Paulo State University (UNESP)
item CALONEGO, JULIANO - Sao Paulo State University (UNESP)

Submitted to: Nutrient Cycling in Agroecosystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2019
Publication Date: 2/23/2019
Citation: Tanaka, K., Crusciol, C.A., Soratto, R.P., Momesso, L., Martins De Costa, C.H., Franzluebbers, A.J., Junior, A.O., Calonego, J.C. 2019. Nutrients released by Urochloa cover crop prior to soybean production. Nutrient Cycling in Agroecosystems. 113:267-281.

Interpretive Summary: Enhancing productivity and maintaining soil and water resources are two important goals of agricultural sustainability in agricultural expansion areas around the world. Optimizing soybean production while minimizing soil loss from erosion are concerns in Brazil and other tropical and sub-tropical regions. A scientist at USDA-ARS in Raleigh, North Carolina collaborated with scientists at Sao Paulo State University to study the impacts of nitrogen fertilization of grass cover crops prior to soybean production on straw nutrient content and soybean grain production. Nutrient content of cover crop straw was enhanced due to greater biomass production in treatments with nitrogen applied 20 and 10 days before desiccation. Soybean grain yield was greater following Urochloa brizantha than following Urochloa ruziziensis. Nitrogen application at different times did not affect soybean grain yield. These results suggest that Urochloa biomass and nutrient cycling can be enhanced with nitrogen application, but it had little short-term impact on soybean yield components. These results will be useful for farmers and agricultural advisors to design more efficient conservation agricultural systems for the tropics and subtropics.

Technical Abstract: The Urochloa genus grows vigorously in the dry-season of the tropics, and has been used successfully to provide abundant surface residue as cover crop for no-till soybean (Glycine max). Nitrogen (N) fertilizer application could enhance cover crop biomass production and ground cover, but how this affects nutrient cycling during the subsequent soybean growing season is not known. We evaluated nutrient cycling and soybean yield components following different timings of N application to Urochloa cover crops. The experiment was conducted in two growing seasons at Botucatu, São Paulo State, Brazil. Treatments consisted of two forage grasses (Urochloa brizantha and Urochloa ruziziensis) and six N management systems [control (0 kg N/ha), N application at soybean sowing and topdressing (40 kg N/ha + 60 kg N/ha, respectively), N 20 days before grass desiccation (DBD), N 10 days DBD, N 5 days DBD, and N 1 day before soybean sowing, using the dose of 100 kg N/ha in the latter 4 treatments]. Both grasses as cover crop were productive, but U. brizantha had greater biomass than U. ruziziensis. Nutrient content of cover crop straw was enhanced due to greater biomass production in treatments with N applied 20 and 10 days before desiccation. Soybean grain yield was greater following U. brizantha than following U. ruziziensis. Nitrogen application at different times did not affect soybean grain yield. These results suggest that Urochloa biomass and nutrient cycling can be enhanced with N application, but it had little short-term impact on soybean yield components.