2nd UF Water Institute Symposium Abstract

Submitter's Name Adriana Artur
Session Name Poster Session: Optimal Use of Integrated Water Supplies 1
Category Optimal use of integrated water supplies
Poster Number 401
Author(s) Adriana Artur,  University of Sao Paulo
  Dayana Santos,  Uniiversity of Sao Paulo
  Francisco Monteiro, University of Sao Paulo
  Water Use Efficiency by Marandu Palisadegrass as Affected by Nitrogen and Sulphur Fertilization
  Water is a renewable resource, but its availability is variable and limited in many parts of the world. Thus, it is important to develop management alternatives that improve water use efficiency in agricultural systems to minimize the conflict between agriculture and urban societies for limited water resources. The objective of this study was to evaluate the effects of various N and S application rates on water use efficiency by Brachiaria brizantha cv. Marandu (Marandu palisadegrass). The experiment was conducted under greenhouse conditions, in Piracicaba, Sao Paulo State, Brazil from September to December, 2008. Soil was an Entisol that exhibited low organic matter content (0.95%), pH CaCl2 = 4.0. Treatments consisted of fractionated factorial combination of five N rates (0; 100; 200; 300; and 400 mg dm-3) and five S rates (0; 10; 20; 30; and 40 mg dm-3) with four replications. Aboveground forage biomass was harvest at 28-d intervals. The first harvest occurred 35 days after seedlings were transferred to the pots. Soil moisture was maintained at 70% of soil retention capacity by irrigation system. Water use efficiency was calculated by dividing the water consumption and the dry mass produced during each growing period. Maximum water use efficiency of the Marandu palisadegrass was obtained with 219 mg dm-3 of N during the first 35 days. N and S rates that promoted maximum water use efficiency were 311 and 29 mg dm-3, respectively, for the second growing period and 292 and 30 mg dm-3, respectively, for the third growing period. Greater dry mass production per unit of water consumed was obtained when Marandu palisadegrass received increasing rates of N and S fertilization.