Nitrous oxide emissions, N uptake, biomass, and rubber yield in N-fertilized, surface-irrigated guayule

Nitrous oxide (N2O) emissions from N fertilizer applied to row crops makes up a large portion of the greenhouse gas loading atmosphere. Guayule (Parthenium argentatum A. Gray) is desert perennial shrub being promoted for Central Arizona farmers as source natural rubber and hypoallergenic latex. Emissions N2O crop uptake have not been previously quantified in this multi-year cropping system. A 2.5-year study was conducted on transplanted surface-irrigated guayule Casa Grande sandy loam Maricopa, AZ assess agronomic environmental responses application rate. Four rates ranging 0 252 kg ha−1 were ammonium sulfate three splits. measured with 1-L vented chambers 34 times over 98 weeks 17 April 2013 6 March 2015 pauses during winter dormant seasons. Nitrogen rate significantly affected emissions, which ranged 1.2 4.5 rates. Emission factors 1.5, 1.4, 1.3 % added sulfate-N emitted 84, 168, 250 ha−1, respectively, are range those other better-studied such corn (Zea mays L.) cotton (Gossypium hirsutum by averaged 191 biomass yields 19 Mg 1070 respectively. There no effect uptake, biomass, or because initial soil profile nitrate (NO3) levels 85–150 NO3-N ha−1. balance inputs (initial NO3, fertilizer, irrigation) outputs (N N2O, dinitrogen (N2) emissions) constructed. Unaccounted-for apparently lost NO3 leaching below root zone. In conclusion, informative data presented first guayule, reported here can be used updated, improved recommendations guayule.