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N2-Fixation in Field Settings: Estimations Based on Natural 15N Abundance
Estimates based on this method compare favourably with other methods for field evaluation of N2-fixation, provided that the site and the sampling strategy are appropriate for application of the method. Expand
Variable expression of the nitrogen isotope effect associated with denitrification of nitrite.
Results indicate that variation of beta obs in intact cells is due entirely to variation in the relative rates of intracellular steps of the denitrification process, and the linear relation between beta obs and velocity imposes constraints on any proposed mechanism of denitification. Expand
Foliar 15N natural abundance in Hawaiian rainforest: patterns and possible mechanisms
It is suggested that inputs of 15N-depleted nitrogen from precipitation coupled with very low nitrogen outputs cause the strongly negative δ15N values in non-nitrogen-fixing plants on early successional sites in Hawai'i. Expand
Organic farming in the corn belt.
A small minority of farmers in the Midwest produces crops on a commercial scale without using modern fertilizers and pesticides. On the basis of a 5-year study, it appears that these farmers haveExpand
Isotopic Fractionation Associated With Symbiotic N(2) Fixation and Uptake of NO(3) by Plants.
Isotopic fractionation associated with N(2) fixation and NO(3) (-) uptake by plants does not have a critical effect on estimates of N( 2) fixation which are based on natural abundance of ( 15)N since the (15)N abundance of soil-derived N in plants is measured directly. Expand
Estimates of N2-fixation from variation in the natural abundance of 15N in Sonoran desert ecosystems
It is concluded that N2-fixation is very important to Prosopis at six of seven sites in the Sonoran Desert and at the site where prosopis did not appear to be fixing N2, N2 -fixation was important only for legumes of the sub-family Papilionoideae. Expand
Variation in the Natural Nitrogen-15 Abundance in Nitrate Mineralized During Incubation of Several Illinois Soils 1
Samples of the surface layer of soil (0-30 cm) were collected from five sites in central Illinois. The soils were incubated under controlled conditions for an extended period of time in an effort toExpand
The Nitrogen-15 Abundance in a Wide Variety of Soils
One hundred thirty-nine soil samples from 20 states were analyzed for ¹⁵N abundance. Soil characteristics and environmental conditions at the sampling sites varied widely. The total N of surface soilExpand