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Amino compounds (AC) generally constitute the bulk of N in soil, so understanding their cycling is critical for efficient N use in crop production. In this work, we quantified 19 amino acids and two amino sugars in 23 poultry litters (PL), five pasture soils with different PL application histories, and the grass grown on these pastures. Concentration of AC-N averaged 37.0 mg g-1 dry matter(DM) for the 23 PL samples, which represented approximately 76% of their total N. Pasture soils had received annual PL applications for 0, 5, 10, 15, and 20 years at rates of 0, 2.27, 2.27, 3.63, and 1.36 Mg ha-1 yr-1, respectively. Highest levels of AC-N were observed in soils receiving 10- and 15-yr PL, which implied that both freshly applied and residual PL contributed tosoil AC-N. However, the proportion of total soil N comprised of AC-N decreased with PL application, with AC-N accounting for 97% of total N in the control pasture soil, but only 40% insoils receiving PL for 20 years. Plants harvested from the control pasture field contained the least abundant AC-N (10.5 mg g-1 DM). Plant leaves harvested from the pasture field with 5-year PL application contained the greatest AC-N (23.7 mg g-1 DM). It is clear that additional research is needed for understanding the roles and transformations of amino compounds in soil N dynamics and plant N uptake in PL amended soils.

'Huntsville '96' was an experiment in ground-based remote sensing to acquire data needed to test and refine algorithms to estimate soil moisture on bare and vegetated plots. Remote sensing instruments included a L, S, and C band microwave radiometer and a L, C, and X-band radar. The remote sensing measurements were supported with automated and manual measurements of numerous soil and vegetation variables. The remote sensing instruments were able to detect both the large surface moisture changes due to rainfall and subsequent drying as well as the diurnal fluctuations in moisture. These data will be used to refine techniques to estimate moisture in the surface layer of soil, address issues related to the sensitivity of algorithms, the integration of data from passive and active systems, and the use of surface soil moisture estimates to increase the accuracy of soil moisture profile estimates. Although in-depth analyses of the data are underway, collaboration with other investigators is being encouraged. [ABSTRACT FROM AUTHOR]