Soil fertility requirements for sweet sorghum [Sorghum bicolor (L.) Moench] as an alcohol fuel crop have not been well defined. The primary objective of this study was to determine the biomass and sugar (% Brix ✕ extracted juice) yield response of sweet sorghum to N‐P‐K and lime. The study was conducted for 2 years on a Wynnville silt loam (fine‐loamy, siliceous, thermic Glossic Fragiudult) soil in the Cumberland Plateau region of northern Alabama. Experimental design was a split‐plot with 0 or 8 Mg ha−1 dolomitic limestone and combinations of 0, 45, 90, or 180 kg ha−1 N, 30 or 90 kg ha−1 P, and 40 or 120 kg ha−1 K. Liming significantly increased yields of fresh and dry biomass, grain, and juice sugar extracted from stalks. The lime also greatly reduced exchangeable soil Mn and Al and increased Mg and decreased Mn concentrations of the biomass. Due to the dominant effect of lime and other interactions, biomass and juice sugar yields were not consistently related to applied N, P, or K. In nonlimed soil, biomass and sugar yields decreased with high N in the presence of low P‐K, but not with high P or K. This suggests an acidity ✕ P and/or K interaction related to toxicity of soil Mn and/or Al. In the limed soil the maximum dry biomass and sugar yields occurred with 180‐90‐120 (1981) or 90‐90‐120 (1982) kg ha−1 N‐P‐K, however yields from some treatments with lower levels of N, P, or K were often not significantly different at the 0.05 level. Inherent soil acidity and related Mg deficiency must be corrected to obtain maximum response of sweet sorghum to fertilization in Wynnville and associated soils of the Cumberland Plateau region.

Five greenhouse pot experiments were conducted to study the utilization or disposal of urban waste compost on agricultural soils. Highly carbonaceous compost applied without additional N induced N deficiency in corn (Zea mays L.) grown on very N‐deficient Mountview sil. This was corrected by applying soluble N. Apparent N deficiency of corn was not induced by compost on soils higher in crop‐available N. Compost supplied considerable N, P, K, Ca, and Zn for corn and tall fescue (Fescue arundinacea Schreb.); P and K in the compost were relatively more available than its content of N. Placing P with compost did not increase availability of the P for corn.Heavy applications of compost (made from garbage and sewage sludge solids) to soil had a considerable liming effect and increased Zn concentrations and uptake by corn and tall fescue. The liming effect apparently prevented toxicity to corn and snap beans (Phaseolus vulgaris L.) from Zn accumulations from compost on an acid Sango sil.

Fly ash residues from several sites in which solid municipal refuse is being incinerated for energy production were found to contain excessive amounts of cadmium and/or lead according to an empirical extraction test (0.5 N acetic acid) developed by the Environmental Protection Agency. Samples of associated bottom ashes contained acceptable levels of Cd and Pb, but several were marginal with respect to Pb content. Leaching tests clearly demonstrated that Cd and, to a lesser extent, Pb were mobile in soil when applied in a fly ash matrix. The high chloride content (10-12%), which is characteristic of these ashes, resulted in metal complexation and enhanced Cd and Pb mobility in soil. Normally these elements are relatively immobile in soils when applied as inorganic salts or contained in municipal sewage sludge. Plant uptake of Cd and Pb in a greenhouse test was marked when fly or finely ground bottom ashes were soil applied. Phytotoxicity of fly ash appeared to be associated with the high salt content rather than with a specific metal.

Soil measurements of 137Cs, a fallout component of nuclear testing, were made within a 3.8‐ha research watershed in the Limestone Valley of northern Alabama. Objectives of the study were to: (i) compare 137Cs activity in soil profiles on eroded and depositional landscape positions, and (ii) relate soil erosion and deposition calculated by 137Cs methods to erosion estimated by the Universal Soil Loss Equation (USLE) and to sediment discharge measured at the watershed outlet. Triplicate soil profiles were analyzed for 137Cs activity to a 46‐cm depth in cultivated sites representing slightly eroded ridgetop, eroded side‐slope, and depositional downslope positions. These data were compared with baseline 137Cs measurements in undisturbed adjacent woodland. Erosion calculated by 137Cs activity losses from baseline values were compared with the USLE estimates on slope transects. Mean total 137Cs activities on baseline, eroded, slightly eroded, and depositional sites were 4860, 1804, 2807, and 5367 Bq m−2, respectively. Peak 137Cs activity and depth to zero activity were much greater in depositional than in eroded and slightly eroded sites. Estimated mean annual (1954–1987) soil‐erosion rates were similar between 137Cs and USLE methods for a slope transect with slight erosion (28 and 26 Mg ha−1 yr−1). On eroded side‐slopes, 137Cs estimates of erosion were 27 to 80% higher than the USLE estimates. This may be due to rill erosion unaccounted for by the USLE. The USLE estimated losses between 9 and 52 Mg ha−1 yr−1 for uplands during 1984 to 1988 cotton production. Sediment losses measured below the downslope depositional area of the small watershed (Gilbert Farm Research Watershed) were only 1 to 4 Mg ha−1 yr−1. This indirect evidence of extensive sediment deposition in a representative small watershed of karst terrain was supported by 137Cs activity in depositional soil profiles.

Techniques are described for preparing and sampling soil columns and undisturbed soil peds used for ion movement studies. These methods utilize a block of paraffin wax-petrolatum jelly mixture to hold soil peds or to provide a cylindrical cavity for a soil column. A microtome and holder apparatus capable of holding the wax blocks containing the soil is used for precision slicing at increments of 0.5 mm or more.Additional Key Words for Indexing: diffusion in soil, soil column sectioning, ped coatings.