Potential Adherence of Flue Gas Desulfurization Gypsum to Forage as a Consideration for Excessive Ingestion by Ruminants.

Gypsum (calcium sulfate dihydrate, CaSO⋅2HO) has long been used to improve soils and crop production, and its use has recently been encouraged by the USDA-NRCS for soil conservation through a new Conservation Practice Standard: Code 333. However, there is concern regarding the adverse effects of excessive direct ingestion of sulfate in gypsum by ruminants. The standard requires ruminants to be removed from grazing after application until after a rainfall, but there has been no research documenting gypsum adherence to forage or the potential for rainfall to reduce gypsum adherence. A study was established to examine the adherence and persistence of gypsum on different forage species. Two forages (bermudagrass [ L.] and tall fescue [ Schreb.]) were examined after gypsum applications at rates of 0, 1, and 5 Mg ha. The forage was sampled immediately after application, 1 wk after application, after a 1.5-cm rain, and after a 3.3-cm rain. Immediately after gypsum application, more gypsum adhered to the tall fescue (27.9 g gypsum kg) compared with bermudagrass (8.6 g gypsum kg), likely due to differences in the leaf structure. This represents S concentrations of 0.16 and 0.52% for any grazing ruminants feeding exclusively on the bermudagrass and tall fescue pastures. On succeeding sampling dates, substantial amounts of gypsum persisted only on the wider-leaved tall fescue. With tall fescue, a difference in gypsum adherence could be observed after a 1.5-cm rain, but no significant difference was observed between the gypsum application and the control after an additional 3.3-cm rain. Results indicate that care should be observed with grazing after gypsum application, especially on wide-leaved forages. However, using application rates within normal agronomic beneficial use guidelines (NRCS standard 333), negative results from direct ingestion of gypsum are not likely if grazing is discontinued several weeks and until a rainfall event occurs.

Subsurface application of poultry litter and its influence on nutrient losses in runoff water from permanent pastures.

Environmental pressure to reduce nutrient losses from agricultural fields has increased in recent years. To abate this nutrient loss to the environment, better management practices and new technologies need to be developed. Thus, research was conducted to evaluate if subsurface banding poultry litter (PL) would reduce nitrogen (N) and phosphorus (P) loss in surface water runoff using a four-row prototype implement. Rainfall simulations were conducted to create a 40-min runoff event in an established bermudagrass (Cynodon dactylon L.) pasture on soil types common to the Coastal Plain and Piedmont regions. The Coastal Plain soil type was a Marvyn loamy sand (fine-loamy, kaolinitic, thermic Typic Kanhapludults) and the Piedmont soil type was a Hard Labor loamy sand (fine, kaolinitic, thermic Oxyaquic Kanhapludults). Treatments consisted of surface- and subsurface-applied PL at a rate of 9 Mg ha(-1), surface broadcast-applied commercial fertilizer (CF; urea and triple superphosphate blend) at the equivalent N (330 kg N ha(-1)) and P (315 kg N ha(-1)) content of PL, and a nonfertilized control. The greatest loss for inorganic N, total N, dissolved reactive P (DRP), and total P occurred with the surface broadcast treatments, with CF contributing to the greatest loss. Nutrient losses from the subsurface banded treatment reduced N and P in surface water runoff to levels of the control. Subsurface banding of PL reduced concentrations of inorganic N 91%, total N 90%, DRP 86%, and total P 86% in runoff water compared with surface broadcasted PL. These results show that subsurface band-applied PL can greatly reduce the impact of N and P loss to the environment compared with conventional surface-applied PL and CF practices.

Impact of gypsum applied to grass buffer strips on reducing soluble p in surface water runoff.

The threat of P transport from land applied manure has resulted in water quality concerns. Research was conducted to evaluate gypsum as a soil amendment applied to grass buffer strips for reducing soluble P in surface runoff. A simulated concentrated flow was created in an established tall fescue (Festuca arundinacea Schreb.) pasture. Poultry litter (PL) was applied at a rate of 250 kg N ha(-1) to the upper 3.05 m of each plot, while gypsum was applied at rates of 0, 1, 3.2, and 5.6 Mg ha-1to the lower 1.52 m of the plot functioning as a grass buffer strip. Two 30-min runoff events ( approximately 4 L min(-1)) were conducted, immediately after PL application and 4 wk later to determined soluble P concentration in the surface water samples. The greatest concentration of soluble P was in the runoff event occurring immediately after the PL application. Gypsum applied to grass buffer strips was effective in reducing soluble P concentrations (32-40%) in surface runoff, while the untreated buffer strip was somewhat effective in reducing soluble P (18%). No significant differences were observed between gypsum rates, suggesting that land managers would achieve the greatest benefit from the lowest application rate (1Mgha(-1)). In the second runoff event, although concentrations of soluble P in the surface water runoff were greatly reduced, the effect of gypsum had disappeared. Thus, these results show that gypsum is most effective in reducing the initial P losses from PL application when applied to grass buffer strips. The information obtained from this study may be useful in aiding land managers in developing management practices that reduce soluble P loss at the edge of a field.

Pregnancy complicated by Gorham disease.

BACKGROUND: A pregnancy with Gorham disease (massive osteolysis syndrome) is described. To our knowledge, this is the first reported case of a pregnancy associated with this disease. CASE: A 25-year-old woman was seen for pre-conception counseling with the diagnosis of Gorham disease. Before pregnancy, magnetic resonance imaging confirmed a stable disease process. The woman and fetus were followed during pregnancy with ultrasound and consultations. Severe preeclampsia developed at delivery, with a significant thrombocytopenia. We delivered the infant by low forceps, with a good outcome. Subsequently, the mother and child were doing well at 18 months postpartum. CONCLUSION: We briefly review this rare bone disease as it relates to pregnancy and provide information for preconception counseling.