Poultry Litter Application Rate Research Articles

Simulated Phosphorus and Sediment Loadings in Two Representative Subbasins of the Illinois River

Quantification of the factors affecting phosphorus (P) loading to surface waters is important in assessing the contribution from agricultural activities to water quality. This study investigated the long-term impact of applications of P in poultry litter on the loadings of P and sediment to streams in two subbasins of the Illinois River Watershed. The influences of application rate and environmental characteristics were examined utilizing a transport model, a geographical information system (GIS), and 30 years of daily weather data. Simulated runoff and sediment concentrations of P increased linearly with poultry litter application rate. Most P loadings to streams were in the dissolved form, as overall sediment transport was low, particularly in areas with excellent stands of forage. Because only pasturelands received poultry litter and the initial concentrations of P in the soils in the forested areas were low, the forested areas contributed little runoff and sediment P to streams. Areas of high P loadings coincided with soils having high Curve Numbers (CN) and poor internal drainage. Therefore, subbasins of the watershed containing a greater proportion of pasture and soils with poor drainage characteristics have higher loading rates to streams. Predicted runoff, sediment, and P loadings in both subbasins were highly variable.

Potential of Cool-Season Legumes for Removing Excess P From Poultry Litter Application

Phosphorus (P) concentration in surface waters from non-point agricultural sources is an increasing resource management concern. This study was conducted at Overton, Texas, on a Bowie fine sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) to evaluate cool-season legumes for P uptake following poultry litter (PL) application rates on spring vegetables. Treatments were PL rate (0, 1X, 2X, 4X) and a commercial blend (CB) for comparison. Cool-season legumes, consisting of crimson clover, berseem clover, hairy vetch, and red clover, were the subplots. The vegetable crop in Spring 1995 was watermelon. The 1X PL rate was 2.2 t·ha-1 and the CB was 44.8N-0P-32.5K kg·ha-1. Dry matter yield was decreased by the 4X PL rate. Plant P concentration increased linearly as PL rate was increased. The greatest P uptake (4.1 kg·ha-1) was at the 2X rate. Hairy vetch had the greatest yield (1,875 kg·ha-1), plant P concentration (0.53%), and P uptake (9.6 kg·ha-1). PL rate increased soil P concentration at all depths. The least amount of P accumulation was from CB and was equal to the control. Hairy vetch appears to have the capability of removing a greater amount of P and reducing soil concentration when compared to the other legume species tested.

Solids Transport and Erodibility of Poultry Litter Surface-applied to Fescue

Poultry (Gallus gallus domesticus) litter is land-applied to make beneficial use of litter nutrients for plant growth. Runoff can transport litter particles off application sites and thus diminish the quality of downstream waters. This study assessed how solids (sediment and litter particles) yield and erodibility for fescue (Festuca arundinacea Schreb.) pasture are influenced by poultry litter application. The experimental variables were poultry litter application rate (0, 5.9, 11.8, and 23.5 Mg/ha), simulated rainfall intensity (50 and 100 mm/h), interval between litter application and simulated rainfall (1, 4, 7, and 14 days), and number of simulated rainfall events (four eventsone each at 7, 14, 36, and 68 days following litter application). Solids yields were determined from composite runoff samples. Erodibility values were computed from the Modified Universal Soil Loss Equation. Solids yield increased with increasing rainfall intensity and litter application rate. Erodibility increased linearly (r2 = 0.98) with litter application rate, but was unaffected by rainfall intensity. Neither solids yield nor erodibility was influenced by interval between litter application and first post-application rainfall. The number of rainfall events affected both solids yield and erodibility of litter-treated plots, but both approached levels observed for untreated plots by the third rainfall. The results indicate that models estimating erosion from fescue pasture treated with poultry litter should incorporate increased erodibility values to account for the presence of the litter. The adjustment, however, should be decreased with successive post-application rainfall events.

Effects of Poultry Litter Application Rate and Rainfall Intensity on Quality of Runoff from Fescuegrass Plots

AbstractA 4 × 2 factorial experiment with three replications was conducted to determine how quality of runoff from grassed areas treated with poultry (Gallus gallus domesticus) litter is impacted by litter application rate and rainfall intensity for storms occurring 1 d after application. Poultry litter was applied at 0, 218, 435, and 870 kg N ha−1 to plots established with fescuegrass (Festuca arundinacea Schreb.) on a Captina silt loam soil (fine‐silty, mixed, mesic Typic Fragiudult). Simulated rainfall was applied 24 h after litter application at 5 and 10 cm h−1 until runoff had occurred for a duration of 0.5 h. Flow‐weighed composite samples were collected and analyzed for total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH3‐N), nitrate nitrogen (NO3‐N), total phosphorus (TP), dissolved reactive phosphorus (DP), chemical oxygen demand (COD), total suspended solids, and electrical conductivity. Increasing the litter application rate significantly increased runoff concentrations of all litter constituents investigated. Concentrations of TKN, TP, DP, and COD significantly decreased with increasing rainfall intensity because of more runoff and the associated dilution. Masses of litter constituents transported off the plots via runoff significantly increased with both litter application rate and rainfall intensity. For a given rainfall intensity, the proportions of applied litter constituents lost in runoff were generally indendent of application rate with the exception of total N at the high rainfall intensity.