Effects of Fresh and Composted Dairy Manure Applications on Alfalfa Yield and the Environment in Arizona

Abstract

The Unified Animal Feeding Operation Strategy requires that field application of animal waste, a common fertilization and disposal practice, may not exceed crop nutrient needs. Additional guidelines set forth by the Arizona Department of Environmental Quality state that animal waste applications on agricultural fields in designated Confined Animal Feeding Operations (CAFOs) must be made in a manner such that the total N applied to the field cannot exceed the uptake from the crop grown. Because alfalfa is grown year round and can take up large quantities of N, many operators of CAFOs apply animal waste to their production alfalfa fields as method of waste disposal. In this research, fresh and composted dairy manure was applied to plots in a production alfalfa (Medicago sativa L.) field to determine the impact on alfalfa yield, soil nitrogen (N), phosphorus (P), and electrical conductivity (EC) levels and the potential for nitrate (NO 3) and phosphate (PO 4) leaching. Unfertilized plots were maintained as controls. Fresh and composted manure was applied to fertilized plots after each harvest at a rate intended to replace N removed from the previous cutting. After 1.5 yr and 13 cuttings, soil analysis down to 150 cm depth showed no significant difference in soil N between treatments. At study end, NO 3-N made up 1.1% of total N in the fertilized plots but only 0.6% in control plots. Changes in soil N were not significant. Soil P content increased in fertilized plots but remained stable in control plots. Final soil PO 4 measurements were 16, 99, and 116 kg ha 21 in the control, manure-treated, and compost-treated plots, respectively. Leachate from three drainage lysimeters contained no detectable NO 3 or PO 4 from any of the treatments. LSD showed no difference in EC between the beginning and the end of study, and alfalfa yield did not vary among treatments.

Yield and Environmental Effects of Summer Pig Slurry Applications to Irrigated Alfalfa under Mediterranean Conditions

“…The low soil inorganic N content found in this study agrees with previous studies of fertilized alfalfa (Martin et al, 2006; Daliparthy et al, 1994; Schmitt et al, 1994). It is possible that soil inorganic N content increased after pig slurry applications in the upper soil layers, as observed by Ceotto and Spallacci (2006), but the high N uptake of alfalfa (608 kg N ha −1 yr −1 ) allowed a reduction of this transient high N content in the soil avoiding soil inorganic N accumulation and subsequent leaching in drainage water.…”

“…It is possible that soil inorganic N content increased after pig slurry applications in the upper soil layers, as observed by Ceotto and Spallacci (2006), but the high N uptake of alfalfa (608 kg N ha −1 yr −1 ) allowed a reduction of this transient high N content in the soil avoiding soil inorganic N accumulation and subsequent leaching in drainage water. This high efficiency could be also explained by the relatively high water holding capacity of the soil and the deep rooting system of alfalfa, which makes this crop a relevant scavenger of subsoil N (Schmitt et al, 1994; Martin et al, 2006).…”

Available nitrogen and phosphorus in soil amended with fresh or composted cattle manure containing straw or wood-chip bedding

“…They reported similar soil NO 3 -N for fresh and composted cattle manure for one soil type, but found higher NO 3 -N for FM than CM in July and October for another soil type. Others have reported no significant difference in soil NO 3 (0Á150 cm) under fresh and composted manure for dairy manure (Martin et al 2006). Greater soil (Fig.…”

Nitrogen Sources and Sinks Within the Middle Rio Grande, New Mexico1

“…By comparison, alfalfa comprises approximately 23% of irrigated cropland in other western states (USDA NASS, 2006). Alfalfa is considered a legume and does not require much nitrogen fertilization to improve crop yields because it is able to fix nitrogen from the atmosphere based on a symbiotic relationship with the nitrogen-fixing bacteria rhizobia (Daliparthy et al, 1994;Lloveras et al, 2004;Lamb et al, 2005;Martin et al, 2006).…”