Dairy Diet Phosphorus Effects on Phosphorus Losses in Runoff from Land‐Applied Manure

Abstract

Phosphorus losses from land-applied manure can contribute to that the average dairy diet in the USA is supplemented nonpoint source pollution of surface waters. Dietary P forms and levels influence P concentrations in animal manures and may affect P to contain 4.8 g P kg Ϫ1 , while only 3.8 g P kg Ϫ1 is needed losses from land-applied manure. The objective of this study was to for optimum milk production and reproductive effidetermine the effects of dairy diet P concentration on P losses in ciency. This is a 25% over-supplementation of dietary P, runoff from land-applied manure. Dairy manures from two dietary P based on National Research Council standards (Nalevels were applied (24 May 1999) at 56 wet Mg ha Ϫ1 to a silt loam tional Research Council, 1989). Valk et al. (2000) dissoil, to provide 40 and 108 kg P ha Ϫ1 , respectively. The high P diet cussed the possibility of decreasing P in dairy cow diets manure was also applied at 21 wet Mg ha Ϫ1 (40 kg P ha Ϫ1) to provide without negatively affecting performance and reproduca P rate equivalent to the low P diet manure. Plots were subjected tive ability, and cited the work of Brodison et al. (1989) to simulated rainfall (75 mm h Ϫ1) just prior to corn (Zea mays L.) showing that dietary P could be lowered from 6.5 to planting in June and again after harvest in October 1999. Runoff 4.5 g P kg Ϫ1 without consistently influencing milk prowas analyzed for dissolved reactive P (DRP), bioavailable P (BAP), total P (TP), and sediment concentration. Natural runoff from the duction or reproductive performance. One study has same plots was collected from November 1999 through July 2000 and shown that a 40% decrease in dietary P lowered exanalyzed for DRP. At equivalent manure rates, DRP concentration in creted P by 23% (Morse et al., 1992), and another study June runoff from the high P diet manure was ≈10 times higher (2.84 vs. reported that reduced dietary P levels lowered P excre-0.30 mg L Ϫ1) than the low P diet manure, and four times higher (1.18 tion by 30% (Metcalf et al., 1996). vs. 0.30 mg L Ϫ1) when applied at equivalent P rates. Phosphorus Phosphorus excretion in manure depends largely on concentrations in October runoff and November to July natural runoff the level of P intake (Ternouth, 1989; Morse et al., were lower (0.02 to 1.69 mg L Ϫ1), but treatment effects were the same 1992; Metcalf et al., 1996; Khorasani et al., 1997). If P as for the June runoff. These results show that excessive addition of Dairy (Bos taurus) diet P effects on P losses in runoff in no-till corn (Zea mays L.) were determined in a field experi

Nutrient excretion and odorant production in manure from cattle fed corn wet distillers grains with solubles1,2

“…This could potentially increase P runoff when manure is applied to cropland. Ebeling et al (2002) reported that P concentration in dairy diets influenced the forms and amounts of P in manure. Greater P concentration in the diet resulted iii greater dissolved reactive P in manure.…”

“…Dietary P intake influences the amount of P excreted in livestock manure (Morse et al, 1992;Wu et al. 2000;Ebeling et al 2002) and affects the amount of land necessary for manure application and the potential for 2The supplement provided 8,800,000 IU of vitamin A: 880,000 IU of vitamin D; and 880 mg/kg of vitamin E per kg. 'Trace mineral premix contained 13% Ca, 12% Zn, 8% Mn, 10% Fe.…”

Land use scenarios for England and Wales: evaluation of management options to support ‘good ecological status’ in surface freshwaters

“…This soluble P is more liable to P loss in runoff in comparison to particulate P. One study in the USA suggested that the P loss of cows fed a standard high P diet was 10 times that of cows fed with a lowered level of P, which was still adequate for milk production and cow health (Dou et al. , 2002; Ebeling et al. , 2002).…”

Phosphorus in Organic Waste-Soil Systems

“…Recently, intensified livestock production has generated an increased production of organic residues and environmental regulations have been adopted for the application of manures in agriculture (Pandey, et al, 2001), as they are a diffuse source of pollution, with P in particular being directly associated with eutrophication in bodies of water (Haygarth and Jarvis, 1997;Gale et al, 2000;Withers et al, 2001;Ebeling et al, 2002;Hodgkinson et al, 2002;Ajiboye et al, 2004;He et al, 2004).…”