Presentation on theme: "Enrichment of Trace Metals in an Ultisol Impacted by Applied Broiler Litter Irenus A. Tazisong Zachary Senwo Robert Taylor."— Presentation transcript:
Enrichment of Trace Metals in an Ultisol Impacted by Applied Broiler Litter Irenus A. Tazisong Zachary Senwo Robert Taylor
Introduction In the United States, the broiler industry is a major source of agricultural income. The livestock industry produces 50% of the profits of U.S. agriculture. It is also presumably the most rapidly expanding livestock generating system in the world. In the US, Alabama is ranked third in terms of broiler chicken (Gallus gallus) production. In 1999, Alabama accounted for over 970 million birds.
Introduction cont. Generated about 1.5 million Mg of broiler litter. Broiler litter generated is composed of birds droppings, feathers, bedding materials etc. Broiler litter is highly rich in macro and micro nutrients as well as pathogens. A critical problem facing the burgeoning industry in the southeastern US is the vast amount of wastes generated yearly and problem of safe disposal.
Introduction cont. Broiler waste are mainly applied to agricultural lands as organic fertilizer. Inexpensive source of macro and micronutrients. Enhance soil productivity and quality e.g. improve aggregate formation and stability. Repeated land application results to detrimental buildup of elements.
Introduction cont. Buildup of elements beyond required concentration for plant growth may result to:- 1) leaching into ground water 2) elements washed into surface water 3)elements being toxic to plants
OBJECTIVES a) evaluate enrichment trends of 5 plant nutrients(Cu, Fe, Mn, Ni, Zn) and two potential pollutants (Pb, Cd). b) To assess the degree of the enriched trace metals in this soils.
Materials and Method Soil samples collected in triplicate from 0-20cm, 20-40cm, and 40-60cm depth. Soil samples collected on a 3-8% slope in the Sand Mountain region of north Alabama. Soils has been managed for pasture and received annual broiler litter applications for 0, 5, 10, 15, and 20 years. Rate of application has 0, 2.27, 2.27, 3.63, and 1.36 Mg ha -1 yr -1.
Materials and Method cont. Soil samples were air-dried, ground to pass a 2-mm sieve and stored at room temperature. Soils samples were characterized for :- -pH -Electrical conductivity (EC) -Total C, N and S -NO 3 -N and NH 4 -N -Ca, K, Mg and Na (Mehlich 1984).
Materials and Method cont. Trace metal and extractable Al were extracted with Diethylenetriamine pentaacetic acid (DTPA) (Lindsay and Norvell 1978). Trend analysis was determined using polynomial contrast analysis. Enrichment factor was calculated using the formula:- EF = (Z/Al) amended /(Z/Al) control Where: EF = enrichment factor Z = trace metal concentration (mg kg -1 ) Al = total Al concentration (g kg -1 ) Statistical analysis were performed using Statistical Analysis System (SAS) 2005 version 9.1.
Conclusion Results obtained from this study revealed that continuous applying broiler litter to land will lead to: a) metal build up in soil leading to plant toxicity b) alteration of soil physiochemical properties. c) leaching and washing of elements into ground and surface water.
Conclusion cont. It can be deduced from trend analysis that metal accumulation in soils from long-term applied broiler litter did not follow a linear trend. Applying broiler litter to agricultural land as a source of nutrients and waste disposal is not a risk-free management practice.