INTRODUCTIONPoultry litter (PL) is a combination of poultry manure and bedding materials (e.g. pine shavings, saw dust, or peanut hulls). It also varies in nutrient concentration depending on the type and amount of bedding material used. Poultry litter is an organic source of N, P, & K, and other micronutrients, if properly handled can be a valuable source of essential plant nutrients and as an amendment can improve soil quality. Poultry litter also contains small amounts of micronutrients that may be beneficial to crops. In recent years, due to a shift in animal operations, environmental and economic issues, the utilization and disposal of animal manures and litters have become a focal point of certain conservation efforts (USDA& USEPA,1999). Application of poultry litter to agricultural lands at recommended rates can be an environmentally sound method for recycling essential nutrients. Soil quality based on application rates, can be assessed by looking at enzyme activities and microbial diversity. Results have shown that agricultural management practices affect enzymatic activities (Dick,1994). Changes in the soil microbial communities and enzyme activities are a major concern because it impacts environmental quality. Therefore, enzyme analysis may be a possible indicator of biological changes in soils of various management practices.

Figure 1A and B. DGGE profiles of cropped and un-cropped soils with PL for rates of 0, 2, and 4 tons/acre over time.

Evaluation of Rates of Poultry Litter Application On Selected Phosphatase Enzyme Activity and Microbial Diversity

King, Shantel., R.O. Ankumah, L. Githinji, E.G. Rhoden, J.R. Bartlett, and V.A. Khan. Department of Agricultural and Environmental Sciences, Tuskegee University, Tuskegee, AL 36088.

SUMMARY AND CONCLUSIONS• Preliminary DGGE data suggested that PL application may influence soils microbial community composition and diversity over time.•Rates of application of PL affected the activities of the phosphomonestrases. Acosta-Martinez, (2006) indicated that long-term and/or high rate application of poultry litter or manure can produce elevated soil test phosphorus (P) levels that in turn can have a direct effect on phosphatase enzyme activities. Addition of farmyard manure (FYM) has been observed to result in increases soil enzyme activities over soils that have not received any organic or inorganic amendments ( Dick, 1992). .

REFERENCES• Acosta-Martinez, V., Daren Harmel, R. (2006). JEQ : 35: 1309-1318• Eivazi,F., Tabatabai, M.A., (1977). Phosphatases in Soils. Soil Biol & Biochem . 9:167-172.•USDA & USEPA,(1999)-Unified National Strategy for Animal Feeding Operations•Ibekwe et.al. (2003).App.Envrn.Micro: 69: 5060-5069.•Dick, R.P. (1992). Agr Eco & Environ.: 40: 25-36.•Dick, R.P. (1994) Soil Science Society of America, Madison, pp. 107–124. •Burns G.R. (1982). Soil. Biol. Biochem.: 14: 423-427.

ABSTRACTPoultry litter (PL) is an abundant by-product of the poultry industry in the south-eastern states of the U.S. Used as a valuable source of essential plant nutrients, it can help to improve soil quality and function. Poultry litter also contains a considerable amount of organic matter, which has a known positive effect on soil structure, and microbial activity. In this study, a two factor experiment was conducted to look at the effects of different application rates of PL (0, 2, 4 tons litter/acre) on soil microbial communities and enzyme activities under cropped and un-cropped systems. Preliminary DGGE data suggest a difference in the microbial population based on poultry litter application rates over time. Significant differences was also observed on the activities of both phosphomonoesterase and phosphodiesterase in response to PL application rates. Increased application rates generally resulted in increased activity for the phosphomoesterses. This may be attributed partially to increase in organic matter. Changes in enzyme activities were also observed during the growing season, these changes may affect the management of PL applied as an amendment and nutrient source. Crop enzymes were different for both cropped and un-cropped systems as well as over time. Further studies will be done to determine statistical differences within DGGE experimentation.

Table 1. Activity of phospohodiesterase, phosphomonoesterase (alkaline), and phosphomonoesterase (acid) enzymes in soils where poultry litter was applied at 0, 2 and 4 tons/acre

Enzyme Analysis

Sampling Time 5-7-08 Sample Time 6-25-08 Sample Time 7-28-08 Sample Time 10-15-08

Hind III Marker

Hind III Marker

Figure 1A Figure 1B

MATERIALS & METHODSSite Preparation and PL Application: Experimental site was located on demonstration plot on an Okolona silty clay loam (fine, smectitic, thermic, oxyaquic hapludert in Sundown Ranch in Uniontown, AL. • Poultry litter (PL) was applied at 0-, 2- and 4-tons/acre broadcasting was done in the Fall of 2007 and was subsequently incorporated into the soil by tilling.•Cropped plots were planted with a winter crop of wheat followed by sorghum x sudan grass post PL application. •A buffer zone was created between treatment plotsEnzyme Assay: Determination of the phosphomonesterases and diesterases were performed using methods described by Tabatabai and Bremer respectively. Microbial Diversity Analysis: Microbial diversity was determined using whole DNA extraction (Mobio Kit), followed by PCR and DGGE according to procedure as described by Ibekwe et al. (2003).Statistical Design: Split-split plot with random sampling. Analysis done using SAS.

Cropped

Application rates (tons/acre)

0 2 4

Application rates (tons/acre)

0 2 4

Application rates (tons/acre)

0 2 4

Days after application Phospohodiesterase

(ug PNP hr-1g soil-1 )

Phosphomonoesterase (alkaline)

(ug PNP hr-1g soil-1 )

Phosphomonoesterase (acid)

(ug PNP hr-1g soil-1 )

203 DAP (W) 1.02 0.63 1.61 0.04 .28 1.24 4.02 4.55 8.11

253 DAP (W) 1.23 1.98 1.21 1.99 3.00 5.88 6.16 9.73 8.56

297 DAP (W) 1.84 1.54 1.41 2.68 1.68 2.22 6.67 8.97 6.71

324 DAP (W) 0.78 0.77 0.45 3.00 4.97 3.68 3.81 3.85 7.33

Non Cropped

203 DAP (W) 1.08 1.18 1.60 0.28 2.15 0.98 4.11 5.13 3.91

253 DAP (W) 0.39 0.67 1.24 4.96 0.33 3.03 10.49 8.11 5.82

297 DAP (W) 0.89 1.59 1.45 0.92 3.06 2.68 7.84 8.96 6.11

324 DAP (W) 1.36 1.49 1.81 1.68 1.11 4.42 5.47 8.67 3.01

Significance of F test from

ANOVA

Sampling Periods (S) NS ** **

Rates (R) * * **

Cropped vs Non Cropped NS NS NS

S X R * NS **

S X Cropped & Non cropped ** * NS

RX Cropped & Non cropped ** ** **

3 Way Interactions NS NS NS

**, *, and NS significant at 1%, %* and not significant, respectively

OBJECTIVES•To determine the enzyme activities of phosphomonoesterases (acid and alkaline) and phosphodiesterases when poultry litter was applied at 0,2, and 4 tons/acre, in a field that was planted with cool and warm season annuals, winter wheat, followed by sorghum x sudan grass.

•To assess the microbial diversity of the soils where poultry litter was applied at 0, 2, and 4 tons/acre, using PCR-DGGE.

•To determine if soil enzyme activities and microbial communities are affected by PL application.

0, 2, 4 tons cropped 0,2,4 tons cropped 0,2,4 tons cropped0,2,4 tons cropped

RESULTS/DISCUSSION1. Significant changes in community composition and intensity (numbers) were observed

as the growing season progressed (Figure 1 (A & B), for example, community compositions observed at the end of the winter wheat growing season were much different than those found at the end of beginning of planting.

2. Generally the community profiles did not change as a result of higher application rates but population numbers, i.e. intensity of bands tended to increase with application rates.

3. Application rates had significant effect on the activities of all enzymes activities evaluated (Table 1, Figs 1, 2, 3). Generally Acid Phosphatase (AP) activities increased with increasing application rates on the cropped plots (Table 1 and Fig 1) but increased initially and then decreased in the un-cropped plots during the third sampling period.

4. Significant differences were also observed with time on the activities of the monoesterases in contrast to the diesterases (Table 1, Figs 1, 2, and 3).

5. Significant interactions between rates and cropping practices on all enzymes studied was also observed (Table 1).

ACKNOWLEDGEMENTSPROJECT WAS FUNDED PARTIALLY BY USDA AND GEORGE WASHINGTON

CARVER AGRICULTURAL EXPERIMENT STATION