Effect of Liquid Cattle Manure on Corn Yield, Composition, and Soil Properties Anastasios S. Lithourgidis, Theodora Matsi,* Nikolaos Barbayiannis, and Christos A. Dordas ABSTRACT The effects of liquid dairy cattle (Bos taurus) manure on corn (Zea mays L.) yield and composition were studied in a 4-yr field experiment conducted under a Mediterranean environment. In addi- tion, long-term impact of (8-yr) manure application on soil-available NO 3 –N, P, and K; organic C; Kjeldahl N; and salinity was investigated. Four treatments were established in plots, previously used for a simi- lar 4-yr experiment with winter wheat (Triticum aestivum L.). Treat- ments were: (i) application of 80 Mg manure ha 21 yr 21 ; (ii) single application of the equivalent N–P as inorganic fertilization (260 kg N ha 21 yr 21 and 57 kg P ha 21 yr 21 ); (iii) identical to (ii), but with split N application; and (iv) no fertilization. Corn grain and silage yields, N–P–K plant concentration, and uptake were significantly increased by manure or inorganic fertilizer addition relative to the control. Dur- ing the 4-yr corn experiment, the amounts of available NO 3 –N in the soil profile of manure plots were higher than control, but similar to both inorganic fertilization treatments. Manure application main- tained the amounts of soil available NO 3 –N, P, and K at desirable levels, almost each year of the total 8-yr application. However, soil organic C and Kjeldahl N remained unchanged. At the end of the experiment, soil salinity below 30 cm was significantly increased on manure or inorganic fertilizer addition relative to the control, but at levels acceptable for most crops. In conclusion, soil application of liquid dairy cattle manure at a rate equivalent to the recommended inorganic fertilization can enhance corn yield and composition and main- tain soil fertility at desirable levels, without increasing soil salinity at unacceptable levels. A PPLICATION of cattle manure (solid or liquid) to soil can improve soil chemical and physical properties (Sutton et al., 1986; Randall et al., 2000; Eghball, 2002; Butler and Muir, 2006), and consequently, increase crop yields, plant nutrient concentration, uptake (Evans et al., 1977; Beauchamp, 1983; Griffin et al., 2002; Butler and Muir, 2006). The beneficial effect of cattle manure on crop yield and growth is similar or lower than inorganic fertil- izers and this is dependent on the manure N applied (Beauchamp, 1986; Sutton et al., 1986; Randall et al., 2000; Griffin et al., 2002). In general, crop availability of N in manure is lower than N from inorganic fertilizers, because of the slow release of organically bound N and the volatilization of NH 3 from surface-applied manure (Beauchamp 1983; Jokela, 1992). Compensation for this reduced availability is generally achieved through in- creased manure N application rates, in comparison to the N fertilizers (Evans et al., 1977; Beauchamp, 1986; Sutton et al., 1986; Zebarth et al., 1996). However, simi- lar crop yield and plant uptake of macronutrients were obtained after soil application of liquid cattle manure at rates equivalent to the recommended inorganic fer- tilization (Beauchamp, 1986; Randall et al., 2000; Matsi et al., 2003). Although both solid and liquid dairy manures are valuable sources of nutrients for crop production (Sutton et al., 1986), liquid manure was found to be better than solid in promoting plant growth (Beauchamp, 1986; Zhang et al., 2006). This is probably due to the higher quantity of immediately available N in liquid than solid manure (Sutton et al., 1986). Beauchamp (1986) reported that average NH 4 –N/total N ratios were 0.53 for liquid dairy cattle manure and 0.09 for solid beef cattle manure. To preserve the ammoniacal-N from applied manure, espe- cially in the case of liquid manure, injection or incor- poration into the soil immediately after application is recommended (Beauchamp, 1983; Randall et al., 2000). The beneficial effect of cattle manure (solid or liquid) on soil is connected to the enhancement of soil fertility and the improvement of soil structure through the addi- tion of organic matter (Sutton et al., 1986; Randall et al., 2000; Eghball, 2002; Butler and Muir, 2006). However, long-term heavy application rates of cattle manure can have adverse effects on plants (Chang et al., 1991, 1993) and can increase soil salinity and NO 3 –N leaching, espe- cially in the case of liquid manure (Evans et al., 1977; Chang and Entz, 1996; Vellidis et al., 1996). Crop nutrition and soil properties are two important factors that must be taken into consideration, for the proper agronomic use of cattle manure as a fertilizer. In addition, any effect of manure application on crops and soil properties should be evaluated in any particular environment. The objectives of this study were to eval- uate the effects of liquid dairy cattle manure on corn grain and silage yields, and macronutrient concentra- tion, and uptake, in comparison to those of commercial fertilizers (both applied at equivalent N recommended rates), by means of a field experiment that was con- ducted under a Mediterranean environment. Since the field where the corn experiment was established had a manure application history, long-term (8-yr) effects of manure on soil-available NO 3 –N, P, and K; organic C; Kjeldahl N; and salinity were also studied. MATERIALS AND METHODS Soil and Manure Matsi et al. (2003) described the site, manure, and soil used for the field experiment. Briefly, the experimental field was located at the Farm of the Aristotle University of Thessaloniki. The soil was classified as Typic Xerorthent (USDA-NRCS,1996) and was a calcareous loam, with average pH values (1:2 soil/water ratio) 8.3 6 0.1; CaCO 3 content 71 6 11 g kg 21 ; and sand, silt, A.S. Lithourgidis, University Farm, Aristotle Univ. of Thessaloniki, Thermi 57001, Greece; T. Matsi and N. Barbayiannis, Soil Science Lab., Faculty of Agriculture, Aristotle Univ. of Thessaloniki, Thessa- loniki 54124, Greece; and C.A. Dordas, Lab. of Agronomy, Faculty of Agriculture, Aristotle Univ. of Thessaloniki, Thessaloniki 54124, Greece. Received 23 Nov. 2006. *Corresponding author (thmatsi@agro.auth.gr). Published in Agron. J. 99:1041–1047 (2007). Waste Management doi:10.2134/agronj2006.0332 ª American Society of Agronomy 677 S. Segoe Rd., Madison, WI 53711 USA Reproduced from Agronomy Journal. Published by American Society of Agronomy. All copyrights reserved. 1041 Published online June 5, 2007