MANURE MANAGEMENT Effects of Broiler Litter on Soybean Production and Soil Nitrogen and Phosphorus Concentrations

potential for decreasing the amount of symbiotic N2 fixation. In contrast, Lory et al. (1992) reported that Although most of the N required by soybean [Glycine max (L.) topdressed manure addition to alfalfa (Medicago sativa L.) Merr.] is provided through the process of symbiotic N2 fixation, supplemental N using broiler litter may boost soybean grain yields. The efdid not affect N2 fixation. Gates and Muller (1979) refects of broiler litter and commercial fertilizer applications on soybean ported that application of fertilizer containing N, P, and yield, N and P uptake, and residual soil N and P were evaluated on S to soybean contributed to forming a stronger symbioa Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epitic mechanism and more active N2 fixation. Since broiler aquepts) at the Mississippi Agriculture and Forestry Experiment Stalitter contains N, P, and S (Sharpley et al., 1993), its tion in Starkville, MS. Treatments were broiler litter application at the applications to soybean could be beneficial. rates of 0, 40, 80, 160 kg plant available N (PAN) ha 1 and commercial A survey of university fertilizer recommendations infertilizer at equivalent to broiler litter PAN and P rates. Soybean grain dicated that no N or only small amounts (22 to 67 kg ha 1) yield and N and P uptake were quadratically increased with increasing of N were recommended for pure legume stand estabbroiler litter and commercial fertilizer application rates. Soybean grain lishment in most states (Hojjati et al., 1978). However, yield and N uptake from broiler litter applications were significantly greater than those from commercial fertilizer. Soybean grain yield other studies reported that fertilizer N application inwas not correlated to soybean P uptake but linearly increased with increased soybean yield and N utilization potential. For creasing N uptake. Application of broiler litter at rates 80 kg PAN example, Lamb et al. (1990) reported that soybean grain ha 1 were not effectively used by soybean as evidenced by declining yield increased with increasing N fertilizer rate; but its apparent recovery values, increasing residual soil NO3–N concentraresponse strongly related to soil NO3–N content. They tions, and increasing P accumulation at the top 15 cm of the soil proreported that when soil NO3–N content was greater than file. For every unit of N uptake, broiler litter treatment produced 3.4% 90 kg ha 1 at 0to 30-cm depth, there was no response to more grain yield than commercial fertilizer. The results of this study applied N. Brevedan et al. (1978) reported a 22 to 32% indicate that application of broiler litter to soybean may be beneficial. soybean yield increase with an application of 168 kg N ha 1 to soybean at bloom initiation. Varvel and Peterson (1992) reported that soybean is a net N sink, removing S is a major crop in Mississippi. Production approximately 150 to 200 kg N ha 1 yr 1 at grain yield of this crop significantly contributes to the state’s levels of 2.5 to 3.4 Mg ha 1, which ultimately reduces the economy. Because of nutritional and industrial properamount of soil N available for leaching. Shibles (1998) ties of soybean products, there is substantial incentive to stated that total annual N uptake for high-yielding soyincrease soybean yield (Helms and Watt, 1991). Commerbean can be as high as 385 kg ha 1. cial broiler production in Mississippi generates 450 000 Mg Soybean not only requires considerable amounts of yr 1 of broiler litter (manure and bedding material), which N to produce a crop (Schmidt et al., 2001), but it requires is applied to nearby pastures or cropland (Mississippi State a constant supply of available P to maintain rapid growth Univ., 1998). Continued broiler litter application increases and development (Hariston et al., 1990). Phosphorus the potential for enrichment of NO3–N in groundwater fertilization has been shown to increase the number of and P in surface water (Edwards et al., 1992; Sharpley et nodules and their weight as well as the number of pods al., 1996). To minimize these risks, producers must obtain per plant (Jones et al., 1977). Since P requirement by additional land area to dilute the litter using N-demanding crops is in much lower quantities than N, Sharpley et al. crops and/or use alternative crops to receive broiler litter. (1993) reported that 72% of the applied P from broiler Several studies have been conducted on broiler litter litter retained in the soil profile. Using an alternative application on corn (Zea mays L.) (Brown et al., 1994; crop to remove a large portion of soil P could be advanWood et al., 1999) and cotton (Gossypium hirsutum L.) tageous. Does added N in the broiler litter boost soy(Burmster et al., 1991; Glover and Vories, 1998; Malik bean grain yield enough to allow for the removal of a and Reddy, 1999). However, application of animal malarge portion of the P in broiler litter? Knowing this innure to soybean has been discouraged because of the formation could help broiler producers in applying the litter locally before exceeding the soil P-holding capacity. USDA-ARS, Waste Manage. and Forage Res. Unit, 810 Hwy. 12 East, Soybean has a relatively high requirement for P, K, Mississippi State, MS 39762. Contribution of the Mississippi Agric. and Forestry Exp. Stn. Journal paper no. J10318. Received 1 July 2004. *Corresponding author ([email protected]). Abbreviations: ANR, apparent nitrogen recovery; APR, apparent phosphorus recovery; DM, dry matter; ICP, inductively coupled plasma; Published in Agron. J. 97:314–321 (2005). © American Society of Agronomy NUE, nitrogen utilization efficiency; PAN, plant available nitrogen; PUE, phosphorus utilization efficiency. 677 S. Segoe Rd., Madison, WI 53711 USA