|Costa, M K|
|Alves, B J|
Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2012
Publication Date: 10/8/2012
Citation: Shigaki, F., Costa, M.L., Kleinman, P.J., Alves, B.R. 2012. Ammonia volatilization, corn and forage yield as a function of poultry litter application methods. II International Symposium on Integrated Crop-livestock Systems. p 1. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: Introduction Manure management has emerged as a significant agronomic and environmental concern in Brazil. Most manure is broadcast to the soil surface where it remains vulnerable to environmental processes that significantly lower the manure’s nitrogen fertilizer value and negatively impact air quality. In general, incorporation of manure into the soil has proven to be an effective technique to decrease ammonia emissions. Because most land in Brazil is in no-till management, options are needed to incorporate manure that do not rely upon tillage. While low-disturbance injection systems have long been available for liquid manure, only recently have similar systems been developed for dry manure. In the U.S., several generations of dry manure applicators have been developed by the US Department of Agriculture (USDA) with the purpose of applying poultry litter into row crop and grassland soils with the minimal disturbance. Through a collaborative research project between the Federal University of Maranhão (Brazil) and the USDA we sought to evaluate the potential for using subsurface application technology in Brazil. Subsurface poultry litter application was compared with surface application of litter and tillage incorporation of litter. We report the effects of this subsurface application of poultry litter on ammonia (NH**3) volatilization, crop and forage yields. Materials and methods Two experiments were conducted in different locations of Brazil. One experiment was established in November, 2009 in the city of Rio Verde, state of Goiás, located in the Center-west region of Brazil (Experimental Area 1); and the second experiment was established in March, 2010 in the city of Chapadinha, state of Maranhão, located in the Northeast region of Brazil (Experimental Area 2). Four treatments were evaluated in both experiments: (1) control-without poultry litter application, (2) surface application, (3) incorporated with tillage and (4) subsurface applied. In Experimental Area 1, hybrid corn (Zea mays L.) AG8021 was planted twenty days after poultry litter application. In Experimental area 2, the perennial grass Brachiaria brizantha cv. Piatã was established three days after poultry litter application. Volatilized NH**3 was captured by a semi-opened free static chamber as described and calibrated by Araújo et al. (2009). The chambers were installed in each plot just after poultry litter application, and samples were collected by replacing the foam sorption 24, 48, 144, 196 and 296 hours after poultry litter application for both site areas. Analysis of variance (ANOVA), Tukey’s mean separation and Student’s t-test were performed in Minitab v. 15 (Minitab Inc., 2001) for all data obtained. Results and discussion Experimental Area 1: Rio Verde, Goiás - Brazil : At the time of poultry litter application the soil was moist due to 55 mm rainfall three days before litter application, and the temperature ranged between 26 and 28 deg C (Figure 1). For the first 24 hours N-NH**3 emissions were not significant, and the average emission across all treatments was 1.6 kg N-NH**3 ha**-1. According to Hargrove (1998), 10 to 20 mm of precipitation is enough to minimize ammonia emissions for most of soils. This effect is due to the lower gas diffusion in moist soil. In the following days there was no additional rainfall, and air temperature increased to 34 deg C. The greatest NH**3 losses (97 and 124 Kg N-NH**3 respectively) were observed at 48 and 144 hrs after litter application. During this period, as the temperature increased, the drying soil increased the potential for NH**3 emissions After 144 hours of poultry litter application, Twenty-nine mm rainfall fell 144 hrs after litter application, at which point the temperature decreased to 19 deg C. This weather change corresponded with a decrease in ammonia emission rates to 31 kg N- NH**3 ha**-1