Track 2-3-2: Impact of Grass and Legumes on Livestock Production, Soil Conservation and the Nitrogen Cycle in Grassland and Forage Ecosystems
Description
Liquid manure is an important source of nutrients on many modern dairy farms. Nitrogen (N) use efficiency of slurry is usually less than chemical fertilizer, but the difference is less when tested in trials lasting at least 7 years than in short term trials (Schröder et al., 2007). The efficiency of slurry manure N can be improved by minimizing loss of ammonia after application using low emission applicators. In grass stands where injection is impractical, mitigation methods often involve spreading the slurry in narrow bands directly on the soil surface. Losses of N as ammonia, nitrous oxide and leaching have been measured in many trials, but few have measured all three, while other N pathways such as runoff, denitrification to N2, and immobilization into stable soil N often go unmeasured. An alternative approach to determine total losses is to calculate the N balance (losses=inputs-outputs), but long term trials are needed to allow recovery of legacy N from manure and to account for soil N changes. This 7-year study was set up on a long term study with seven previous years of nutrient applications, where the slurry was applied with a low-emission trailing shoe applicator. The objective of the study was to assess crop yield, N use efficiency and N recovery, and to infer N losses by three important forage grasses: perennial ryegrass (PRG, Lolium perenne L.), orchardgrass (OG, Dactylis glomerata L.) and tall fescue (TF, Festuca arundinacea Schreb.).
Included in
Yield and N Recovery by Grass Species in Response to Long Term Applications of Manure and Mineral Fertilizer in a Cool Maritime Climate
Liquid manure is an important source of nutrients on many modern dairy farms. Nitrogen (N) use efficiency of slurry is usually less than chemical fertilizer, but the difference is less when tested in trials lasting at least 7 years than in short term trials (Schröder et al., 2007). The efficiency of slurry manure N can be improved by minimizing loss of ammonia after application using low emission applicators. In grass stands where injection is impractical, mitigation methods often involve spreading the slurry in narrow bands directly on the soil surface. Losses of N as ammonia, nitrous oxide and leaching have been measured in many trials, but few have measured all three, while other N pathways such as runoff, denitrification to N2, and immobilization into stable soil N often go unmeasured. An alternative approach to determine total losses is to calculate the N balance (losses=inputs-outputs), but long term trials are needed to allow recovery of legacy N from manure and to account for soil N changes. This 7-year study was set up on a long term study with seven previous years of nutrient applications, where the slurry was applied with a low-emission trailing shoe applicator. The objective of the study was to assess crop yield, N use efficiency and N recovery, and to infer N losses by three important forage grasses: perennial ryegrass (PRG, Lolium perenne L.), orchardgrass (OG, Dactylis glomerata L.) and tall fescue (TF, Festuca arundinacea Schreb.).
