Effect of nitrogen fertilization on nitrate leaching in relation to grain yield response on loamy sand in Sweden |
| |
| Institution: | 1. Bioforsk – Norwegian Institute for Agricultural and Environmental Research, Frederik A. Dahls vei 20, 1430 Ås, Norway;2. Latvia University of Agriculture, Department of Environmental Engineering and Water Management, 19 Akademijas Street, LV-3001 Jelgava, Latvia;3. Swedish University of Agricultural Sciences, Department of Soil and Environment, Box 7014, SE-750 07 Uppsala, Sweden;4. Institute of Water Resources Engineering, Aleksandras Stulginskis University, Studentu 10, LT-53361 Kaunas, Lithuania;5. Department of Environmental Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia;1. National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Tai’an, 271018, China;2. State Key Laboratory of Nutrition Resources Integrated Utilization, Kingenta Ecological Engineering Group Co., Ltd. Linshu 276700, China;3. Soil and Fertilization Station of Shandong Province, Jinan, Shandong 250100, China;4. Shandong Agricultural University Fertilizer Science & Technology Co., Ltd., Taian 271000,China;1. Key Laboratory of Crop Ecophysiology and Farming System, Ministry of Agriculture, College of Agronomy, Shandong Agricultural University, Tai''an 271018, China;2. Key laboratory of Crop Growth Regulation, Hebei Province, College of Agronomy, Hebei Agricultural University, Baoding 071000, China;3. Polytechnic College, Hebei University of Science and Technology, Shijiazhuang, Hebei Province 050000, China;1. Key Laboratory of Agricultural Environment, Ministry of Agriculture/Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China;2. Ningxia Academy of Agriculture and Forestry Sciences, Ningxia 750000, P.R.China;1. Jiangsu Collaborative Innovation Center for Modern Crop Production/ National Engineering and Technology Center for Information Agriculture/Key Laboratory of Crop Physiology and Ecology in Southern China, Nanjing Agricultural University, Nanjing 210095, China;2. College of Agronomy, Anhui Agricultural University, Hefei 230036, China;3. Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China |
| |
| Abstract: | High rates of nitrogen (N) fertilizer may increase N leaching with drainage, especially when there is no further crop response. It is often discussed whether leaching is affected only at levels that no longer give an economic return, or whether reducing fertilization below the economic optimum could reduce leaching further. To study nitrate leaching with different fertilizer N rates (0–135 kg N ha?1) and grain yield responses, field experiments in spring oats were conducted in 2007, 2008 and 2009 on loamy sand in south-west Sweden. Nitrate leaching was determined from nitrate concentrations in soil water sampled with ceramic suction cups and measured discharge at a nearby measuring station. The results showed that nitrate leaching per kg grain produced had its minimum around the economic optimum, here defined as the fertilization level where each extra kg of fertilizer N resulted in a 10 kg increase in grain yield (85% DM). There were no statistically significant differences in leaching between treatments fertilized below this level. However, N leaching was significantly elevated in some of the treatments with higher fertilization rates and the increase in nitrate leaching from increased N fertilization could be described with an exponential function. According to this function, the increase was <0.04 kg kg?1 fertilizer N at and below the economic optimum. Above this fertilization level, the nitrate leaching response gradually increased as the yield response ceased and the increase amounted to 0.1 and 0.5 kg kg?1 when the economic optimum was exceeded by 35 and 100 kg N ha?1, respectively. The economic optimum fertilization level depends on the price relationship between grain and fertilizer, which in Sweden can vary between 5:1 and 15:1. In other words, precision fertilization that provides no more or no less than a 10 kg increase in grain yield per kg extra N fertilizer can be optimal for both crop profitability and the environment. To predict this level already at fertilization is a great challenge, and it could be argued that rates should be kept down further to ensure that they are not exceeded due to overestimation of the optimum rate. However, the development of precision agriculture with new tools for prediction may reduce this risk. |
| |
| Keywords: | Nitrate leaching Nitrogen fertilization Site-specific fertilization |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
