밭작물 연작재배에 따른 비료 시용이 질소 동태에 미치는 영향

Abstract

The concept of nutrient balance is a key approach for managing optimal nutrient levels and sustaining soil productivity while reducing environmental loading in agroecosystems. Fertilizer applications that do not account for crop nutrient uptake often lead to nutrient imbalances and nutrient losses from arable soils during cultivation. Nitrogen is essential for crop growth and productivity, while its dynamic behavior—through leaching and gaseous emissions—can substantially affect both aquatic and atmospheric environments. Therefore, managing the nitrogen balance in soil is crucial for enhancing agricultural productivity and ensuring environmental sustainability. This study evaluated the effects of various fertilizer application practices on nitrogen dynamics in upland cropping systems to develop optimal fertilization strategies that improve crop productivity while minimizing environmental nitrogen loading. The combined application of chemical fertilizers and compost proved more effective in enhancing crop productivity than either fertilizer used alone. Ammonia volatilization was significantly influenced by nitrogen- phosphorus-potassium (NPK) fertilization; however, mixed fertilization reduced ammonia emissions by 11-40%. Denitrification rates under mixed fertilization were also approximately 2.5-3.0 times higher than those under NPK-only treatments. In contrast, compost-only application reduced ammonia volatilization and denitrification by 91.4-98.0% and 38.0- 48.0%, respectively, compared with those under NPK, indicating its strong potential for mitigating atmospheric nitrogen emissions. Fertilizer application during upland crop cultivation tended to increase nitrogen content in plant tissues at harvest. Notably, nitrogen loss to water systems under the maize-Chinese cabbage double-cropping system was most strongly affected by compost application. Overall, the findings suggest that optimal fertilization strategies for sustaining upland crop production and managing environmental nitrogen loading include adjusting compost application rates or supplementing compost with appropriate amounts of chemical fertilizers. In conclusion, alternative nitrogen application strategies may be necessary for maintaining an optimal nitrogen balance for sustainable agricultural productivity and reduced environmental loading in arable soils.