The development of soil structure, characterized by fractal geometry, improves plant-rooting development and improves water retention, drainage, and air permeability. However, due to this function to increase fertility, excessive intensive cultivation contributes to environmental load. The amount of nitrogen in rivers in agricultural watersheds is significantly related to the surplus nitrogen in the watershed, and since the nitrogen load increases with the increase in the crop field proportion, it is important to manage the surplus nitrogen in crop field. On the other hand, since wetlands have reduced the surplus nitrogen in the watershed through the purification of nitrate nitrogen in river water, it is possible to reduce the environmental load by optimizing land use. Replacing a part of chemical fertilizer application with organic fertilizer application increased soil organic carbon and contribute to the prevention of global warming without reducing crop yield. In Japanese grasslands, the annual application of 3.5tC ha-1 of compost offset greenhouse gas emissions. Furthermore, the continuous use of compost mitigated soil acidification and suppressed N2O emissions. I investigated the impact of greenhouse gas emissions associated with agricultural development on permafrost and peat soils, which are the world's soil carbon reservoirs. In eastern Siberia, disturbance of taiga forests caused permafrost melting and increased CH4 emissions. Drainage of peatland reduced CH4 emissions, but increased CO2 and N2O emissions due to peat decomposition, which was exacerbated by the application of chemical fertilizers. It was essential to keep the groundwater level at -20 cm to -40 cm to suppress greenhouse gas emissions. Environmental load means that soil health is being damaged. It is necessary to develop agricultural techniques to maintain and restore soil health. In particular, organic matter management can restore soil structure by increasing soil organic matter, and also reduce the amount of chemical fertilizer used, which has the effect of reducing greenhouse gas emissions. On the other hand, excessive continuous use of organic fertilizer can increase nitrogen loads. It has been pointed out that the relationship between cover crops and tillage is also important for organic matter management. Regional research is increasingly essential.

来源平台：SOIL SCIENCE AND PLANT NUTRITION