Causes of fertility decline and countermeasures for protection and utilization of upland black soil—an analysis from the perspective of nutrient resources high-efficient utilization

Black soil has the characteristics of good texture, high fertility and well arability, which contributes one quarter of the total grain yield in China. However, the fertility decline of upland black soil due to long-term intensive utilization is being paid more attention. We analyzed the main characteristics of fertility decline of upland black soils, emphatically explored the causes of fertility decline of upland black soil and put forward countermeasures for the protection and utilization of upland black soil from the perspective of nutrient resources high-efficient utilization. The main characteristics of fertility decline of upland black soil are soil organic matter decline, soil structure deterioration, soil nutrient imbalance, soil serious acidification and thinning of black soil layer. From the perspective of nutrient resources high-efficient utilization, the main causes of fertility decline of upland black soil are the long-term straw removal out of soil, insufficient inputs of organic materials, and the unreasonable application of chemical fertilizers such as unsuitable nutrient types, rate, and time under the intensive utilization. Therefore, the integrated management countermeasures are sponsored, including the nutrients precision management based on the current nutrients high-efficient utilization technology, conservation tillage based on straw returned to soil as the primary practices, and integration system of soil-crop-animal production based on the nutrient recycling utilization of organic materials. In conclusion, the nutrients high-efficient recycling utilization is one of the important practices for the protection and utilization of upland black soil.