Principle, technique and application of grassland improvement

Global grassland degradation poses a significant threat to the sustainable socio-economic development of humanity. However, this trend can be effectively mitigated through scientifically sound and rational grassland improvement measures. Grassland improvement utilizes the theory of pratacultural science, especially the theory of the four production levels of grassland agro-ecosystems, to solve the fundamental contradiction between the seasonal imbalance of grassland supply and livestock demand through integrates a number of improvement techniques. In order to clarify the implementation subject, target and specific measures of grassland improvement and to improve the science and efficiency of management and conservation, we classify grassland improvement into four types according to the target, scale and attributes of grassland and livestock feedback mechanism. Grassland improvement is generally based on one key technology, with multiple technologies used in combination, and synergy or superposition formed between integrated technologies. Individual technologies mainly include enclosure of livestock, reclamation, ripping, overseeding, fertilization, irrigation, fire work and grazing management, while integrated technologies are a combination of two or more technologies. Compared to individual techniques, the integrated approach resulted in a significant enhancement of community aboveground biomass by 17-38% and species richness by 2-24%, with no discernible impact on soil properties in the short term. The establishment of a standardized grazing-based improvement process while adhering to the principles of improvement after utilization, comprehensiveness, standardization and scale consistence to improve the structure and function of grassland ecosystems. Strategy of grassland improvement reassesses "nuisance" species as "citizens" of the ecosystem because they supply productivity, species biodiversity and other ecosystem services, and they can be managed at an unharmful and even benefitful level through identifying the ecological and economic thresholds.