Abstract:
As a crucial ecological security barrier and an important region for characteristic agriculture and animal husbandry in China, the Tibet Plateau faces challenges including an imbalance between forage supply and livestock demand, relatively low farmland quality, and inefficient utilization of agricultural waste resources. To promote the coordinated development of ecological protection and agriculture production, this study evaluated the resource availability and recycling potential of crop straw and livestock manure in Tibet. Taking 2023 as the baseline year, the production amounts, spatial distribution, and nutrient characteristics of major crop straw recourses (including highland barley, wheat, and rapeseed straw.) and livestock manure (including cattle, sheep, and pig manure.) were systematically assessed based on the Technical Specification for Investigating and Evaluating Crop Straw Resources (NY/T
1701-2009) and the Manual of Pollution Production and Discharge Coefficients for Livestock and Poultry Manure. The straw-to-grain ratio, land carrying capacity, and nutrient equivalent methods were applied. In addition, field surveys and literature analysis were used to identify the current utilization patterns, problems, and recycling potential of straw and manure as fertilizer, feed, and energy resources. The results showed that: 1) In 2023, the theoretical amount of straw resources in Tibet reached
1.7649 million tons, with highland barley straw accounted for 74.56%. Straw resources mainly concentrated in Shigatse City. The total amount of livestock manure reached
50.4113 million tons, dominated by cattle manure, with the highest production concentrated in Nagqu City and Qamdo City. 2) The comprehensive utilization rates of straw and livestock manure reached approximately 97.09% and more than 92%, respectively. However, straw utilization was mainly based on direct feeding, while manure was primarily managed through dry manure combustion and simple composting, resulting in relatively low nutrient recovery efficiency and substantial losses of nitrogen and phosphorus. 3) The alpine, low-pressure, and hypoxic environment of the plateau restricts waste decomposition and limits the applicability of conventional recycling technologies. Moreover, the connection between crop production and livestock farming remains weak, preventing the formation of an effective planting-breeding-waste recycling loop. (4) Differentiated recycling models should be developed according to regional resource endowments and climatic conditions, including planting-breeding-feeding cycles in southeastern Tibet, integrated energy-fertilizer utilization in central Tibet, and forage-livestock-manure cycles in northwestern Tibet. Regional collaborative utilization networks should be established by improving waste collection, storage, and transportation and developing low-temperature composting, feed processing, and distributed energy conversion technologies. These measures can improve nutrient recycling, alleviate forage shortages, reduce agricultural non-point source pollution, and facilitate the green and low-carbon development of agriculture and animal husbandry in the Tibet Plateau.