Abstract:

Forage yield and quality are the basis of reasonable livestock carrying capacity, which is of great significance for livestock production. Based on the field survey data and spatial information of natural alpine meadows in Chatan wetland of Dangqu basin, this paper analyzes the spatial distribution of forage nutrient quality indexes and explores their spatial heterogeneity under the change of soil types by combining with the laboratory test. The results showed that: crude protein content decreased and then increased from south to north in Cambisols pasture, with the minimum value occurring at about 32.90°N; neutral detergent fiber content increased and then decreased from south to north in highly active lyophilized soil pasture, with the maximum value occurring at about 32.85°N; and acidic detergent fiber content increased and then decreased from south to north in Cambisols pasture, with the maximum value occurring at about 32.90°N. Between 4 650 and 4 850 m, the crude protein content of Cambisols pasture had an extremely significant positive correlation with elevation (R²=0.61, p<0.01); the acid detergent fiber content of Cambisols pasture had a significant negative correlation with elevation (R²=0.43, p<0.05). High-quality alpine pastures are mainly distributed in a U-shape from south to north with 32.90°N as the lowest point. Forage nutritional quality was positively correlated with elevation between 4 650 and 4 850 m. The research results can deepen the knowledge of the nutritional quality of the alpine grassland in the Yangtze River source, improve the rational utilization of the alpine grassland in the Yangtze River source, and provide auxiliary suggestions for the intensive, large-scale, ecological and digital development of the animal husbandry industry.

Key words: herbage nutrition, alpine meadows, crude protein, neutral detergent fiber, acid detergent fiber, Chatan wetland