藏北高原土壤和植物硫含量及其与牦牛硫营养需求的关系

Relationships between sulphur status of soils and plants and its requirements of ruminants in the northern Tibetan Plateau

摘要:

【目的】 探究藏北高原植物和土壤硫含量能否满足放牧家畜生长和生产对硫营养的需求。 【方法】 通过对藏北高原4种主要高寒草地类型13种主要植物、群落以及土壤全硫含量的分析，结合主要放牧家畜牦牛硫营养需求标准，综合评价了高寒草地硫的营养状况。【结果】 4种主要高寒草地0~ 10 cm土壤中有机硫的含量变化很大，平均为0.01%~0.20%，有机硫的含量与土壤中有机碳和全氮含量呈极显著正相关（P＜0.001）。所测定的13种优势植物64个样品中，有70%的植物体内硫含量低于 0. 16%，有90%以上的植物氮∶硫比大于14。【结论】 与主要放牧家畜牦牛的硫营养需要相比，约有 70%~90%的植物缺硫，说明青藏高原北部植物硫元素含量普遍较低，可能限制了家畜的生产性能，未来亟需对放牧动物的硫营养需求进行评估。

Abstract:

【Objective】 This study aims to assess whether the sulfur content of plants and soils of the northern Tibetan Plateau meets the sulfur nutrition requirements for growth and production of grazing livestock.【Method】 The sulphur content in the main plants，plant communities，and soils of 4 alpine steppes were investigated. The sulfur nutrient status of these alpine steppes was evaluated in relation to the sulfur requirements of the primary livestock specie， 【Result】 The mean organic sulphur content ranged from 0. 01% to 0. 20% in the 0~10cm soils，A strong positive correlation was found between the ratio of nitrogen-to-sulphur （NS） in soils and in plants，The sulfur content of 70% of the plants was lower than 0. 16%，and more than 90% of the plants had an NS ratio greater than 14.【Conclusion】 More than 70%~90% of the plants were sulfur-deficient for grazing livestock，suggesting that sulphur deficiency is widespread in the northern Tibetan Plateau. This deficiency limits the production performance of livestock. Future evaluations of sulphur nutritional requirements for grazing animals are recommended.