Study On Seasonal Dynamic Of Macro-minerals On Soil-Grass-Sheep In Alpine Meadow Ecosystem

The trial was made to study the seasonal tendency and deficiency of macro-minerals (sulfur, nitrogen, phosphorus, calcium, magnesium, sodium, potassium) on soil-grass-sheep by using thirteen Qinghai fine-wool sheep( ), during three periods on the basis of the seedling (Jun.) , maturity (Sept.)and withered stage(Dec.) of grass in alpine meadow ecosystem in Qinghai Province. The faces excrement and daily feed intake of the sheep were measured by the means of offering Cr2O3 and the Tilly and Terry's in vitro digestion trials, and urine was sampled with metabolism trail. The content of the macro-minerals in the soil, grass and sheep were determined by the lab analysis.The results showed as follows:(l)In the soil: the content of the available S and P and the total Mg and Ca in the Dec.(555.75mg/kg, 8.33mg/kg, 3.79mg/kg, 10757.50mg/kg, respectively) was relatively less than that in the Jun. and Sept, the sequence of the content of the total N was Dec. (0.30%)>Sept.(0.25%)>Jun.(0.23%), the content of total Na was the highest (13875.01mg/kg), in contrast, hydrolysable N and available K was the lowest (68.63mg/kg, 210.00mg/kg, respectively) in the Sept.. (2)In the grass: the content of S, N, P, Mg, Na was the highest in the Jun. (2.93g/kg, 36.90g/kg, 2.58g/kg, 8.84g/kg, 5.77g/kg, respectively), K and Ca was the highest in the Sept.(6.06g/kg, 5.96g/kg, respectively). All the macro-minerals was the lowest in the Dec. except that Na was the lowest in the Sept.. (3) S and Ca in the sheep body were in the negative balance in the Jun. and Sept. , and their daily feed intake was less than the requirements of the sheep. Nitrogen was in the positive balance during the three periods. The content of the album in the serum of the sheep in the Dec. was as the same as 0.64 to 0.67% at the Sept., which was the highest, as means the content of thecrude protein in the grass in the Dec. was deficient. The content of P in the daily feed intake was under the requirement of the sheep. The content of the inorganic phosphorus in the serum of the sheep was the lowest in the Dec. Mg was in the negative balance in the Sept. and Dec., but the daily feed intake of which were over the requirement of the sheep during the three periods, the content of the plasma Mg was under the normal value in the Dec.. Na was in the positive balance during the three periods, and the daily feed intake was over the requirement of the sheep, in contrast, K was in the negative balance, and the content of the K in the daily feed intake was under the requirement of the sheep. Na and K in the blood of the sheep lower the normal values. The ratio of the Na and K in the saliva in the Jun. and Sept. were under the normal values, too. In conclusion, it is necessary to supplement the Macro-minerals according to the requirements of the sheep at the different season at the district.