天祝高寒珠芽蓼草甸群落的热值和营养成分的初步研究

 本文报告了甘肃天祝高寒珠芽蓼(Polygonum viviparum)草甸群落地上及地下四部分生物量的热值和营养成分动态，并对其放牧利用的价值进行了总的评价。 6—9月现存量的热值平均为18330焦／克干物质，或20279焦／克去灰分物质，较立枯物+凋落物、活根、死根的平均值为大；死根略大于活根。在珠芽蓼及其他大多数植物种子成熟期的8月下旬，现存量的热值最大，其他三部分的热值变化也有其各自的特点。现存量6—9月的平均营养成分以绝对干重计为：粗蛋白13.52%，粗脂肪2.25，粗纤维22.99，无氮浸出物51.88，粗灰分9.61(其中钙1.627，磷0.164)；在时间变化上四部分各有其特点。根据地形、植物组成、产量、易食性、适口性、热值和营养成分等综合条件，认为珠芽蓼草甸是良好的放牧地。

PRELIMINARY STUDIES ON CALORIFIC VALUE AND NUTRIENT COMPOSITION IN TIANZHU ALPINE POLYGONUM VIVIPARUM MEADOW

The calorific values and nutrient compositions of 4 parts of the biomass of the Polygonum viviparum in the meadow from June to September or November were determined. The results obtained are as follows:1. The average calorific value of standing crop was 18330 j/g DM (20279 ash-free matter, AFM) and ranged from 17980 to 18763 j/g DM(19751 to 20830 AFM). It was higher than that of the standing dead+litter,live roots or dead roots, while that of dead roots is higher than that of live roots. There was some seasonal fluctuation of the calorific value, the highest value of standing crop being in the seed ripening period (August 22) of the dominant species Polygonum viviparum, the lowest being in the withering period. The values of standing dead+litter decreased significantly (P<0.05) as time went on, with live roots and dead roots showing opposite trends.2. The average nutrient components of standing crop were crude protein 13.52, crude fat 2.00, crude fiber 22.99, nitrogen-free extract 51.88. crude ash 9.61% and calcium 1.627 and phosphorus 0.164. Compared with the other 3 parts, the characteristics of the standing crop were: higher crude protein and phophorus and lower crude fiber and crude ash. There were clear seasonal changes in the nutrient compositions of the 4 parts of the biomass and each was different from the others.3. Considering the topography, and its floristic composition, production, easiness of grazing, palatability, and caloric and nutritious values, the authors regard the alpine Polygonum viviparum a good grass for grazing.