COLD RESISTANCE AND CHEMICAL COMPOSITION IN OVERWINTERING ALFALFA, RED CLOVER, AND SWEETCLOVER
COLD RESISTANCE AND CHEMICAL COMPOSITION IN OVERWINTERING ALFALFA, RED CLOVER, AND SWEETCLOVER
复制标题
DOI：
10.2134/agronj1954.00021962004600090001x
复制
发表时间：
1954-01-01
期刊：
影响因子：
2.1
通讯作者：
SMITH, D
中科院分区：
文献类型：
--
作者：
BULA, RJ;SMITH, D
春播游侠苜蓿和二年生草木樨根系和冠层的抗寒性在秋季表现稳定，草木樨的抗寒性最高。中红三叶草的生长发育较晚，生长速度较慢，最高生长量低于紫花苜蓿和甜三叶草。在永久性土壤冻结后不久，在豆科植物达到近最大值。每周的气温，开始保持在冰点以下。普遍的温度，以及第一次大量积雪的到来决定了所达到的水平。在春季，甜三叶草的抗寒性比苜蓿或红三叶草保持得更长，但在雪消失和土壤解冻后，这三种豆科植物的抗寒性迅速下降。在初冬抗寒性发展到较高水平时，根和冠中的总有效碳水化合物主要是总糖。甜三叶草中总糖含量最高，红三叶草中总糖含量最低。在冬季休眠期间总有效碳水化合物的相对减少表明，在每个豆科植物的代谢活动是相反的抗寒性发展。冬季总氮和总灰分的变化与抗寒性趋势没有密切关系。
Cold resistance in the roots and crowns of spring-sown Ranger alfalfa and biennial sweetclover developed steadily during the fall months, reaching the highest level in sweetclover. In medium red clover, it developed later, more slowly, and the maximum level reachedwas less than in alfalfa or sweetclover. A near maximum was reached in the legumes shortly after permanent soil freezing and after the ave. weekly air temps, began to stay below freezing. Prevailing temps, and the advent of the first substantial snow cover conditioned the level attained. In the spring, cold resistance was retained longer in sweetclover than in alfalfa or red clover, but it decreased rapidly in all three legumes after the snow was gone and the soil thawed. Total available carbo-hydrates in the roots and crowns were largely total sugars by the time a high level of cold resistance was developed in early winter. The highest level of total sugars was found in sweet-clover and it was generally lowest in red clover. Relative reductions in total available carbohydrates during winter dormancy indicated that the metabolic activity in each legume was inverse to the cold resistance developed. Variations in % total nitrogen and total ash over winter did not appear closely associated with the cold resistance trends.