Effects of Cutting on Nodule Development and Nitrogen Fixation in Alfalfa

예취가 알팔파 근류의 발달과 질소고정활성에 미치는 영향

  • Jong Won Ryoo (Livestock Experiment Station, RDA) ;
  • Ho Jin Lee (College of Agriculture, Seoul National University)
  • Published : 1987.09.01

Abstract

This experiment was conducted to evaluate the effects of cutting in field and solution culture. Periodical samplings of alfalfa in cutting and uncutting plots were taken to measure nodule development and nodule activity. Regrowth of plant and nodule development after shoot cutting by different heights and nodule removal at different levels were investigated in solution culture of alfalfa plant. 1. Nodule weight in the field was reduced 30% after the first cutting and 25% after the second cutting, but during the following 30 days after second cutting, there was no significant difference between cutting and uncutting plots. 2. Specific nodule activities of cutting plots at the beginning of June and at the beginning of September were 80% and loo%, higher than those of uncutting plots respectively. Total nodule activities of cutting plots in late August and early September were 40% higher than those of uncutting plot. The decrease of nodule activity can be prevented by cutting at flowering stage. 3. The decrease of nodules in solution culture when 50% of the shoot was cut, was as much as that when shoot was not cut or flower buds were removered. But when 90% of the shoot was cut, the number of the nodules were decreased more remarkably than the above treatments. New nodules, when 90% of the shoot was cut, were reformed slowly and did not grow fully until 15 days after cutting.

刈取가 알팔파根瘤의 着生 및 發達과 室素固定活性에 미치는 影響을 檢討하기 위하여 圃場實驗에서는 刈取區와 非刈取區로 구분하여 時期別로 Acetylene還元法에 의하여 根瘤의 室素固定活性을 測定하였다. 養液栽培實驗에서는 地上部의 50%와 90%刈取, 花芽의 除法, 根瘤의 50%와 100% 除法등을 組合處理後 알팔파 再生과 根瘤의 着生과 發達에 미치는 影響을 檢討하였다. 1. 圃場實驗에서 根瘤의 무게는 1回刈取後 30%, 2 回刈取後 25%의 減少가 있었고 2 回刈取後 30日부터는 減少가 없었다. 2. 7月初, 8月初, 9月初에 刈取區의 specific nodule activity(SNA)는 非刈取區보다 높았으며 total nodule activity도 刈取區가 非刈取區보다 높았다. 開花期의 刈取는 根瘤의 室素固定活性 유지에 도움이 되는 것으로 나타났다. 3. 養液栽培實驗에서는 地上部의 50% 刈取는 알팔카의 再生과 根瘤의 發達에 影響이 없었으나 地上部의 90% 刈取는 再生을 느리게 하고 根瘤의 脫落을 심하게 조장하고 着生된 根瘤나 새로이 着生된 根瘤의 發達을 나쁘게 한 것으로 보아 알팔파根瘤의 室素固定活性을 높은 狀態로 維持하기 위해서는 너무 낮은 刈取를 피하는 것이 바람직할 것으로 보여진다.

Keywords