수종의 사료작물에 대한 비료유래 질소율과 A-value에 관한 연구

Studies on Percentage of Nitrogen Derived from Fertilizer ( P. N. D. F. ) and A-Value in Seuveral Forage Corps

화본과(禾本科) 및 두과사료작물(荳科飼料作物)의 단파(單播)와 혼파(混播)에서 중질소(重窒素)를 시용(施用)하여 시비질소(施肥窒素)의 작물별(作物別) 건물수량(乾物收量), 총질소함량(總窒素含量), 비료유내질소율(肥料由來窒素率), 토양중(土壤中) 유효질소량 등을 조사(調査)한 결과(結果)는 다음과 같다. 1. 건물수량(乾物收量)에 대(對)한 질소시비효과는 orchardgrass에서만 높이 인정(認定)되었고 alfalfa와 birdsfoot treoil은 혼파(混播)의 경우 초기(初期)에만 인정(認定)되었다. 2. 건물수량(乾物收量)은 단파(單播)에서는 alfalfa>red clover>orchardgrass>birdsfoot trefoli의 순(順)이었고 혼파(混播)에서는 orchardgrass + alfalfa> orchardgrass + red clover> orchardgrass+birdsfoot trefoil순(順)으로 나타났다. 3. 비료유내질소율(肥料由來窒素率)는 단파(單播)에서 orchardgrass가 두과(荳科)보다 높았으나 혼파(混播)한 경우는 전구(全區) 공(共)히 두과(荳科)가 orchargrass보다 높아서 orchardgrass가 두과(荳科)로부터 시비질소(施肥窒素)보다 토양질소(土壤窒素)를 공급(供給)받는 것으로 보였다. 또한 비료유내질소율(肥料由來窒素率)은 단파시(單播時) 모든 작물(作物)에서 후기(後期)로 갈수록 작아졌으며 혼파시(混播時) orchardgrass에는 일정한 경향(傾向)이 없었다. 4. 토양중(土壤中) 유효질소량은 단파시(單播時) alfalfa>red clover> orchardgrass> birdsfoot trefoil 순(順)이었으며 혼파시(混播時)는 orchardgrass+alfalfa(3 : 7) > orchardgrass + red clover (3 : 7) > orchardgrass + alfalfa(5 : 5) > orchardgrass + birdsfoot trefoil(5 : 5) > orchardgrass + red clover (5 : 5) > orchardgrass + bidsfoot trefoil(3 : 7)의 순(順)이었다.

Effects of nitrogen incorporated with 15N-nitrogen, which was applied to grown alone and in mixture with grass and legumes of forage crops, on the yield of dry matter, total nitrogen content, percentage of nitrogen derived from fertilizer (P.N.D.F.), A-value were studied, and the results obtained are as follows: 1. With nitrogen for the yield of dry matter was highly effective only to orchardgrass and were also effect to the early stages of alfalfa and birdsfoot trefoil in case of a mixed sowing. 2. Alone and mixed sowings showed the yield of dry matter in decreasing order of alfalfa<red clover>orchardgrass>birdsfoot trefoil, and orchardgrass + alfalfa>orchardgrass + red clover>orchardgrass + birdsfoot trefoil, respectively. 3. In case of grown alone, orchardgrass gave higher percentage of nitrogen derived from fertilizer (P.N.D.F.) than legume, whereas in case of grown in mixture it was in reverse order throughout the plots. It appears likely that orchardgrass was rather supplied soil nitrogen by legume then by nitrogen application. And P.N.D.F. was getting smaller in the latter stage of all forage crops in case of grown alone. In case of grown in mixture, however, and inconsistent P.N.D.F. was obtained from orchardgrass. 4. The A-value in case of grown alone was decreased in order of alfalfa>red clover>orchardgrass>birdsfoot trefoil. In contrast, however, the A-value in case of grown in mixture wes decreased in order of orchardgasss+alfalfa (3:7)>orchardgrass+red clover (3:7)>orchardgrass+red clover (3:7)>orchardgrass+alfalfa(5:5)>orchardgrass+birdsfoot trefoil (5:5)>orchardgrass+red clover (5:5)>orchardgrass+birdsfoot trefoil (3:7).