석회 및 3 요소 시용수준이 겉뿌림 산지초지에 미치는 영향 1 . 토양특성 , 초기생육 , 총 건물수량 및 내용연한의 변화

정연규,박병훈,이종열 ( Yeun Kyu Jung,Byung Hoon Park,Jong Yeal Lee ) 한국축산학회 1982 한국축산학회지 Vol.24 No.6

This field experiment was undertaken to assess the effects of two rates of Ca(OH)₂ (0, 250 Kg/l0a) and five rates of N-P₂O_5-K₂O (0-0-0, 0-10-10, 6-15-15, 12-20-20, 24-25-20 Kg/l0a) on the grassland establishment, forage yield and quality, botanical composition, and persistence of different forage species in a mixed grass/clover sward established by oversowing method on new reclaimed steep mountain. This first part is concerned with the soil properties, vigour of early growth, total yield of mixed forages, and persistence of grassland. The results obtained were summarized as follows; 1. Organic matter in soil was increased by both landuse of grassland and liming. Liming raised pH, increased P and Ca, and reduced Mg in soil, whereas that had inconsistent effect on concentrations cf K and Na. Organic matter, pH, P, Ca, Mg, and K in soil after a 7-year experiment were lower at the optimum rate of NPK than at the low rate. 2. The vigour at early growth of forages was enhanced by liming. Averaging over all NPK treatments and 7 experimental years, the yearly mean yield of mixed forages was increased 21% by liming over no lime. The only one-time liming at establishment of oversown grassland had consistent effect on the yield during 7 experiment years without depression of lime effiency. By increasing the NPK rate, emergence and early growth of seeded forages were enhanced, and yields of mixed forages were greatly increased. 3. The oversown grassland in mountainous area was well established and had high yielding during 7 experiment years with both liming at establishment and 24-25-20 (N-P₂O_5-K₂O) Kg/l0a/year. Lowest application rates of N-P₂O_5-K₂O to perform the economical yielding of oversown grassland ($gt;650 Kg/l0a in DM, and$gt;50% in rate of seeded forages) were 12-20-20Kg/l0a rate at no lime and 6-15-15 at lining.

Homes의 Systematic Variations에 의(依)한 비료시험법의 개선(改善)에 관하여

정연규,Jung, Yeun-Kyu 한국토양비료학회 1980 한국토양비료학회지 Vol.12 No.4

$Hom{\acute{e}}s$의 Systematic variations에 의(依)한 시비시험방법(施肥試驗方法)의 이론(理論)과 실제(實際)를 논의(論議)하였다. 본방법(本方法)의 특성(特性)은 : (가) 양분(養分)의 적정상대비(適定相對比)와 적정량(適定量)을 규명(糾明)한다. (나) N-P-K 관행시비시험(慣行施肥試驗)의 문제점(問題點)을 보완개선(補完改善)한 식물영양학적(植物營養學的)으로 합리적(合理的) 방법(方法)이다. (다) 다수획(多收獲) 증진(增進)을 위(爲)한 비료시험법(肥料試驗法)으로 추천(推薦)될 수 있다. (라). 미량요소(微量要素)의 비료시험(肥料試驗)에도 적용(適用)될 수 있다. (마). 관행시비결과(慣行施肥結果)의 원인규명(原因糾明)을 위(爲)한 시험법(試驗法)이 될 수 있다. (바). 관행법(慣行法)에 비(比)해 시간(時間), 인력(人力) 및 경비(經費)를 줄일 수 있는 시험법(試驗法)이다. This is a review of the theory and practical uses of the $Hom{\grave{e}}s$' systematic variations in the fertilizer experiments. General characteristics of the method are as follows : 1 ) It could be recommended as a reasonable met hod for fertilizer experiments in order to improve the weak points in the conventional methods. 2 ) This met hod is a determination of the total amount of nutrients and the relative proportion of each nutrient in the total. 3 ) Concerning of the high yields of crops this met hod should be adapted for the systematic fertilization. 4 ) This is an usable method not only for the macro- but also micro elements investigations.

Homes방법(方法)에 의(依)한 다량요소(多量要素)의 적정(適正) 시비비율(施肥比率) 결정(決定)에 관한 연구 -III. 초지토양별(草地土壤別) 음(陰)이온 성분총량(成分總量) : 양(陽)이온 성분총량(成分總量) 적정(適正) 시비비율(施肥比率) 및 적정(適正) 총시비량(總施肥量)

정연규,김상철,Jung, Yeun-Kyu,Kim, Sang-Chul,Weinberger, P. 한국토양비료학회 1982 한국토양비료학회지 Vol.15 No.3

This pot experiment was undertaken to find out the optimum fertilization ratios of total anions to total cations, ${\Sigma}A/{\Sigma}C$, and the optimum application rates of total macro-nutrients in various soil conditions. Soil samples were collected from uncultivated mountains and hills where grassland development was under consideration. 1. The optimum application ratios of ${\Sigma}A/{\Sigma}C$ and the optimum application rates of total macro-nutrients for the high yields of mixed grass-clover sward in various grassland soils were computed by the Hom$\acute{e}$s systematic variation techniqu.e. 2. With respect to the optimum application ratios of ${\Sigma}A/{\Sigma}C$ in fertilization in a mixed grass-clover sward, the grass yield and botanical composition were distinctly proportional to ${\Sigma}A$ wheras the regume yield and botanical composition were proportional to ${\Sigma}C$. 3. The optimum fertilization rates of total macro-nutrients for the high legume yields were depended upon ${\Sigma}A/{\Sigma}C$ ratios. These optimum rates were in proportional to ${\Sigma}C$ ratios and were inversely proportional to ${\Sigma}A$ ratios. 4. The efficiencies of ${\Sigma}A$ and ${\Sigma}C$ in relation to the grass and grass plus legume yields were highest with the low ratios of each other and the low fertilization rates of total macronutrients. The ${\Sigma}A$ effieiency in the legume yield tended to be similar to that of ${\Sigma}A$ related to the grass yield noted above except Daegu soil. The ${\Sigma}C$ efficiency, however, was proportional to the ${\Sigma}C$ ratio, although that was varied with the fertilization rates of total macro-nutrients and with the kinds of soils. 5. The yield of mixed forages, yield component, and botanical composition in a mixed sward were greatly influenced by the ${\Sigma}A/{\Sigma}C$ ratios, the fertilization rates of total macronutrients, and the interactions of ratio and rate noted above. In addition, these effects were generally different and opposite according to grass and legume. 초지개발이 유망시되는 전국각지의 미개간(未開墾) 산지토양(山地土壤)의 표토(表土)를 채취(採取)하여 다량(多量) 요소(要素)의 음(陰)이온총량(?量) : 양(陽)이온총량(?量)(${\Sigma}$ Anion: ${\Sigma}$ Cation) 적정시비비율(適正施肥比率)과 적정총시비량(適正?施肥量)(${\Sigma}$ion)결정(決定)을 위한 Pot시험(試驗)을 수원(水原)에서 수행(遂行)한 결과(結果)는, 1. 제주등 5개지역(個地域)의 토양(土壤)에 대한 혼파목초재배시(混播牧草栽培市) 각토양(各土壤) 및 초종별(草種別) 다수획(多收獲)을 얻기 위한 당량비기준의 음(陰)과 양(陽)이온 총량간(?量間)의 적정(適正) 시비비율(施肥比率)과 적정총시비량(適正?施肥量)이 계산(計算)되었다(표(表)6,7) 2. 혼파재배(混播栽培)에서 화본과목초(禾本科牧草)는 음(陰)이온총량(?量), 두과목초(荳科牧草)는 양(陽)이온총량(?量) 비율(比率)이 높을수록 이들의 수량(收量)과 식생구성비율(植生構成比率)이 증가(增加)하였다. 적정(適正) 음(陰)과 양(陽)이온총량(?量) 비율(比率)은 화본과목초(禾本科牧草)에서는 음(陰)이온총량(?量)이 두과목초(荳科牧草)에서는 양(陽)이온총량비율(?量比率)이 각각(各各) 타(他)이온총량비율(?量比率)보다 훨씬 높을 때였다. 3. 두과목초(荳科牧草)의 수량제고(收量提高)를 위(爲)한 적정총시비량(適正?施肥量)은 음(陰)과 양(陽)이온총량비율(?量比率)에 따라 달렀다. 양(陽)이온총량비율(?量比率)이 높아질수록 적정총(適正?)이온농도(濃度)(총시비량(?施肥量))는 증가(增加)하였고 이의 역(逆)도 성립(成立)하였다. 4. 화본과목초(禾本科牧草) 및 총수량(?收量)(화본과(禾本科)+두과(荳科))에 미치는 음(陰)과 양(陽)이온총량(?量)의 각(各) 효율(效率)은 이들의 비율(比率)이 낮을때 그리고 총(?)이온농도(濃度)가 낮을때 제일(第一) 높았다. 5. 두과목초수량(荳科牧草收量)에 미치는 음(陰)이온총량효율은 대구토양(大邱土壤)을 제외(除外)하고는 화본과목초(禾本科牧草)와 같은 경향(傾向)이였고, 양(陽)이온총량효율은 총(?)이온농도(濃度)와 토양종류(土壤種類)에 따라 달랐으나 보편적(普遍的)으로 양(陽)이온총량비율(?量比率)이 높아질수록 본효율도 높아졌다. 6. 각(各) 구성초종(構成草種)의 수량(收量), 식생비율(植生比率)은 음(陰)과 양(陽)이온총량비율(?量比率), 총(?)이온농도(濃度)와 이들의 상호작용(相互作用)에 크게 영향(影響)을 받았고, 화본과(禾本科)와 두과목초(荳科牧草)는 서로 상반적영향(相反的影響)을 받았다.

Homes 방법(方法)에 의(依)한 다량요소(多量要素)의 적정시용(適正施用) 비율(比率) 결정(決定)에 관(關)한 연구(硏究) I. 초지(草地) 토양별(土壤別) 음(陰)이온 N : S : P 적정시용(適正施用) 비율(比率)

정연규,윤상기,Jung, Yeun-Kyu,Yoon, Sang-Gi,Weinberger, P. 한국토양비료학회 1981 한국토양비료학회지 Vol.14 No.1

This pot experiment was conducted to find out the optimal fertilization ratio of the anions (N : S : P) in various soil conditions. Soil samples were collected from uncultivated mountains and hills where development for grasslands is under consideration. The optimum ratios were computed by the $Hom{\grave{e}}s$ systematic variation technique. The results were summarized as follows : 1. The optimum fertilization ratios of the anions (N : S : P) for the high yields of grass - clover mixed sward at various areas were obtained (Table 5). 2. The grass yields in mixed sward were increased by the increase of specific soil characteristics, CEC, OM, T-N, avail-$P_2O_5$. However. it was not recognizable by the contents of the cations, the base saturation, and the pH. 3. The relatively high yields of clover were positively related to the Ca and Mg contents in soils, and it was a factor of the increased total yields of mixed sward. 4. The relatively high optimum fertilization ratios of S in volcanic ash soil in the Cheju district and P in sediment lithosol in Daegu should be taken into account in determing the fertilization rate for high yield of clover in mixed sward. 초지개발(草地開發)이 유망시(有望視)되는 전국각지(全國各地)의 미개간(未開墾) 산지(山地)의 표토토양(表土土壤)을 채취(採取)하여 $Hom{\grave{e}}s$의 Systematic Variation방법(方法)에 의(依)한 다량요소(多量要素) Anions N: S: P 적정시용비율(適正施用比率) 결정(決定)을 위(爲)한 pot시험(試驗)을 에서 수행(遂行)한 결과(結果)는 1. 안양등(安養等) 6개(個) 지역(地域)의 토양(土壤)에 대(對)한 혼파목초재배시(混播牧草栽培時) 각(各) 토양(土壤) 및 초종별(草種別) 다수확(多收穫)을 위(爲)한 당량비 기준(基準) N: S: P적정시용비율(適正施用比率)이 계산(計算)되었다(표(表)5). 2. 혼파목초(混播牧草)에서 화목과목초(禾木科牧草)의 수량증수(收量增收)는 각토양(各土壤)이 C.E.C, OM, T-N, Avl $P_2O_5$ 특성(特性)들과 정상관관계(正相關關系)가 있고 무기(無機)Cation 함량(含量), 염기포화도 및 pH와의 관계(關係)는 뚜렷하지 않았다. 3. 각토양중(各土壤中) Ca, Mg함량(含量)과 정상관(正相關)을 보인 두과목초(荳科牧草)의 수량증가(收量增加)는 혼파목초(混播牧草) 총수량증가(總收量增加)의 요인(要因)이 되었다. 4. 두과목초(荳科牧草)의 수량증수(收量增收)를 위(爲)하여 제주(濟州)의 화산회토(火山灰土)에서 S, 대구(大邱)의 수성암(水成岩) 암쇄토(岩碎土)에서 P시비비율(施肥比率)이 높게 나온것은 초지조성(草地造成) 및 비배관리(肥培管理)에 유의(留意)되어져야 할 것이다.

예취빈도 및 질소수준이 혼파초지에 미치는 영향 1 보 . 건물수량 및 수량구성요소의 변화

정연규,윤상기,김상철,이종열 ( Yeun Kyu Jung,Sang Gi Yoon,Sang Chul Kim,Jong Yeal Lee ) 한국축산학회 1981 한국축산학회지 Vol.23 No.4

This field experiment was undertaken to assess the effects of cutting frequency (3,4,5,6 times) and N rate (1,15,30,40 ㎏/l0a) on the yield and persistence of different forage species within a mixed grass/clover sward. 1. Under frequent cutting, dry matter yields of grasses were usually reduced at all of the rates of N, whereas yields of legumes generally increased except at a cutting frequency of 6 at the low rate of N. Weeds increased at high rate of N and reduced at the low rates. Total yield was highest with 4 cuttings. 2. By increasing the N rate, yields of grasses, weeds and the total yield were increased at all cutting frequencies, whereas yields of legumes were reduced. N fertilizer had a greater effect on grass yield than on weeds, so the percentage of weeds in the sward was reduced as a result of fertilizing with N. 3. Optimum cutting frequency and N rate were correlated with each other. Grass and total yields were highest with 4 cuttings and 30 N, legume was highest with 5 cuttings and O N, and weeds was highest with 5 cuttings and 40 N. Generally, infrequent cutting and high rate of N had negative effects on clover and weeds. 4. At the low rate of N, yields of grass and weeds, and total yield were highest with infrequent cuttings. At the high rate of N, the yield of legume was highest with frequent cuttings. 5. Yields of grass, legume and weeds in mixed sward were differentially influenced by cutting and N fertilizer (main effects and interaction = P $lt; 0.01).

Homes 방법(方法)에 의(依)한 다량요소(多量要素)의 적정시용(適正施用) 비율(比率) 결정(決定)에 관(關)한 연구(硏究) II. 초지토양별(草地土壤別) 음(陰)이온 N : Ca : Mg 적정시용(適正施用) 비율(比率)

정연규,윤상기,Jung, Yeun-Kyu,Yoon, Sang-Gi,Weinberger, P. 한국토양비료학회 1981 한국토양비료학회지 Vol.14 No.1

초지개발(草地開發)이 유망시(有望視)되는 전국각지(全國各地)의 미개간(未開墾) 산지토양(山地土壤)의 표토(表土)를 채취(採取)하여 Hom$\grave{e}$s의 Systematic Variation 방법(方法)에 의(依)한 다량요소(多量要素) Cations K: Ca: Mg 적정시비비율(適正施肥比率) 결정(決定)을 위(爲)한 Pot 시험(試驗)을 수원(水原)에서 수행(遂行)한 결과(結果)는: 1. 안양등(安養等) 6개지역(個地域)의 토양(土壤)에 대(對)한 혼파재배(混播栽培) 시(時) 각(各) 토양(土壤) 및 초종별(草種別) 다수확(多收穫)을 위(爲)한 당량비 기준(基準) Cations K: Ca: Mg 적정시비비율(適正施肥比率)이 계산(計算)되었다. (표(表)4). 2. 혼파목초중(混播牧草中) 두과수량증수(荳科收量增收)를 위(爲)해서는 대구(大邱), 대관령토양(大關嶺土壤)에서는 K, 광주(光州), 운봉(雲峰)은 Ca, 제주(濟州)는 Mg 적정시비비율(適正施肥比率)이 높았고 이는 토양중(土壤中) 이들 이온들의 함량(含量) 또는 함량비율(含量比率)이 낮은 것과 병관되었다. 3. 두과목초수량(荳科牧草收量)은 화본과수량(禾本科收量)보다 Cations 시비비율(施肥比率) 및 시비량(施肥量)에 크게 영향(影響)을 받고 이에따라 혼파목초(混播牧草)의 총수량(總收量), 품질(品質), 식생비율(植生比率)이 또한 영향(影響)을 받는다. 4. 화본과(禾本科) 및 두과목초(荳科牧草)의 K, Ca, Mg 함량(含量)에 미치는 이들 ion간(間)의 길항효과(拮抗效果)의 차(差)와 그리고 이들 ion들이 Na, Fe, Mn, Cu, Zn 함량(含量)에 미치는 영향(影響)에 관(關)해 논하였다. 5. 화본과목초(禾本科牧草)에서 K-group 처리(處理)에서만 K/(Ca+Mg) 당량비가 grass tetany 한계치(限界値)인 2.2보다 훨씬 높은 2.4~3.3에 달(達)했고 반면(反面)에 두과목초(荳科牧草)는 0.9~1.2로 미달(未達)되었다. 이는 적당한 화본과(禾本科) 두과(荳科) 식생비율유지(植生比率維持)는 grass tetany 유발(誘發)을 크게 줄일 수 있음을 나타낸다. This pot experiment was conducted to find out the optimal fertilization ratio of the cations(K: Ca: Mg) in various soil conditions. Soil samples were collected from uncultivated mountains and hills where development for grass lands is under consideration. The optimum ratios were computed by the Homes systematic variation technique. The results were summarized as follows : 1. The optimum fertilization ratios of the cations (K : Ca : Mg) for the high yields of grass-clover mixed sward at various areas were obtained (Table 4) 2. The relatively high optimum fertilization ratios of K in Daegu and Taegwalryong, Ca in Unbong, and Mg in Cheju district gave the high yields of clover in mixed sward. They were positively related to the low contents of the above cations in the soils or the relatively low content ratio comparing with other cations. 3. The yields of clover in mixed sward were seriously affected by the changes in both the fertilization ratio and total concentration of cations comparing to those of the grass yields. As a consequence, total yields, quality, and botanical composition of the mixed sward were also affected. 4. The antagonis among the cations K, Ca, and Mg was known from the point of mineral contents of grass and clover. 5. The equivalent ratio K/(Ca+Mg) or grass was greatly increased by the range of 2.4 and 3.3 in the K-group treatment, which was higher than the critical level 2.2 of grass tetany, otherwise that. of clover by the range of 0.9 and 1.2. Therfore, it may be concluded that if the botanical composition of grass/legume sward is optimum, the incidence of grass tetany can be eliminated.

다양한 질소 분리방법이 북방형 목초의 수량 , N - 회수율 , 식생비율 , 영양성분에 미치는 영향 제 1 보 . Orchardgrass 및 Italian ryegrass 혼파초지에 대한 효과

정연규,이종렬 ( Yeun Kyu Jung,Jong Yeal Lee ) 한국축산학회 1980 한국축산학회지 Vol.22 No.6

This field experiment was conducted to investigate the effects of different patterns of nitrogen distribution in a year on DM yields, botanical composition, N recovery rate, and chemical composition of the mixed sward of Orchardgrass and Italian ryegrass. The N-Distributions were ranged from 4 to l0 ㎏/10a, which were applied after each cut. However, in all treatments, the total amounts of N was 34 ㎏/l0a/year and the grasses was Gutted by 5 times. The results obtained were summarized as: 1. Generally, DM yields of each cut was affected significantly by N-distributions in a year, but total DM yields of each treatment was shown io be relatively less affected than DM yields of each cut. 2. The highest DM yields was obtained in $quot;heavy N-distribution in the spring (10-8-6-4-6 ㎏/cut), but the lowest in $quot;heavy N-distribution in the summer (4-6-8-10-6 ㎏/cut).$quot; However DM yields in $quot;equal N-Distribution in a year$quot; was similar to $quot;heavy N-distribution in the spring.$quot; 3. It seems that the productivity of grasses and the rhythm of growth was affected by the seasonal factors rather than these N-distribution factors. 4. It was not recognized that the botanical compositions and the chemical compositions in terms of crude protein and crude fiber was affected by these N-distributions. 5. The N recovery rate was decreased in the second year compared to that in the first year. It seems that in the following early spring the grasses might be able to make good use of the residual N nutrients fertilized in the autumn, due to the small amounts of precipitation in the winter in Korea.

예취빈도 및 질소수준이 혼파초지에 미치는 영향 2 . 예취 및 N의 효율 , 식생구성비율 , N의 함량 및 회수율

정연규,윤상기,이종열 ( Yeun Kyu Jung,Sang Gi Yun,Jong Yeal Lee ) 한국축산학회 1981 한국축산학회지 Vol.23 No.6

This field experiment was undertaken to assess the effects of cutting frequency (3, 4, 5, 6 times) and N rate (0, 15, 30, 40 ㎏/l0a) on the efficiencies of cutting, the efficiency of the N, the botanical composition, and the percentage recovery and content of N of different forage species and mixed forages within a mixed grass/clover sward, 1. By increasing the cutting frequency, the efficiency of cutting(DM ㎏ per cut) to grass and total yields was reduced, whereas with legumes yield did not change or increased slightly until 5 cuttings. At 6 cuttings it reduced, Efficiency of weed yield was highest with 5 cuttings, 2. The efficiency of N (DM ㎏ per ㎏ N) to grass and total yield was highest with 15㎏ N at all cutting frequencies, It was reduced by increasing the N rate over 15㎏ N, N application to legume yield had minus value with the lowest at 15 ㎏ N, This minus value was lower under frequent cutting, 3. The ratio of grass/clover was greatly increased by increasing the N rate, but this increase was eliminated by increasing the cutting frequency, This ratio was further reduced by increasing cutting until 5 cuttings, which was the lowest. At the 6 cuttings, there was a small increase in the ratio 4. By increasing cutting (spring-summer-autumn), grass was reduced and legume increased. 5. Percentage recovery of N in the mixed sward was increased by increasing the cutting, This was mainly due to the increasing N content in the mixed forage according to the increased ratio of legume and by cutting at a younger stage, and the efficiency of N etc. 6. The efficiencies of cutting and the efficiency of N, the grass/clover ratio, the percentage recovery and the content of N in a mixed sward were all differentially influenced by botanical composition, cutting frequency, N rate and the interaction between all of these factors.

석회 및 3 요소 시용수준이 겉뿌림 산지초지에 미치는 영향 2 . 수량구성요소 식생구성비율 및 목초율의 변화

정연규,윤상기,김정갑 ( Yeun Kyu Jung,Sang Gi Yun,Jeong Gab Kim ) 한국축산학회 1982 한국축산학회지 Vol.24 No.6

This field experiment was undertaken to assess the effects of two rates of Ca(OH)₂ (0, 250 ㎏/l0a) and five rates of N-P₂O_5-K₂O (0-0-0, 0-10-10, 6-15-15, 12-20-20, 24-25-20 ㎏/l0a) on the grassland establishment, forage yield and quality, botanical composition,, and persistence of different forage species in a mixed grass/ clover sward established by oversowing method on new reclaimed steep mountain. This second part is concerned with the yield components, botanical composition, and performance of different grass species. The results obtained were summarized as follows; 1. Yields and botanical compositions of grasses and legume, and rate of seeded forages in mixed sward were greatly increased by liming. The yield and botanical composition of weeds were reduced by both liming and increasing the NPK rate. By increasing the NPK rate, the yield and botanical composition of grasses, and the rate of seeded forages were greatly increased. The regrowth of cut shrubs was controlled by both lime and NPK applications The rate of yield increase of grasses in mixed sward by increasing the NPK rates tended to be relative higher with liming than no lime. 2. At no lime, legume in mixed sward was almost disappeard, and no significant effect of NPK application on persistence of legume was found. On the other hand, legume in mixed sward was good established by liming, and that yield and botanical composition were highest with 6-15-15 (N-P₂O_5-K₂O ㎏/l0a) rate. The yield of weeds in mixed sward was highest with low rates of NPK, and that reduced with control and moderate rate of NPK. 3. Lowest application rates of N-P₂O_5-K₂O to maintain the above 50% in the mean rate of seeded forages were 12-20-20 ㎏/l0a rate at no lime and 6-10-10 rate at liming. Increments of rate of seeded forages and legume as affected by liming resulted in the forage production with good quality. 4. Mean botanical compositions of the seeded different grass species (∑ grass=100%) in a mixed grass/clover sward were highest in the following order; Orchardgrass (65%)$gt;Tall, Meadow and Red feseues (25%)$gt; Redtop (4.5%)$gt;K. bluegrass (4%)$gt;P. ryegrass (1.5%). Liming increased gently mean botanical composition of Fescues and reduced that of Redtop in seeded grasses, while these of Orchardgrass, K. bluegrass, and P. ryegrass were inconsistent. By increasing the NPK rate, that was increased markedly in Orchardgrass and gently in Fescues, whereas that tended to be reduced in other grass species.

석회 및 3 요소 수준이 겉뿌림 산지초지에 미치는 영향 4 . 토양 및 목초중 무기양분의 상호균형과 Grass tetany 위험성

정연규,김강식,심재성 ( Yeun Kyu Jung,Kang Sik Kim,Jai Sung Shim ) 한국축산학회 1982 한국축산학회지 Vol.24 No.6

This field experiment was undertaken to assess the effects of two rates of Ca(OH)₂(0, 250 ㎏/l0a) and five rates of N-P₂O_5-K₂O (0-0-0, 0-10-10, 6-15-15, 12-20-20, 24-25-20 ㎏/l0a) on the grassland establishment, forage yield and quality, botanical composition, and persistence of different forage species in a mixed grass/clover sward established by oversowing method on new reclaimed steep mountain. This fourth part was concerned with the mutual balance of mineral nutrients and grass tetany hazard. The results obtained were summarized as follows; 1. Concentration of exchangeable Mg, relative proportions of Mg to CEC, K, and Ca in soil were considerably below the critical level for good forage growth and likelihood of grass tetany. These properties were handicapped by liming and increasing the NPK rate. 2. Comparing with the critical level for likelihood of tetany (Mg$lt;0.2%, K$gt;2.5%, and K/(Ca+Mg)$gt;2.2 in forages), mean concentration of Mg ranged from 0.09 to 0.15%, that of K exceeded 2.5% from 15㎏ K₂O/ l0a rate. The K/(Ca+Mg) ratios of mixed forages showed above 2.2 at no lime and below at liming, when averaged over NPK rates. The increase of Ca concentration and botanical composition of legume in mixed sward by liming resulted in the reduce of K/(Ca+Mg) ratio in mixed forages. 3. The ratios of K/(Ca+Mg) in mixed forages were increased by increasing the NPK rate and that exceeded 2.2 from 10㎏ K20/l0a rate at no lime and showed around 2.2 from 20㎏/l0a rate at liming. 4. The value of % (N x 6.25) x % K in mixed forages was increased and Mg concentration was reduced by increasing the NPK rate. As a result, it was expected for decrease of blood serum-Mg concentration in cattle, and for increase of tetany hazard. 5. To prevent grass tetany resulting from low Mg concentration and unbalanced ratios of mineral nutrients, Mg fertilization on grassland and/or extra Mg supplement to cattle were to be necessary. 6. The Ca/P ratios ranged from 1:1 to 3.2:1, and they varied with the levels of lime and NPK applications. At liming, higher amount of P fertilizer should be applied to maintain the optimum Ca/P ratio in mixed forages.