In order to study the effect of barley, Italian ryegrass (IRG), and legume mixture on nitrogen fixation and transfer to grasses on spring paddy field, an experiment was carried out from Oct. 2006 to June 2007 in Naju, Korea. A split plot design with three replications was used for the experiment. One reference plot was assigned for each treatment to determine nitrogen fixation. Main plots consisted of Chinese milk vetch, crimson clover, forage pea, and hairy vetch with barley, respectively. Subplot treatment were barley or IRG with four seeding ratio of legumes (50:50, 60:40, 70:30, and 80:20). To estimate N fixation by legumes, 15N isotope dilution technique was used. 15N fertilizer [(15NH4)2SO4 solution at 99.8 atom N] was uniformly applied to 600 cm2 in the middle of each plot on April 15, 2007. Plots were harvest by hand on June 8, 2007. Dried sample were ground to a fine power and analyzed for total N isotope N. 15N was determined using elemental analyzer-isotope ratio mass spectrometry. The calculation of N transfer was determined with the isotope dilution method. The content of N was higher in legumes than that in barley or Italian ryegrass. Nitrogen level in forage pea was significantly higher than that of other legumes. There were significantly differences in N content between legumes in IRG mixture. Atom % 15N excess was significantly different in legumes with barley. The 60:40 sub plot had higher (p<0.05) atom % 15N than other seeding ratio treatments. The enrichment ranged from 0 to 0.58. Compared to barley, the enrichment of IRG with its accompanied legumes was higher, ranging from 0.38 to 1.0. The N derived from the atmosphere (Ndfa) ranged from 0% to 49.5% with barley-legume mixture. It ranged from 0 to 60.5% in IRG-legume plots. N transfer from legumes to neighboring grasses was 12.3 to 90.9 kg/ha for barley-legume mixture and 31.7 to 107.8 kg/ha for IRG plots. IRG plots showed higher N transfer for IRG-legume mixture in general based on difference method. Based on 15N dilution method, the N transfer was 0 to 36.1 kg/ha for barley-legume mixture and 0 to 50.6 kg/ha for IRG plots. There was a tendency toward higher N transfer on the difference method than that of the 15N dilution method.

본 연구는 환경오염을 감소시키고 유기축산물의 생산에 기여할 수 있는 유기조사료를 효율적으로 생산하기 위해 대표적인 동계작물인 청보리에 콩과 사료작물의 혼파와 발효우분을 시용하여 생산성과 사료가치를 평가하고, 토양의 지력 향상과 가축분뇨의 자원화를 위한 가축분뇨의 적정시용수준을 구명하여 단위면적당 유기한우 사육능력을 추정하고자 하였다. 콩과 사료작물의 혼파에 따른 평균 청보리의 건물, 조단백질 및 TDN 수량은 5.09~5.21, 0.48~0.51 및 3.19~3.21 톤/ha으로 단파로 재배했을 경우의 4.28, 0.38 및 2.8톤/ha 보다 유의하게 증가하였으나 혼파구 간에는 차이가 없었고, 발효우분의 질소시용수준이 증가함에 따라 청보리의 평균건물, 조단백질 및 TDN 수량은 무비구(3.97, 0.37 및 2.56 톤/ha)에 비해 100~150 kg N/ha (5.23~5.76, 0.49~0.54 및 3.28~3.55)에서 유의하게 증가하였다(p<0.05). 콩과사료작물의 혼파에 따른 조단백질과 ADF 함량은 헤어리베치 혼파구(각각 9.7과 34.5%) >사료용 완구 혼파구(각각 9.3과 33.0%) >청보리의 단파구(각각 8.7과 30.5%) 순으로 유의하게 낮아졌으며 우분 질소시용수준에 따른 청보리의 조단백질 함량과 NDF 함량은 처리수준 간 유의한 차이가 인정되지 않았지만 ADF 함량은 시용수준이 증가함에 따라 유의하게 증가하였고 TDN 함량은 반대로 감소하였다(p<0.05). 콩과 사료작물의 혼파에 따른 청보리에 의한 유기한우 사육능력(체중 450 kg, 400 g 일당증체 목표)은 평균 2.62~2.72두로 유의하게 증가하였고. 발효우분 질소시용수준이 증가됨에 따라 청보리에 의한 유기한우 사육능력은 유의하게 증가하였다(p<0.05). 이상의 결과를 종합해 볼 때, 청보리 재배 시 콩과 사료 작물의 혼파 하였을 경우에는 단파재배 보다 발효우분의 질소시용수준을 ha 당 50 kg 이상 줄이면서도 건물수량을 포함한 생산성과 유기한우 사육능력 증대는 물론 조단백질 함량 등 사료가치를 향상을 시켜 한우 사양 시 조사료자원의 다양화 뿐 아니라 저투입에 의한 고품질 조사료 생산으로 유기축산물 생산에 크게 기여하리라 사료된다.

This study was conducted to assess the feasibility of near-infrared reflectance spectroscopy (NIRS) as a rapid and reliable method for the estimation of crude protein (CP) fractions in forage legume mixtures (sudangrass and pea mixture, and kidney bean and potato mixture). A total of 178 samples were collected and their spectral reflectance obtained in the range of 400~2,500 nm. Of these, 50 samples were selected for calibration and validation, and 35 samples were used for calibration of the data set, and the modified partial least square regression (MPLSR) analysis was performed. The correlation coefficient (r2) and the standard error of cross-validation (SECV) of the calibration models in the CP fractions, A, B1, B2, B3, and C, were 0.94 (1.05), 0.92 (0.74), 0.96 (0.95), 0.91 (0.42), and 0.83 (0.38), respectively. Fifteen samples were used for equation validation, and the r2 and the standard error of prediction (SEP) were 0.87 (1.45), 0.91 (0.49), 0.94 (1.13), 0.36 (0.96), and 0.74 (0.67), respectively. This study showed that NIRS could be an effective tool for the rapid and precise estimation of CP fractions in forage legume mixtures.

Nitrogen fíxatíon by legumes can be valuable sources for organíc farmíng. Thís study was to ínvestígate the effect of dífferent legume mixtures on nitrogen fíxatíon and transfer to grasses on sp끼ng paddy fíeld. Three different mixtures were used (rye+haíry vetch, Italían ryegrass+crímson clover, oat+pea) in a randomized complete block design with three replications and sowed ín pots wíth different sowing rate (5:5 rye:haíry vetch,7:3=ltalian:crimson, 6:4=oat:pea) on early March. t 5NH4hS04 solutíon at. 99.8 atom%15N was applied to the each pot at the rate of 2kg N ha.1 on 16h Ap끼1. Forage were harvested at ground level ín heading stage and separated ínto legume and grass. Total N content and 15N value were determíned using a continuous f10w stable ísotope ratio mass spectrometry. DM yield of rye+vetch, Italian+crimson and 。at+pea were 6,607, 3,213 and 4,312kg/ha, respectively. Proportion of N from fixatíon was 0.73(rye+vetch), 0.42(1talian+crimson) and 0.93(oat+pea). The percentages of N transfer from legume to grass were from 61% to 24% in dífferent method by treatments and -35% to 21% in ísotope dilutíon method.