The objective of this study was to verify the effect of pig slurry application with acidification and biochar on feed value, nitrogen use efficiency (NUE) of maize forage, and ammonia (NH3) emission. The four treatments were applied: 1) non-pig slurry (only water as a control, C), 2) only pig slurry application (P), 3) acidified pig slurry application (AP), 4) acidified pig slurry application with biochar (APB). The pig slurry and biochar were applied at a rate of 150 kg N ha-1 and 300 kg ha-1, respectively. The AP and APB treatments enhanced all feed values compared to C and P treatments. The NUE for plant N was significantly increased 92.1% by AP and APB treatment, respectively, compared to the P treatment. On the other hand, feed values were not significantly different between AP and APB treatments. The acidification treatment with/without biochar significantly mitigated NH3 emission compared to the P treatment. The cumulative NH3 emission throughout the period of measurement decreased by 71.4% and 74.8% in the AP and APB treatments. Also, APB treatment reduced ammonia emission by 11.9% compared to AP treatment. The present study clearly showed that acidification and biochar can reduce ammonia emission from pig slurry application, and pig slurry application with acidification and biochar exhibited potential effects in feed value, NUE, and reducing N losses from pig slurry application through reduction of NH3 emission.

The objective of this study was to prove the effect of pig slurry application with charcoal on nitrogen use efficiency (NUE), feed value and ammonia (NH3) emission from maize forage. The four treatments were applied: 1) non-pig slurry (only water as a control), 2) only pig slurry application (PS), 3) pig slurry application with large particle charcoal (LC), 4) pig slurry application with small particle charcoal (SC). The pig slurry was applied at a rate of 150 kg N ha-1, and the charcoal was applied at a rate of 300 kg ha-1 regardless of the size. To determine the feed value of maize, crude protein, dry matter intake, digestible dry matter, total digestible nutrient, and relative feed value were investigated. All feed value was increased by charcoal treatment compared to water and PS treatment. Also, the NUE for plant N was significantly higher in charcoal treatments (LC and SC) compared to PS treatment. On the other hand, there is no significant difference for feed value and NUE between LC and SC. The NH3 emission was significantly reduced 15.2% and 27.9% by LC and SC, respectively, compared to PS. Especially, SC significantly decreased NH3 emission by 15% compared to LC. The present study clearly showed that charcoal application exhibited positive potential in nitrogen use efficiency, feed value and reducing N losses through NH3 emission.

This study was conducted to evaluate the effects of green manures and complemental fertilization with oil cake or liquid fertilizer on growth and nitrogen use efficiency of Chinese cabbage cultivated in organi systems. Field experiments were carried out at the National Institute of Agricultural Science in Suwon, South Korea from 2012 to 2014. Two green manure crops, Crotalaria and Hairy vetch, was cultivated in summer and in winter, respectively. The application methods of the green manure consisted of three tillage systems (overall tillage, partial tillage and no tillage). Oil cake and liquid fertilizer were used as complemental fertilizer. The results showed that when used as covering material in the upland soil without tillage, green manure fertilization was more effective in increasing growth and yield of Chinese cabbage than when incorporated into soil. It was possible to grow and harvest Chinese cabbage in the spring season by the application of hairy vetch as winter green manure. The higher yield of Chinese cabbage with green manure application was caused by the lower incidence rate of soft rot and tip-burn. The yield of the Chines cabbage that received green manure applications over two consecutive seasons followed by the supplemental fertilization with oil cake was similar to that of the conventional chemical fertilization. Following a single season green manure application in summer, however, the yield of cabbage was only about 70% of the conventional treatment. Green manure cultivation with additional liquid fertilization produced a yield similar to the conventional fertilization treat-ment, soil inorganic nitrogen concentration remained stable and the nitrogen use efficiency increased in the green manure applied soil. In conclusion, the organic cultivation of Chinese cabbage in the autumn season could be outperformed in the upland soil receiving two seasons (winter and summer) of green manure fertilization followed by the supplemental fertilization with liquid fertilizer.

A field study was conducted to understand nitrogen use efficiency of high yielding Japonica rice varieties under three levels of nitrogen fertilizer (90, 150 and 210 kg N ha -1 ) in Iksan, Korea. Two high yielding rice varieties, Boramchan and Deuraechan, and an control variety, Dongjin2, were grown in fine silty paddy. Nitrogen use efficiencies (NUE) were 83.3, 56.3, and 41.2 in 90, 150, and 210 kg N ha -1 fertilizer level, respectively. Total nitrogen uptake varied significantly among nitrogen levels and varieties. Variety Dongjin2 showed the highest nitrogen uptake efficiency (NUpE), while Boramchan and Deuraechan showed higher nitrogen utilization efficiency (NUtE). However, Nitrogen harvest index (NHI) was higher in Boramchan (0.58) than Deuraechan (0.57) and Dongjin2 (0.53). Rough rice yield showed linear relationship with total nitrogen uptake (R 2 =0.72) within the range of nitrogen treatments. Boramchan produced significantly higher rough rice yield (8546 kg ha -1 ) which mainly due to higher number of panicles per m 2 compared to Deuraechan (7714 kg ha -1 ). Deuraechan showed higher number of spikelets per panicle, but showed lower yield due to lower number of panicle per m 2 . Rice varieties showed different nitrogen uptake ability and NUE at different nitrogen level. Plant breeders and agronomist should take advantage of the significant variations and relationships among grain yield, NUpE, and NUE.

2001년 국립식량과학원 인공기상실에서 수경재배로 규산의 시용 여부가 영양생장기 벼의 수분과 질소흡수량에 미치는 효과를 조사하여 규산시용 여부 및 공급된 질소의 형태별 처리에 의한 시험품종들의 수분과 질소이용효율을 산출한 결과는 다음과 같다.1. 처리 67일 후의 벼 건물중은 규산처리 시험구 및NH4+NO3 혼합시용 처리구가 규산을 처리하지 않은시험구 및 NH4 단독시용 처리구보다 유의하게 증가하였음.2. 이앙 후 67일간 조사된 벼의 수분흡수량은 규산처리와 규산 무처리 간의 차이가 없었으나 질소흡수량은규산 무처리에 비해 규산처리구에서 유의하게 증가하였음.3. 질소형태별로는 NH4 단독 시용보다 NH4+NO3 혼합시용에서 규산처리 여부와 관계없이 수분과 질소흡수량이 월등히 많았음.4. 수분이용효율은 규산처리 시험구가 규산을 처리하지않은 시험구에 비해 유의하게 증가하였으나 질소형태별 처리에서는 차이가 없었음.5. 질소형태의 혼합처리가 암모늄태 단독처리보다 질소흡수량은 유의하게 많았으나 질소이용효율은 감소하였음.

Agriculture plays a vital role in the sustenance of human society and is the fundamental of developing economies. Nitrogen is one of the most critical inputs that define crop productivity. To ensure better value for investment as well as to minimize the adverse impacts of the accumulative nitrogen species in environment, improving nitrogen use efficiency of crop plants is of key importance. Efforts have been made to study the genetic and molecular biological basis as well as the biochemical mechanisms involved in nitrogen uptake, assimilation, translocation and remobilization in crops and model plants. This review gives an overview of metabolic, enzymatic, genetic and biotechnological aspects of nitrogen uptake, assimilation, remobilization and regulation. This review presents the complexity of nitrogen use efficiency and the need for an integrated approach combining physiology, quantitative trait genetics, system biology, soil science, ecophysiology and biotechnological interventions to improve nitrogen use efficiency.

　A total of 41 microsatellite markers were used with 29 genotypes to examine the relationship between SSR polymorphisms and N‐use efficiency related traits with a goal to identify the putative QTLs related to these traits. These primers yielded a total of 183 alleles (average 4.46 alleles per primer), and polymorphism information content (PIC) values of the SSRs ranged from 0.119 to 0.805 with mean value of 0.425. Correlation coefficients were obtained among the four N‐use efficiency traits in the 34 accessions and significant positive correlations of relative ratios between grain yield and harvest index (r=0.3404) and total dry matter (r=0.7976), while N uptake showed a moderate level of correlation with the ratios of the grain yield and total dry matter, respectively. 36.5% (15/41) SSR markers were monomorphic among the 25 japonica accessions out of the 29 accessions. Association between SSR genotypes and phenotypic performances from the total (29) or japonica (25) accessions was tested based on a single point analysis. Three putative QTL regions were detected for the ratio of grain yield. These include the chromosomal region containing the RM283 locus on chromosome 1 and RM25 on chromosome 8 (all and japonica accessions) and the region with the SSR marker, RM206 on chromosome 11 (the japonica accessions). For the total dry matter ratio, two chromosomal regions were identified as the putative QTL region. One is the region with the SSR marker, RM162 on chromosome 6 (all and japonica accessions) and the other was the one with the SSR marker RM25 on chromosome 8 (the japonica accessions). Among these markers, RM25 showed associations with both traits.

This study was carried out to evaluate the variation of physiological nitrogen-use efficiency (PNUE: Grains yield/total nitrogen content of shoot) in rice under different nitrogen (N) fertilizer levels, and to investigate the relationship of PNUE with agr

This experiment was conducted to investigate the variation of nitrogen(N) uptake efficiency and their relationships withciency and partitioning parameters as physiological N use efficiency [PNUE], agronomic N use efficiency [ANUE], apparentrecovery [AR],