• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.141-150
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• 2008

The response of grain yield(GY) and milled-rice protein content(PC) to crop growth status and nitrogen(N) rates at panicle initiation stage(PIS) is critical information for prescribing topdress N rate at PIS(Npi) for target GY and PC. Three split-split-plot experiments including various N treatments and rice cultivars were conducted in Experimental Farm, Seoul National University, Korea in 2003-2005. Shoot N density(SND, g N in shoot $m^{-2}$) and canopy reflectance were measured before N application at PIS, and GY, PC, and SND were measured at harvest. Data from the first two years(2003-2004) were used for calibrating the predictive models for GY, PC, and SND accumulated from PIS to harvest using SND at PIS and Npi by multiple stepwise regression. After that the calibrated models were used for calculating N requirement at PIS for each of nine plots based on the target PC of 6.8% and the values of SND at PIS that was estimated by canopy reflectance method in the 2005 experiment. The result showed that SND at PIS in combination with Npi were successful to predict GY, PC, and SND from PIS to harvest in the calibration dataset with the coefficients of determination ($R^2$) of 0.87, 0.73, and 0.82 and the relative errors in prediction(REP, %) of 5.5, 4.3, and 21.1%, respectively. In general, the calibrated model equations showed a little lower performance in calculating GY, PC, and SND in the validation dataset(data from 2005) but REP ranging from 3.3% for PC and 13.9% for SND accumulated from PIS to harvest was acceptable. Nitrogen rate prescription treatment(PRT) for the target PC of 6.8% reduced the coefficient of variation in PC from 4.6% in the fixed rate treatment(FRT, 3.6g N $m^{-2}$) to 2.4% in PRT and the average PC of PRT was 6.78%, being very close to the target PC of 6.8%. In addition, PRT increased GY by 42.1 $gm^{-2}$ while Npi increased by 0.63 $gm^{-2}$ compared to the FRT, resulting in high agronomic N-use efficiency of 68.8 kg grain from additional kg N. The high agronomic N-use efficiency might have resulted from the higher response of grain yield to the applied N in the prescribed N rate treatment because N rate was prescribed based on the crop growth and N status of each plot.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.630-635
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• 2000

Previous research has not evaluated the effects of various rates and frequencies of manure application and frequencies of cutting on yield and stand persistence of cool-season grasses and alfalfa-grass mixtures. The primary objective of this study was to compare the effects of cutting management systems on herbage yield and stand persistence of orchardgrass (Dactylis glomerata L.) and an alfalfa (Medicago sativa L.)-orchardgrass mixture from various rates and frequencies of dairy slurry application. A randomized complete block design with treatments in a sub-subplot arrangement with four replicates was used. The main plot consisted of 2 cutting management systems (4 and 5 annual cuttings). The subplots were 9 fertility treatments: 7 slurry rate and frequency of application treatments, one inorganic fertilizer treatment, and an unfertilized control. The split-split-plots were the two forage species: orchardgrass and alfalfa-orchardgrass mixture. The study was initiated after 1st cutting in 1995. Cumulative yields of the 2nd and subsequent cuttings of both orchardgrass and alfalfa-orchardgrass in 1995 were higher for the 5-cutting system than the 4-cutting system. The 1995 growing season was abnormally dry. In 1996, an abnormally wet year, the reverse was true, total herbage yields being higher for the 4-cutting system than the 5-cutting system. Species response to fertility rate/frequency treatments was different in both years. Higher application rates early in the season and carryover of nutrients from late season applications the previous year appear to be responsible for the yield increases of those fertility treatments having significant yield differences between the cutting management systems. The stand ratings of orchardgrass were not affected by cutting management. In the spring of 1997, however, the stand ratings of alfalfa-orchardgrass in the 4-cutting management system were significantly greater than the 5-cutting management system. The very high manure application rate significantly reduced the stand ratings of alfalfa-orchardgrass in the 5-cutting system.

• 한국작물학회지
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• 제32권1호
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• pp.61-66
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• 1987

삼투처리와 무처리의 대두종자(품종 :Williams)에 대하여 두가지 온도(15, 3$0^{\circ}C$)에서 두가지의 종자수분함량(30%, 50%)으로 조절된 조건으로 0. 2, 4 및 8일간 전처리함에 있어서 시간별 세세구배치법 4반복으로 배치하여 발아와 묘신장을 조사하였던 바 주요결과는 다음과 같다. 1. 콩의 묘신장은 30에서 2일간 전처리함으로서 촉진되었으나 같은 온도에서 전처리기간이 길수록 억제되었다. 2. 삼투처리후 전처리된 종자는 수분흡수와 묘신장이 떨어졌다. 3. 종자수분함량이 50%로 조절된 뒤 전처리된 것은 체의 수분함량을 증가시켰으며 4일간까지의 전처리는 묘신장을 크게 하였다. 4. 묘의 건물중에서는 전처리온도가 3$0^{\circ}C$ 일때와 종자수분함량이 50%로 조절되어 8일간 전처리하였을 때 감소되었다.

• 한국작물학회지
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• 제14권
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• pp.91-96
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• 1973

우리나라 대두의 단위면적당 생산량은 제외국에 비해 낮은 편이며 그 원인은 여러 가지로 생각할 수 있으나 단시일내에 기존품종으로서 생산량을 높이는데 대두 초형에 따르는 재식방법의 개선이 중요하다고 여겨져 중부지방에서의 밀식적응대두형과 밀식정도의 구명을 위해 본 시험이 수행되었다. 본 시험에서는 모형과 각종 형질이 서로 상이한 품종인 장단백목, 충북백, Clark 등 3개 품종이 공시되었으며 휴폭을 세구로 그리고 주간거리를 세세구로 한 3반복으로서 시험하였다. 주당 분지수와 협수는 밀식에 따라 감소되었으나 동일한 밀도에서는 Clark에서 보다 충북백과 장단백목에서 더 많은 분지수를 가지고 있었으며, 협수에 관해서는 휴폭과 주간거리에 유의한 수준의 상호작용이 있었다. 절수는 품종간에 차이가 현저하였으며 휴폭에 의해서는 전혀 변화가 없었으며 주간거리가 커짐에 따라 Clark에서 약간 증가하였다. 간장도 주간거리에 관해서만 유의차가 현저하였으나 절수의 증가와는 관계없이 도장에 기인하였다. 도복성에는 Clark가 가장 강했으며 이는 이 품종 주경의 탄력성 때문인 것으로 여겨졌다. 밀식조건하에서는 다지성이고 광엽성인 재래품종들보다 절수가 많고 초장이 큰 도입품종 Clark가 공시된 3개 품종중 가장 수량이 많았으며 밀식재배용으로의 가장 알맞은 초형임이 명확하였고 파종은 재래식 점파보다는 조파로 밀식함이 노력이 절약되고 단위면적당 수량도 현저히 증가될 것이다.

• 한국초지조사료학회지
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• 제20권1호
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• pp.41-48
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• 2000

This study was conducted to investigate the effects of the application rate of fermented swine manure and additional mineral fertilizer on productivity and nutritive value of corn(Zea mays L.) for silage. Swine manures used in this study were the compost of swine manure fermented with sawdust(SMFWS) and swine sluny(SS). This study was arranged in split-split plot design. Main plots were the types of swine manure, subplots were the application rate of swine manure, such as 100, 200 and 400kgN/ha, and sub-subplots were the application rate of mineral fertilizer, such as 50 and 100kgNiha. Corn DM(dry matter) and TDN(tota1 digestible nutrient) yields increased as application rate of SMFWS and SS increased. DM and TDN yields in SS treatments were higher than those in SMFWS treatments. The effect of fermented swine manure improved positively as application rate of urea increased. Net energy for lactation(NE1) and TDN content in corn decreased as application rate of SMFWS and SS increased, but crude protein(CP) content increased by the application of SMFWS and SS. NE, and TDN contents in SMFWS treatments were lower than those in SS treatments, but CP content in SMFWS was higher than that in SS. The growth and nutritive value of corn were improved by the application of mineral fertilizer. (Key words : Swine manure, Swine sluury, Compost, Zea may, TDN, Net energy)

• 한국초지조사료학회지
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• 제17권3호
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• pp.293-304
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• 1997

A field experiment was conducted at the forage experimental plots, Seoul National University, Suweon h m 1995 to 1996 to determine the effect of legume residues as a N source and N fertilizer on corn (Zea mays L.) silage yield, N uptake, and availability of inorganic N in the soil. Corn was grown following (i) red clover (Trifolium pratense L.), (ii) crimson clover (Trifolium incarnatum L.), (iii) alfalfa (Medicago sativa L.) and (iv) winter fallow. The plots were split into two rates of fertilizer N (0 and 90kg Nlha) in a split-plot experimental plan. Compared with fallow treatment, legumes depleted soil water in the surface 15cm at corn planting by 17 to 26%. As a result, corn emergence was markedly delayed with legume residues by 8 to 11 days. Corn silage DM yield was significantly reduced in the presence of legume residues by 2.0 to 3.4 and 1.5 to 2.5 tonlha compared with winter fallow treatment at 0 and 90kg fertilizer Nlha, respectively, but no significant difference in the corn DM yield was found between legume residue treatments. There was an overall tendency for increased corn yields with 90kg fertilizer Nlha compared to Okg fertilizer Nlha, although not all yield increases were significantly greater. The corn yield response to applied N suggests that a source of N from legume residues was not sufficient for a succeeding corn crop. There was significantly more N (P

• 한국작물학회지
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• 제55권2호
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• pp.91-97
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• 2010

The growth, yield and chemical properties of waxy corn $Sonjajang{\times}KNU-7$ and $Asan{\times}KNU-7$ planted in different dates and mulch types in a converted paddy field was investigated. Experiment was carried out in a randomized complete block design in a split split-plot arrangement with four replications. Planting dates (D) [May 16 (D1, early), June 1 (D2, middle), June 6 (D3, late)] represented main plots, plastic mulch (M) [(BM, black mulch; TM, transparent mulch)] for subplots while waxy corn crosses [$Sonjajang{\times}KNU-7$ (‘Sonja’) and $Asan{\times}KNU-7$ (‘Asan’)] for sub-subplots. Results showed that D had a significant effect on growth characters except emergence, ear quality except ear diameter, and yield whereas M showed significant effect on growth characters only. Superior growth and ear quality performance were recorded in D1 and BM. In terms of crosses, ‘Sonja’ had better growth performance than ‘Asan’ regardless of D and M, but performed better at D1 and BM. Highest yield was obtained in D1 for BM (2,131 kg $10a^{-1}$) and TM (1,655 kg $10a^{-1}$) but no significant difference in the yield across V was recorded. In terms of starch and sugar contents, a decreasing trend was observed from D1 to D3 regardless of M and V.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1098-1113
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• 2021

Maturation process of alfalfa (Medicago sativa L.) could be prevented by the reduction of lignin content in terms of conventional breeding or transgenic technology. Alfalfa could exhibit higher leaf/stem ratio, with a concern of yield loss. The objective of this study was to compare forage yield and nutritive value of low lignin alfalfa and two reference varieties subjecting to two harvest intervals and three seeding rates. The experimental design was a randomized complete block in a split-split plot arrangement with four replicates, where harvest intervals (28-day and 35-day) were assigned to whole plots, seeding rates were subplots, and varieties were sub-subplots. The weighted mean nutritive value was applied to two production years of 2016 and 2017. Hi-Gest 360 (low lignin alfalfa) provided similar yield potential and increased nutritive value compared to two reference varieties. Over a two-year production period, alfalfa harvested at every 28-day interval provided more economic returns than those at 35-day interval. For the seeding year and first production year, five cuts made by the 28-day interval produced more yield than four cuts by the 35-day interval. Due to limited rainfall in May 2017, a sharp drop of the first cutting overturned the advantage of the five-cut system. Shorter intervals between harvests generally increased crude protein (CP) concentrations. The differences of relative feed value (RFV) between two harvest intervals tended to be great during the first and second cuttings. Overall, harvest interval had a large effect on nutritive value and a more significant effect on alfalfa dry matter yield than variety selection. Seeding rate did not affect alfalfa yield and nutritive value.

• 한국초지조사료학회지
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• 제20권2호
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• pp.115-122
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• 2000

This study was carried out to determine a fertilization rate for productivity and nutritive value improvement of silage corn, using two kinds of composts, and to examine the potential possibility of utilization as an organic fertilizer. The experiment was conducted on the field plot at Gongiam, Kwangju, Kyunggi-Do for 3 years, from 1996 to 1998, and arranged in split-plot design with three replications. The main plots were two kinds of composts such as swine manure fermented with sawdust (SMFWS) and swine manure fermented without sawdust (SMF). Subplots were the nitrogen fertilization rates (0, 100, 200, 300 and 400kgN/ha/year). The dry matter (DM) yield increased as the nitrogen fertilization rate increased up to a rate of 300 kg N/ha, but decreased at rate of 400 kg N/ha. Dry matter yield in SMFWS treatment was higher than that of SMF treatment, but there was no significant difference between SMFWS and SMF treatments. Net energy for lactation (NEI) and total digestible nutrients (TDN) in corn increased as the fertilization rate of SMFWS and SMF increased, and crude protein (CP) content increased by the fertilization of SMFWS and SMF. No difference of CP, NEI and TDN was found between SMFWS and SMF treatments.

• 농업과학연구
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• 제42권3호
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• pp.151-158
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• 2015

This study was conducted to know the variation and relationship of rice grain quality and starch pasting properties by transplanting times. Two early maturing rice cultivars which accounted for the most area of early maturing rice cultivar in Chungnam province were used. The experiment was laid out in a split-plot design with 3 replications. The main plot consisted of three transplanting times viz. early (April 25), ordinary (May 25) and late (June 25) with sub-plots containing two cultivars. According to the transplanting times, most of rice grain quality and starch pasting properties showed significant difference and Joami showed higher grain quality than Unkwang in all transplanting times. Especially, rice grain quality was improved when transplanted late, showing high head rice and glossiness of cooked rice due to the lower mean temperature during grain filling stage. Glossiness of cooked rice was positively correlated with head rice ratio, amylose content and setback value, and negatively correlated with chalky rice ratio and protein content. The highest positive and negative correlation were observed between breakdown value and peak viscosity ($r=0.98^{**}$), and breakdown and setback ($r=-0.94^{**}$), respectively. These results provide some information for rice researchers and producers producing cultivars with an improved quality, suggesting that rice quality is highly influenced by temperature at grain filling stage, and transplanting times is crucial in improving rice quality. In addition, starch pasting properties are useful for determining rice quality because rice grain quality and starch pasting properties are dependent on each other.