The purpose of this study was to investigate the appropriate amount of oats to add to rice and the merits of oat meal. We analyzed the physicochemical characteristics, cooking properties, functional components, and sensory evaluation according to the amount of oats added in the cooked rice. Compared with rice, the oat showed higher level in protein, fat, total β-glucan and total polyphenol, but not for starch. Therefore, the amount of chemical and functional components was increased significantly with the increase in the amount of oats added. Water absorption and expansion were decreased with the increase in the amount of oat added. Oleic acid content was increased and linoleic acid content was decreased slightly. Unsaturated fatty acid content was greatly increased. The DPPH and ABTS radical scavenging activity were increased significantly according to the amount of oats added. As a result of sensory evaluation, the most appropriate amount of oat added was 20% and 30%. By the addition of oat, the β- glucan content of the cooked rice and the antioxidant activity could increase.

The cultivation of green manure crops provide various beneficial influences on agricultural systems. However, there have been few studies on the use of green manure crops on upland field in Korea. The purpose of this study is the selection of green manure crop species suitable for subsequent upland crops. For this study, two leguminous green manure crops and four graminaceous crops were used as following: (1) hairy vetch (Vicia villosa Roth), (2) crimson clover (Trifolium incarnatum), (3) barley (Hordeum vulgare L.), (4) rye (Secale cereale L.), (5) triticale (Triticosecale wittmack), (6) wheat (Triticum aestivum L.). Plant-available nitrogen (PAN) release from each green manure crops was estimated using PAN prediction equation. Graminaceous green manure crops produced more biomass (dry plant matter) up to 1.5 times than leguminous crops. However, PAN % was much higher in leguminous crops due to their high nitrogen content (2.4 ～ 4.4%). In late may, hairy vetch was estimated to provide PAN as much as 11kg/10a which meet nitrogen need for nearly all (except waxy corn) upland crops used in this study. However, PAN from crimson clover and graminaceous green manure crops was much lower mainly due to low biomass production and low nitrogen content, respectively. Overall, hairy vetch could be most appropriate green manure crop for upland crop cultivation in Korea.

This study evaluated the effect of organic fertilizer on the yield of sesame and the movement of nitrogen and carbon in soil under mulching cultivation. The seven fertilizer treatments investigated are as follows: 1) 8-4-9 kg N-P2O5-K2O 10a-1-control, 2) 80% of control treatment N from mixed expeller cake (MEC)-MEC 80%, 3) 100% of control treatment N from MEC-MEC 100%, 4) 80% of control treatment N from mixed organic fertilizer (MOF)MOF 80%, 5) 100% of control treatment N from MOF-MOF 100%, 6) 80% of control treatment N from latex coated urea complex fertilizer (LCU)-LCU 80%, and 7) no nitrogen. The soil mineral N available in the applied organic MEC and MOF fertilizers was less than the available N in the applied urea fertilizer during the early growth stage of sesame but the amount was observed to increase with time. The concentration of nitrate-N in leached solution 35 days after application was highest at 75 mg l-1 in the control, followed in descending order by MEC 100%, MOF 100%, LCU 80%, MOF 80% and MEC 80%. The concentration of nitrate-N in the leachate in all treatments was observed to rapidly decrease 45 days after fertilizer application and recorded at less than 20 mg l-1 65 days after application. The concentration of dissolved organic carbon in the leached solution and organic carbon in the soil of the organic fertilizer plots was higher than in the urea- and LCU-fertilized plots during the whole growing period. The yields of sesame applied with MEC and MOF organic fertilizers were 2 to 7% higher than those fertilized with urea. The amount of retained mineral N or organic carbon in the soil is higher in the LCU and organic fertilizer plots than in the urea-fertilized treatments, which resulted in the reduction of nitrate leaching, increasing N efficiency and sesame yield.

Ammonia (NH3 ) volatilization from a silty clay loam paddy soil applied with non, straight urea, and coated urea, respectively, under transplanting in Milyang, Korea from 2002 and 2003 was simulated by a Water and Nitrogen Management Model (WNMM). Based on the data from the in-situ measurements, NH3 volatilization during the rice growth was 6.04% and 1.46% of the applied nitrogen (N) from straight urea and coated urea, respectively. The bulk aerodynamic approach in WNMM satisfactorily predicted the difference in NH3 loss during the given rice growing seasons from the two urea fertilizers. R2 for the correlation between the predicted and observed NH3 loss during the calibration year (2002) was 0.53 less than 0.68 of the application year (2003). This difference could be due to the weather condition such as heavy rainfall and temperature during the calibration year.

This study was conducted to evaluate the effect of slow release fertilizers (SRF), crotonylidene diurea (CDU) and latex coated urea (LCU), on nitrogen (N) use efficiency (NUE) and nitrate-N leaching in a silty clay loam soil under polyethylene film mulching (PFM) for sesame cultivation. In PFM plot, concentrations of NO3-N and NH4-N in SRF applied soils were less than that in the urea plot during the whole growing period. However, NO3-N and NH4-N in all the non-mulched plots (NM) were not significantly different. Urea-N in soil treated with SRF was higher than urea plot until 50 days after application and was comparable in all the treatments after 50 days. NO3-N concentrations in leached solution in 21 days after urea fertilization in PFM and NM were 26 mg L-1 and 83 mg L-1 , respectively. However, NO3-N in leached solution at applied CDU and LCU was less than that of urea similar to nitrate concentration in soil. NO3-N in leached solution in applied CDU and LCU in 44 days after application was about 25% lower than that urea plot and PFM, while the NO3-N concentration of CDU and LCU treatment in NM did not changed. Application of SRF increased the yield of sesame and N recovery compared to urea and there was a little difference between SRF and N levels. In conclusion, application of 80% N level with SRF increased N recovery and reduced nitrate leaching without reduction of yields compared with urea application.

In Korea, silicate fertilization (SF) is being practiced every four years to enhance rice production. However, the relationship between nitrogen (N) and SF in view of growth characteristics and grain yield of rice has not been examined after watermelon cropping in plastic film house. This study was carried out to identify useful critical N and Si fertilizer levels to sustain grain yield and to improve N use efficiency for rice. The watermelon-rice cropping system has maintained for three seasons in each year from 1998 to 2001 by farmer before this experiment. Experiments on N and Si fertilization levels were evaluated with Hwayoungbyeo (Oryza sativa L.) in 2002 and 2003 at Uiryeong, Korea. The goal of this experiment was to find out the optimum N and Si levels to sustain rice yield by reducing excessive N fertilizer in watermelon-rice cropping system. Nitrogen fertilization (NF) levels were three (0,~;57,~;114kg~;ha-1;0,~;50,~;100% of conventional NF amount) and five (0, 25, 50, 75, 100%) in 2002 and 2003, respectively, and combined with three SF levels (70,~;130,~;180mg~;kg-1;100,~;150,~;200% which were adjusted with Si fertilizer in soil) were evaluated for the improvement of N and Si fertilization level in both years. Rice yielded 3.98-5.95 and 2.84-4.02 t/ha in 2002 and 2003, respectively. Our results showed the combinations of 50% and 100% of N with 200% level of Si produced the highest grain yield in both years, respectably. The grain yield was greatly improved in plot of N25% level when compared to conventional NF (Nl00%) in 2003. In conclusion, NF amount could be reduced about 50% compared to recommended level by specific fertilization of N and Si combination levels for rice growing and grain yield after cultivation watermelon in paddy field.

Korea, rice cultivars have been changing to 'quality' rice rather than high yielding cultivars. However, more than 10% of paddy field has been changed to greenhouse in winter season for cropping of water-melon, oriental-melon, straw berry and et cetra. This experiment has been made to identify the usefulness of critical N and Si fertilization(SF) level to obtain high grain quality rice with reduced insect pest damage by N and SF combination. Before the experiment, watermelon-rice cropping system was maintained for three seasons by farmer from 1998 to 2001. The experiment of N and Si (silicate) fertilization levels was evaluated with Hwayoung-byeo (Oryza sativa L., medium-maturing variety) in 2002 and 2003 in Uiryeong, Korea. Nitrogen fertilization (NF) levels were three and five in 2002 and 2003, respectively, and three SF levels were compared for getting the valuable N/SF level in both years. TOYO-value was positively affected by Si application in N100% plot but it was negatively related with NF level. Normal grain percentage was positively related with TOYO-value and it was highest in 0N plot and Si plots in N100%. Other appearance qualities like powdered, damaged, and cracked grain, were decreased with increasing N fertilization level. SF improved appearance quality in N100% plots but no effects in other treatments. Leaf sheath related diseases were significantly decreased by SF but it was negatively related with NF. In conclusion, SF could be improve grain quality at the same yield levels of conventional fertilization and it also could be reduce the diseases damages of rice plant in all N treatments. NF treatment reduced grain quality and improved grain yield at N50% level, however NF above N50% could not get any kind of benefits. So, compared with conventional fertilizer, reduced NF level is recommended for high grain quality with reduced insect pest damage.

A long-term experiment was carried out to examine the effects of compost on the long-term trends and synergy effects with chemical fertilizer and saving the chemical fertilizers of paddy cropping. The experiment was conducted for the past 36 years with constant amounts of N, P, K and compost in a paddy field at Milyang, South Korea. Grain yield was significantly increased in the plots with compost application. Twenty five years after the compost treatment, grain yield was significantly increased and it reached almost 90% of NPK plots. The effect of rice straw compost on grain yield was not clear during the early cropping years about 60%, but it slightly increased there after about 95% during the late five years. In compost plots, soil organic matter content, K and SiO2 was greater in the compost applied plots than with application of recommended doses of NPK. However, soil pH was reduced in compost applied plots and Ca, and Mg were remained unchanged when compared to the application of recommended doses NPK. Soil nutrient contents were less in compost applied plots than with the application of recommended doses of NPK along with compost but was found to be increased than that of un-fertilized plots. The present study indicated that the application of rice straw compost with NPK is the best of all and followed by NPK and Compost. However, treatment of Compost is time consuming and hard working desired and eventually non economical practice in mechanized agricultural systems, even though Compost is very useful source of improving the soil fertility and its physical characteristics and also the application of inorganic N and P are essential for sustaining high yield.