• Journal of Plant Biology
• /
• v.11 no.3
• /
• pp.1-7
• /
• 1968

Organic matter in rice-paddy soils exercises two antagonistic effects on the rice plant under water-logged conditions in growing season in the course of its decomposition: It liberates mineral nutrients and promotes soil fertility. On the other hand, however, it demands oxygen for its decay and therefore competes with rice roots for this element, when applied in large quantity of fresh status. For the practical end of rice culture, it is most desirable that these two effects should not contend with each other. To determine the proper content of organic materials to be applied, the influences of varied amounts of a homogeneous mixture of dried green manure, ranging from 0 to 20g/pot (1/20,000 tanbo), upon hte growth of rice was investigated in a sand culture. Labeled phosphorus fertilizer was also used in the form of KH232PO4 to evaluate the availability of this nutrient in the soil. Under the present experimental conditions, green mature seems to have influenced little on the growth of rice, except on number of grains produced and grains/straw ratio. Moreover, no sympton of growth inhibition is obsrvable even by the largest amount of its application. The available phosphorus, as estimated by A-value, appears to have increased, as the amount of organic materials applied increases. In view of the fact that pure sand instead of a paddy soil is used in this culture, the present results would not be directly applicable to practical rice farming. Besides, the estimated A-value is in need of further study, since it varies according to method of application, as suggested by Nishigki et. al. (1958).

• Journal of Environmental Science International
• /
• v.23 no.1
• /
• pp.153-156
• /
• 2014

This study was conducted to evaluate the effects of sea urchin shell powder on nitrogen characteristics in poultry litter by assigning ninety 1-d-old male broiler chicks (Arbor Acres) to one of 3 treatments (control, 1% sea urchin shell powder, and 1% feed additives) in 3 replicates of 10 birds each. For all treatments, the overall dry matter contents were decreased (P < 0.05) as time increased, except for at 1 week. When compared with controls, the dietary sea urchin shell powder and feed additives for 0 and 3 weeks did influence their TN contents, but not for 1, 2 and 4 weeks. The treatments with sea urchin shell powder and feed additives had a significant (P < 0.05) influence on $NH_3$-N in poultry litter compared with controls. However, at 4 weeks, no marked differences were observed in $NH_3$-N contents among treatments. Treatments with 1% sea urchin shell powder might enhance the value of poultry litter as N fertilizer.

• Journal of Environmental Science International
• /
• v.23 no.10
• /
• pp.1693-1701
• /
• 2014

A rapid and simple method for the quantitative determination of volatile fatty acids (VFAs; propionic acid, n-butyric acid, i-valeric acid and n-valeric acid) and indoles (phenol, p-cresol, 4-ethyl phenol, indole and skatole) in pig slurry and dog excrement using solid-phase micro-extraction (SPME) coupled to gas chromatography was evaluated. $50/30{\mu}m$ DVB/CAR/PDMS (Divinylbenzene/Carboxen/Polydimethylsiloxane) fiber was used to extract the target compounds in aqueous media. Sample amount and adsorption time was standardized for the routine analysis. Detection limits were from 0.11 to $0.15{\mu}gL$ for VFAs and from 0.12 to $0.28{\mu}gL$ for indoles and the correlations observed ($R^2$) were 0.975~1.000. This method was applied to the pig slurry, fertilizer, compost and dog excrement. In nearly all cases, the indoles were detected in concentrations of higher than their limits of detection (DOLs). But the VFAs in swine manure were below their DOLs.

• Korean Journal of Medicinal Crop Science
• /
• v.17 no.6
• /
• pp.415-420
• /
• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.

• Korean Journal of Organic Agriculture
• /
• v.19 no.spc
• /
• pp.242-246
• /
• 2011

Organic kiwifruit orchard soils were compared with conventional ones in Korea. Soil structure of organic soil had higher gaseous and liquous phase as well as soil porosity in the surface soil. Although the nutritional level of each orchards were quite different among soils, the analysis of both system revealed that organic kiwifruit orchard soil had similar or even higher nutrient level (N and organic matter content in surface soil) compared to conventional ones. The organic matter content of deep soil also had the high tendency in deep soil of organic soil. Higher level of nitrogen in organic surface soil is presumably due to the excessive application of organic compost and liquid fertilizer rather than the contribution by grasses such as green manure. Available phosphorous level of organic system was quite high but similar in surface soil of both system, compared to the recommended level. Potassium, calcium and magnesium levels were also enough in organic kiwifruit orchard soils.

• Journal of Soil and Groundwater Environment
• /
• v.22 no.4
• /
• pp.49-59
• /
• 2017

This study estimated the nitrogen budget, including gaseous nitrogen oxides ($NO_x$), of South Korea in 2012~2014. The nitrogen budget was classified into three categories: agricultural and livestock, forest, and city. To estimate the nitrogen budget, several input and output parameters were investigated, including deposition, fixation, irrigation, chemical fertilizer use, compost, fuel, denitrification, volatilization, runoff, crop uptake, leaching, and $NO_x$ emissions. The annual nitrogen inputs from 2012 to 2014 were 6,202,828, 6,137,708, and 6,022,379 ton/yr, respectively. The corresponding annual nitrogen outputs were 1,393,763, 1,380,406, and 1,360,819 ton/yr, respectively, signifying a slight decrease from 2012 to 2014. $NO_x$ was the parameter contributing to the nitrogen budget to the greatest extent. The annual ratios of $NO_x$ emissions by vehicles, power plants, and businesses were 0.31, 0.31, and 0.30 in 2012, 2013, and 2014, respectively. A change in government policy that prohibited the disposal of livestock manure and sewage sludge in the ocean from 2012 affected nitrogen budget profile. As a result, the ocean disposal ratio completely diminished, which differs from previous studies.

• Korean Journal of Agricultural Science
• /
• v.49 no.4
• /
• pp.971-978
• /
• 2022

Fertigation, which has been introduced in agricultural fields since 1990, has been widely practiced in upland fields as well as in plastic film houses as part of the crop production system. In accordance with demands in the agricultural sector, a huge number of scientific studies on fertigation have been conducted worldwide. Moreover, with a combination of advanced technologies such as big-data, machine learning, etc., fertigation is positioned as an indispensable tool to achieve sustainable crop production and to enhance nutrient and water use efficiency. In this review, we focused on providing valuable information in terms of crop production and nutrient/water use efficiency. A variety of fertigation studies have described that enhancement of crop production did not differ relative to conventional method or slightly increased. In contrast, fertigation significantly improved nutrient/water use efficiency, with a reduction in use ranging from 20 to 50%. Water-soluble organic resources such as livestock manure and agricultural byproducts also have been identified as useful resources like chemical fertilizers. Furthermore, the initial irrigation point was generally recommended in a range of -10 - -40 kPa, although the point differed according to the crop and crop growth stage. From this review, we suggest that fertigation, which is closely integrated with advanced technology, could be a leading technology to attain not only food security but also carbon neutrality via improvement of nutrient/water use efficiency.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.6
• /
• pp.484-489
• /
• 2003

It is well known that root distribution of rice is a crucial factor for nutrient absorbtion and affect by soil fertility management. However, the findings on root distribution are limited due to laborious and tedious work. The characteristics of root distribution were investigated in long-term fertilizer experiment plots that were established in paddy soil, a fine silty family of typic Hal-paqueps (Pyeongtaeg series) in 1967. fertilizer experiment plots of no fertilizer, compost, NPK and NPK+compost plot have been maintained consistently for the past thirty six year and Npk+silicate plot for the past twenty two years. In NPK plot, 150kg N (urea), 100kg -$\textrm{P}_2\textrm{O}_5$ (fused phosphate) and 100kg $\textrm{K}_2\textrm{O}$(potassium chloride) per hectare have been applied. For NPK+silicate plot, 500kg $\textrm{Si}\textrm{O}_2$ (silicate) was applied in addition to fertilizer in NPK plot. For the compost plot, 10,000kg rice straw compost per hectare were applied. Root samples were taken from the positions of hill-center (below hill) and mid-point of four adjacent rice hills at heading stage by cylinder monolith (CM) method. The soil cores were sampled 20cm depth from the soil surface and partitioned four into layers at an interval of 5cm. The soil particles surrounding roots were washed out with tap water, Length and weight of the roots in each soil layer were measured and root length density (RLD), root weight density (RWD), specific root length(SRL) and rooting depth index (RDI) were calculated. Total root length was measured by intersection method. Plant height, tiller and shoot dry weight were the highest in NPK+compost plot. But RLD of hill-center soil cores was the highest in no-fertilizer plots. In the soil cores from mid-point position of four adjacent hills, RLD at 15-20cm soil depth was higher in compost plot than NPK plot. RLD in compost plots showed even distribution compared to those in chemical- fertilizer plots. RWD was the highest in the NPK+compost plot. SRL was the lowest in the NPK+silicate plot. RDI was the highest in the compost plot. Also, in this experiment it was found that the distribution of roots was closely related to the physical properties of the soil as affected by fertilization management.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.2
• /
• pp.194-199
• /
• 2011

This study was conducted to evaluate fertigation effects of pig slurry (PS) and chemical fertilizer (CF) in cucumber by investigating the growth and yield, nutrient content and uptake, nutrient use efficiency, and soil characteristics in greenhouse cultivation. The cropping patterns of cucumber were semi-forcing culture and retarding culture, and the experiment involves four treatments: No fertilizer (NF), $26mg\;L^{-1}$ and $52mg\;L^{-1}$ of N application by slurry composting biofiltration liquefied fertilizer (SCBLF), and $52mg\;L^{-1}$ of N treatment by chemical fertilizer. The difference on the plant height of cucumber between SCBLF and CF treatments was no significant, but fresh weight and dry weight of stem and root were higher in $26mg\;L^{-1}$ SCBLF treatment. The Ca content of the leaf was lower in the treatments of SCBLF and the K content of the root was lower in the $52mg\;L^{-1}$ CF treatment. The Ca content of the stem was lowest in the $52mg\;L^{-1}$ CF treatment and the mineral content of the fruit showed no significant difference. In case of semi-forcing culture, the gross yield was lower in the $52mg\;L^{-1}$ CF treatment and the yield of unmarketable fruit was lower in the SCBLF treatments. The nutrient use efficiency of cucumber is as follows: K (8.3 ~ 30.9%), N (4.2 ~ 13.0%), P (1.9 ~ 2.0%). The SCBLF treatments showed higher figure in the soil pH than that of the CF treatment, while EC and the content of $NO_3$-N were higher in the CF treatment than the former. The content of exchangeable K was higher in the plot treated with $52mg\;L^{-1}$ SCBLF, and there were no significant differences in the content of Ca and Mg between the treatments. In conclusion, it is suggested that the application of liquefied manure made from pig slurry may be able to replace the use of chemical fertilizer in nitrogen and potassium.

• Korean Journal of Soil Science and Fertilizer
• /
• v.32 no.3
• /
• pp.304-311
• /
• 1999

This experiment was conducted to find out the optimum condition of aeration rates for removal of malodor and to improve the compost quality. The aspect of ammonia emission and amounts of volatilization were investigated in the enclosed composting reactor of 242 liters piled with mixed materials of dairy manure and rice straw, which adjusted to 65% of initial moisture content and controlled by four different aeration rates. Mature temperature increased suddenly in initial composting time and decreased with Increasing aeration rates. The treatment of $1.79l\;min^{-1}kg\;dry-solids^{-1}$ results in overcooling and rapid drying of composting materials because of too much aeration. The average concentration of ammonia emitted from composting for 24 days was the range of 25.3 to $239.8mg\;l^{-1}$ and was highest in the treatment of $0.09l\;min^{-1}kg\;dry-solids^{-1}$, followed by 0.90. 0.18 and $1.79l\;min^{-1}kg\;dry-solids^{-1}$. The range of maximum concentration by different aeration rates was $335{\sim}2279mg\;l^{-1}$ and it wan highest in the treatment of $0.09l\;min^{-1}kg\;dry-solids^{-1}$, followed by 0.18, 0.09 and $1.79l\;min^{-1}kg\;dry-solids^{-1}$. Relationship between the ammonia concentration emitted and temperature matured under different aeration rates showed an exponential positive correlation with 1% significance and had a trend of clear increase in ammonia concentration with increasing temperature over $50^{\circ}C$. Most of ammonia volatilized within plays after composting. The volatilization rate of ammonia ranged from 0.056 to 0.453 per dry solids of materials and it was highest in the treatment of $0.09l\;min^{-1}kg\;dry-solids^{-1}$, followed by 0.18, 0.09 and $1.79l\;min^{-1}kg\;dry-solids^{-1}$. Amounts of ammonia volatilized under composting condition of this experiment was estimated to be highest in the aeration range of 0.9 to $1.0l\;min^{-1}kg\;dry-solids^{-1}$.