• Korean Journal of Soil Science and Fertilizer
• /
• v.22 no.1
• /
• pp.45-52
• /
• 1989

The effects of soil properties and N, P and K application rates on the contents of inorganic constituents in the rhizomas of Ji-whang were investigated to know the condition for producing the better quality rhizoma of Ji-whang. Most of soil texture for Ji-whang cultivating belongs to sandy clay loam and sandy loam soils. The nitrogen contents in the rhizomas of Ji-whang was negatively correlated with the contents of organic matter and total nitrogen in surface soils, whereas positively correlated with the sand contents in subsoils. The calcium contents in the rhizomas of Ji-whang were negatively correlated with the sand contents, however, positively correlated with the contents of clay and organic matter in soils. The iron contents was positively correlated with the contents of clay, available phosphorus and exchangeable potassium in surface soils. Much more contents of the inorganic constituents in the leaf of Ji-whang was generally detected than that in the rhizoma of Ji-whang. The contents of iron and copper in the leaf was determined to be more than that in the rhizomas by ten times. In the results of field experiments, it is apparent that the nitrogen contents in the rhizoma and leaf increased with increasing N application rate more than 20kg/10a and 10kg/10a, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.1
• /
• pp.21-28
• /
• 2009

Detailed information on soil characteristics is of great importance for the use and conservation of soil resources that are essential for human welfare and ecosystem sustainability. This paper introduces soil inventory of Korea focusing on national soil database establishment, information systems, use, and future direction for natural resources management. Different scales of soil maps surveyed and soil test data collected by RDA (Rural Development Administration) were computerized to construct digital soil maps and database. Soil chemical properties and heavy metal concentrations in agricultural soils including vulnerable agricultural soils were investigated regularly at fixed sampling points. Internet-based information systems for soil and agro-environmental resources were developed based on 'National Soil Survey Projects' for managing soil resources and for providing soil information to the public, and 'Agroenvironmental Change Monitoring Project' to monitor spatial and temporal changes of agricultural environment will be opened soon. Soils data has a great potential of further application in estimation of soil carbon storage, water capacity, and soil loss. Digital mapping of soil and environment using state-of-the-art and emerging technologies with a pedometrics concept will lead to future direction.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.1
• /
• pp.39-48
• /
• 2019

Objective of this study was to evaluate an optimum biochar application rate and estimate the carbon sequestration based on the soil chemical properties and growth responses for biochar application during tomatoes cultivation. The treatments consisted of control as recommended application rates of fertilizers, 0.01%, 0.03%, 0.05%, and 0.07% of biochar application(w/w, biochar:soil). For effects of soil chemical properties, the $NO_3-N$contents in the soil were peaked at 9 days after transplanting. But there was not significant difference(p>0.05) among the treatments during cultivation periods. However, $NH_4-N$ contents in the biochar treatment were lower than the control until 14 days of transplanting. $P_2O_5$ contents in the biochar treatments were lower than that of the control until 19 days after transplanting except 0.01% of biochar application plot. $K_2O$ contents in soils treated with 0.01% and 0.03% of biochar were higher until 6 days after transplanting than that in the control. For N use efficiency of biochar application, it was observed that the 0.05% biochar application plot was highest among the treatments. The highest carbon sequestration was estimated at $2.83mg\;kg^{-1}$ for 0.03% of biochar application. However, it is considered that the optimum biochar application rate was 0.05% for tomato cultivation, considering the growth characteristics and yield components.

• Korean Journal of Organic Agriculture
• /
• v.26 no.4
• /
• pp.677-686
• /
• 2018

This study was carried out to determine the effect of Kluyvera sp. CL-2 (KACC 91283P) on the growth of watermelon (Citrullus vulgaris L.). The study consisted of three treatments, no treatment (NT), twice application of Kluyvera sp. CL-2 before transplanting (KC1), and five times application around transplanting (KC2). We determined the chemical properties of soil before and after the treatments, and compared the growth characteristics of watermelon among treatments. The treatment of Kluyvera sp. CL-2 at $1.0{\times}10^6cfu\;mL^{-1}$ significantly increased available $P_2O_5$. The organic matter showed to increase for all treatments, while soil pH, exchangeable Ca and Mg tended to decrease for all treatments. The leaf width was increased by 11.6% for KC1 and 26.2% for KC2 compared to NT. But there were no significant differences in yield, leaf length, fruit weight, fruit length, fruit width, and pericarp thickness among treatments. The contents of free sugars such as fructose and glucose were increased by microbial treatments but sucrose was not different from NT. The content of glucose in watermelon was increased by 13.8% in KC1 and 12.8% in KC2 compared to NT. The content of fructose increased by 14.6% in KC1 and by 39.8% in KC2 compared to NT. The results from the study imply that Kluyvera sp. CL-2 can be used to increase sugar content in watermelon.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.26 no.4
• /
• pp.11-19
• /
• 2018

This study was conducted to develop the manufacturing method of biochar using pruned stems of pear tree and its application effect on the crop growth and soil physico-chemical properties. In this study, biochar derived from pruned stems of pear tree at heating temperature of $300^{\circ}C$, $500^{\circ}C$ and $700^{\circ}C$ in heating times of 2, 3 and 4 hours, were tested in the changes of their chemical properties during biochar processing. The pH, Exch. K, Exch. Mg and cation exchange capacity (CEC) increased as the pyrolysis temperature increased during the production of biochar, and the change of these properties rapidly occurred at $500^{\circ}C$. However, as the pyrolysis temperature increased, ash content increased and total carbon (T-C), yield decreased. And the change of the properties in response to the heating time was not shown. It was thought that it would be desirable to set the production conditions of biochar at $500^{\circ}C$ for 2 hours in consideration of the change of chemical properties and the ash content and yield. And also, were conducted the experiments to establish manufacturing method of farm-made biochar using drum biochar manufacturing machine and investigate the application effects of biochar on the cultivation of chinese cabbage and tomato. Application of biochar derived from pruned stems of pear tree could enhance pH, organic matter (OM), total carbon (T-C) of soil. On the other hand, soil electrical conductivity (EC), NO3-N were lowered compared to the control which has no application. The bulk density, porosity and aggregate formation of soil were improved by biochar application. The fresh matter yields of chinese cabbage and tomato were significantly increased in proportion to the application rate of biochar. This study demonstrated the effect of the biochar derived from agricultural byproduct to be as a low cost potential soil ameliorant by physico-chemical properties in eco-friendly greenhouse cultivation.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.460-467
• /
• 2022

The purpose of this study is to enhance utilization of the waste nutrient solution (WNS) disposed at the hydroponic greenhouse. Several sets of testing were conducted to examine the effects of WNS: (a) a fertilizer effect, (b) soil column leaching, and (c) crop cultivation. The fertilizer effect test was applied in young radish cultivation by examining the growth characteristics of young radish and soil based on inorganic nitrogen according to the soil treatment of the nitrogen fertilizer (NF) and the WNS. The fertilizer effects and crop cultivation test were conducted with five treatments (A-E): A, non-treatment (water); B, 100% of NF; C, 70% of NF + 30% of WNS; D, 50% of NF + 50% of WNS; and E, 30% of NF + 70% of WNS. The soil column leaching test was conducted with three treatments: non-treatment (water), 100% of NF, 50% of WNS + 50% of NF. As a result, the chemical properties of the WNS were pH 6.0, EC 2.4dS·m^-1, total phosphorus (T-P) 28mg·L^-1, ammonium nitrogen (NH₄-N) 5.0mg·L^-1, and nitrate nitrogen (NO₃-N) 301mg·L^-1. The chemical properties of the soil were pH 5.51, EC 0.31dS/m, organic matter 2.08g·kg^-1, NO₃-N 9.64mg·kg^-1, and NH₄-N 3.20mg·kg^-1. The results of fertilizer effects showed that the ratio of 50% or less of NF and 50% or more of WNS was high in young radish growth. There was no statistically significant difference between the soil chemistry in the C-E treatments where WNS was mixed with NF and the B treatment where only NF was applied. As a result of the soil column leaching test, there was no significant difference in the concentrations of NO₃ and NH₄ in the treatment of 100% of NF and 50% of NF + 50% of WNS. The study indicates, if the mixed fertilizer of WNS and NF is applied in the soil cultivation of young radish, it will reduce the use of NF and environmental pollution. This also helps reduce production costs on farmers and increase the yield of young radish.