• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.6
• /
• pp.904-909
• /
• 2012

Acid sulfate soil (ASS) and potential acid sulfate soil (PASS) are distribution in worldwide and originate from sedimentary process, volcanic activity, or metamorphism and are problematic in agriculture and environmental due to their present and potential acidity developed by the oxidation. The PASS was defined as soil materials that had sulfidic layer more than 20 cm thick within 4 m of the soil profile and contained more than 0.15% of total-sulfur (T-S). A tentative interpretative soil classification system was proposed weak potential acid sulfate (T-S, 0.15-0.5%), moderate potential acid sulfate (T-S, 0.5-0.75%) and strong potential acid sulfate (T-S, more than 0.75%). PASS due to excess of pyrite over soil neutralizing capacity are formed. It provides no information on the kinetic rates of acid generation or neutralization; therefore, the test procedures used in acid base account (ABA) are referred to as static procedures. The net acid generation (NAG) test is a direct method to measure the ability of the sample to produce acid through sulfide oxidation and also provides and indication. The NAG test can evaluated easily whether the soils is PASS. The samples are mixed sandy loam and the PAS from the hydrothermal altered andesite (1:3, 1:8, 1:16, 1:20, 1:40, 1:80 and 1:200 ratios) in this study. We could find out that the NAG pH of the soil containing 0.75% of T-S was 2.5, and that of the soil has 0.15% of T-S was 3.8. NAG pH test can be proposed as soil classification criteria for the potential acid sulfate soils. The strong type has NAG pH of 2.5, the moderate one has NAG pH of 3.0, and the weak one has NAG pH of 3.5.

• Asian Journal of Turfgrass Science
• /
• v.23 no.1
• /
• pp.133-142
• /
• 2009

This study was initiated to evaluate the K leaching potential in the green soils and K uptake by the turfgrass in the golf course using the K fertilizers. The turfgrass, Floradwarf bermudagrass(Cynodon dactylon L. $P_{ERS}$.) was planted and grown in the mixture of sand and peat moss in this lysimeter study. Eight representative K fertilizers, such as, monopotassium phosphate (MKP), KCL, $K_2SO_4$, $KNO_3$, CKCl, $CK_2SO_4$, $CKNO_3$, and 0-20-20(liquid) were used in this study. Based on the total K quantity of leachate collected during the whole 12 weeks, 0-20-20 is the K fertilizers the most contributing to the leaching of K, then MKP, the second, KCL, the third, and finally $KNO_3$ are K fertilizers contributing to the K leaching. However, most amount of K applied and collected in the lysimeter were leached during the first period of two and four weeks, compared to that of K leached during the second period of six, eight, ten, and twelve weeks. Application of CKCL and $CK_2SO_4$ producted the largest amount of total dry matter, then MKP and KCL, $KNO_3$ and $CKNO_3$, 0-20-20 in second group. However, except $K_2SO_4$, most K fertilizer sources such as MKP, KCL, $KNO_3$, CKCL, $CK_2SO_4$, $CKNO_3$, 0-20-20 showed the largest amount of K uptake, except $K_2SO_4$. Therefore, based on the K leaching, dry matter production, and plant K uptake, it appears that the coated fertilizers, CKCL, $CKNO_3$, and $CK_2SO_4$ are the environmentally sound fertilizers recommended in the turfgrass green soil of golf course.

• Journal of the Mineralogical Society of Korea
• /
• v.19 no.2 s.48
• /
• pp.71-80
• /
• 2006

We examined the mineralogical composition of pyrite-bearing rocks by quantitative powder X-ray diffraction analysis using the matrix-flushing method and ROCKJOCK (a full pattern fitting computer program). The neutralization potential (NP) and acid generating potential (AP) were calculated on the basis of mineralogical compositions. The mineralogical AP was compared with the conventional AP calculated from bulk sulfur concentration to assess the applicability to the prediction of acid rock drainage(ARD). The pyrite content calculated by matrix-flushing method showed a high positive correlation($r^2$=0.95) with those by ROCKJOCK. The pyrite contents by matrix-flushing method was 1.45 times larger than those by ROCKJOCK. The pyrite content and mineralogical AP obtained by the matrix-flushing method had a better correlation($r^2$=0.98) with those by the total sulfur concentrations in the all samples except KB sample. The mineralogical NPs of YJ sample were 23.0 and 34.0(kg $CaCO_3$ equivalent per tonne) by matrix-flushing method and ROCKJOCK, respectively. The AP calculated by matrix-flushing method and ROCKJOCK program were 47% and 72% of those by the conventional ABA test. We hereby suggested that the quantitative analysis using XRD data can be applied to prediction of ARD. For more reliable calculation of the mineralogical NP and AP, other sulfide and carbonate minerals such as pyrrhotite, dolomite, ankerite, siderite, rhodochrosite which can affact the mineralogical NP and AP should be considered.

• Journal of Oral Medicine and Pain
• /
• v.31 no.1
• /
• pp.79-89
• /
• 2006

The aim of this study is to know how the rat submandibular gland changes under various emotional stress condition, using molecular biological methods. Restraint and chronic unpredictable mild stress (CUMS) experiment is conducted on fifty one 7-week old Sprague-Dawley rats (restraint stress experiment: 21, CUMS: 30). The rats were sacrificed, the submandibular glands were excised immediately at certain time, and examined by the use of immunohistochemistry and western blotting. In CUMS experiment, sucrose preference test, water intake change, weight change were implemented at 1 week interval for the experimental period The results are as follows: 1. The number of clusterin-secreting cells of restraint stress group compared to control group showed significantly decreasing tendency in all experimental groups except for the 1st hour group (p<0.001 in the 9th, 24th, 72nd, 120th, and 168th hour group). 2. The number of clusterin-secreting cells of CUMS group compared to control group showed significantly increasing tendency in the 2nd week group (p<0.01), and significantly decreasing tendency in the 4th and 5th week group (p<0.001). 3. Sucrose preference test in CUMS experiment showed significant difference between the 5th week experimental group and control group (p<0.01). 4. Weight change in CUMS experiment showed significant difference between the 5th week experimental group and control group (p<0.01), but water intake change didn't show significant difference compared to control group. 5. In western blot analysis, clusterin expression was decreased on a gradual basis in due time compared to the control group in the restraint stress group. As for CUMS group (chronic unpredictable mild stress group), it was increased till the 2nd week and decreased till the 5th week after that, which is similar to immunohistochemical analysis result and the decreasing tendency of sucrose preference and weigh changes. Through the test, it was proved that expression of clusterin in saliva glands decreases after receiving either acute or chronic stress, indicating relation with depression caused by chronic stress. Unlike other data, however, apoptotic tendency was hardly found in tissues. Diverse possibilities could be suggested on that: first, the stress was not enough to expedite apoptosis; second, apoptosis-related protein was already being secreted though not detected with microscope; third, clusterin, a major secretion molecule of saliva, decreased with saliva's malfunction due to stress. In the respect, it will be necessary to examine proteins expressed in case of cell death or other heat-shock proteins at the same time, in order to see whether any cellular change or death is caused by decreasing clusterin under high stress, and whether the original state is restored as time goes by under mild stress, through longer-term tests using even higher acute stress.