Soil texture affects the conversion factor of electrical conductivity from 1:5 soil-water to saturated paste extracts     

Bo-Seong SEO  Young-Jae JEONG  Nu-Ri BAEK  Hyun-Jin PARK  Hye In YANG  Se-In PARK  Woo-Jung CHOI 《土壤圈》2022,32(6):905-915

Electrical conductivity (EC) of soil-water extracts is commonly used to assess soil salinity. However, its conversion to the EC of saturated soil paste extracts (EC_e), the standard measure of soil salinity, is currently required for practical applications. Although many regression models can be used to obtain EC_e from the EC of soil-water extracts, the application of a site-specific model to different sites is not straightforward due to confounding soil factors such as soil texture. This study was conducted to develop a universal regression model to estimate a conversion factor (CF) for predicting EC_e from EC of soil-water extracts at a 1:5 ratio (EC_1:5), by employing a site-specific soil texture (i.e., sand content). A regression model, CF=8.910 5e^{0.010 6sand}/1.298 4 (r²=0.97, P < 0.001), was developed based on the results of coastal saline soil surveys (n=173) and laboratory experiments using artificial saline soils with different textures (n=6, sand content=10%-65%) and salinity levels (n=7, salinity=1-24 dS m^-1). Model performance was validated using an independent dataset and demonstrated that EC_e prediction using the developed model is more suitable for highly saline soils than for low saline soils. The feasibility of the regression model should be tested at other sites. Other soil factors affecting EC conversion factor also need to be explored to revise and improve the model through further studies.  相似文献   

Land-use management for sustainable rice production and carbon sequestration in reclaimed coastal tideland soils of South Korea: a review     

Sang-Sun Lim  Hye In Yang  Hyun-Jin Park  Se-In Park  Bo-Seong Seo  Kwang-Seung Lee 《Soil Science and Plant Nutrition》2020,66(1):60-75

ABSTRACT

The properties of secondary salt-affected soils developed from improper irrigation and drainage management and their effects on rice growth and yield are well documented. However, relevant information on coastal reclaimed tideland (RTL) soils, which are classified as primary salt-affected soils developed through salt-accumulated sediments is lacking. In this paper, we reviewed the physical and chemical properties of RTL soils in comparison with non-RTL soils and analyzed the relationship between rice production and soil salinity in RTL to suggest agricultural management practices for sustainable rice production and soil carbon sequestration in RTL. Similar to the secondary salt-affected soils, RTL soils were characterized by high alkalinity, salinity, and sodicity, and rice yield was negatively correlated with salinity. However, it was also found that lower fertility (e.g., organic matter and phosphorus) of RTL soils than non-RTL soils might also hamper rice growth and thus carbon input via plant residues in RTL soils. Correlation between years after reclamation and soil properties of RTL showed that cultivation of rice with annual fertilization and organic matter inputs increased soil fertility but salinity and sodicity did not show a significant tendency of change, suggesting that natural desalinization in RTL soils is hard to be achieved with conventional rice cultivation. Therefore, it is suggested that fertilization management as well as salinity management via drainage, gypsum application, tillage, and proper irrigation may be necessary to improve rice production and carbon sequestration in RTL soils.  相似文献   

Land use types with different fertilization management affected isotope ratios of bulk and water-extractable C and N of soils in an intensive agricultural area     

Jeong  Young-Jae  Park  Hyun-Jin  Jeon  Byeong-Jun  Seo  Bo-Seong  Baek  Nuri  Yang  Hye In  Kwak  Jin-Hyeob  Lee  Sang-Mo  Choi  Woo-Jung 《Journal of Soils and Sediments》2022,22(2):429-442

Journal of Soils and Sediments - This study was conducted to investigate variations in the stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) of agricultural soils under different...  相似文献   

Vegetated ridge and sandbag may not reduce soil erosion and loss of carbon and nutrients from upland fields     

Se-In Park  Hye In Yang  Hyun-Jin Park  Bo-Seong Seo  Dong-Hwan Lee  Young-Jae Jeong 《Soil Science and Plant Nutrition》2020,66(1):195-205

ABSTRACT

Though construction of vegetated ridge (VR) and placement of sandbag (SB) across the slope of upland fields are believed to be effective in reducing soil erosion and nutrient loss, relevant data are lacking to confirm such expectations. In this study, the effects of VR and SB on loss of soils, carbon (C), nitrogen (N), and phosphorus (P) (CNP) were investigated through both artificial (in dry season) and natural (in rainy season) runoff experiments on upland fields cultivated with maize (Zea mays L. var. ceratina). Contrary to expectations, both VR and SB were not effective in reducing the loss of soils and CNP. For VR, accelerated convergent flow caused by ridge failure, which occurred when part of the ridges collapsed because the amount of water collected in the furrows exceeded the water storage capacity of the ridges, led to excessive loss of soils and CNP. For SB, the loss of soils and CNP could be ascribed to the malfunction of SB; i.e., soil and CNP were lost by seepage through the gaps between SBs and between SB and soil surface. Maize growth and yield were not affected by VR and SB, coinciding with the lack of beneficial effects of VR and SB on soil and nutrient loss. As VR and SB are easy to be implemented and cost-effective, however, further study is necessary to correct the flaws of VR and SB found in this study.  相似文献