• 한국연초학회지
• /
• 제21권1호
• /
• pp.36-48
• /
• 1999

Field test was conducted in Chungbuk province to evaluate the soil fertility using landscape and soil attributes by application of geographic information system(GIS) in 48 tobacco fields during 2 years(1996 ; 23 fields, 1997 ; 25 fields). The soil fertility factors and fertilizer effects were estimated by twenty five independent variables including 13 chemical properties and 12 GIS databases. Twenty five independent variables were classified by two groups, 15 quantitative indexes and 10 qualitative indexes and were analyzed by multiple linear regression (MLR) of SAS, REG and GLM models. The estimation model for evaluation of soil fertility and fertilizer effect was made by giving the estimate coefficient for each quantitative index and for each group of qualitative index significantly selected by MLR. Estimation for soil fertility factors and fertilizer effects by independent variables was better by MLR than single regression showing gradually improvement by adding chemical properties, quantitative indexes and qualitative indexes of GIS. Consequently, it is assumed that this approach by MLR with quantitative and qualitative indexes was available as an evaluation model of soil fertility and recommendation of optimum fertilization for tobacco field.

• Journal of Forest and Environmental Science
• /
• 제31권4호
• /
• pp.280-287
• /
• 2015

Soil samples were collected from three depths (0-10 cm, 10-40 cm and 40-80 cm) of two forest sites including one plantation dominated by teak with some other minor species and another degraded natural forest in Cox's Bazar, Bangladesh to compare their soil properties. Some vegetation parameters were also studied. For this study $10{\times}10\;m$ and $2{\times}2\;m$ quadrats were used for the tree and undergrowth parameters, respectively. Soil samples were also collected from these quadrats. Between the two forest types, the highest levels of organic carbon, total nitrogen, available phosphorus, exchangeable bases and cation exchange capacity (CEC) were found in soils of the plantation. The soils were acidic in nature and exchangeable Al concentrations were low. Teak dominated forest plantation had higher soil fertility index (SFI) than the degraded natural forest site. Steps for reforestation and appropriate protection are needed to improve the situation.

• 한국토양비료학회지
• /
• 제46권3호
• /
• pp.223-229
• /
• 2013

Sustainability index was calculated to determine the best management for rice productivity under long-term inorganic fertilizer management's practices. It is based on nutrient index, microbiological index and crop index related to sustainability as soil function. Indicators for calculating sustainability index were selected by the comparison of soil properties and rice response in paddy soil with fertilization. Total twenty two indicators were determined to assess nutrient index, microbiological index and crop index in order to compare the effect of different fertilization. The indices were applied to assess the sustainability with different inorganic fertilizer treatments such as control, N, NK, NP, NPK, NPK+Si, and NPK+Compost. The long-term application of compost with NPK was the highest sustainability index value because it increased nutrient index, microbial index and crop index. The use of chemical fertilizers resulted in poor soil microbial index and crop index, but the treatments like NP, NPK, and NPK+Si were maintained sustainability in paddy soil. These results indicate that application of organic and chemical fertilizer could be a good management to improve rice sustainability in paddy soil.

• 한국토양비료학회지
• /
• 제32권2호
• /
• pp.95-108
• /
• 1999

충북 진천, 음성, 괴산, 중원군과 충남 천원군, 그리고 경북 청도, 성주, 안동군에 분포하는 101개 연초 경작지에 대하여 토양의 화학성 및 토양도 자료들을 이용한 토양 비옥도를 평가하기 위하여 1985년부터 2년 동안포장시험이 수행되었으며 또한 동일 토양에 대한 포트시험도 병행하여 서로 비교하였다. 무비구의 연초 수량을 토양 비옥도 요인으로 고려하여 9개 화학성과 10개 토양도 자료들을 포함하는 19개 독려변수들로 평가하였다. 19개 독립변수들은 11개의 정량적 지표들과 9개의 정성적 지표들로 구분하여 BAS의 REO와 CLM model로 다중선형 회귀분석을 수행하였다. 무비구 연초 수량은 최저치와 최고치 간에 포트시험의 경우 5.0-5.5배, 포장시험의 경우 8.2-14.9배의 차이를 보여 공시토양의 다양한 비옥도 특성을 나타냈다. 무비구 수량과 밀접한 상관을 보인 화학적 지표는 포장시험과 포트시험간뿐 아니라 년차 간에도 상이하였으며, 또한 포장시험의 무비구 수량에 기여하는 정량적 지표들의 표준화 편회귀계수는 모두 1.0 미만을 보여 비옥도 평가를 위한 탄일 유효도지표의 선발이 어렵다는 것을 시사하였다. 비옥도에 대한 독립변수들의 다중선형회귀 평가는 단일 지표에 의한 평가보다 매우 양호하였으며 화학적 지표들 이외에 토양도의 정량적 및 정성적 지표들을 평가에 포함시킴에 따라 결정계수($R^2$)는 점진적으로 증가되었다. 즉 예를 들면 1985년도 무비구 수량에 대한 다중선형회귀의 결정계수는 단일지표 $NO_3-N$ 함량에 의한 평가 0.244에 비하여 화학적 지표들에 의한 평가는 0.422, 토양도의 정량적 지표들의 추가되면 0.503, 그리고 정성적 지표들을 추가하면 0.633으로 증가되었다. 따라서 토양 화학성 이외에 토양도 자료들을 포함하는 정량적 및 정성적 지표들에 의한 다중선형회귀 분석방법은 연초 경작지의 비옥도 평가를 위한 유의성 있는 모델로 추정되었다.

• 한국연초학회지
• /
• 제22권2호
• /
• pp.123-132
• /
• 2000

Evaluation method of soil fertility by combination of soil color characteristics and survey data from soil map as well as chemical properties was investigated on total 35 field and pot experiments. Total 35 tobacco fields including 11 fields located at Cheonweon county in Chungnam Province, 9 fields located at Goesan county in Chungbuk Province, and 15 fields located at Youngcheon county in Kyongbuk Province were selected in 1984 to cover the wide range of distribution in landscape and soil attributes. Yields of tobacco grown on the plots of both the pot and field experiment which were not applied with any fertilizer were considered as basic fertility of the soil (BFS). The BFS was estimated by 32 independent variables including 15 chemical properties, 3 color characteristics, and 14 soil survey data from soil map. Twenty-four independent variables containing 16 quantitative variables selected from 24 quantitative variables by collinearity diagnostics and 8 qualitative variables, were classified and analyzed by multiple linear regression (MLR) of REG and GLM models of SAS. Tobacco yield of field experiment showed high variations by eight times in difference between minimum and maximum yield indicating the diverse soil fertility among the experimental fields. Evaluation for the BFS by the MLR including quantitative variables was still more confidential than that by a single index and that showed more improvement of coefficient of determination ($R^2$) in pot experiment than in field experiment. Evaluation for the BFS by MLR in field experiment was still improved by adding qualitative variables as well as quantitative variables. The variability in the BFS of field experiment was explained 43.2% by quantitative variables and 67.95% by adding both the quantitative and qualitative variables compared with 21.7% by simple regression with NO$_3$-N content in soil. The regression evaluation for the best evaluation of the BFS of field experiment by MLR included NO$_3$-N content, L value, and a value of soil color as quantitative variables and available soil depth and topography as qualitative variables. Consequently, it is assumed that this approach by the MLR including both the quantitative and qualitative variables was available as an evaluation model of soil fertility for tobacco field.

• 한국토양비료학회지
• /
• 제19권1호
• /
• pp.63-69
• /
• 1986

1. 각(各) 비종(肥種)의 시비수준별(施肥水準別) 잎중 양분함량(養分含量)은 질소(窒素)의 경우 증비(增肥)할수록 비옥지(肥沃地), 척박지(瘠薄地)에서 모두 증가(增加)하였으며, 인산(燐酸)은 증비(增肥)에 관계없이 비옥도간(肥沃度間), 시비수준간(施肥水準間)에 함량차이(含量差異)가 없었고, 가리(加里)의 경우에는 비옥지(肥沃地)가 척박지(瘠薄地)보다 동일시비수준(同一施肥水準)에서 칼륨함량(含量)이 다소 높았으나 척박지(瘠薄地)는 변화폭(變化幅)이 작았다. 2. 질소질비료(窒素質肥料)의 증비(增肥)는 특히 비옥(肥沃)한 경작지(耕作地)일수록 수확엽(收護葉)의 성숙(成熟)을 지연(遲延)시켰으며, 생육후기(生育後期)의 지나친 질소흡수(窒素吸收)는 니코틴함량(含量)을 증가(增加)시킴과 동시에 환원당함량(還元糖含量)을 저하(低下)시킴으로써 품질지수(品質指數)(환원당(還元糖)/니코틴비(比); Coulson계수(係數))도 낮아졌다. 3. 토양(土壤)의 비옥도(肥沃度)와 관계없이 잎담배중 질소함량(窒素含量)이 높아짐에 따라 니코틴함량(含量)도 비례(比例)하여 증가(增加)되었으나 니코틴함량(含量)의 점증(漸增)에 따라 환원당함량(還元糖含量)은 점감(漸減)하는 부(負)의 관계가 인정(認定)되었으며, 잎담배중 니코틴함량(含量)이나 환원당함량(還元糖含量)은 척박지(瘠薄地)에서보다 비옥지(肥沃地)에서 전반적으로 더 높았다. 4. 니코틴함량(含量)과 잎담배등급감정가격(等級鑑定價格)과는 부(負)의 상관(相關), 환원당함량(還元糖含量)과는 고도(高度)의 정상관(正相關)을 보임으로써 잎담배등급감정가격(等級鑑定價格)을 근거(根據)로 한 품질지수(品質指數)는 화학성분(化學成分)에 의한 품질측정치(品質測定値)와 매우 밀접한 관련이 있는것으로 인정(認定)되었다.

• Journal of Ecology and Environment
• /
• 제46권3호
• /
• pp.204-217
• /
• 2022

Background: Increasing land demands for food production have led to biodiversity loss and land degradation in the Madhupur Sal forest. Reforestation activities such as agroforestry and woodlot plantation support the conservation of diversity, restoration of forest and prevention of soil erosion in degraded natural Sal forest. Knowing about these reforestation activities, this study is needed to compare the species composition, richness, and soil nutrients of these two plantation activities to the natural Sal forest in the degraded Madhupur Sal forest in Bangladesh. Results: The analysis showed that in between the reforestation activities, the highest Shannon-Wiener index (1.79), evenness (0.60) and Simpson's index (0.79) were found in the agroforestry site compared to the woodlot plantation site. On the contrary, the highest species richness (n = 14), tree basal area (19.56 m² ha^-1), Margalef's index (1.96) were recorded in woodlot plantation than in the agroforestry site. We observed that at 0-15 cm depth, soil organic matter (2.39%), total nitrogen (0.14%), available phosphorous (62.67 ㎍ g^-1) and exchangeable potassium (0.36 meq/100 g) in agroforestry plots were significantly higher compared to other forest sites. At topsoil (15-30 cm depth), soil organic matter (1.67%) and available phosphorous (21.09 ㎍ g^-1) were found to be higher in agroforestry site. Conclusions: Both reforestation approaches improved soil function, although woodlot plantation had the higher species richness. Therefore, plantation activities by the sustainable implementation of these two practices are the best alternative to restore the biodiversity, richness and conserve soil fertility in the Madhupur Sal forest of Bangladesh.

• Journal of Forest and Environmental Science
• /
• 제30권4호
• /
• pp.331-341
• /
• 2014

The present study is an attempt to give an account of the inventory of plant species, phytosociological characteristics of vegetation and pedological characteristics of Rambi Beat Forest under Senchal East Forest Zone, Darjeeling, West Bengal, India. Its plant community were analyzed quantitatively and synthetically. The results reflect dominancy of dicotyledons over monocotyledons in the four studied sites The plant community comprising of 50 plant species belonging to 40 genera of 27 families. Ramhi beat reflected higher diversity of species. Maximum IVI value was recorded by Viola surpense (47.17) in Rambhi forest beat. The Berger parker index and evenness index were found to be highest for Viola surpense, Fragaria nubicola, Pilea umbrosa in Rambhi beat. The soil characteristics of the different pedons revealed alkaline nature of soil in Rambhi beat. Higher levels of soil organic carbon content reflect higher fertility of the soil of Rambhi beat. The response towards soil available nitrogen and phosphate were different among the ten pedons of Rambhi beat. Therefore, proper management and conservative measures needs to be implemented for conservation of bioresources in Senchel wildlife Sanctuary of West Bengal, India.

• 농업과학연구
• /
• 제47권4호
• /
• pp.1097-1107
• /
• 2020

Assessment of soil carbon stock is essential for climate change mitigation and soil fertility. The digital soil mapping (DSM) is well known as a general technique to estimate the soil carbon stocks and upgrade previous soil maps. The aim of this study is to calculate the soil carbon stock in the top soil layer (0 to 30 cm) in Jeolla Province of South Korea using the DSM technique. To predict spatial carbon stock, we used Cubist, which a data-mining algorithm model base on tree regression. Soil samples (130 in total) were collected from three depths (0 to 10 cm, 10 to 20 cm, 20 to 30 cm) considering spatial distribution in Jeolla Province. These data were randomly divided into two sets for model calibration (70%) and validation (30%). The results showed that clay content, topographic wetness index (TWI), and digital elevation model (DEM) were the most important environmental covariate predictors of soil carbon stock. The predicted average soil carbon density was 3.88 kg·m-2. The R2 value representing the model's performance was 0.6, which was relatively high compared to a previous study. The total soil carbon stocks at a depth of 0 to 30 cm in Jeolla Province were estimated to be about 81 megatons.

• 한국작물학회지
• /
• 제24권1호
• /
• pp.84-91
• /
• 1979

$^32$P 표지 중과석과 칼슘으로 대두에 있어서 밭토양별 인산흡수계수에 의한 인산질 비료와 석회의 합리적인 시용량을 알고자 본시험이 수행되었다. 1 ) 석회의 시용은 기개간지, 미개간지 공히 생육 및 수량을 좋게 하였다. 2) 인산시용은 기개간지는 인산흡수계수 5% 미개간지는 15%에서 좋은 경향을 보였으며 석회와 인산간의 상호관계는 인정할 수 없었다. 3) $^32$P 표지 중과석에 의한 시용인산의 기여도는 기개간지는 미개간지보다 다소 높은 수치를 나타내었다. 4) 기여도를 산출한 결까 미개간지는 석회시용구구(P$^{32}$0.2~0.3mi$\mu$) 14~16%가 석회무시용구 14~17%로 근소한 차이를 보였다. 5) 기개간지에서는 석회시용구($^32$P 0.2~0.3 mi$\mu$) 21%가 석회무시용구 14~17%에 비해 높은 경향을 보 였다.