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Plant Testing (3): Influence of Leaf Age, season and Fertilization on Micronutrients in Tea Leaves
No full text(30(3):261-269)Fertility status and response of sorghum to PK fertilizers n the soils of Pescadores Islands
No full text澎湖縣土壤之母質主要為玄武岩，經選取三種土壤包括沖崩積上，殘積土及上層沖崩積土下層殘積土，在24處舉行高粱磷鉀效應田間試驗，從供試土壤性質顯示殘積土之土層厚度多在90cm上下，其他兩種土壤則變化較大，從30cm至90cm不等。pH均在7.7至8.1間，表土含砂量多在70%以上，有機物含量高者僅1.5%，低者不及0.5%，但土壤陽離子交換能量高者可達30me / 100 gm，低者不及3me / 100 gm，兩者相差達10倍。土壤中Bray P1含量甚低，鮮有超出1 ppm P，但交換性鉀則頗高，多在100ppm K以上，一般言之，沖崩積土肥力較高，殘積土較低，上層沖崩積土下層殘積土居中，各種土壤上所得高梁平均收量之高低，亦有此頃向。
土壤中Bray P1或OlSen P各與高梁磷肥效應有關，但其相關係數僅在0.5上下，而土壤中交換性鉀，Mehlich K及OlSen K則與高梁鉀肥效應無關。經利用程式計算機，將土壤其他特性因子，參予磷鉀校正公式中，求出最適合之複相關模式為：
Y1=2.535a-0.1393a2-79.18c+42.58c2+5.819ac-43.96b+430.9 ……..(1)
Y2=1.284a-0.124a2+0.406d+0.0002d2+0.034ad-97.15b+828.6…….(2)
式中Y1及Y2各指估計無磷區（P0 / P × 100）及無鉀區（K0 / K × 100）之高梁收量百分率，a = clay%, b = pH , c = Bray Pl ppm , d＝交換性K ppm，方程式（1）及（2）兩式所得複相關係數各為0.7735及0.8362，均達1%顯著平準，確有改進功效，文中並檢討在一定範圍內，土壤pH，粘土含量以及土壤有效態磷鉀含量與無磷區或無鉀區高梁收量百分率估計值之關係。To clarify the response of sorghum to PK fertilizers, twenty-four field trials involved five treatments with four replications in a randomized block were conducted on soils derived from weathering basalt rock on the Pescadores Islands. These soils may be divided into three groups wind eroded soil, residual soil, and upper eroded soil with residual soil underneath.
Judging from the fertility status of the soils studied, it indicated that the depth of solum of residual soils was rather uniform at 90 cm or so. However a wide variation in solum (30-90cm) was found in the other two soils. The ranges of soil pH and the content of organic matter were at 7.7-8.1 and 0.5-1.5%, respectively. Almost all soils contain more than 70% of sand in the surface soils. Although these soils contain abundence of sand and low level of organic matter, there was a wide range in cation exchange capacity (3-33 me / 100 gm). The available phosphorus index measured by Bray method (0.025N HCl-0.03N NH4F) was extremely low, usually less than 1 ppm P. On the other hand, a wide range in exchangeable K(54-538 ppm K) was found in the surface soils. In general, the fertility level of these soils was ranked in the following order : wind eroded soil, upper eroded soil with residual soil underneath and residual soil. Consequently, the average yields of sorghum obtained from wind eroded soils were higher than those from the other two soils.
The relationship between percentage yield and soil PK tests were improved by participating the constituents of soil pH and clay in the calibration equation. The fitting models of multiple regression equation were found as follows:
Y1=2.535a-0.1393a2-79.18c+42.58c2+5.819ac-43.96b+430.9 ……..(1)
Y2=1.284a-0.124a2+0.406d+0.0002d2+0.034ad-97.15b+828.6……..(2)
where Y1 refers to the predicated percentage yield from P0 / P × 100 and Y2 from K0 / K × 100. From the equations, it indicated that at the soil pH lower than 7.7, mostly no profitable return will be obtained by PK-application except in the case where soil available P was lower than 0.2 ppm. However, when soil pH was greater than 8.1, the responses of sorghum to PK fertilizers will be depended on the contents of clay and levels of soil PK. The predicated percentage yield responses for a range of combination of the test values were discussed in the paper
(27(4):297-308)Potassium release characteristics of some selected soils of central Taiwan
No full text為探討土壤中鉀之釋放特性，在本省中那選取20種土塊，經連續4作盆栽水稻及用熱水與四酚鈉硼(Sodium tetraphenyl boron, NaTBP)抽取，所得結果扼要如下：
用30gm土壤加30ml熱水，抽取時問從15、30、60、120、180至240分鐘，所抽出鉀量與抽出時間之對數成極頭著之直線迴婦，其抽出速率之變異從8.62~50.01 ppm K/log(min)。另從複迴歸方得式中顯示用熱水抽出之K抽出速率與土壤中置換性鉀成正比，而與土壤pH或游離鐵含量成反比。
用1.0gm土壤加NaTPB液，抽取時間從15、120、240、480至960分鐘，所抽出的鉀量與抽出時問成極顯著的直線迴歸，其變異範圍從0.4~3.09ppm K/min。又從複迥歸方程式顯示以NaTPB所得之K抽出速率與土壤中非置換性鉀含量成正比，而與土壤pH成反比。
同一土壤，連續盆栽4作水稻，其K總吸取量之變異範圍，在無肥處理之下為405~1176mg K/5.0kg Soil，-K處理者為414~2498mg K/5.0kg Soil，+K處理者為1537~3436mg K/5.0kg Soil，從-K處理4作水稻總吸取量及栽培後，土壤中置換性鉀誓遍劇降，顯示水稻生長期中，必然利用土壤中部分的非置換性鉀。
水稻之K吸取速率與土壤中K釋放速率有著顯著的關係。但從各溶劑所抽出的K有效指數，以估計土壤中K供應情形時，仍以Mehlich氏鉀與水稻吸取量之相關係數最高，其法亦最便捷。
To evaluate K release, twenty soils from central Taiwan were intensively cropped with rice in pots, and soil K was extracted with hot water as well as sodium tetraphnyl-boron (NaTPB) for varying periods. When 30-gm soil samples were equilibrated with 30 ml hot water for 15, 30, 60, 120, 180, and 240 min., K extracted with hot water was linearly correlated with the logarithm of time from 15 to 240 mm. Rate of K release varied from 8.62 to 50.01 ppm K/log (min.). Multiple regression equation between K release and other soil factors indicated that the rate of K release with hot water was positively proportional to the amount of exchangeable K present in the soil, but negatively to the soil pH or to the content of free iron oxides.
When 1-gm soil samples were equilibrated with solution containing NaTPB for 15, 120, 240, 480, and 960 min. Rate of K release varied from 0.4 to 3.09 ppm K/min. It was also found that the rate of K release was positively correlated with the content of non-exchangeable K (extracted by boiling N nitric acid) and negatively with soil pH as shown in a multiple regression equation.
Amounts of plant available K, as determined from cumulative K uptake by four successive croppings of rice plant varied from 405 to 1176, 414-2498, and 1537-3436 mg K/5.0 kg soil for the none, -K and +K treatments, respectively. The rate of K uptake was fairly well correlated with the rate of K release from the soil extracted either with hot water or with NaTPB. However, for the purpose of soil testing, the K values obtained by Mehlich procedure may adequately predicate the K supplying power of the soil
(24(1-2):32-43)STUDY ON MICRONUTRIENTS CONTENT OF THE SOILS FROM MAIN VEGETABLE GROWING AREAS IN TAIWAN - I. BORON
No full text採取本省主要蔬菜產區土壤共61種，經土壤一般性質及含硼量測定後，選取性質及含硼量差距較大之土壤共30種，在網室盆栽蔬菜，分施硼與不施硼兩處理，以花椰菜及萵苣為指示作物，觀察硼對蔬菜生長及產量之影響。由本試驗結果知本省蔬菜產區土壤含硼量一般均低，其熱水溶性硼含量在0.5ppm以下者約佔80%。但蔬菜在種植過程中並未發生缺硼徵象，施硼與否對產量亦無顯著影響，雖植物體中硼含量確因施硼而增加，其Ca/B比亦因而減低。土壤中硼含量與其他土壤性質之關係因土壤PH值不同而異：當PH在6.5以下時，其含硼量與土壤PH值，有機物含量及土壤質地關係最為密切；當土壤PH在6.6以上時，則受土壤PH，有效性磷、鉀含量影響最大。
This study was carried out to investigate the micronutrients content and supplying power of the soils from the main vegetable growing areas in Taiwan. The micronutrient studied in the first year was boron.
Sixty-one soils were collected from different vegetable growing areas all over this island. After analyzing its properties, thirty were selected for pot experiment. Califlower and lettuce was used as the indicator plants. It was planted in plastic pots and irrigated with demineralized water.
Two treatments, with and without boron (l0kgs/ha as borax) replicated twice, a total of 120 pots were arranged in two rows according to the randomized complete block design in the green house. The fertilizers applied were the same for both treatments.
The following results have been obtained:
1. I-lot H2O-soluble boron content of the 30 soils used in this study ranged from 0.1 to 1.75 ppm, 24 of them were below 0. 5ppm. Thus most of the vegetable growing soils in Taiwan are low in boron content.
2. When soil pH is higher than 6.6, hot H2O-soluble boron content is positively correlated with soil pH, available phosphorus and potassium content of the soil; when soil pH is lower than 6.5, H2O-soluble boron is positively correlated with soil pH, organic matter and silt content of the soil.
3. No boron deficiency or toxicity symptoms occured during the growth of these vegetables, nor did the application of boron affected its yield.
4. plant analysis data indicated that the boron content of lettuce leaf was increased by
17 percent, and the Ca/B ratio decreased 25 percent as a result of the supply of boron to the soil. This shows that plant in the borax treated soil really absorbed more boron than the untreated ones
(21(4):233-249)EFFECT OF DRYING ON THE AVAILABILITY INDEX OF SOIL PHOSPHORUS AND POTASSIUM
No full text本文之目的乃探討土壤樣本乾燥後，對於磷、鉀有效指數之影響，與土壤性質、作物收量以及磷、鉀吸收量之關係；同時并探討其抑制方法。經選用20種本省主要土壤之樣本，予以不同乾燥處理後，分別用兩種磷、鉀速測法加以測定，所得結果摘要如下：
(1) 田間濕土經乾燥後，磷有效指數因個別土壤而變異，或增或減，相差甚大。在Bray氏法中平均較田間濕土增加25％～40%，其變異幅度與土壤之C.E.C大小有關。在Melllich氏法中磷有效指數之變異幅度較Bray氏法為低，可能因土壤中Al-P及Fe-P受烘乾之後，變異甚大，而Ca-P則較小所致。就平均數而言，風乾、曬乾或40℃烘乾約較田間濕土增加5%～7%，但110℃烘乾者可提高至32%，其變異幅度與粕土，Fe-P，及Ca-P等含量有關。
(2) 田間濕土經乾燥之後，鉀有效指數普遍提高。在醋酸銨法中，平均較田間濕土增加15%～17%，烘乾者可達30%，而在Mehlich氏法中則可提高至28%~34%,110℃烘乾者可達49%，其變異情形與土壤之C.E.C成顯著之正相關。
(3) 烘乾前加Doxtrose，或風乾後加水濕潤，或施以Octanol處理，確可抑制磷、鉀因乾燥而釋放，但無汰將個別土壤完全恢復至與田間濕土一致。
(4) 利用Neubuaer法檢定土壤，經不同乾燥處理後，所得磷、鉀有效指數與稻苗乾重或磷、鉀吸收量之相關情形，顯示Mehlich氏法不適於稻田速測之用，Bray-P所得之相關係數，以田間濕土最高，且達極顯著平準，其次為再濕潤處理或二Octanol處理，亦達顯著或極顯著平準；風乾、曬乾或烘乾處理者最低，甚至有未達顯著平準。但Bray法應用於鈣質土壤時，其相關係數有減低趨勢。Melllich-K及酷酸銨-K之相關係數均達極顯著平準，烘乾者其相關係數較田間濕土者有更高之趨勢，此可能因為烘乾可提高鉀有效指數之測定值。而在Neubauer法栽培之下，所用土壤有限，但播種量高，其相關係數受土壤中鉀量(Quantity)之影響較鉀強度(Intansity)為大。
因此就土壤速測值與作物收量或PK吸收量之相關而言，樣本乾燥對於土壤中Al-P及Fe-P變異甚大，利用Bray’s法測定時，以田間濕土為宜，對於Mehlich-K及醋酸銨-K之影響雖然較小，但因K之釋放受乾燥溫度之影響甚大，樣本乾燥條件必須一致，否則將影響推薦量估計之偏差。
The aim of this study was to find out the effect of drying on the soil PK and its relation to dry matter content as well as PK-uptake of rice seedlings. The control of PK-releasei/fixation on drying by addition of chemicals was also involved.
Twenty soil samples including 8 main soil groups of Taiwan were taken for study. Each soil sample was treated with four methods of drying and determined by two extrac- tants. To control PK-release/fixation on drying, chemical compounds (dextrose/octanol/water) were added either before or after drying. The relation between soil P and P-uptake as well as soil K and K-uptake was detected by the Neubauer test in which rice was used instead of rye seeds and soil was kept under submerging condition. The results may be summarized as follows:
1. The effect of drying on the availability index of soil P was extremely great especially in the case of the Bray P-1 test. However, the average increase of soil P-value on different methods of drying as compared to that of field moist soil was at 25%-40% for the Bray’s method and 5%-32% for the Mchich’s method. The decrease was also found in Schist alluvial soils. The change of soil P on drying was found to be related to the C.E.C. and the contents of clay, Al-P, Fe-P, and Ca-P of the soil.
2. The soil K was almost unanimously increased by drying. However, the magnitude of increase was different from soil to soil. The average increase as compared to that of field moist soil was 15 %-30% and 20%-49% for the ammonium acetate and Mehlich’s method, respectively. The C. E. C. was one of the dominant factors in responsoring the change of soil K on drying.
3. The control of PK-release/fixation on drying by addition of dextrose/octanol/water was found effective for certain soil but not for all soils.
4. Evidences from Neubauer test indicated that the available P determined by Bray’s method with undried soil samples gave the best estimation of plant-available P in the soil. Those with air-dry rewet as well as air-dry octanol treated improved the estimation of available P over those obtainable with either air-dry or oven-dry soils. The relation- ships of Mehlich’s P to the dry matter content or to the P-uptake of rice seedlings were insignificant. Soil K-value measured by ammonium acetate method was significantly related to the dry matter content as well as to K-uptake of rice seedlings in spite of drying effect. It was also true in the case of Mehlich’s method. As the release of soil K was closely related to the drying temperature, the condition for drying soil samples should be carefully controlled in order to avoid a fictitious recommendation for K fertilization
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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