scholarly journals Correspondence

2002 ◽  
Vol 139 (4) ◽  
pp. 455-458
Author(s):  
M. F. Allison ◽  
J. H. Fowler ◽  
E. J. Allen
Keyword(s):  
Solanum Tuberosum ◽  
Rapid Method ◽  
Soil Types ◽  
Exchangeable Potassium ◽  
K Fertilizer

In Volume 136, 407–426, you published a paper entitled ‘Responses of potato (Solanum tuberosum) to potassium fertilizers’ by M. F. Allison, J. H. Fowler and E. J. Allen. We consider that the authors' conclusions were not justified and they have mis-interpreted and criticized earlier published work. One of their criticisms is levelled at the use of exchangeable potassium (Kex – rapidly plant-available K) to categorize soils on the basis of the likely response of crops to an application of potassium (K) fertilizer. While Kex is not perfect, it is the best rapid method currently available (Johnston & Goulding 1990). To support their contention about Kex, the authors quote in Table 15 data from Rothamsted experiments done in the late 1950s and early 1960s. They state that despite the large amounts of K applied in fertilizers and manures the effect on Kex was relatively small. This comment fails to recognize that it is the K balance (K applied minus K removed) that must be related to Kex, not the K applied, and the inevitable transfer of part of the K balance from Kex to fixed K (less readily available K). Warren & Johnston (1962) showed that on these soil types as much as 60% of the K balance is rapidly transferred to fixed K.

Effects of rice (Oryza sativaL.) cultivation and soil type on potassium mobilization and transformation behavior

2018 ◽  
Vol 98 (3) ◽  
pp. 500-507
Author(s):  
D.D. Zhu ◽  
L.P. Zhan ◽  
R.H. Cong ◽  
X.K. Li
Keyword(s):  
Soil Type ◽  
Root Zone ◽  
Water Soluble ◽  
Soil Types ◽  
Chemical Behavior ◽  
Transformation Behavior ◽  
Cultivated Rice ◽  
K Uptake ◽  
K Fertilizer ◽  
Cinnamon Soil

To understand the chemical behavior of potassium (K) in soil, rhizobox experiments were conducted to study the effects of K uptake by cultivated rice and soil type on K migration and transformation in soils. The aim of this study was to guide reasonable application of K fertilizer in different soil types. The results showed that at the maximum tillering stage, the migration distances of water-soluble K (Sol-K) were 6 and 5 cm, the depletion of exchangeable K (Ex-K) was 7 and 4 cm, and depletion of nonexchangeable K (Nonex-K) was 1 and 5 cm, respectively, in yellow cinnamon soil (YCS) and fluvo-aquic soil (FS). With the growth of rice, the migration distances of Sol-K showed little difference between YCS and FS. Throughout the season, the contributions of Sol-K, Ex-K, and Nonex-K to K uptake in YCS were 12.0%, 40.0%, and 48.0%, respectively, whereas their contributions in FS were 25.7%, 25.8%, and 48.5%, respectively. K uptake by rice was linearly related to the concentration of different forms of K in soils (R2 = 0.687*). In conclusion, soil type significantly affected K mobilization and transformation behavior. This indicated that the location of K fertilizer addition in the root zone should differ with soil type.

Take-all distribution and soil type on Chalky Boulder Clay

1986 ◽  
Vol 106 (1) ◽  
pp. 61-66 ◽  
Author(s):  
J. A. Catt ◽  
R. J. Gutteridge ◽  
D. B. Slope
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Soil Type ◽  
Soil Characteristics ◽  
Soil Types ◽  
Exchangeable Potassium ◽  
Boulder Clay ◽  
Extractable Phosphorus ◽  
Take All ◽  
Partial Immunity

SUMMARYIn 1980 a field of winter wheat at Little Raveley, Cambridgeshire (U.K.) suffered a bad attack of take-all, which was confined mainly to areas dominated by Ragdale series, one of five soil types on the field. Take-all and yield were assessed on experimental areas within the field in the three subsequent years (1981–3). On a strip 50 m wide, which was sown with wheat in each of these years, take-all was in decline and although slight differences in take-all occurred between some of the soil types, they had no effect on grain yield. Following a break crop of beans in 1981, the remainder of the field carried wheat in 1982 and 1983. Here take-all was generally less and yields generally greater in the area that suffered the 1980 attack, probably because it had developed a natural partial immunity to the disease. However, measurements of takeall in relation to soil characteristics on 1 m2 plots suggested that the disease was becoming more prevalent on soils that are less well drained in winter, are more deeply decalcified, and contain less extractable phosphorus or more exchangeable potassium.

Response of potato ( Solanum tuberosum L.) to fertilizers applied on different soil types in Kenyan Highlands

2021 ◽  
Author(s):  
James Njeru Mugo ◽  
Nancy Karanja ◽  
Charles Gachene ◽  
Klaus Dittert ◽  
Elmar Schulte‐Geldermann
Keyword(s):  
Solanum Tuberosum ◽  
Solanum Tuberosum L ◽  
Soil Types

Texture measurements in Al2O3 using BEKP

1994 ◽  
Vol 52 ◽  
pp. 608-609
Author(s):  
M. D. Vaudin ◽  
J. P. Cline
Keyword(s):  
Neutron Diffraction ◽  
Rapid Method ◽  
Crystallographic Orientation ◽  
Specimen Surface ◽  
X Ray Diffraction ◽  
Anisotropic Crystal ◽  
X Ray ◽  
Verification Method ◽  
Crystal Properties ◽  
Backscattered Electron

The study of preferred crystallographic orientation (texture) in ceramics is assuming greater importance as their anisotropic crystal properties are being used to advantage in an increasing number of applications. The quantification of texture by a reliable and rapid method is required. Analysis of backscattered electron Kikuchi patterns (BEKPs) can be used to provide the crystallographic orientation of as many grains as time and resources allow. The technique is relatively slow, particularly for noncubic materials, but the data are more accurate than any comparable technique when a sufficient number of grains are analyzed. Thus, BEKP is well-suited as a verification method for data obtained in faster ways, such as x-ray or neutron diffraction. We have compared texture data obtained using BEKP, x-ray diffraction and neutron diffraction. Alumina specimens displaying differing levels of axisymmetric (0001) texture normal to the specimen surface were investigated.BEKP patterns were obtained from about a hundred grains selected at random in each specimen.

Situación económica y social de la población de San José del Carmen, San Cristóbal de las Casas, Chiapas

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Pedro Cadena-Iñiguez ◽  
Eileen Salinas-Cruz ◽  
Jesús Martínez-Sánchez ◽  
Mariano Morales-Guerra ◽  
Romualdo Vásquez-Ortiz ◽  
...  
Keyword(s):  
Solanum Tuberosum ◽  
Theobroma Cacao ◽  
Zea Mays L ◽  
Solanum Tuberosum L ◽  
San Jose ◽  
Phaseolus Vulgaris L ◽  
Las Casas ◽  
Vicia Faba L ◽  
Las Mujeres ◽  
Theobroma Cacao L

Objetivo: Establecer una línea base como fundamento para la intervención e inducción de innovaciones a través de escuelas de campo y planes de negocios. Diseño/metodología/aproximación: El estudio se desarrolló en San José del Carmen, San Cristóbal de Las Casas, Chiapas, México. Se elaboró una encuesta como instrumento para recabar en campo información de familias de la localidad con la finalidad de conocer su situación actual. La localidad de trabajo se eligió utilizando como criterio las poblaciones que se encuentran dentro de Cruzada Nacional contra el hambre y en la clasificación de la pobreza extrema Resultados: La localidad de San José del Carmen es considerada como de alta marginación, la población es bilingüe, su principal lengua es el Tzotzil, el nivel de estudios promedio es hasta el tercer año de primaria, las principales actividades productivas son la siembra de maíz (Zea mays L.), frijol (Phaseolus vulgaris L.), papa (Solanum tuberosum L.) y haba (Vicia faba L.) que son utilizadas principalmente para autoconsumo.  No cuentan con agua potable ya que su sistema es a través de la recaudación de agua de lluvia o a través de un jagüey. Sus principales actividades económicas son la albañilería por parte de los hombres, y venta de productos, tales como el pozol (bebida energética a base de maíz y cacao (Theobroma cacao L.), tostadas y algunos vegetales por parte de las mujeres. Las tostadas son producidas en forma artesanal con un proceso de doble nixtamalización y vendida en bolsas de 20 tostadas cada una, a un costo de MX$10.00 en los mercados de San Cristóbal de las Casas, una a dos veces por semana alrededor de 40 bolsas por día de venta. Limitaciones del estudio/implicaciones: La afiliación zapatista de alguno de los pobladores y el hecho de que algunos habitantes no hablen español, fueron factores que limitaron desarrollar al 100% el estudio; sin embargo, se considera que se tienen los elementos necesarios para establecer la línea base de la situación de San José del Carmen. Conclusiones: El diagnóstico servirá como una herramienta para establecer una intervención a través de innovaciones y planes de negocios en la comunidad de estudio. Los pobladores cuentan con herramientas necesarias para obtener nuevos conocimientos que ayuden a un desarrollo de su producción. El idioma no deberá de ser una limitante para ello.

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