scholarly journals 528 Use of Cultivar and Plant Characteristics as the Basis for Fertilizer Nitrogen Applications in Cranberry (Vaccinium macrocarpon Ait.)

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 536E-537
Author(s):  
Carolyn DeMoranville ◽  
Joan Davenport

The relationship between yield and applied N in cranberry has been investigated. Cultivar was important in determining optimum seasonal N rate. Sustained production for the hybrid `Stevens' required an annual seasonal total of N at up to 67 kg·ha–1, higher than was optimal for native selections `Early Black' and `Howes'. High N rates were associated with increased fruit rot and vine overgrowth. Optimum N rate varied within cultivar, likely due to variation in soil conditions, but soil N test results have not correlated well with subsequent yield in cranberry. Soil organic matter content can predict potential N release, but plant response must also be taken into account. To refine N rate recommendations, plant characteristics that might predict N requirements/status of cranberry were investigated. A standard of 0.9% to 1.1% N in August tissue has been established for cranberry. To find characteristics that could be used earlier, we surveyed 30 sites for percentage of N in tissue, length of new growth, SPAD chlorophyll meter ratings, fertilizer N use, and yield. Length of new growth could be used as an indicator of cranberry N status from June until bloom, being positively correlated with subsequent yield. The SPAD meter proved to be a viable alternative to in-season monitoring of tissue N during June and July. Readings below proposed standard values indicated the need for N fertilizer if vegetative growth was in the standard range. Thus, the easily determined factors of upright length and SPAD rating could be used to refine fertilizer rates during the active growing season, while tissue testing for percentage of N could be used as a “report card” on the fertilizer program at the end of the season.

Weed Research ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 490-500
Author(s):  
W Kaczmarek‐Derda ◽  
M Helgheim ◽  
J Netland ◽  
H Riley ◽  
K Wærnhus ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3158
Author(s):  
Tomoyo Kurozumi ◽  
Yasushi Mori ◽  
Hiroaki Somura ◽  
Milagros O-How

Rice terraces in Cordillera, Philippines, a world cultural heritage site, are threatened by the risk of collapse. It is crucial to manage these rice terraces for their conservation, while simultaneously practicing traditional farming. We examined the soil environment and investigated its effects on rice terrace conservation, by focusing on the hardpan condition; infiltration process, which is related to the collapse of rice terraces; and soil nutrition conditions in these sites. Field survey and soil analysis revealed that in areas where the hardpan was not sufficiently developed and water infiltration was effectively suppressed, organic matter content was significantly high, suggesting organic matter clogging. In these rice terraces, the amounts of P, K, Ca, and Mn were significantly low, showing the mineral leaching under reductive soil conditions. Therefore, hardpan formation, rather than organic matter clogging, is essential for the suppression of infiltration and prevention of potential terrace collapse. Because hardpan formation or organic matter clogging cannot be identified from the surface of flooded rice paddies, it is difficult to identify the influencing factor. Thus, we suggest that the hard soil layer should be checked before the planting season and drainage is allowed after the cropping season in the rainy season.


2004 ◽  
Vol 5 (1) ◽  
pp. 31 ◽  
Author(s):  
Ana María Serralde O. ◽  
María Margarita Ramírez G.

<p>Mediante el seguimiento de cultivos experimentales en suelos ácidos de los Llanos Orientales, durante un periodo de cinco años consecutivos (1997-2001), se evaluaron las poblaciones nativas de hongos micorrícicos arbusculares (MA) asociados con dos variedades de maíz: ICA- Sikuani V-110 y la variedad regional criolla Clavito, analizando su comportamiento bajo distintos tratamientos con abono orgánico (gallinaza), abono verde (Caupí) y testigo sin aplicación de materiales orgánicos, para un total de seis tratamientos. De 7.924 esporas analizadas se aislaron veinticuatro morfotipos identificados morfológica y molecularmente. Se determinó la relación de las condiciones del suelo (pH, los contenidos de materia orgánica, P, K, Al+++ y % saturación Al) con el comportamiento de las poblaciones de MA. Con la aplicación del Análisis de Regresión Múltiple (Stepwise), se obtuvieron coeficientes significativos (P≤ 0.001 y R2 ≥ 83) para todas las variables y se seleccionaron como variables predictivas principales el pH y la materia orgánica del suelo, que presentaron coeficientes significativos para cinco y cuatro de los siete modelos establecidos, respectivamente. La técnica molecular empleada basada en la Reacción en Cadena de la Polimerasa (PCR), con el uso de primers específicos, permitió la identificación confirmatoria de las esporas aisladas de los géneros <em>Glomus, Entrophospora </em>y <em>Gigaspora</em>. Además, mediante el uso de esta metodología se logró identificar la presencia del género <em>Glomus</em>en raíces de maíz altamente colonizadas.</p><p> </p><p><strong>Mycorrhiza populations analysis in corn (<em>Zea mays</em>) cultivated in acid soils under different agronomic treatments</strong></p><p>A study was carried out to evaluate the populations of native arbuscular mycorrhizas (AM) fungi on established crops on acid soils of the Colombian Eastern Plains, for a period of five years (1997-2001). Fungi spores were isolated from the crop-fungi association of two maize cultivars: ICASikuani V-110 and the regional cultivar Clavito. The mycorrhizal behavior was evaluated under six different organic fertilization treatments, which included green manure (cowpea), chicken manure and a control treatment (no application). From a total of 7924 spores, 24 different types of mycorrhiza were characterized using morphological and molecular analysis. The relation between soil conditions (pH, organic matter contents, P, K, Al+++ and % Al saturation) and AM fungi populations was analysed using a Stepwise Multiple Regression model. According to the regression coefficients obtained (P≤ 0.001 y R2 ≥ 0.83), soil pH and organic matter content were the independent variables that explained most of the variation observed in AM populations. The molecular methodology was based on the Polymerase Chain Reaction (PCR) and the use of specific primers allowed to identify spores from <em>Glomus</em>, <em>Entrophospora </em>and <em>Gigaspora</em>. This methodology also provided the identification of fungi from the <em>Glomus </em>genera in highly colonized maize roots.</p>


Author(s):  
István Harta ◽  
Barbara Simon ◽  
Szergej Vinogradov ◽  
Dániel Winkler

Abstract The challenges of a changing climate have directed greater attention to afforestation, but the effects of afforestation on soil fertility and soil biota have not been fully clarified. To explore changes in the soil conditions in two 20-year-old forest plantations established in formerly intensively fertilized plots of agricultural land, we focused on the current developmental state of the sites that received the most fertilizer and evaluated soil properties and Collembola (springtails) communities. Sessile oak (Quercus petraea) and black locust (Robinia pseudoacacia) that had been planted in the afforestation sites were assessed for differences between plantations of native and invasive species. Five adjacent reference associations, including forests and open habitats, were also analyzed and compared. Results showed that the soils in the two afforested sites were similar in their properties and Collembola communities to those of the control cultivated forests, but differed from each other in pH, calcium, phosphorus, and ammonium content. The available potassium and phosphorus contents in the soil of the sessile oak plantation were still high, while the soil organic matter content was adequate (SOM > 2.0%) in both plantations. Species richness of Collembola ranged from 18 in the cultivated arable land to 43 in the relict forest. Only a few species typical for forests (e.g., Neanura muscorum, Isotomiella minor, Entomobrya muscorum) were detected in the young plantations, while species characteristic of open habitats (e.g., Protaphorura campata, Lepidocyrtus cyaneus) occurred as well. Although more individuals and species of Collembola were present in the soil of young plantations than in arable fields, their community diversities were significantly lower compared to the control forest stands. Collembola community diversity differed significantly also between the two plantation types (with native and non-native tree species). Mean abundance in the afforested sites was about 2.5 times higher than in the cultivated arable land, yet far lower than the mean abundance in the control forests.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Marcus Vinicius Moreira Barbosa ◽  
Taynara Augusta Fernandes ◽  
Guilherme Benko Siqueira ◽  
Flávia Lucila Tonani de Siqueira ◽  
Paula Benevides de Morais

Flooded ecosystems are conditioned to seasonal floods that promote specific soil conditions, such as low oxygen, hydromorphism, and peculiar chemical reactions. These environments are dependent on flood pulses that determine specific ecological conditions. Ipucas are seasonally flooded discontinuous forest patches that occur exclusively in the Araguaia Plain in Central Brazil. They are located 0.40 to 1.20 m lower than the surrounding plain, which promotes an accumulation of rainwater for five to six months of the year, being entirely or partially dry during the dry season. The aim of this study was to evaluate the horizontal (centre and edge) and vertical (depths: 0–0.20 m and 0.20–0.40 m) variability of physicochemical parameters in Ipucas soils, attempting to establish the importance of flood pulses and the leaching of surrounding areas in soil formation and composition. Samples were collected during the dry season in three Ipucas of similar size and circularity using a Dutch auger. The results reveal that flood pulses promote the deposition of sediments eroded from the surrounding plain, homogenizing the characteristics of the surface soil, from the edge to the centre of the Ipucas. However, biogeochemical processes, also linked to temporary flooding, account for the differences between the surface and deeper soil horizons because anoxic conditions during flooding promote chemical reactions characteristic of anaerobic environments, modifying the pH and organic matter content, in addition to the gleying of soils subjected to flooding, which are then covered by sediments after the dry season. Finally, Ipucas soils are susceptible to anthropic changes and are dependent on seasonal flood pulses.


1959 ◽  
Vol 50 (2) ◽  
pp. 259-263 ◽  
Author(s):  
G. H. Bünzli ◽  
W. W. Büttiker

An investigation was made to determine the factors governing the distribution pattern of the larvae of certain species of Melolonthids and Tenebrionids; these are known to be serious pests of tobacco plants in Southern Rhodesia.Observations were made on mixed populations of the white grubs, larvae of Anomala exitialis Pér. and Schizonycha profuga Pér. (MELOLONTHINAE), on the one hand, and on those of the false wireworms, larvae of Psammodes similis Pér. and P. scrobicollis (Fhs.) (TENEBRIONIDAE), on the other.It was found that the habitats favoured by white grubs had a higher clay, silt and organic matter content than those favoured by false wireworms. This was indicated by the darker brown colour of the soil; the clay ratio of the soils of the two types of habitat was as 1 to 0·725 and the nitrogen ratio as 1 to 0·524, respectively.Heavy infestations of tobacco fields are associated with 60,000 white grubs or 1,500 false wireworms per acre. The white grubs complete their life-cycle in one year, the larvae obtaining the food requirements necessary for their develop ment in the 4 to 5 months of the wet season. The false wireworms have a two-year life-cycle, the active feeding stages of the larvae being spread over 18 to 21 months, comprising both wet and dry seasons.The infestations by the two classes of insect do not overlap in space to any great extent but are governed by the nature of the soil, the white grubs favouring areas in which the soil has a higher nutrient value and the false wireworms areas where the soil is poorer.Reference is made to parasitisation of white-grub larvae in two areas, where the soil had an abnormally high nitrogen content, by a species of Tiphia in the one area and by entomogenous fungi in the other.False wireworms have not been found to be similarly attacked under field conditions.


2010 ◽  
Vol 67 (5) ◽  
pp. 570-578 ◽  
Author(s):  
Fabiano Daniel De Bona ◽  
Francisco Antonio Monteiro

The degradation of Brachiaria decumbens Stapf. (Signal grass) pastures has resulted in a big problem for the Brazilian cattlemen. The objective of this study was to assess fertilization with nitrogen (N) and sulphur (S) rates on yield of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. cv. Marandu (Marandu palisadegrass) under establishment in a soil supporting degrading pasture of Brachiaria decumbens Stapf. Additionally, the N and S concentrations in plant tissue and soil according to the rates of these nutrients were evaluated. The study was carried out in a greenhouse in pots filled with an Entisol with high organic matter content. Five rates of N (0; 100; 200; 300 and 400 mg dm-3) and five rates of S (0; 10; 20; 30 and 40 mg dm-3) were tested in a 5² fractionated factorial. Plants were harvest three times. The interaction N rates × S rates was significant for the variables leaf area, tiller number, shoot dry matter, N concentration and N:S ratio in plants, and total N and sulphur-sulphate in the soil in at least one of the three growth periods of Marandu palisadegrass in establishment. The supply of both S and N to reach the N:S ratio about 10:1 in the fertilization promoted high yield, adequate N and S concentrations for plant metabolism and forage production, as well as kept and/or raised the soil fertility in relation to these nutrients.


Author(s):  
Adônis Moreira ◽  
Larissa Alexandra Cardoso Moraes ◽  
Thiago Assis Rodrigues Nogueira ◽  
Bruna Trovo Canizella

Abstract: The objective of this work was to evaluate the effect of copper use efficiency in soybean cultivars, grown on a typical Ultisol with a high organic matter content, on soil chemical properties and on plant grain yield, nutritional state, and physiological components. The experiment was carried out in greenhouse conditions, in a 5×4 factorial arrangement, with five soybean cultivars (TMG 1066RR, BRS 360RR, NA 6262RR, BMX Turbo RR, and BRS 359RR) and four Cu rates (0, 2, 4, and 8 mg kg-1). Under the studied soil conditions, the DTPA-TEA and Mehlich-1 extractants were efficient in determining available Cu in the soil. Regardless of the cultivars, Cu application increased grain yield (GY), shoot dry weight yield (SDWY), number of pods per pot, GY/SDWY ratio, photosynthetic rate, stomatal conductance, internal CO2 concentration, transpiration rate, and chlorophyll content. However, Cu use efficiency varied significantly among the different soybean genotypes. Except for Cu, soil chemical attributes and foliar and grain nutrient contents are not influenced by Cu rates nor by soybean cultivars.


Author(s):  
Vandana Gupta ◽  
Sonal Deshmukh

A pesticide is a substance used for controlling pests that damage the crops. Azadirachta indica (Neem) is widely studied and commercially used as a biopesticide against various pests. The present study aims to explore Momardica charantia (Bitter gourd) leaves as a biopesticide and compare its effectiveness with the Azadirachta indica (Neem) leaves and chemical pesticide (Admire). The test plant used for study is Hibiscus rosa-sinensis infected with Red Hibiscus mealy bug. Soil parameters (pH, conductivity, organic matter content, available potassium and available phosphorus) and plant characteristics (height, leaves count, flowering and chlorophyll content) of all test plants under study were estimated and compared. The soil parameter like pH showed no changes in control and treated plants while organic matter, available potassium and available phosphorus comparatively showed slight increase in concentration in plants treated with all pesticides. The plant characteristics viz. height, leaf count and branching showed improvement in growth after treatment with pesticides.All the pesticides under study were capable to kill mealy bugs in one month. Even though the biopesticidal property of Momardicacharantia leaves was found to be less as compared to Azadirachta indica leaves and chemical pesticide (Admire), it can be used effectively to control mealy bugs infecting Hibiscus plant.


2016 ◽  
Vol 75 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Dario Kremer ◽  
Renata Jurišić Grubešić ◽  
Dalibor Ballian ◽  
Danijela Stešević ◽  
Ivan Kosalec ◽  
...  

Abstract The Illyric–Balkan endemic species Moltkia petraea (Tratt.) Griseb. is very interesting as a potential horticultural and medicinal plant. The aim of this study was to investigate soil conditions of M. petraea habitats, the phenolic content in plant parts, and the influence of soil properties on the phenolic contents. The results were evaluated using Spearman rank order correlations. Analyzed soil samples contained very low to intermediate levels of physiologically active phosphorus, but were very rich in potash. Organic matter content of soil was high. Phenolic compound content was higher in leaves than in flowers or stems. The analyses showed that M. petraea possesses considerable quantities of phenolic compounds and has no specific demands for particular soil conditions. A negative correlation was found between soil phosphorus content and total phenols content in leaves and stems, and with the total phenolic acids content in flowers. Organic matter in soil also found to have a negative influence on total tannins content in stems. Among the tested geographical locations, the Mljet population showed a higher degree of separation from the remaining locations.


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