scholarly journals Nitrogen, phosphorus, potassium, calcium and magnesium release from two compressed fertilizers: column experiments

2014 ◽  
Vol 6 (2) ◽  
pp. 1555-1578
Author(s):  
M. J. Fernández-Sanjurjo ◽  
E. Alvarez-Rodríguez ◽  
A. Núñez-Delgado ◽  
M. L. Fernández-Marcos ◽  
A. Romar-Gasalla
Keyword(s):  
Slow Release ◽  
Nutrient Release ◽  
Geographic Area ◽  
Nutrient Concentrations ◽  
Chemical Parameters ◽  
Soil Columns ◽  
Npk Fertilizers ◽  
Soil Material ◽  
Nutrient Demand ◽  
Nitrogen Phosphorus

Abstract. We used soil columns to study nutrients release from two compressed NPK fertilizers. The columns were filled with soil material from the surface horizon of a granitic soil. Tablets of two slow-release NPK fertilizers (11-18-11 or 8-8-16) were placed into the soil, and then water was percolated through the columns in a saturated regime. Percolates were analyzed for N, P, K, Ca and Mg. These nutrients were also determined in soil and fertilizer tablets at the end of the trials. Nutrient concentrations were high in the first percolates, reaching a steady state when 1426 mm water have percolated, which is equivalent to approximately 1.5 years of rainfall in the geographic area. In the whole trial, both tablets lost more than 80% of their initial N, P and K contents. However, K, Ca and Mg were the most leached, whereas N and P were lost in leachates to a lesser extent. Nutrient release was slower from the tablet with composition 8-8-16 than from the 11-18-11 fertilizer. In view of that, the 8-8-16 tablet can be considered more adequate for crops with a nutrient demand sustained over time. At the end of the trial, the effects of these fertilizers on soil chemical parameters were still evident.

scholarly journals Nitrogen, phosphorus, potassium, calcium and magnesium release from two compressed fertilizers: column experiments

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 1351-1360 ◽  
Author(s):  
M. J. Fernández-Sanjurjo ◽  
E. Alvarez-Rodríguez ◽  
A. Núñez-Delgado ◽  
M. L. Fernández-Marcos ◽  
A. Romar-Gasalla
Keyword(s):  
Nutrient Release ◽  
Geographic Area ◽  
Exchange Capacity ◽  
Nutrient Concentrations ◽  
Chemical Parameters ◽  
Npk Fertilizers ◽  
Nutrient Demand ◽  
Inner Diameter ◽  
Nitrogen Phosphorus ◽  
Controlled Release Fertilizers

Abstract. The objective of this work was to study nutrients release from two compressed nitrogen–potassium–phosphorous (NPK) fertilizers. In the Lourizán Forest Center, tablet-type controlled-release fertilizers (CRF) were prepared by compressing various mixtures of fertilizers without covers or binders. We used soil columns (50 cm long and 7.3 cm inner diameter) that were filled with soil from the surface layer (0–20 cm) of an A horizon corresponding to a Cambic Umbrisol. Tablets of two slow-release NPK fertilizers (11–18–11 or 8–8–16) were placed into the soil (within the first 3 cm), and then water was percolated through the columns in a saturated regime for 80 days. Percolates were analyzed for N, P, K+, Ca2+ and Mg2+. These elements were also determined in soil and fertilizer tablets at the end of the trials. Nutrient concentrations were high in the first leachates and reached a steady state when 1426 mm of water had been percolated, which is equivalent to approximately 1.5 years of rainfall in this geographic area. In the whole trial, both tablets lost more than 80% of their initial N, P and K contents. However, K+, Ca2+ and Mg2+ were the most leached, whereas N and P were lost in leachates to a lesser extent. Nutrient release was slower from the tablet with a composition of 8–8–16 than from the 11–18–11 fertilizer. In view of that, the 8–8–16 tablet can be considered more adequate for crops with a nutrient demand sustained over time. At the end of the trial, the effects of these fertilizers on soil chemical parameters were still evident, with a significant increase of pH, available Ca2+, Mg2+, K+, P and effective cation exchange capacity (eCEC) in the fertilized columns, as well as a significant decrease in exchangeable Al3+, reaching values < 0.08 cmol (+) kg−1.

scholarly journals Nutrient Release Performance of Starch Coated NPK Fertilizers and Their Effects on Corn Growth

2018 ◽  
Vol 15 (2) ◽  
pp. 104 ◽  
Author(s):  
Nur Izza Faiqotul Himmah ◽  
Gunawan Djajakirana ◽  
Darmawan Darmawan
Keyword(s):  
Release Rate ◽  
Slow Release ◽  
Slow Growth ◽  
Nutrient Release ◽  
Environmental Issues ◽  
Coating Materials ◽  
Npk Fertilizers ◽  
Glutinous Rice ◽  
Npk Fertilizer ◽  
Coated Fertilizers

<p>One way to control or slow down the nutrient release rate from fertilizer is by coating technique.  Nowadays the use of biodegradable coating materials for slow-release fertilizer (SRF) is preferable because of environmental issues.  This research was aimed to make SRF using starches and cellulose as the coating materials and to test the release rate of the nutrients.  Five kinds of starches (cassava, corn, sago, wheat, and glutinous rice) and carboxymethyl cellulose (CMC) were used as coating material for granulated NPK fertilizer.  The coated fertilizers (NPK SRF) were tested for their leaching rate in the soil by percolation experiment.  The results showed that the kind of starch used influenced the release rate of the NPK SRFs. The NPK SRF coated with sago starch exhibited slow release rate and low leached nutrients which also resulted in slow growth of corn plant, as expected of SRF.  The use of starch and CMC as biodegradable coating materials in this research has a possibility to affect the microbial activity in the soil so that the nutrient release became faster than the uncoated NPK fertilizer.</p>

Development of a water temperature-ecological model to stimulate global warming effects on lake ecosystem

1996 ◽  
Vol 34 (7-8) ◽  
pp. 237-244 ◽  
Author(s):  
Masaaki Hosomi ◽  
Tetsu Saigusa ◽  
Kenichi Yabunaka ◽  
Takuya Okubo ◽  
Akihiko Murakami
Keyword(s):  
Global Warming ◽  
Water Temperature ◽  
Thermal Stratification ◽  
Ecological Model ◽  
Nutrient Release ◽  
Eddy Diffusion ◽  
Nutrient Concentrations ◽  
Lake Ecosystem ◽  
Phytoplankton Species ◽  
Freezing And Thawing

This paper describes a newly developed combined water temperature-ecological (WT-ECO) model which is employed to simulate the effects of global warming on lake and reservoir ecosystems. The WT model includes (i) variations in the eddy diffusion coefficient based on the degree of thermal stratification and the velocity of wind, and (ii) a sub-model for simulating the freezing and thawing processes of surface water, water temperatures, and the mixing rates between two adjacent layers of water. The ECO model then uses these results to calculate the resultant effect on a lake's ecological dynamics, e.g., composition of phytoplankton species, their respective concentrations, and nutrient concentrations. When the model was benchmarked against Lake Yunoko, a dimictic lake, fairly good agreement was obtained over a 4-yr period; thereby indicating it is suitably calibrated. In addition, to assess the effects of global warming on a lake ecosystem, changes in Lake Yunoko's water temperature/quality were simulated in response to an increase in air temperature of 2 - 4°C. Results indicate that such an increase will (i) increase thermal stratification in summer, which increases the nutrient concentrations in bottom water due to nutrient release from bottom sediment, (ii) increase the concentration of phytoplankton at the beginning of the autumn circulation period, and (iii) change the composition of phytoplankton species.

scholarly journals Uptake and translocation of nitrogen, phosphorus and calcium in soybean infected with Meloidogyne incognita and M. javanica

2002 ◽  
Vol 27 (2) ◽  
pp. 141-150 ◽  
Author(s):  
RUI G. CARNEIRO ◽  
PAULO MAZZAFERA ◽  
LUIZ CARLOS C.B. FERRAZ ◽  
TAKASHI MURAOKA ◽  
PAULO CESAR O. TRIVELIN
Keyword(s):  
Nutrient Uptake ◽  
Meloidogyne Incognita ◽  
Nutrient Concentrations ◽  
Tissue Mass ◽  
Split Root ◽  
Split Root System ◽  
Shoot Mass ◽  
Moderately Resistant ◽  
Nitrogen Phosphorus ◽  
Uptake And Transport

Two soybean (Glycine max) cultivars were used in this study, Ocepar 4, rated as moderately resistant to Meloidogyne incognita race 3 but susceptible to M. javanica, and 'BR 16', susceptible to both nematodes. The effect of nematodes infection on the uptake and transport of N, P and Ca to the shoot was studied in plants growing in a split root system. The upper half was inoculated with 0, 3,000, 9,000 or 27,000 eggs/plant while the lower half received 15N, 32P or 45Ca. Infected plants showed an increase of root but a decrease of shoot mass with increasing inoculum levels. In general, total endogenous nutrients increased in the roots and tended to decrease in the shoots with increasing inoculum levels. When concentrations were calculated, there was an increase in the three nutrients in the roots, and an increase of Ca but no significant variation of N and P was observed in the shoots. The total amount of 15N in the roots increased at the highest inoculum levels but 32P and 45Ca decreased. In the shoots there was a reduction of 32P and 45Ca. The specific concentrations of the labelled nutrients (abundance or radioactivity/tissue mass) also showed a decrease of 32P and 45Ca in the shoots and roots of infected plants and an increase of 15N in the shoots. Considering that overall nutrient concentrations reflect cumulative nutrient uptake and the data from labelled elements gave information at a specific moment of the infection, thus nematodes do interfere with nutrient uptake and translocation.

scholarly journals Litter mixing effect on decomposition rate and nutrient release: low quality leaves of coastal species

2021 ◽  
Author(s):  
Lili Wei
Keyword(s):  
Litter Decomposition ◽  
Decomposition Rate ◽  
Nutrient Release ◽  
Additive Effect ◽  
Nutrient Concentrations ◽  
Mangrove Species ◽  
Litter Bag ◽  
Litter Mixtures ◽  
Coastal Species ◽  
Litter Mixing

Coastal wetlands are among the most carbon-rich ecosystems in the world. Litter decomposition is a major process controlling soil carbon input. Litter mixing has shown a non-additive effect on the litter decomposition of terrestrial plants particularly of those species having contrasting litter quality. But the non-additive effect has been rarely tested in coastal plants which generally having low-quality litters. We selected three common mangrove species and one saltmarsh species, co-occurring in subtropical coasts, to test whether the non-additive effect occurs when the litters of these coastal species mixing together. We are also concerned whether the changes in the decomposition rate of litter will affect the nutrient contents in waters. A litter-bag experiment was carried out in a glasshouse with single and mixed leaf litters. A non-additive effect was observed in the litter mixtures of mangrove species Aegiceras corniculatum vs. Kandelia obovata (antagonistic) and A. corniculatum vs. Avicennia marina (synergistic). Whereas, the mixture of A. corniculatum (mangrove species) and Spartina alterniflora (saltmarsh species) showed an additive effect. The strength of the non-additive effect was unrelated to the initial trait dissimilarity of litters. Instead, the decomposition rate and mass remaining of litter mixtures were strongly related to the carbon concentrations in litters. Nutrient content in waters was dependent on the decomposition rate of litter mixtures but not on the initial nutrient concentrations in litters. Despite the behind mechanisms were not yet revealed by the current study, these findings have improved our understanding of the litter decomposition of coastal species and the consequent nutrient release.

A LABORATORY STUDY OF GLEYING

1965 ◽  
Vol 45 (2) ◽  
pp. 199-206 ◽  
Author(s):  
J. A. McKeague
Keyword(s):  
Organic Matter ◽  
Acetic Acid ◽  
Room Temperature ◽  
Rate Of Change ◽  
Redox Potentials ◽  
Soil Columns ◽  
Flooded Soils ◽  
Soil Material ◽  
Effects Of Temperature ◽  
Extractable Iron

Columns of different soil materials with ground leaves at the surface were maintained for 18 months with the water table continuously above the surface, or fluctuating between the surface and 15 cm. Redox potentials, colors, and extractable iron were determined. The effects of temperature and of organic matter on the rate of change of Eh were studied with flooded soils in test tubes.The rate and degree of development of dull colors and mottling in the soil columns was influenced greatly by the nature of the soil material. Reduction effected marked increases in acetic acid extractable iron from all of the soil materials. Low redox potentials developed rapidly at room temperature in flooded soils containing appreciable amounts of organic matter. Eh values below 0 mv developed slowly in soils at 1 °C and at room temperature in some soils that were almost devoid of organic matter. Release of Fe+2 from ferrous minerals was thought to account for these low Eh values.

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