scholarly journals Effect of molybdenum treatment on the element uptake of plants in a long-term experiment

2012 ◽  
pp. 121-125
Author(s):  
Anita Puskás-Preszner ◽  
Béla Kovács ◽  
Dávid Andrási ◽  
Zita Kata Burján

Molybdenum as a constituent of several inmportant enzymes is an essential micorelement. It can be found in all kind of food naturally at low level, however, environmental pollution, from natural or anthropogenic sources, can lead to high level of the metal in plants. Our study is based on the long-term field experiments of Nagyhörcsök, where different levels of soil contamination conditions are simulated. Plant samples were collected from the experiment station to study the behaviour of elements: uptake by and transport within the plants, accumulation in different organs, phytotoxicity and effects on the quantity and quality of the crop.In this work we present the effect of molybdenum treatment on the uptake of other elements. Molybdenum is proved to be in an antagonist relationship with copper and sulphur, while molybdenum-phosphorus is a synergist interaction.However, in most of the plants we studied increasing molybdenum-treatment enhanced cadmium-uptake. We have found the most significant cadmium-accumulation in the case of pea, spinach and red beet.

2011 ◽  
pp. 75-79
Author(s):  
Anita Puskás-Preszner ◽  
Béla Kovács ◽  
Dávid Andrási ◽  
Zita Kata Burján

Molybdenum, as a constituent of several important enzymes, is an essential microelement. It can be found in all kind of food naturally at lowlevels. However, environmental pollution, from natural or anthropogenic sources, can lead to high levels of the metal in plants. Our study is based on long-term field experiments at Nagyhörcsök, where different levels of soil contamination conditions are simulated. Plant samples were collected from the experiment station to study the behavior of elements: uptake by and transport within the plants, accumulation in different organs, phytotoxicity and effects on the quantity and quality of the crop. In this study, we present the effect of molybdenum treatment on the uptake of other elements. Molybdenum is proved to be in an antagonist relationship with copper and sulphur, while molybdenum-phosphorus is a synergist interaction. However, in most of the plants we studied, increasing molybdenum-treatment enhanced cadmium uptake. We found the most significant cadmium accumulation in the case of pea, spinach and red beet. 


2009 ◽  
pp. 117-122 ◽  
Author(s):  
Anita Puskás-Preszner ◽  
Béla Kovács

Molybdenum is not a well-known microelement, but being a constituent of several important cellular enzymes it is an essential microelement. Molybdenum occurs in all foods, but at very low levels. There does not appear to be any particular foods or types of foods, which in the absence of extrinsic factors, naturally have high levels of molybdenum. However, environmental pollution, from natural or anthropogenic sources, can lead to high level of the metal in plants.Our study is based on the long-term field experiments of Nagyhörcsök, where different levels of soil contamination conditions are simulated. Soil and plant samples were collected from the experiment station to study the behaviour of molybdenum: total concentration, available  concentration, leaching, transformation, uptake by and transport within the plants, accumulation in different organs, phytotoxicity and effects on the quantity and quality of the crop. In this work we present the results of maize and peas and the soil samples related to them.According to our data molybdenum is leaching from the topsoil at a medium rate and it appears in the deeper layers. In the case of plant samples we found that molybdenum level in the straw is many times higher than that is in the grain, so molybdenum accumulates in the vegetative organs of the plant. The data also show differences in the molybdenum-uptake of cereals and Fabaceae (or Leguminosae).


2017 ◽  
Author(s):  
Kendra L. Lawrence ◽  
David H Wise

Background. Theory predicts strong bottom-up control in detritus-based food webs, yet field experiments with detritus-based terrestrial systems have uncovered contradictory evidence regarding the strength and pervasiveness of bottom-up control processes. Two factors likely leading to contradictory results are experiment duration, which influences exposure to temporal variation in abiotic factors such as rainfall and affects the likelihood of detecting approach to a new equilibrium; and openness of the experimental units to immigration and migration. To investigate the contribution of these two factors, we conducted a long-term experiment with open and fenced plots in the forest that was the site of an earlier, short-term experiment (3.5 months) with open plots (Chen & Wise 1999) that produced evidence of strong bottom-up control for 14 taxonomic groupings of primary consumers of litter and fungi (microbi-detritivores) and their predators. Methods. We added artificial high-quality detritus to ten 2 x 2-m forest-floor plots at bi-weekly intervals from April through September in three consecutive years (Supplemented treatment). Ten comparable Ambient plots were controls. Half of the Supplemented and Ambient plots were enclosed by metal fencing. Results. Arthropod community structure (based upon 18 response variables) diverged over time between Supplemented and Ambient treatments, with no effect of Fencing on the multivariate response pattern. Fencing possibly influenced only ca. 20% of the subsequent univariate analyses. Multi- and univariate analyses revealed bottom-up control by fall of Year 1 of some, but not all, microbi-detritivores and predators. During the following two years the pattern of responses became more complex than that observed by Chen & Wise (1999). Some taxa showed consistent bottom-up control whereas many did not. Variation across years could not be explained completely by differences in rainfall because some taxa exhibited negative, not positive, responses to detrital supplementation. Discussion. Our 3-yr experiment did not confirm the conclusion of strong, pervasive bottom-up control of microbi-detritivores and predators reported by Chen and Wise (1999). Our longer-term experiment revealed a more complex pattern of responses, a pattern much closer to the range of outcomes reported in the literature for many short-term experiments. Much of the variation in responses across studies likely reflects variation in factors such as rainfall and the quality of added detritus. Nevertheless, it is also possible that long-term resource enhancement can drive a community towards a new equilibrium state that differs from what would have been predicted from the initial short-term responses exhibited by primary and secondary consumers.


2015 ◽  
Vol 12 (19) ◽  
pp. 16527-16551 ◽  
Author(s):  
C. Poeplau ◽  
M. A. Bolinder ◽  
H. Kirchmann ◽  
T. Kätterer

Abstract. Increasing soil organic carbon (SOC) in agricultural soils can mitigate atmospheric CO2 concentration and also contribute to increase soil fertility and ecosystem resilience. The role of major nutrients on SOC dynamics is complex, due to simultaneous effects on net primary productivity (NPP) that influence crop residue carbon inputs and on the rate of heterotrophic respiration (carbon outputs). This study investigated the effect on SOC stocks of three different levels of phosphorus and potassium (PK) fertilisation rates in the absence of nitrogen fertilisation and of three different levels of nitrogen in the absence of PK. This was done by analysing data from 10 meta-replicated Swedish long-term field experiments (> 45 years). With N fertilisation, SOC stocks followed yield increases. However, for all PK levels, we found average SOC losses ranging from −0.04 ± 0.09 Mg ha−1 yr−1 (ns) for the lowest to −0.09 ± 0.07 Mg ha−1 yr−1 (p = 0.008) for the highest application rate, while crop yields as a proxy for carbon input increased significantly with PK fertilization by 1, 10 and 15 %. We conclude that SOC dynamics are mainly output-driven in the PK fertilised regime but mostly input-driven in the N fertilised regime, due to the much more pronounced response of NPP to N than to PK fertilisation. It has been established that P rather than K is the element affecting ecosystem carbon fluxes, where P fertilisation has been shown to: (i) stimulate heterotrophic respiration, (ii) reduce the abundance of arbuscular mycorrhizal fungi and (iii) decrease crop root : shoot ratio, leading to lower root-derived carbon input. The higher export of N in the PK fertilised plots in this study could (iv) have led to increased N mining and thus mineralisation of organic matter. More integrated experiments are needed to gain a better understanding of the relative importance of each of the above-mentioned mechanisms leading to SOC losses after P addition.


2016 ◽  
Vol 13 (4) ◽  
pp. 1119-1127 ◽  
Author(s):  
Christopher Poeplau ◽  
Martin A. Bolinder ◽  
Holger Kirchmann ◽  
Thomas Kätterer

Abstract. Increasing soil organic carbon (SOC) in agricultural soils can mitigate atmospheric CO2 concentration and also contribute to increased soil fertility and ecosystem resilience. The role of major nutrients in SOC dynamics is complex, due to simultaneous effects on net primary productivity (NPP) that influence crop residue carbon inputs and in the rate of heterotrophic respiration (carbon outputs). This study investigated the effect on SOC stocks of three different levels of phosphorus and potassium (PK) fertilisation rates in the absence of nitrogen fertilisation and of three different levels of nitrogen fertiliser in the absence of PK fertiliser. This was done by analysing data from 10 meta-replicated Swedish long-term field experiments (> 45 years). With N fertilisation, SOC stocks followed yield increases. However, for all PK levels, we found average SOC losses ranging from −0.04 ± 0.09 Mg ha−1 yr−1 (ns) for the lowest to −0.09 ± 0.07 Mg ha−1 yr−1 (p =  0.008) for the highest application rate, while crop yields as a proxy for carbon input increased significantly with PK fertilisation by 1, 10 and 15 %. We conclude that SOC dynamics are mainly output-driven in the PK-fertilised regime but mostly input-driven in the N-fertilised regime, due to the much more pronounced response of NPP to N than to PK fertilisation. It has been established that P rather than K is the element affecting ecosystem carbon fluxes, where P fertilisation has been shown to (i) stimulate heterotrophic respiration, (ii) reduce the abundance of arbuscular mycorrhizal fungi and (iii) decrease the crop root : shoot ratio, leading to higher root-derived carbon input. The higher export of N in the PK-fertilised plots in this study could (iv) have led to increased N mining and thus mineralisation of organic matter. More integrated experiments are needed to gain a better understanding of the relative importance of each of the above-mentioned mechanisms leading to SOC losses after P addition.


2004 ◽  
Vol 18 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Holger Kirchmann ◽  
Georg Haberhauer ◽  
Ellen Kandeler ◽  
Angela Sessitsch ◽  
Martin H. Gerzabek

1995 ◽  
Vol 4 (4) ◽  
pp. 419-427 ◽  
Author(s):  
Risto Tahvonen ◽  
Asko Hannukkala ◽  
Hanna Avikainen

The effect of seed dressing with the antagonist Streptomyces griseoviridis on root rots and yields of wheat and barley was studied in field experiments. In long-term field experiments, where different levels of soil-borne inoculum of root rots were maintained with different crop sequences, seed treatment with the antagonist increased yields slightly on average over all experimental years. However, variations between years, crops and crop sequences were considerable. The highest yield increases were in excess of 600 kg/ha, whilst treatment occasionally resulted in slight yield losses. In experiments in which seed naturally infested with Fusarium spp. was used, seed treatment with S. griseoviridis increased yields of wheat but not those of barley. Seed dressing with an organomercurial fungicide resulted in higher yield increases than the biopreparate.


2020 ◽  
Vol 12 (12) ◽  
pp. 5019 ◽  
Author(s):  
Mirko Castellini ◽  
Alessandro Vittorio Vonella ◽  
Domenico Ventrella ◽  
Michele Rinaldi ◽  
Giorgio Baiamonte

Conservation agriculture is increasingly accepted by farmers, but the modeling studies on agro-environmental processes that characterize these agricultural systems require accurate information on the temporal variability of the soil’s main physical and hydraulic properties. Therefore, specific investigations carried out in long-term experiments can increase our knowledge on the pros and cons of different measurement techniques. In this work, the simplified falling head (SFH) technique and the Beerkan Estimation of Soil Transfer (BEST) procedure were applied to investigate the temporal variability of some main soil physical and hydraulic properties, including bulk density (BD), field saturated hydraulic conductivity (Kfs), macroporosity (Pmac), air capacity (AC), plant available water capacity (PAWC), and relative field capacity (RFC). For this purpose, a long-term experiment was selected, and the experimental information obtained was used to verify the long-term impact (fifteen years) determined by two alternative forms of soil management, minimum tillage (MT) and no tillage (NT), for the cultivation of durum wheat. The main results of the comparison between MT and NT showed: (i) A comparable temporal variability in Kfs values when SFH was considered, given that in 75% of considered cases, the same result (i.e., significant or not significant) was obtained; (ii) a comparable temporal variability in Kfs values under MT (but not under NT) when both SFH and BEST were used, as a result of a possible Kfs,SFH overestimation under NT; (iii) differences in Kfs estimations by a factor of 6 or 7 (Kfs,SFH > Kfs,BEST) when comparable soil conditions (moisture and soil density) were considered; (iv) a comparable temporal variability when other soil indicators (BD, Pmac, AC, PAWC, and RFC) were simultaneously considered. After about fifteen years of field experiments characterized by continuous soil management and conducted with the methodological rigor typical of experimental farms, the SFH- and BEST-derived experimental information showed a substantial equivalence between MT and NT for the fine-textured soil investigated.


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