scholarly journals Microbial alterations of the soil influenced by induced compaction

2009 ◽  
Vol 33 (5) ◽  
pp. 1207-1213 ◽  
Author(s):  
Breno Pupin ◽  
Onã da Silva Freddi ◽  
Ely Nahas
Keyword(s):  
Enzyme Activity ◽  
Microbial Community ◽  
Soil Compaction ◽  
Crop Yields ◽  
Organic Matter Content ◽  
Denitrifying Bacteria ◽  
Matter Content ◽  
Nitrifying Bacteria ◽  
Soil Microbial ◽  
Agricultural Machines

Compaction is one of the most destructive factors of soil quality, however the effects on the microbial community and enzyme activity have not been investigated in detail so far. The objective of this study was to evaluate the effects of soil compaction caused by the traffic of agricultural machines on the soil microbial community and its enzyme activity. Six compaction levels were induced by tractors with different weights driving over a Eutrustox soil and the final density was measured. Soil samples were collected after corn from the layers 0-0.10 and 0.10-0.20 m. The compaction effect on all studied properties was evident. Total bacteria counts were reduced significantly (by 22-30 %) and by 38-41 % of nitrifying bacteria in the soil with highest bulk density compared to the control. On the other hand, fungi populations increased 55-86 % and denitrifying bacteria 49-53 %. Dehydrogenase activity decreased 20-34 %, urease 44-46 % and phosphatase 26-28 %. The organic matter content and soil pH decreased more in the 0-0.10 than in the 0.10-0.20 m layer and possibly influenced the reduction of the microbial counts, except denitrifying bacteria, and all enzyme activities, except urease. Results indicated that soil compaction influences the community of aerobic microorganisms and their activity. This effect can alter nutrient cycling and reduce crop yields.

scholarly journals Effect of Organic Residues on Pesticide Behavior in Soils: A Review of Laboratory Research

Environments ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 32
Author(s):  
María J. Carpio ◽  
María J. Sánchez-Martín ◽  
M. Sonia Rodríguez-Cruz ◽  
Jesús M. Marín-Benito
Keyword(s):  
Crop Yields ◽  
Organic Matter Content ◽  
Organic Amendments ◽  
Matter Content ◽  
Laboratory Research ◽  
Laboratory Studies ◽  
Future Perspectives ◽  
Organic Residues ◽  
Multiple Factors ◽  
Adsorption Desorption

The management of large volumes of organic residues generated in different livestock, urban, agricultural and industrial activities is a topic of environmental and social interest. The high organic matter content of these residues means that their application as soil organic amendments in agriculture is considered one of the more sustainable options, as it could solve the problem of the accumulation of uncontrolled wastes while improving soil quality and avoiding its irreversible degradation. However, the behavior of pesticides applied to increase crop yields could be modified in the presence of these amendments in the soil. This review article addresses how the adsorption–desorption, dissipation and leaching of pesticides in soils is affected by different organic residues usually applied as organic amendments. Based on the results reported from laboratory studies, the influence on these processes has been evaluated of multiple factors related to organic residues (e.g., origin, nature, composition, rates, and incubation time of the amended soils), pesticides (e.g., with different use, structure, characteristics, and application method), and soils with different physicochemical properties. Future perspectives on this topic are also included for highlighting the need to extend these laboratory studies to field and modelling scale to better assess and predict pesticide fate in amended soil scenarios.

scholarly journals The Influence of Mineral Fertilizer Combined With a Nitrification Inhibitor on Microbial Populations and Activities in Calcareous Uzbekistanian Soil Under Cotton Cultivation

2001 ◽  
Vol 1 ◽  
pp. 108-113 ◽  
Author(s):  
Dilfuza Egamberdiyeva ◽  
Muhiddin Mamiev ◽  
Svetlana K. Poberejskaya
Keyword(s):  
Nitrification Inhibitor ◽  
Mineral Fertilizer ◽  
Denitrifying Bacteria ◽  
Nitrifying Bacteria ◽  
Most Probable Number ◽  
Nitrification Rate ◽  
Nitrification Inhibitors ◽  
Probable Number ◽  
Soil Microbial ◽  
Soil Microbial Population

Application of fertilizers combined with nitrification inhibitors affects soil microbial biomass and activity. The objective of this research was to determine the effects of fertilizer application combined with the nitrification inhibitor potassium oxalate (PO) on soil microbial population and activities in nitrogen-poor soil under cotton cultivation in Uzbekistan. Fertilizer treatments were N as urea, P as ammophos, and K as potassium chloride. The nitrification inhibitor PO was added to urea and ammophos at the rate of 2%. Three treatments—N200P140K60(T1), N200P140 POK60(T2), and N200P140 POK60(T3) mg kg-1soil—were applied for this study. The control (C) was without fertilizer and PO. The populations of oligotrophic bacteria, ammonifying bacteria, nitrifying bacteria, denitrifying bacteria, mineral assimilating bacteria, oligonitrophilic bacteria, and bacteria group Azotobacter were determined by the most probable number method. The treatments T2 and T3 increased the number of oligonitrophilic bacteria and utilization mineral forms of nitrogen on the background of reducing number of ammonifying bacteria. T2 and T3 also decreased the number of nitrifying bacteria, denitrifying bacteria, and net nitrification. In conclusion, our experiments showed that PO combined with mineral fertilizer is one of the most promising compounds for inhibiting nitrification rate, which was reflected in the increased availability and efficiency of fertilizer nitrogen to the cotton plants. PO combined with mineral fertilizer has no negative effects on nitrogen-fixing bacteria Azotobacter and oligo-nitrophilic bacteria.

scholarly journals Effect of Plant Extracts and Metam Sodium on the Soilborne Fungal Pathogens, Meloidogyne spp., and Soil Microbial Community

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 513
Author(s):  
María del Mar Montiel-Rozas ◽  
Miguel Ángel Díez-Rojo ◽  
Margarita Ros ◽  
José Antonio Pascual
Keyword(s):  
Microbial Community ◽  
Plant Extracts ◽  
Soil Microbial Community ◽  
Fungal Pathogens ◽  
Crop Yields ◽  
Soil Microbiota ◽  
Metam Sodium ◽  
Soil Microbial ◽  
Meloidogyne Spp ◽  
Treatment Application

In this field study, the fungicidal and nematicidal activity of two plant extracts (Larrea spp. (LR), Liquidambar spp. (LQ)), and an organosulfur soil fungicide metam sodium alone (MS), and a mix of LR and MS (LR + MS) was assayed under pepper cropping in southeastern Spain. Metam sodium treatments (MS and LR + MS) produced the highest crop yields and were more effective in controlling root-knot nematodes and fungal pathogens (Fusarium, Pythium, and Rhizoctonia solani) than the plant extracts treatments (LQ and LR). Furthermore, the effect of the metam sodium treatments applied negatively affected the soil microbial community, principally bacteria, but not fungi. These microbial community changes of the soil were principally observed after treatment application; the differences between the treatments were reduced at the end of the experiment, when recovery of the soil microbiota communities occurred.

Compaction of forest soils. A review

Soil Research ◽  
1980 ◽  
Vol 18 (2) ◽  
pp. 163 ◽  
Author(s):  
EL Greacen ◽  
R Sands
Keyword(s):  
Organic Matter ◽  
Forest Soils ◽  
Soil Compaction ◽  
Water Regime ◽  
Management Practices ◽  
Organic Matter Content ◽  
Matter Content ◽  
Predictive Tool ◽  
Soil Water Regime ◽  
Heavy Loads

The problem of soil compaction in forestry differs from that in agriculture because of differences in the nature of the crop, in particular the weight and size of the plant members and the length of time that they persist. The roots compact the soil as they increase in size, but they also transmit the weight of the tree and forces generated by the wind onto the soil. There are important differences in management practices; in forestry modern harvesting machines apply heavy loads and, for reasons of cost, tend to be kept in operation throughout the year. As a consequence the structure of the soil suffers some damage, often manifested as compaction. Compaction arising from such sources may reduce the growth of the current trees or trees subsequently planted on the site. But it is difficult to predict the extent of such reduction, if any, because of the complex of interactions involved. Important factors concerned, namely, the soil water regime and the organic matter content, are emphasized. A conceptual model is proposed as a predictive tool. The mechanics of soil compaction, the effects of compaction on the physical properties of the soil, and techniques for the prevention and amelioration of compaction of forest soils, are discussed.

An experiment on the effects of straw ploughed in or composted on a three-course rotation of crops

1960 ◽  
Vol 54 (2) ◽  
pp. 222-230 ◽  
Author(s):  
H. D. Patterson
Keyword(s):  
Sugar Beet ◽  
Crop Yields ◽  
Organic Matter Content ◽  
Matter Content ◽  
N Fertilizer ◽  
Available Nitrogen ◽  
Npk Fertilizers ◽  
K Fertilizer ◽  
Nitrogen Deficiencies ◽  
Second Year

An experiment on the use of wheat straw (ploughed in or composted at the rate of 53⅓ cwt./acre every second year) and NPK fertilizers in the maintenance of fertility was carried out at Rothamsted between 1933 and 1958. The effects of these treatments on the yields of the crops of the rotation used in the experiment—barley, sugar beet, potatoes—are discussed in the present paper.The treatments appear to have had no effect on crop yields through improvements to the soil caused by better structure or increased organic matter content. All the effects obtained can be attributed to changes in the supplies of available nutrients. The most important of these changes appear to have been: (1) nitrogen deficiencies due to the immobilization of soil nitrogen or nitrogen fertilizer by the straw: there is some evidence that this added to the store of slowly available nitrogen; (2) additions to potassium supplies from potassium in the straw. Factor (1) affected all three crops. Factor (2) affected potatoes, the only crop of the three to give good responses to potassium.It was found that when the straw was ploughed in directly about 0·08 ewt. N fertilizer applied to the crops for each ton of straw was sufficient to overcome losses in yield due to nitrogen deficiencies. The straw improved the yields of potatoes in the first and second years after application. Provided that allowance was made for losses of available nitrogen the yields of potatoes from ploughed-in straw were about the same as the yields obtained by adding K fertilizer to the crop, equal in amount to the potassium in the straw. When part of the fertilizers was ploughed in with the straw instead of being given directly to the crop the yields of potatoes were reduced.Compost made with NT fertilizers and straw and ploughed in with K fertilizer gave much poorer yields than were obtained by ploughing the straw in directly and applying the fertilizers to the crops. Losses of available nitrogen were severe, all the N fertilizer used in making the compost (0·15 cwt. N for each ton of straw) being either lost through drainage or immobilized by the straw. In addition, more than one half of the potassium in the straw was lost in composting.There was no evidence that any of the nitrogen immobilized in the decomposition of the straw became available in the first or second years after application. Residues from repeated applications of straw every second year over 18 years increased the yields of potatoes and sugar beet in the last 6 years of the experiment. The increases may have been due to the release of previously immobilized nitrogen.

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