scholarly journals Contrasting effects of nitrogen forms and soil pH on ammonia oxidizing microorganisms and their responses to long-term nitrogen fertilization in a typical steppe ecosystem

2017 ◽  
Vol 107 ◽  
pp. 10-18 ◽  
Author(s):  
Jiaoyan Ying ◽  
Xiaoxiao Li ◽  
Nana Wang ◽  
Zhichun Lan ◽  
Jizheng He ◽  
...  
Keyword(s):  
Soil Ph ◽  
Nitrogen Fertilization ◽  
Nitrogen Forms ◽  
Typical Steppe ◽  
Steppe Ecosystem

scholarly journals Negative impacts of excessive nitrogen fertilization on the abundance and diversity of diazotrophs in black soil with monocropping maize

2020 ◽  
Author(s):  
La Chen ◽  
Keke Li ◽  
Wenjun Shi ◽  
Xiaolin Wang ◽  
Entao Wang ◽  
...  
Keyword(s):  
Soil Ph ◽  
Nitrogen Fertilizer ◽  
Nitrogen Fertilization ◽  
Black Soil ◽  
Maize Rhizosphere ◽  
N Input ◽  
Use Efficiency ◽  
Abundance And Diversity ◽  
Diazotrophic Community

Abstract Background: Excessive nitrogen fertilizer input and low nitrogen fertilizer use efficiency in maize in China are serious ecological and economic problems, which might affect the procedures in the nitrogen cycle. To reveal the effects of long-term excessive nitrogen fertilization on diazotrophs in maize rhizosphere and bulk soil, we performed a long-term (five-year) N-input experiment (N rates from 0 to 300 kg N ha -1 ) in black soil maize in northeast China. The effect of N fertilizer application rates on the abundance, structure and compositions of diazotrophic community in both the bulk soil and rhizosphere of maize were investigated by Real-time quantitative PCR and high-throughput sequencing, and a structural equation model was constructed based on this study.Results: 1) Excessive N fertilization significantly reduced the abundance and diversity of diazotrophs. 2) The accumulation of Sphingobium was correlated positively with soil nitrate concentration and soil EC, and negatively with soil pH. The contrast correlation was found in Burkholderia . 3) Diazotrophs were enriched in maize rhizosphere, but the diversity and compositions of diazotrophic community were less affected by maize rhizosphere effect. 4) The enriched Bradyrhizobium and Methylobacterium in maize rhizosphere showed a significant positive correlation with of maize plant biomass. Conclusions: Our results suggest that through affecting soil pH, nitrate and EC values, long-term excessive N input increase Sphingobium accumulation and reduce the abundance of beneficial diazotrophs such as Bradyrhizobium and Burkholderia ，which contribute to the decreased nitrogen use efficiency.

Soil nitrous oxide emissions as affected by long-term tillage, cropping systems and nitrogen fertilization in Southern Brazil

2015 ◽  
Vol 146 ◽  
pp. 213-222 ◽  
Author(s):  
Cimélio Bayer ◽  
Juliana Gomes ◽  
Josiléia Accordi Zanatta ◽  
Frederico Costa Beber Vieira ◽  
Marisa de Cássia Piccolo ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Fertilization ◽  
Cropping Systems ◽  
Nitrous Oxide Emissions ◽  
Southern Brazil

scholarly journals Improvement of Tea (Camellia sinensis L.) Soil Properties by Growing Different Green Crops

2015 ◽  
Vol 12 (2) ◽  
pp. 34-38 ◽  
Author(s):  
Ashim Kumar Saha ◽  
Apu Biswas ◽  
Abdul Qayyum Khan ◽  
Md. Mohashin Farazi ◽  
Md. Habibur Rahman
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Total Nitrogen ◽  
Soil Ph ◽  
Nutritional Value ◽  
Soil Health ◽  
Critical Value ◽  
Available Phosphorus ◽  
Organic Carbon Content

Long-term tea cultivation has led to degradation of the soil. Old tea soils require rehabilitation for restoring soil health. Soil rehabilitation by growing different green crops can break the chain of monoculture of tea. An experiment was conducted at The Bangladesh Tea Research Institute (BTRI) Farm during 2008-2011 to find out the efficiency of different green crops on the improvement of soil properties. Four green crops such as Guatemala, Citronella, Mimosa and Calopogonium were grown to develop the nutritional value of the degraded tea soil. Soil samples were collected and analyzed before and at the end of experiment. Soil pH was increased in all four green crops treated plots with the highest increase in Citronella treated plots (from 4.1 to 4.5). Highest content of organic carbon (1.19%) and total nitrogen (0.119%) were found in Mimosa and Calopogonium treated plots, respectively. Concentration of available phosphorus, calcium and magnesium in all green crops treated plots were above the critical values, while available potassium content was above the critical value in Guatemala, Citronella and Mimosa treated plots. Changes in soil pH and available potassium were significant, while changes in organic carbon content, total nitrogen and available calcium were insignificant. Changes in available phosphorus and magnesium were significant. The Agriculturists 2014; 12(2) 34-38

scholarly journals Change of mineral and organic nitrogen forms in a long term fertilization experiment (literature)

2014 ◽  
pp. 43-47
Author(s):  
Judit Horváth ◽  
János Kátai
Keyword(s):  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Essential Element ◽  
Nitrogen Forms ◽  
Organic Form ◽  
The Sustainable Development ◽  
Nitrogen Turnover ◽  
Mineralization Processes ◽  
Living Organisms

The research topic has timeliness, since the rational utilization and protection of the soil, besides the conservation of its diverse functions is part of the sustainable development. Research of the long-term experiments is esentially important, because it can model the term effects in the same place, under the same conditions. If we want to get accurate informations about the occured changes, way and danger of changes, we should track the resupply and effect of the mineral nutrients and the removed quantity of nutrients with the harvest. Nitrogen is an essential element for living organisms, it is present in the soil mainly in organic form. In general only only a low percentage of the total nitrogent content can be used directly by plants in the soil. This inorganic nitrogen is produced by the transformation of organic contents through mineralization processes and it get into the soil by the fertilization. The plants incorporote the mineral nitrogen into our bodies. This is how nitrogen turnover is realized when mineral forms become organic and organic forms become mineral. The purpose of our paper is to make a literature before our research.

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