scholarly journals Responses of Ammonia-Oxidizing Microorganisms to Intercropping Systems in Different Seasons

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 195
Author(s):  
Xingjia He ◽  
Sen Li ◽  
Fengzhi Wu
Keyword(s):  
Seasonal Variation ◽  
Chemical Properties ◽  
Community Diversity ◽  
Scaling Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
Continuous Cropping ◽  
Physical And Chemical Properties ◽  
Growing Seasons ◽  
Physical And Chemical ◽  
And Chemical Properties

Intercropping plays an essential role in agricultural production, impacting the soil’s physical and chemical properties and microbial communities. However, the responses of ammonia-oxidizing microorganisms in the continuous-cropping soil to different intercropping systems in different growing seasons are still insufficiently studied. Here, we investigated the effects of seven intercropping systems (alfalfa (Medicago sativa L.)/cucumber, trifolium (Trifolium repens L.)/cucumber, wheat (Triticum aestivum L.)/cucumber, rye (Secale cereale L.)/cucumber, chrysanthemum (Chrysanthemum coronrium L.)/cucumber, rape (Brassica campestris L.)/cucumber, mustard (Brassica juncea L.)/cucumber) on soil physical and chemical properties, potential nitrification rate (PNR), soil ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) communities in the greenhouse in spring and autumn. The results showed that, compared with cucumber monoculture, intercropping increased the soil NH4+-N and NO3−-N. The chrysanthemum–cucumber, rape–cucumber, and mustard–cucumber treatments increased soil PNR. Intercropping increased the AOA and AOB abundances in two seasons, especially in rape–cucumber, wheat–cucumber, chrysanthemum–cucumber, and trifolium–cucumber treatments. The ratio of AOA and AOB decreased with seasonal variation. The wheat–cucumber and rape–cucumber treatments increased soil AOA community diversity. Seasonal variation had a significant effect on the relative abundance of the AOB community. Nonmetric multidimensional scaling analysis showed that the AOA and AOB community structures were obviously different from spring to autumn. Redundancy analysis showed that the AOA community was significantly regulated by moisture, NO3−–N, and available potassium (AK), while the AOB community was significantly regulated by moisture, available phosphorus (AP), AK, NO3−-N, and pH. Network analysis showed that the co-occurrence relationship and complexity of AOA and AOB communities were different in two growing seasons. The AOB community may play a critical role in ammonia oxidation in autumn. Taken together, intercropping improved soil physicochemical state, increased soil PNR and significantly altered soil AOA and AOB communities. Seasonal variation significantly altered the AOA and AOB communities’ structure and interaction between them. The effect of seasonal variation on AOA and AOB communities was greater than intercropping.

scholarly journals Effects of Continuous Cropping of Dictyophora on Soil Physical and Chemical Properties, Microbial Biomass and Enzyme Activity

2021 ◽  
Vol 8 (7) ◽  
pp. 214-220
Author(s):  
Long Tong ◽  
◽  
Hongyan Li ◽  
Xiaoming Liu ◽  
Bin Li ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Ph Value ◽  
Chemical Properties ◽  
Available Phosphorus ◽  
Continuous Cropping ◽  
Physical And Chemical Properties ◽  
Factors Affecting ◽  
The One ◽  
Physical And Chemical ◽  
And Chemical Properties

The continuous obstacle of Dictyophora indusiata has become the one of the main factors affecting the healthy development of D. indusiata industry. In order to study the effects of continuous cropping of D. indusiata on the soil environment, four treatments were used in this study: no planted (CK), planted for 1 years (1Y), continuous cropping for 2 years (2Y) and continuous cropping for 3 years (3Y), to determined of the yield of D. indusiata, soil physical and chemical properties, microbial content and enzyme activity. The results showed that the yield and soil pH value decreased with the increase of continuous cropping years, and the contents of organic matter, total nitrogen, total phosphorus and total potassium, C/N and C/P also increased with the increase of continuous cropping years. Soil availability decreased with the increase of continuous cropping years, the content of alkaline nitrogen, available phosphorus and available potassium decreased by 12.25%, 28.91% and 24.86% at 3Y compared with 1Y, respectively. The biomass of bacteria, actinomycetes and fungi and the total amount of microorganism in soil increased at 1Y compared with CK, but with the increase of continuous cropping years, the biomass of bacteria and actinomycetes and the total amount of microorganism decreased significantly, while the biomass of fungi increased significantly; the continuous cropping of D. indusiata also decreased the value of bacteria/fungi in soil. The enzyme activities of the soil were higher than those of the unplanted plots, however, the activities of urease, catalase, peroxidase, sucrase, phosphatase and protease decreased with the increase of continuous cropping years. In a word, with the increase of continuous cropping, the acidity of rhizosphere soil increased, the availability of soil nutrients and the activity of soil enzymes decreased, the biomass of soil microorganisms, bacteria and actinomycetes decreased. However, the increase of fungal biomass led to the decline of soil texture.

Effects of subsoil amendments on soil physical properties, crop response, and soil water quality in a dry year

Soil Research ◽  
2010 ◽  
Vol 48 (2) ◽  
pp. 140 ◽  
Author(s):  
T. M. McBeath ◽  
C. D. Grant ◽  
R. S. Murray ◽  
D. J. Chittleborough
Keyword(s):  
Soil Water ◽  
Chemical Properties ◽  
Crop Productivity ◽  
Residual Effects ◽  
Physical And Chemical Properties ◽  
Deep Placement ◽  
Growing Seasons ◽  
Texture Contrast ◽  
Physical And Chemical ◽  
And Chemical Properties

In southern Australia the ability of field crops to extract soil moisture and nutrients from depth depends on the physical and chemical properties of the subsoil. In texture-contrast soils accumulation of water and nutrients in the E or A2 horizon, immediately above a clay B horizon of much lower hydraulic conductivity (herein called the interface), may generate lateral flows and enhanced nutrient and solute transfer to water bodies. Evidence that deep-ripping with addition of subsoil nutrients can increase crop productivity in regions having hostile, alkaline subsoils led to experiments to test whether this response was related to an increase in the use of water and nutrients in the subsoil. Our study measured the effects of deep-ripping with and without amendments on soil physical and chemical properties of the A and upper B horizons of 2 South Australian soils. Deep-ripping and deep-placement of nutrients increased grain harvest weight even in an exceptionally dry season. The greater yield was accompanied by significantly lower field-penetration resistance to 0.35–0.50 m depth, which we hypothesise enabled the crop to better access stored soil water and deep placed nutrients in the subsoil. Residual effects from deep-ripping were minimal after 4 growing seasons; therefore, ripping will need to be practiced at regular intervals to maintain treatment effects. The ripping and nutrient amendments had no significant effect on exchangeable sodium percentage, electrical conductivity, and readily extractable phosphorus and nitrate-nitrogen, despite changes in these soil properties between spring and harvest sampling.

scholarly journals Co-application of biochar and nitrogen fertilizer reduced nitrogen losses from soil

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248100
Author(s):  
Xiuwen Li ◽  
Sutie Xu ◽  
Avishesh Neupane ◽  
Nourredine Abdoulmoumine ◽  
Jennifer M. DeBruyn ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Ash Content ◽  
N Fertilizer ◽  
Initial Increase ◽  
Ammonia Oxidizing Bacteria ◽  
Physical And Chemical Properties ◽  
Nitrate N ◽  
N Concentration ◽  
Physical And Chemical ◽  
And Chemical Properties

Combined application of biochar and nitrogen (N) fertilizer has the potential to reduce N losses from soil. However, the effectiveness of biochar amendment on N management can vary with biochar types with different physical and chemical properties. This study aimed to assess the effect of two types of hardwood biochar with different ash contents and cation exchange capacity (CEC) on soil N mineralization and nitrous oxide (N2O) production when applied alone and in combination with N fertilizer. Soil samples collected from a temperate pasture system were amended with two types of biochar (B1 and B2), urea, and urea plus biochar, and incubated for 60 days along with soil control (without biochar or urea addition). Soil nitrate N, ammonium N, ammonia-oxidizing bacteria amoA gene transcripts, and N2O production were measured during the experiment. Compared to control, addition of B1 (higher CEC and lower ash content) alone decreased nitrate N concentration by 21% to 45% during the incubation period while the addition of B2 (lower CEC and higher ash content) alone increased the nitrate N concentration during the first 10 days. Biochar B1 also reduced the abundance of amoA transcripts by 71% after 60 days. Compared to B1 + urea, B2 + urea resulted in a significantly greater initial increase in soil ammonium and nitrate N concentrations. However, B2 + urea had a significantly lower 60-day cumulative N2O emission compared to B1 + urea. Overall, when applied with urea, the biochar with higher CEC reduced ammonification and nitrification rates, while biochar with higher ash content reduced N N2O production. Our study demonstrated that biochar has the potential to enhance N retention in soil and reduce N2O emission when it is applied with urea, but the specific effects of the added biochar depend on its physical and chemical properties.

scholarly journals Research Progress on Continuous Cropping Obstacle and Green Control of Strawberry

2021 ◽  
Vol 251 ◽  
pp. 02044
Author(s):  
Zhengwei Xie ◽  
Qianqian Ma ◽  
Wanyun Peng ◽  
Zhide Wang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Research Progress ◽  
Continuous Cropping ◽  
Physical And Chemical Properties ◽  
Urgent Problem ◽  
Sharp Decline ◽  
Yield And Quality ◽  
Prevention And Cure ◽  
Physical And Chemical ◽  
And Chemical Properties

Continuous cropping obstacle is a big problem of Strawberry planting. Continuous cropping obstacle leads to the accumulation of phenolic acids, imbalance of soil microorganism, deterioration of physical and chemical properties, resulting in sharp decline in Strawberry yield and quality. At present, the prevention and cure of continuous cropping obstacle of Strawberry is an urgent problem to be solved. The pathogen does not produce drug resistance, is safe to fresh fruit and does not pollute the environment.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

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