scholarly journals Evolution of Soil Biochemical Parameters in Rainfed Crops: Effect of Organic and Mineral Fertilization

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Marta M. Moreno ◽  
Carmen Moreno ◽  
Carlos Lacasta ◽  
Ramón Meco

In organic farming, crop fertilization is largely based on the decomposition of organic matter and biological fixation of nutrients. It is therefore necessary to develop studies conducted to know and understand the soil biological processes for the natural nutrient supplies. The effect of three fertilizer managements (chemical with synthetic fertilizers, organic with 2500 kg compost ha−1, and no fertilizer) in a rainfed crop rotation (durum wheat-fallow-barley-vetch as green manure) on different soil biochemical parameters in semi-arid conditions was investigated. Soil organic matter, microbial biomass carbon, organic matter mineralization, CO2production-to-ATP ratio, and NO3-N content were analysed. Fertilization was only applied to cereals. The results showed the scarce effect of the organic fertilization on soil quality, which resulted more dependent on weather conditions. Only soil organic matter and NO3-N were affected by fertilization (significantly higher in the inorganic treatment, 1.28 g 100 g−1and 17.3 ppm, resp.). Soil organic matter was maintained throughout the study period by the inclusion of a legume in the cropping system and the burying of crop residues. In fallow, soil microbial biomass carbon increased considerably (816 ng g−1), and NO3-N at the end of this period was around 35 ppm, equivalent to 100 kg N ha−1.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mara Regina Moitinho ◽  
Daniel De Bortoli Teixeira ◽  
Elton da Silva Bicalho ◽  
Alan Rodrigo Panosso ◽  
Antonio Sergio Ferraudo ◽  
...  

AbstractThe spatial structure of soil CO2 emission (FCO2) and soil attributes are affected by different factors in a highly complex way. In this context, this study aimed to characterize the spatial variability patterns of FCO2 and soil physical, chemical, and microbiological attributes in a sugarcane field area after reform activities. The study was conducted in an Oxisol with the measurement of FCO2, soil temperature (Ts), and soil moisture (Ms) in a regular 90 × 90-m grid with 100 sampling points. Soil samples were collected at each sampling point at a depth of 0–0.20 m to determine soil physical (density, macroporosity, and microporosity), particle size (sand, silt, and clay), and chemical attributes (soil organic matter, pH, P, K, Ca, Mg, Al, H + Al, cation exchange capacity, and base saturation). Geostatistical analyses were performed to assess the spatial variability and map soil attributes. Two regions (R1 and R2) with contrasting emission values were identified after mapping FCO2. The abundance of bacterial 16S rRNA, pmoA, and nifH genes, determined by real-time quantitative PCR (qPCR), enzymatic activity (dehydrogenase, urease, cellulase, and amylase), and microbial biomass carbon were determined in R1 and R2. The mean values of FCO2 (2.91 µmol m−2 s−1), Ts (22.6 °C), and Ms (16.9%) over the 28-day period were similar to those observed in studies also conducted under Oxisols in sugarcane areas and conventional soil tillage. The spatial pattern of FCO2 was similar to that of macropores, air-filled pore space, silt content, soil organic matter, and soil carbon decay constant. No significant difference was observed between R1 and R2 for the copy number of bacterial 16S rRNA and nifH genes, but the results of qPCR for the pmoA gene presented differences (p < 0.01) between regions. The region R1, with the highest FCO2 (2.9 to 4.2 µmol m−2 s−1), showed higher enzymatic activity of dehydrogenase (33.02 µg TPF g−1 dry soil 24 h−1), urease (41.15 µg NH4–N g−1 dry soil 3 h−1), amylase (73.84 µg glucose g−1 dry soil 24 h−1), and microbial biomass carbon (41.35 µg C g−1 soil) than R2, which had the lowest emission (1.9 to 2.7 µmol m−2 s−1). In addition, the soil C/N ratio was higher in R2 (15.43) than in R1 (12.18). The spatial pattern of FCO2 in R1 and R2 may not be directly related to the total amount of the microbial community (bacterial 16S rRNA) in the soil but to the specific function that these microorganisms play regarding soil carbon degradation (pmoA).


1981 ◽  
Vol 97 (3) ◽  
pp. 713-721 ◽  
Author(s):  
D. S. Powlson ◽  
D. S. Jenkinson

SUMMARYSoil samples were taken from four field experiments on the growth of cereals in direct-drilled and in mouldboard-ploughed soil. When sampled, one of the experiments had run for 5 years, one for 6, one for 8 and one for 10 years. Sampling was to just below plough depth and was done on an ‘equivalent depth’ basis, i.e. the more compact direct-drilled plots were sampled more shallowly than the ploughed plots in such a way that both samples represented the same weight of soil per unit area. No significant differences in total nitrogen or in total organic carbon were observed between cultivation treatments at any of the four sites.In three of the four sites, there was no significant difference in microbial biomass carbon, adenosine 5'-triphosphate (ATP), or mineralizable nitrogen between directdrilled and ploughed soils. In the fourth, which contained more clay than the others, there was slightly more biomass carbon and ATP in the direct-drilled soil. As microbial biomass carbon (or ATP, which is closely correlated with microbial biomass carbon) responds more rapidly to changes in management than do total carbon and nitrogen, a change in biomass carbon should provide early warning of changes in soil organic matter, long before changes in total carbon and nitrogen become measurable. That no such change was observed, with one partial exception, is evidence that a change from traditional methods of cultivation to direct drilling has little effect on soil organic matter other than altering its distribution in the soil profile.


2018 ◽  
Vol 2 ◽  
pp. 96-101
Author(s):  
Dil Kumar Limbu ◽  
Madan Koirala

The soil microbial biomass carbon to soil organic carbon ratio is a useful measure to monitor soil organic matter and serves as a sensitive index than soil organic carbon alone. Thus, the objective of this study is to identify and quantify the present status of ratio of soil microbial biomass carbon to soil organic carbon in Himalayan rangeland and to make recommendations for enhancing balance between microbial carbon and organic carbon of the soil. To meet the aforementioned objective, a field study was conducted from 2011 to 2013 following the Walkley-Black, Chromic acid wet oxidation method, and chloroform fumigation method for analysis of microbial carbon and organic carbon respectively. The study showed that the heavily grazed plot had significantly less value of ratio than occasionally grazed and ungrazed plots. The ratio was significantly high on legume seeding plot compared to nonlegume plot, but the ratio was independent of soil depth. Soil microbial biomass appeared to be more responsive than soil organic matter.


2012 ◽  
Vol 599 ◽  
pp. 124-127
Author(s):  
Cheng Hu Zhang ◽  
Ting Ting Song ◽  
Ju Liu ◽  
Hui Juan Xia ◽  
Jian Zhu Wang

Natural restoration slope and vegetation-growing concrete slope were selected as plots. Soil water content (SWC), pH, and soil organic matter, total nitrogen content (TN), total organic carbon (TOC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), basal respiration, microbial quotient and metabolic quotient (qCO2) were analyzed. The main results show that: Soil organic matter, TN and MBC of 0-10 cm soil in the natural restoration slope are significantly lower than that in the vegetation-growing concrete slopes at 0.05 level. Both MBC and MBN show a highly significant positive correlation with soil organic matter and TN. Microbial quotient shows a highly significant negative correlation with TOC and MBN, and shows a significant negative correlation with MBC. The qCO2 shows a highly significant negative correlation with pH, and a significant negative correlation with MBC. The vegetation-growing concrete technology can improve the soil ecosystem in the impaired slope.


2018 ◽  
Vol 1 (1) ◽  
pp. 25-36
Author(s):  
Rehmat Ullah ◽  
Shehzada Munawar Mehdi ◽  
Khalid Saif Ullah Khan ◽  
Aftab Ahmed Sheikh ◽  
Endang Sulistyowati ◽  
...  

This study was planned with hypothesis to quantify mineralization rate of wheat and groundnut straw spiked in Kahuta and Guliana soil series. Results revealed that groundnut and wheat strawspiked soils had increased quantum of microbial biomass carbon (Cmic), biomass nitrogen (Nmic) and biomass phosphorous (Pmic) and activities of enzyme dehydrogenase (DHA) and alkaline phosphatase (APA) than un-amended soils. Initially, the contents of soil Cmic, Nmic, Pmic, DHA, and APA increased gradually during 2-14th days of incubation (DAI), again increased significantly at 28th DAI and then decreased slowly at 60th DAI in all treatments under both series. Hence, the addition of groundnut straw mineralized better than to other organic sources in both soil series.  These results suggested that groundnut straw must be incorporated in soil one month before sowing of crop to enhance crop yield under rain-fed dry farming.Key words: Crop Residues, Microbial Biomass, Soil Enzymes, Aridisol, Alfisols


Bragantia ◽  
2010 ◽  
Vol 69 (suppl) ◽  
pp. 85-95 ◽  
Author(s):  
Diego Campana Loureiro ◽  
Helvécio De-Polli ◽  
Marcos Bacis Ceddia ◽  
Adriana Maria de Aquino

The objective of this work was to study the spatial variability of soil microbial biomass (SMB) and labile soil organic matter pools (labile SOM), under different management systems and plant cover. The experiment was conducted in a Haplic Planosol soil on an Integrated Agroecological Production System (SIPA), in Seropédica, Rio de Janeiro. The evaluated management systems were: alley cropping, pasture, and bush garden, the late one was used as reference area. Three grids of regular spacing of 2.5 x 2.5 meters were used for sampling, consisting of 25 georeferenced points each, where soil samples were taken at 0-10 cm depth. The following labile constituents of soil organic matter were determined: free light fraction (FLF), water soluble C and N, C and N of SMB (SMB-C and SMB-N), and glomalin content. The textural fractions (sand, silt, and clay), pH in water, and chemical attributes (organic C, total N, Ca, Mg, Al, P, K, and CEC-cation exchange capacity) were also determined. The areas of alley cropping and pasture showed spatial dependence to the attributes of SOM. The occurrence of high spatial dependence for the attributes associated to microbial biomass in the alley cropping system (C, FLF, SMB-N and respiration), probably was due to external factors related to management, such as: intensive rotational cropping system, diversity of crops and different inputs of organic matter to soil such as pruning material and organic compost.


Author(s):  
Younes Shokuhifar ◽  
Ahmad Mohammadi Ghahsareh ◽  
Karim Shahbazi ◽  
Mohammad Mehdi Tehrani ◽  
Hossein Besharati

AbstractIndicating how different sources of organic matter (OM) may affect the properties of a wide range of soil types, at varying soil moisture (SM), is of significance in the agricultural fields. A large dataset of soil samples (0–30 cm) was collected from different parts of Iran (21 different agricultural regions, with a wide range of physical, chemical, and biological properties) to determine the effects of OM and varying SM on soil chemical (pH, salinity, and organic carbon) and biological (microbial biomass carbon, MBC) properties. The collected soil samples were incubated (9-month period) with the experimental treatments including OM (control (M1), 2% wheat straw (WS) (M2), and 2% biochar (BI) (M3)), at different SM levels (0.2 field capacity, FC (V1), 0.7 variable FC (V2), 0.7 constant FC (V3), and saturated moisture (V4)). Wheat straw was pyrolyzed (at 500°C) to produce BI, and their chemical properties were determined. BI salinity (3.1 dS/m) was significantly higher than WS (2.8 dS/m). The organic treatments, especially BI, significantly increased soil OM and MBC compared with the control treatment. The two sources of organic fertilization increased soil pH, OM, and MBC, though such effects were functions of varying soil moisture (drying and rewetting cycles). Due to higher C percentage (61%), the effects of BI, significantly affected by soil moisture, were more pronounced on soil parameters. The tested sources of organic matter (WS and BI), acting as functions of soil moisture, can strongly affect soil chemical and biological properties and contribute to higher efficiency of agricultural fields.


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