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2021 ◽  
Vol 50 (4) ◽  
pp. 1029-1034
Author(s):  
Md Tareq Bin Salam ◽  
Md Tipu Sultan ◽  
Mehjabin Hossain ◽  
Must Alima Rahman

Effects of cropping pattern on soil carbon sequestration and their aggregate stability in long term agricultural fields was investigated in 2018. Four cropping patterns were selected that have been cultivated for last ten years. Results showed that Soil organic carbon (SOC) value was improved for vegetable field from 4.06 to 9.11 g/kg and carbon stock (20.14 Mg C ha/yr) as well as soil carbon sequestration rate was the highest in vegetable field (1.12 Mg C ha/yr). The logarithmic relationship between the C input and C sequestration rate showed the strong correlation (r = 0.72, p < 0.05). In terms of aggregate stability, vegetable field put the best result (0.41 mm) (p > 0.05). The straight-line relation between aggregate stability and Cstock established that they are strongly correlated (r = 0.81, p < 0.05). Finally, results indicated that Vegetable-Vegetable-Vegetable cropping pattern was the best soil carbon sequester along with the best aggregate stability. Bangladesh J. Bot. 50(4): 1029-1034, 2021 (December)


Agriculture ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 903
Author(s):  
Karin Kauer ◽  
Sandra Pärnpuu ◽  
Liina Talgre ◽  
Viacheslav Eremeev ◽  
Anne Luik

This study aimed to investigate the soil organic carbon (SOC) sequestration rate and soil organic matter (SOM) composition in conventional rotational cropping with mineral fertilization compared with organic cover cropping with and without composted manure addition during 2008–2018 to specify the SOM stabilization under different farming systems. The SOC proportion in particulate organic matter (POM) (63–2000 µm) and mineral-associated organic matter (MAOM) (<63 µm) fractions were estimated in different treatments, and the SOM composition in the fractions was characterized by FTIR spectroscopy. The SOC sequestration rate was treatment-dependent, with the higher SOC sequestration rate (1.26 Mg ha−1 y−1) in the organic treatment with cover crop and composted manure. Across all treatments, 57.3%–77.8% of the SOC stock was in the MAOM fraction. Mineral N fertilization increased POM-C concentration by 19%–52% compared with the unfertilized control. Under the organic treatments, the POM-C concentration was 83%–95% higher than the control. The MAOM-C concentration increased by 8%–20%. The mineral N fertilization and organic treatments (with and without cover crops and composted manure) increased the SOC stock proportion of POM. The highest proportion of SOC stock related to POM was in the cover cropping system, reducing the proportion of C related to the MAOM fraction, but the addition of composted manure with cover cropping also increased the proportion of C in MAOM. Compared with MAOM, the POM had a less resistant organic matter composition, and the POM resistance was higher in organic than conventional treatments. In general, the recalcitrance of SOM increased with SOC concentration. The POM fraction had higher aromaticity (or degree of decomposition) than the MAOM fraction. The aromaticity in POM and MAOM fractions was higher in the organic farming system and depended on mineral N fertilization and cover cropping, but the effect of manure was not significant. Although the SOC sequestration rate was higher under manure addition, resulting in the highest formation of both POM and MAOM in the soil, manure addition had little effect on overall SOM composition compared with cover crops.


2021 ◽  
Vol 13 (16) ◽  
pp. 9434
Author(s):  
Meiling Zhang ◽  
Stephen Nazieh ◽  
Teddy Nkrumah ◽  
Xingyu Wang

China is one of the countries most impacted by desertification, with Gansu Province in the northwest being one of the most affected areas. Efforts have been made in recent decades to restore the natural vegetation, while also producing food. This has implications for the soil carbon sequestration and, as a result, the country’s carbon budget. Studies of carbon (C) dynamics in this region would help to understand the effect of management practices on soil organic carbon (SOC) as well as aboveground biomass (ABVG), and to aid informed decision-making and policy implementation to alleviate the rate of global warming. It would also help to understand the region’s contribution to the national C inventory of China. The CENTURY model, a process-based model that is capable of simulating C dynamics over a long period, has not been calibrated to suit Gansu Province, despite being an effective model for soil C estimation. Using the soil and grassland maps of Gansu, together with weather, soil, and reliable historical data on management practices in the province, we calibrated the CENTURY model for the province’s grasslands. The calibrated model was then used to simulate the C dynamics between 1968 and 2018. The results show that the model is capable of simulating C with significant accuracy. Our measured and observed SOC density (SOCD) and ABVG had correlation coefficients of 0.76 and 0.50, respectively, at p < 0.01. Precipitation correlated with SOCD and ABVG with correlation coefficients of 0.57 and 0.89, respectively, at p < 0.01. The total SOC storage (SOCS) was 436.098 × 106 t C (approximately 0.4356% of the national average) and the average SOCD was 15.75 t C/ha. There was a high ABVG in the southeast and it decreased towards the northwest. The same phenomenon was observed in the spatial distribution of SOCD. Among the soils studied, Hostosols had the highest SOC sequestration rate (25.6 t C/ha) with Gypsisols having the least (7.8 t C/ha). Between 1968 and 2018, the soil carbon stock gradually increased, with the southeast experiencing the greatest increase.


2021 ◽  
Vol 43 (3) ◽  
pp. 34-38
Author(s):  
Caroline A. Dowling ◽  
Rainer Melzer ◽  
Susanne Schilling

Cannabis sativa is well known for its production of psychoactive chemicals and medicinal products, but it also has huge potential to be a multipurpose crop. Cultivated for biofuel, building materials and textiles, Cannabis has a high carbon sequestration rate and is bound to be a key player in future sustainable agriculture. The distinct applications of Cannabis are directly or indirectly connected to flowering and require different flowering time phenotypes. As an annual short-day plant, Cannabis usually flowers in autumn when days get shorter after an initial vegetative growth period. However, differences in latitude, temperature and other environmental factors require the development of new Cannabis cultivars adapted to local climatic conditions. As such, a comprehensive understanding of the physiological and genetic basis of flowering time is crucial to integrating Cannabis into modern agriculture, benefiting global sustainability efforts.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Thomas Paul ◽  
Mark O. Kimberley ◽  
Peter N. Beets

Abstract Background Natural forests cover approximately 29% of New Zealand’s landmass and represent a large terrestrial carbon pool. In 2002 New Zealand implemented its first representative plot-based natural forest inventory to assess carbon stocks and stock changes in these mostly undisturbed old-growth forests. Although previous studies have provided estimates of biomass or carbon stocks, these were either not fully representative or lacked data from important pools such as dead wood (coarse woody debris). The current analysis provides the most complete estimates of carbon stocks and stock changes in natural forests in New Zealand. Results We present estimates of per hectare carbon stocks and stock changes in live and dead organic matter pools excluding soil carbon based on the first two measurement cycles of the New Zealand Natural Forest Inventory carried out from 2002 to 2014. These show that New Zealand’s natural forests are in balance and are neither a carbon source nor a carbon sink. The average total carbon stock was 227.0 ± 14.4 tC·ha− 1 (95% C.I.) and did not change significantly in the 7.7 years between measurements with the net annual change estimated to be 0.03 ± 0.18 tC·ha− 1·yr− 1. There was a wide variation in carbon stocks between forest groups. Regenerating forest had an averaged carbon stock of only 53.6 ± 9.4 tC·ha− 1 but had a significant sequestration rate of 0.63 ± 0.25 tC·ha− 1·yr− 1, while tall forest had an average carbon stock of 252.4 ± 15.5 tC·ha− 1, but its sequestration rate did not differ significantly from zero (− 0.06 ± 0.20 tC·ha− 1·yr− 1). The forest alliance with the largest average carbon stock in above and below ground live and dead organic matter pools was silver beech-red beech-kamahi forest carrying 360.5 ± 34.6 tC·ha− 1. Dead wood and litter comprised 27% of the total carbon stock. Conclusions New Zealand’s Natural Forest Inventory provides estimates of carbon stocks including estimates for difficult to measure pools such as dead wood and roots. It also provides estimates of uncertainties including effects of model prediction error and sampling variation between plots. Importantly it shows that on a national level New Zealand’s natural forests are in balance. Nevertheless, this is a nationally important carbon pool that requires continuous monitoring to identify potential negative or positive changes.


Author(s):  
Cong He ◽  
Jia-Rui Niu ◽  
Cheng-Tang Xu ◽  
Shou-Wei Han ◽  
Wei Bai ◽  
...  

Northeast China(NEC) is the main grain-producing area in China, but soil degradation is severe due to the long-term use of conventional tillage(CT). It is necessary to restore soil fertility, maintain crop yield, and enhance sustainability using conservation tillage in NEC. However, the integrated effects of conservation tillage on crop yield and SOC under different conditions in NEC are still unclear. Using 70 peer-reviewed papers, we assessed the crop yield and SOC sequestration effect, and their relationship under no-till(NT), ridge tillage(RT), and subsoiling tillage(ST) in NEC. The results indicated that in areas with a mean annual temperature (MAT) < 3℃, yield under NT was significantly lower than CT by 3.7% whereas RT and ST were higher than CT by 0.8% and 13.1% (P<0.05). RT generally had a similar effect on yield as NT, but RT did not have a negative impact on yield in colder regions, indicating that this may be a more suitable conservation tillage practice in these areas. ST may be used in rotation with other tillage measures to maintain crop yield if necessary. NT could increase SOC concentration by 24.1%, 43.9%, and 17.4% under high MAT (>6℃), low mean annual precipitation (MAP) (<500mm), and continuous cropping, respectively. The mean SOC sequestration rate under NT, RT, and ST was 0.953, 0.099, and 0.101 Mg C ha-1 yr-1, respectively. Overall, the implementation of different conservation tillage measures in NEC can enhance crop yield as well as carbon sequestration, indicating its potential to be popularized in NEC.


2021 ◽  
Vol 12 ◽  
Author(s):  
Theresa Sporer ◽  
Johannes Körnig ◽  
Natalie Wielsch ◽  
Steffi Gebauer-Jung ◽  
Michael Reichelt ◽  
...  

Myrosinase enzymes play a key role in the chemical defense of plants of the order Brassicales. Upon herbivory, myrosinases hydrolyze the β-S-linked glucose moiety of glucosinolates, the characteristic secondary metabolites of brassicaceous plants, which leads to the formation of different toxic hydrolysis products. The specialist flea beetle, Phyllotreta armoraciae, is capable of accumulating high levels of glucosinolates in the body and can thus at least partially avoid plant myrosinase activity. In feeding experiments with the myrosinase-deficient Arabidopsis thaliana tgg1 × tgg2 (tgg) mutant and the corresponding Arabidopsis Col-0 wild type, we investigated the influence of plant myrosinase activity on the metabolic fate of ingested glucosinolates in adult P. armoraciae beetles. Arabidopsis myrosinases hydrolyzed a fraction of ingested glucosinolates and thereby reduced the glucosinolate sequestration rate by up to 50% in adult beetles. These results show that P. armoraciae cannot fully prevent glucosinolate hydrolysis; however, the exposure of adult beetles to glucosinolate hydrolysis products had no impact on the beetle’s energy budget under our experimental conditions. To understand how P. armoraciae can partially prevent glucosinolate hydrolysis, we analyzed the short-term fate of ingested glucosinolates and found them to be rapidly absorbed from the gut. In addition, we determined the fate of ingested Arabidopsis myrosinase enzymes in P. armoraciae. Although we detected Arabidopsis myrosinase protein in the feces, we found only traces of myrosinase activity, suggesting that P. armoraciae can inactivate plant myrosinases in the gut. Based on our findings, we propose that the ability to tolerate plant myrosinase activity and a fast glucosinolate uptake mechanism represent key adaptations of P. armoraciae to their brassicaceous host plants.


2021 ◽  
Author(s):  
Theresa Sporer ◽  
Johannes Koernig ◽  
Natalie Wielsch ◽  
Steffi Gebauer-Jung ◽  
Michael Reichelt ◽  
...  

Glucosinolates, the characteristic secondary metabolites of Brassicales, are hydrolyzed upon herbivory by myrosinases to toxic and deterrent defense metabolites. The specialist flea beetle, Phyllotreta armoraciae, sequesters glucosinolates in the body despite myrosinase activity, but it is unknown whether plant myrosinase activity influences sequestration and how beetles prevent the hydrolysis of ingested glucosinolates. In feeding experiments performed with the myrosinase-deficient Arabidopsis thaliana tgg1tgg2 (tgg) mutant and the corresponding wild type, we found that plant myrosinases reduced the glucosinolate sequestration rate by up to 50% and hydrolyzed a fraction of ingested glucosinolates in adult beetles. Although these results show that P. armoraciae cannot fully prevent glucosinolate hydrolysis, we observed no negative influence on beetle performance. To understand how P. armoraciae can avoid the hydrolysis of some ingested glucosinolates, we analyzed their fate directly after ingestion. P. armoraciae rapidly absorbed glucosinolates across the gut epithelium, a strategy that has been proposed to prevent hydrolysis in the gut lumen of sequestering insects. Moreover, beetle gut content suppressed in vitro myrosinase activity, and almost no myrosinase activity was detectable in the feces, which indicates that ingested myrosinases are inactivated in the beetle gut. In summary, we show that P. armoraciae uses several strategies to prevent the hydrolysis of ingested glucosinolates but can also tolerate the formation of glucosinolate hydrolysis products.


2021 ◽  
Author(s):  
Kalyan biswal ◽  
Naveen kumar ◽  
Mohd soheb ◽  
Ramanathan al

&lt;p&gt;Understanding of chemical weathering process involved in ionic elution helps in distinguishing the CO&lt;sub&gt;2&lt;/sub&gt; sequestration rate at the different micro-climatic setup of Himalayan catchments. In the present study, we have selected three glaciated basins from two different climatic zones of Western Himalayas (Lato and Phutse from the cold-arid zone of Ladakh and Chhota Shigri from the monsoon-arid zone of Himachal Pradesh, India) for determining various solute sources, CO&lt;sub&gt;2&lt;/sub&gt; sequestration rate and its control over melt-water quality. Solute sourcing models used in this work shows major cations like Ca&lt;sup&gt;2+&lt;/sup&gt;&amp;#160; and Mg&lt;sup&gt;2+ &lt;/sup&gt;are from crustal rock-weathering while Na&lt;sup&gt;+&lt;/sup&gt; and K&lt;sup&gt;+&lt;/sup&gt; sourced out from the sea-salt origin. However, major anions like SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt; (&gt; 85%) were derived from the crustal origin and HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; mostly derived from atmospheric sources (39% to 45 %) in all catchments except HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; contribution from carbonation dissolution and silicate weathering is ~29% and ~16% for Ladakh catchments compared to ~9 % and ~29% in Chhota Shigri respectively. The solute model also reveals that the contribution of sulphate oxidative mediated carbonate dissolution (SOCD) in HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; flux is relatively higher in Chhota Shigri (~16%) than others (~9%). It is also observed that catchment like Chhota Shigri having a combined network of channelized and distributed drainage patterns with lower specific discharge, more glacierized area, low pH, high pCO&lt;sub&gt;2&lt;/sub&gt;, Low molar ratio [Ca&lt;sup&gt;2+&lt;/sup&gt; + Mg&lt;sup&gt;2+&lt;/sup&gt;]/[ Na&lt;sup&gt;+&lt;/sup&gt; + K&lt;sup&gt;+&lt;/sup&gt;], high SMF (~ 0.4), low CO&lt;sub&gt;2 carbonate&lt;/sub&gt;/CO&lt;sub&gt;2 silicate&lt;/sub&gt; ratio (~1.3) show relatively more sulphide oxidative and silicate weathered products than other catchments. Conversely, presence of excess non-glaciated areas in Stok and Phutse having well-channelized subsurface discharge with high CO&lt;sub&gt;2 carbonate&lt;/sub&gt;/CO&lt;sub&gt;2 silicate &lt;/sub&gt;ratio (~10 to ~5) show enhanced carbonation via atmospheric CO&lt;sub&gt;2&lt;/sub&gt; (CAC) and carbonate dissolution with high annual CO&lt;sub&gt;2&lt;/sub&gt; sequestration. Thus, varying subglacial drainage system, specific discharge pattern and reactive rock-types with distinct hydro-micro-climatic set up alters the chemical weathering mechanism in these catchments and control meltwater quality.&lt;/p&gt;


2021 ◽  
Author(s):  
Leonardo de Aro Galera ◽  
Christian Knoblauch ◽  
Tim Eckhardt ◽  
Christian Beer ◽  
Eva-Maria Pfeiffer

&lt;p&gt;In the last two decades, there were registered record high permafrost temperatures promoting permafrost thawing and leading to additional CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; emissions. It is crucial to assess the amount of C that is mineralized to CH&lt;sub&gt;4&lt;/sub&gt;, due to its higher global warming potential (GWP) compared to CO&lt;sub&gt;2&lt;/sub&gt;. The role of CH&lt;sub&gt;4&lt;/sub&gt; in the total C emissions is mainly governed by the hydrological patterns of ecosystems. CH&lt;sub&gt;4&lt;/sub&gt; oxidation is another critical process and is largely controlled by vegetation. The soil CO&lt;sub&gt;2&lt;/sub&gt;:CH&lt;sub&gt;4&lt;/sub&gt; production ratio shows the contribution of CH&lt;sub&gt;4&lt;/sub&gt; to the C emission budget of a determined area. Few studies evaluated &lt;em&gt;in situ&lt;/em&gt; CO&lt;sub&gt;2&lt;/sub&gt;:CH&lt;sub&gt;4&lt;/sub&gt; production ratios. Our objective was to assess CH&lt;sub&gt;4&lt;/sub&gt; emissions and the heterotrophic CO&lt;sub&gt;2&lt;/sub&gt;:CH&lt;sub&gt;4&lt;/sub&gt; production ratios in the Siberian tundra during the growing season. To accomplish these goals, we measured CH&lt;sub&gt;4&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; fluxes using the chamber technique in the polygonal tundra of Samoylov Island in the Lena River Delta, Northeastern Siberia. The plant-mediated CH&lt;sub&gt;4&lt;/sub&gt; transport and the heterotrophic respiration (R&lt;sub&gt;h&lt;/sub&gt;) were determined by comparing plots with and without vegetation through a trenching experiment. To account for the differences between wet and dry tundra, one representative polygon was selected, measurements were made at its water-saturated center and at its drained rim. We also estimated the C budget of the polygonal tundra of Samoylov Island during the measurement period. This is the first study measuring and calculating &lt;em&gt;in situ&lt;/em&gt; CO&lt;sub&gt;2&lt;/sub&gt;:CH&lt;sub&gt;4&lt;/sub&gt; ratios from the R&lt;sub&gt;h&lt;/sub&gt; of the soil. The CH&lt;sub&gt;4&lt;/sub&gt; emissions at the polygon center were much higher than the rim and showed evident seasonality. The polygon center median CH&lt;sub&gt;4&lt;/sub&gt; flux of 26 mg.m&lt;sup&gt;-2&lt;/sup&gt;.d&lt;sup&gt;-1&lt;/sup&gt; decreased by 80% when the vegetation was removed, indicating the relevance of plant-mediated CH&lt;sub&gt;4&lt;/sub&gt; transport in these emissions. This was not detected at the polygon rim that had much lower emissions (1.8 mg.m&lt;sup&gt;-2&lt;/sup&gt;.d&lt;sup&gt;-1&lt;/sup&gt;). The heterotrophic CO&lt;sub&gt;2&lt;/sub&gt;:CH&lt;sub&gt;4 &lt;/sub&gt;ratios varied from 1 to 100 at the polygon center, and from 100 to 1000 at the polygon rim, showing the greater importance of CH&lt;sub&gt;4&lt;/sub&gt; production to the heterotrophic C release at the polygon center. The polygonal tundra on Samoylov Island was a C sink during the measurement period. The wet tundra had a CO&lt;sub&gt;2&lt;/sub&gt;-C sequestration rate (-23 kg CO&lt;sub&gt;2&lt;/sub&gt;-C.ha&lt;sup&gt;-1&lt;/sup&gt;.d&lt;sup&gt;-1&lt;/sup&gt;) more than 3 times higher than the dry tundra (-7 kg CO&lt;sub&gt;2&lt;/sub&gt;-C.ha&lt;sup&gt;-1&lt;/sup&gt;.d&lt;sup&gt;-1&lt;/sup&gt;). Overall, the CH&lt;sub&gt;4&lt;/sub&gt; emissions represent a decrease of just 5% in the total CO&lt;sub&gt;2&lt;/sub&gt;-e offset of the tundra in Samoylov during the growing season. The CH&lt;sub&gt;4&lt;/sub&gt; emissions measured in this study were low. However, it is important to point out that only the growing season is considered, and the off-season and winter C emissions might be significant. Our results stress the high microscale variability of emissions of CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt;, specially related to hydrology, topography, and vegetation.&lt;/p&gt;


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