6 results on '"Kumar, Amit"'
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2. Shifts in plant functional trait dynamics in relation to soil microbiome in modern and wild barley.
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Kumar, Amit, Kuznetsova, Olga, Gschwendtner, Silvia, Chen, Hao, Alonso‐Crespo, Inés M., Yusuf, Mohammad, Schulz, Stefanie, Bonkowski, Michael, Schloter, Michael, and Temperton, Vicky M.
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SUSTAINABLE agriculture , *BARLEY , *SUSTAINABILITY , *AGRICULTURE , *ROOT crops , *HORDEUM - Abstract
Societal Impact Statement: Understanding domestication's impact on crop root traits and interactions with soil microbiomes is vital for improving crop resilience and agricultural sustainability. Using this knowledge to enhance root systems, reduce chemical inputs, and adapt crops to environmental stress will help to increase global food production, promote eco‐friendly farming, and mitigate the effects of climate change. Additionally, identifying microorganisms specific to plant species may help in biodiversity conservation. Advancing scientific understanding and educating future generations on the intricate relationships between plants, soil, and microorganisms is integral to developing innovative, sustainable agricultural practices and improved food security. Summary: Domestication and intensive management practices have significantly shaped characteristics of modern crops. However, our understanding of domestication's impact had mainly focused on aboveground plant traits, neglecting root and rhizospheric traits, as well as trait–trait interactions and root‐microbial interactions.To address this knowledge gap, we grew modern (Hordeum vulgare L. var. Barke) and wild barley (Hordeum spontaneum K. Koch var. spontaneum) in large rhizoboxes. We manipulated the soil microbiome by comparing disturbed (sterilized soil inoculum, DSM) versus non‐disturbed (non‐sterilized inoculum, NSM) microbiome. Results showed that modern barley grew faster and increased organic‐carbon exudation (OCEXU) compared to wild barley.Both barley species exhibited accelerated root growth and enhanced OCEXU under DSM, indicating their ability to partially compensate and exploit the soil resources independently of microbes if need be. Plant trait network analysis revealed that modern barley had a denser, larger, and less modular network of microbes than wild barley indicating domestication's impact on trait–trait coordination. In addition, the relative abundance of bacteria did not vary between wild and modern barley rhizospheres; however, species‐specific unique bacteria were identified, with stronger effects under DSM.Overall, our findings highlight domestication‐driven shifts in root traits, trait coordination, and their modulation by the soil microbiome. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Gone and forgotten: facilitative effects of intercropping combinations did not carry over to affect barley performance in a follow-up crop rotation.
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Kumar, Amit, Rosinger, Christoph, Chen, Hao, Protic, Siobhan, Bonkowski, Michael, and Temperton, Vicky M.
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CATCH crops , *CROP rotation , *INTERCROPPING , *BARLEY , *BIOMASS production , *RETRIEVAL practice , *FAVA bean , *LEGUMES - Abstract
Aim: Intercropping often leads to improved productivity of individual species compared to monocultures. We have practically little knowledge of facilitation effects in different intercropping systems and their importance in creating soil legacies that can indirectly affect the succeeding crop in a crop rotation through plant-soil feedback (PSF) effects. Methods: To test this, we used a two-phased field experiment where we combined intercropping and crop rotation. During intercropping, we grew maize, faba bean, and lupine in monocultures or two-species crop combinations. The following season, we grew winter barley on the soil previously used for intercropping to test PSF effects under field conditions. Results: We found evidence for facilitative effects on aboveground biomass production that were species-specific with faba bean and maize biomass benefitting when intercropped compared to their expected biomasses in monocultures. Lupine, in contrast, performed best in monocultures. After the intercropping phase, total soil mineral nitrogen was higher in legume monocultures creating soil legacies but this did not affect soil microbial parameters and barley biomass production in the follow-up rotation phase. Conclusions: We found support for species-specific positive and negative interactions in intercropping. Our results also demonstrated that soil legacies play no significant role under moderately high nutrient environments. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
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4. Timing matters: Distinct effects of nitrogen and phosphorus fertilizer application timing on root system architecture responses.
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van Duijnen, Richard, Uther, Hannah, Härdtle, Werner, Temperton, Vicky M., and Kumar, Amit
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NITROGEN fertilizers ,PHOSPHATE fertilizers ,BIOMASS ,ROOT growth ,PLANT growth - Abstract
Aims: Although different plant foraging responses to the two macronutrients nitrogen (N) and phosphorus (P) are well researched, the effect of timing of fertilizer application on root system architecture (RSA) remains largely unknown. We, therefore, aimed to understand how RSA of Hordeum vulgare L. responds to timing of N and P application. Methods: Plants were grown in rhizoboxes for 38 days in nutrient‐poor soil and watered with nutrient solution, lacking either N or P, with the absent nutrient applied once either 2/3/4 weeks after sowing. Positive controls were continuously receiving N and P and a negative control receiving both N and P only after 3 weeks. We tracked root growth over time, measured plant biomass and nutrient uptake. Results: Late N application strongly reduced total root biomass and visible root length compared with continuous NP and late P application. Root mass fractions (total root biomass/total plant biomass) remained similar over all treatments, but relative allocation (% of total root biomass) was higher in lower depth with late N application. Shoot P concentrations remained relatively stable, but the plants receiving P later had higher N concentrations. Conclusions: Late N application had overall more negative effects on early plant growth compared with late P. We propose that future studies under field conditions should try to disentangle the effect of timing from the nutrient availability on RSA responses and hence ultimately plant performance. [ABSTRACT FROM AUTHOR]
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- 2021
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5. Barley shoot biomass responds strongly to N:P stoichiometry and intraspecific competition, whereas roots only alter their foraging.
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Kumar, Amit, van Duijnen, Richard, Delory, Benjamin M., Reichel, Rüdiger, Brüggemann, Nicolas, and Temperton, Vicky M.
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COMPETITION (Biology) , *BIOMASS , *STOICHIOMETRY , *PLANT competition , *PLANT performance , *BARLEY , *SOIL depth - Abstract
Aims: Root system responses to the limitation of either nitrogen (N) or phosphorus (P) are well documented, but how the early root system responds to (co-) limitation of one (N or P) or both in a stoichiometric framework is not well-known. In addition, how intraspecific competition alters plant responses to N:P stoichiometry is understudied. Therefore, we aimed to investigate the effects of N:P stoichiometry and competition on root system responses and overall plant performance. Methods: Plants (Hordeum vulgare L.) were grown in rhizoboxes for 24 days in the presence or absence of competition (three vs. one plant per rhizobox), and fertilized with different combinations of N:P (low N + low P, low N + high P, high N + low P, and high N + high P). Results: Shoot biomass was highest when both N and P were provided in high amounts. In competition, shoot biomass decreased on average by 22%. Total root biomass (per plant) was not affected by N:P stoichiometry and competition but differences were observed in specific root length and root biomass allocation across soil depths. Specific root length depended on the identity of limiting nutrient (N or P) and competition. Plants had higher proportion of root biomass in deeper soil layers under N limitation, while a greater proportion of root biomass was found at the top soil layers under P limitation. Conclusions: With low N and P availability during early growth, higher investments in root system development can significantly trade off with aboveground productivity, and strong intraspecific competition can further strengthen such effects. [ABSTRACT FROM AUTHOR]
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- 2020
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6. Development of agri-pellet production cost and optimum size
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Sultana, Arifa, Kumar, Amit, and Harfield, Don
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INDUSTRIAL costs , *WOOD pellets , *PLANT size , *AGRICULTURAL wastes , *BIOMASS energy , *WHEAT , *BARLEY , *OATS , *MATHEMATICAL models of economics - Abstract
Abstract: Minimum production cost and optimum plant size were determined for pellet plants using agricultural biomass residue from wheat, barley and oats. Three scenarios involving minimum, average and maximum yields of straw were considered for developing a techno-economic model. The life cycle cost of producing pellets in Western Canada was estimated. The economically optimum size of production plant for the three yield scenarios in tonne year−1 were 70,000, 150,000 and 150,000, respectively. The corresponding costs of production per tonne are $170.89, $129.42 and $122.17, respectively. However, the cost of pellets does not change much for capacities over 70,000tonne year−1 for both the average and maximum yields. The optimum size is same for both average and maximum yield cases. Sensitivity analyses have showed that the total cost of pellet production is most sensitive to field cost followed by transportation cost. Currently, the cost of energy from agri-pellets is higher than that of energy from natural gas. [Copyright &y& Elsevier]
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- 2010
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