scholarly journals Soil Resources Influence Spatial Patterns of Denitrifying Communities at Scales Compatible with Land Management

2010 ◽  
Vol 76 (7) ◽  
pp. 2243-2250 ◽  
Author(s):  
Karin Enwall ◽  
Ingela N. Throb�ck ◽  
Maria Stenberg ◽  
Mats S�derstr�m ◽  
Sara Hallin
Keyword(s):  
Community Structure ◽  
Spatial Pattern ◽  
Spatial Patterns ◽  
Land Management ◽  
Crop Production ◽  
Cropping Systems ◽  
Abundance Ratio ◽  
Ecosystem Functions ◽  
Soil Parameters ◽  
Gene Pools

ABSTRACT Knowing spatial patterns of functional microbial guilds can increase our understanding of the relationships between microbial community ecology and ecosystem functions. Using geostatistical modeling to map spatial patterns, we explored the distribution of the community structure, size, and activity of one functional group in N cycling, the denitrifiers, in relation to 23 soil parameters over a 44-ha farm divided into one organic and one integrated crop production system. The denitrifiers were targeted by the nirS and nirK genes that encode the two mutually exclusive types of nitrite reductases, the cd1 heme-type and copper reductases, respectively. The spatial pattern of the denitrification activity genes was reflected by the maps of the abundances of nir genes. For the community structure, only the maps of the nirS community were related to the activity. The activity was correlated with nitrate and dissolved organic nitrogen and carbon, whereas the gene pools for denitrification, in terms of size and composition, were influenced by the soil structure. For the nirS community, pH and soil nutrients were also important in shaping the community. The only unique parameter related to the nirK community was the soil Cu content. However, the spatial pattern of the nirK denitrifiers corresponded to the division of the farm into the two cropping systems. The different community patterns, together with the spatial distribution of the nirS/nirK abundance ratio, suggest habitat selection on the nirS- and nirK-type denitrifiers. Our findings constitute a first step in identifying niches for denitrifiers at scales relevant to land management.

scholarly journals Review: Winged bean (Psophocarpus tetragonolobus) cropping systems

2020 ◽  
Vol 21 (12) ◽  
Author(s):  
Graham Eagleton
Keyword(s):  
Crop Production ◽  
Cropping Systems ◽  
New Guinea ◽  
Winged Bean ◽  
Gene Pools ◽  
Psophocarpus Tetragonolobus ◽  
Forage Crops ◽  
Growing Period ◽  
Plant Densities ◽  
Tuber Crop

Abstract. Eagleton GE. 2020. Review: Winged bean (Psophocarpus tetragonolobus) cropping systems. Biodiversitas 21: 5927-5946. Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a rambling, nitrogen-rich, leguminous crop of the Old-World tropics. This review of winged bean (WB) within cropping systems of Southeast Asia and Melanesia revisited four traditional roles that the crop has played: as a minor courtyard vegetable of villages and suburbs throughout the region; as a popular tuber crop in the irrigated plains of Tada-U township in Central Myanmar; as a companion crop in the mixed garden fields of Wamena in Indonesian New Guinea; and as a niche tuber crop in rotation with sweet potato near Goroka in Papua New Guinea (PNG). Drawing upon such traditions, researchers since the 1970s have identified potential new roles for winged bean. In Malaysia, vegetable pod yields up to 35 t ha-1 over a 25-week growing period have been obtained from solidly trellised, branching cultivars. Ratooning the crop through a further two cycles covers the cost of the trellising. Tubers from un-trellised field crops in Myanmar, and of staked, pruned garden crops in highland PNG have been estimated to produce crude protein yields of at least 300 kg ha-1 and 600 kg ha-1, respectively. Synergies between the gene-pools and cultural traditions would be expected to expand the range, raise the yield and stabilize the quality of tuber crop production. Researchers in Sri Lanka intercropped maize with winged bean. At optimal plant densities, they recorded a corn cob yield of 5 t ha-1 together with a cumulative winged bean fresh pod yield of 27 t ha-1. In Kentucky (380N), the combination of maize with winged bean to produce silage resulted in 11-18% greater biomass with 39-67% greater nitrogen per hectare than maize monocrop control plots. Branching winged bean cultivars have significant potential for benign, high-nitrogen cover and forage crops. Promiscuous nodulation and the development of storage root-systems compensate for slow initial top growth which then accelerates to produce a substantial yield of highly digestible leaf protein and vitamins. Hard-seededness and daylength-sensitive phenology are significant, surmountable, barriers to an expanded role for winged beans.

scholarly journals Whole-Systems Analysis of Environmental and Economic Sustainability in Arable Cropping Systems: A Case Study

Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 438 ◽  
Author(s):  
Hawes ◽  
Young ◽  
Banks ◽  
Begg ◽  
Christie ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Crop Production ◽  
Cropping Systems ◽  
Crop Protection ◽  
Ecosystem Functions ◽  
Economic Sustainability ◽  
Commercial Practice ◽  
Management Interventions ◽  
Trade Offs

The long-term sustainability of crop production depends on the complex network of interactions and trade-offs between biotic, abiotic and economic components of agroecosystems. An integrated arable management system was designed to maintain yields, whilst enhancing biodiversity and minimising environmental impact. Management interventions included conservation tillage and organic matter incorporation for soil biophysical health, reduced crop protection inputs and integrated pest management strategies for enhanced biodiversity and ecosystem functions, and intercropping, cover cropping and under-sowing to achieve more sustainable nutrient management. This system was compared directly with standard commercial practice in a split-field experimental design over a six-year crop rotation. The effect of the cropping treatment was assessed according to the responses of a suite of indicators, which were used to parameterise a qualitative multi-attribute model. Scenarios were run to test whether the integrated cropping system achieved greater levels of overall sustainability relative to standard commercial practice. Overall sustainability was rated high for both integrated and conventional management of bean, barley and wheat crops. Winter oilseed crops scored medium for both cropping systems and potatoes scored very low under standard management but achieved a medium level of sustainability with integrated management. In general, high scores for environmental sustainability in integrated cropping systems were offset by low scores for economic sustainability relative to standard commercial practice. This case study demonstrates the value of a ‘whole cropping systems’ approach using qualitative multi-attribute modelling for the assessment of existing cropping systems and for predicting the likely impact of new management interventions on arable sustainability.

Forest Management In Mongolia – A Review Of Challenges And Lessons Learned With Special Reference To Degradation And Deforestation

2019 ◽  
Vol 12 (3) ◽  
pp. 133-166 ◽  
Author(s):  
Alexander Gradel ◽  
Gerelbaatar Sukhbaatar ◽  
Daniel Karthe ◽  
Hoduck Kang
Keyword(s):  
Forest Management ◽  
Land Management ◽  
Management Practices ◽  
Forest Health ◽  
Hydrological Regime ◽  
Lessons Learned ◽  
Ecosystem Functions ◽  
Special Focus ◽  
Driven System ◽  
The Status

The natural conditions, climate change and socio-economic challenges related to the transformation from a socialistic society towards a market-driven system make the implementation of sustainable land management practices in Mongolia especially complicated. Forests play an important role in land management. In addition to providing resources and ecosystem functions, Mongolian forests protect against land degradation.We conducted a literature review of the status of forest management in Mongolia and lessons learned, with special consideration to halting deforestation and degradation. We grouped our review into seven challenges relevant to developing regionally adapted forest management systems that both safeguard forest health and consider socio-economic needs. In our review, we found that current forest management in Mongolia is not always sustainable, and that some practices lack scientific grounding. An overwhelming number of sources noticed a decrease in forest area and quality during the last decades, although afforestation initiatives are reported to have increased. We found that they have had, with few exceptions, only limited success. During our review, however, we found a number of case studies that presented or proposed promising approaches to (re-)establishing and managing forests. These studies are further supported by a body of literature that examines how forest administration, and local participation can be modified to better support sustainable forestry. Based on our review, we conclude that it is necessary to integrate capacity development and forest research into holistic initiatives. A special focus should be given to the linkages between vegetation cover and the hydrological regime.

Dynamic Cropping Systems for Sustainable Crop Production in the Northern Great Plains

2007 ◽  
Vol 99 (4) ◽  
pp. 904-911 ◽  
Author(s):  
D. L. Tanaka ◽  
J. M. Krupinsky ◽  
S. D. Merrill ◽  
M. A. Liebig ◽  
J. D. Hanson
Keyword(s):  
Great Plains ◽  
Crop Production ◽  
Cropping Systems ◽  
Northern Great Plains ◽  
Sustainable Crop Production

scholarly journals Precision agriculture and geospatial techniques for sustainable disease control

2021 ◽  
Author(s):  
Daniel P. Roberts ◽  
Nicholas M. Short ◽  
James Sill ◽  
Dilip K. Lakshman ◽  
Xiaojia Hu ◽  
...  
Keyword(s):  
Big Data ◽  
Disease Control ◽  
Crop Production ◽  
Plant Disease ◽  
Production Systems ◽  
Cropping Systems ◽  
Data Driven ◽  
Agricultural Community ◽  
Plant Disease Control ◽  
Crop Germplasm

AbstractThe agricultural community is confronted with dual challenges; increasing production of nutritionally dense food and decreasing the impacts of these crop production systems on the land, water, and climate. Control of plant pathogens will figure prominently in meeting these challenges as plant diseases cause significant yield and economic losses to crops responsible for feeding a large portion of the world population. New approaches and technologies to enhance sustainability of crop production systems and, importantly, plant disease control need to be developed and adopted. By leveraging advanced geoinformatic techniques, advances in computing and sensing infrastructure (e.g., cloud-based, big data-driven applications) will aid in the monitoring and management of pesticides and biologicals, such as cover crops and beneficial microbes, to reduce the impact of plant disease control and cropping systems on the environment. This includes geospatial tools being developed to aid the farmer in managing cropping system and disease management strategies that are more sustainable but increasingly complex. Geoinformatics and cloud-based, big data-driven applications are also being enlisted to speed up crop germplasm improvement; crop germplasm that has enhanced tolerance to pathogens and abiotic stress and is in tune with different cropping systems and environmental conditions is needed. Finally, advanced geoinformatic techniques and advances in computing infrastructure allow a more collaborative framework amongst scientists, policymakers, and the agricultural community to speed the development, transfer, and adoption of these sustainable technologies.

scholarly journals Potassium Control of Plant Functions: Ecological and Agricultural Implications

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 419
Author(s):  
Jordi Sardans ◽  
Josep Peñuelas
Keyword(s):  
Food Security ◽  
Stress Responses ◽  
Crop Production ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Wood Formation ◽  
Cellular Growth ◽  
Ecosystem Functions ◽  
Metabolite Transport ◽  
Physiological Functions

Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it is more difficult to link it to concrete metabolic pathways than nitrogen or phosphorus. Over the last two decades, many studies have reported on the role of K+ in several physiological functions, including controlling cellular growth and wood formation, xylem–phloem water content and movement, nutrient and metabolite transport, and stress responses. In this paper, we present an overview of contemporary findings associating K+ with various plant functions, emphasizing plant-mediated responses to environmental abiotic and biotic shifts and stresses by controlling transmembrane potentials and water, nutrient, and metabolite transport. These essential roles of K+ account for its high concentrations in the most active plant organs, such as leaves, and are consistent with the increasing number of ecological and agricultural studies that report K+ as a key element in the function and structure of terrestrial ecosystems, crop production, and global food security. We synthesized these roles from an integrated perspective, considering the metabolic and physiological functions of individual plants and their complex roles in terrestrial ecosystem functions and food security within the current context of ongoing global change. Thus, we provide a bridge between studies of K+ at the plant and ecological levels to ultimately claim that K+ should be considered at least at a level similar to N and P in terrestrial ecological studies.

scholarly journals Using a Groundwater Adjusted Water Balance Approach and Copulas to Evaluate Spatial Patterns and Dependence Structures in Remote Sensing Derived Evapotranspiration Products

2021 ◽  
Vol 13 (5) ◽  
pp. 853
Author(s):  
Mohsen Soltani ◽  
Julian Koch ◽  
Simon Stisen
Keyword(s):  
Remote Sensing ◽  
Water Balance ◽  
Spatial Pattern ◽  
Spatial Patterns ◽  
Principal Component ◽  
Small Scale ◽  
Dependence Structure ◽  
Test Case ◽  
Catchment Scale ◽  
Balance Approach

This study aims to improve the standard water balance evapotranspiration (WB ET) estimate, which is typically used as benchmark data for catchment-scale ET estimation, by accounting for net intercatchment groundwater flow in the ET calculation. Using the modified WB ET approach, we examine errors and shortcomings associated with the long-term annual mean (2002–2014) spatial patterns of three remote-sensing (RS) MODIS-based ET products from MODIS16, PML_V2, and TSEB algorithms at 1 km spatial resolution over Denmark, as a test case for small-scale, energy-limited regions. Our results indicate that the novel approach of adding groundwater net in water balance ET calculation results in a more trustworthy ET spatial pattern. This is especially relevant for smaller catchments where groundwater net can be a significant component of the catchment water balance. Nevertheless, large discrepancies are observed both amongst RS ET datasets and compared to modified water balance ET spatial pattern at the national scale; however, catchment-scale analysis highlights that difference in RS ET and WB ET decreases with increasing catchment size and that 90%, 87%, and 93% of all catchments have ∆ET < ±150 mm/year for MODIS16, PML_V2, and TSEB, respectively. In addition, Copula approach captures a nonlinear structure of the joint relationship with multiple densities amongst the RS/WB ET products, showing a complex dependence structure (correlation); however, among the three RS ET datasets, MODIS16 ET shows a closer spatial pattern to the modified WB ET, as identified by a principal component analysis also. This study will help improve the water balance approach by the addition of groundwater net in the ET estimation and contribute to better understand the true correlations amongst RS/WB ET products especially over energy-limited environments.

scholarly journals The Pitfalls of Relating Weeds, Herbicide Use, and Crop Yield: Don't Fall Into the Trap! A Critical Review

2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  
Keyword(s):  
Crop Yield ◽  
Weed Management ◽  
Crop Production ◽  
Yield Loss ◽  
Crop Yields ◽  
Cropping Systems ◽  
Crop Productivity ◽  
Arable Farming ◽  
Herbicide Use ◽  
The Impact

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.

Spatial-Pattern-Induced Evolution of a Self-Replicating Loop Network

2006 ◽  
Vol 12 (4) ◽  
pp. 461-485 ◽  
Author(s):  
Keisuke Suzuki ◽  
Takashi Ikegami
Keyword(s):  
Pattern Formation ◽  
Spatial Pattern ◽  
Spatial Patterns ◽  
Spiral Structure ◽  
Scale Interactions ◽  
Micro Scale ◽  
Macro Scale ◽  
Loop Network ◽  
Spatial Pattern Formation

We study a system of self-replicating loops in which interaction rules between individuals allow competition that leads to the formation of a hypercycle-like network. The main feature of the model is the multiple layers of interaction between loops, which lead to both global spatial patterns and local replication. The network of loops manifests itself as a spiral structure from which new kinds of self-replicating loops emerge at the boundaries between different species. In these regions, larger and more complex self-replicating loops live for longer periods of time, managing to self-replicate in spite of their slower replication. Of particular interest is how micro-scale interactions between replicators lead to macro-scale spatial pattern formation, and how these macro-scale patterns in turn perturb the micro-scale replication dynamics.

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