What Won’t Work

2012 ◽  
Author(s):  
R. Ford Denison
Keyword(s):  
Landscape Scale ◽  
Crop Diversity ◽  
Natural Ecosystems ◽  
Grain Crops ◽  
Local Sources ◽  
Perennial Grain ◽  
Classic Paper

This chapter considers four ideas—suggested by Wes Jackson and Jon Piper in the classic paper, “The necessary marriage between ecology and agriculture”—for how agriculture might attempt to mimic nature: perennial grain crops; reliance on only local sources of nutrients; polyculture or intercropping (that is, deploying crop diversity as mixtures, as in many natural ecosystems); and reliance on biodiversity to control pests. The chapter examines each of the proposals in light of the conclusion that copying landscape-scale patterns from natural ecosystems is not necessarily a good idea, arguing that all of them are representative of many self-styled “agroecologists.” It also discusses complementarity in crop mixtures, specifically spatial complementarity, temporal complementarity, and nutritional complementarity.

Landscape-scale disturbances and regeneration in semi-arid woodlands of southwestern Australia

1994 ◽  
Vol 1 (3) ◽  
pp. 214 ◽  
Author(s):  
Colin J. Yates ◽  
Richard J. Hobbs ◽  
Richard W. Bell
Keyword(s):  
Tree Mortality ◽  
Landscape Scale ◽  
Eucalyptus Species ◽  
Natural Ecosystems ◽  
Fragmented Landscapes ◽  
The Past ◽  
Adult Tree ◽  
Western Australian ◽  
Semi Arid

Woodlands dominated by Eucalyptus salmonophloia occur both in the fragmented landscapes of the Western Australian wheatbelt and in the adjacent unfragmented goldfields area. We examined the responses of the unfragmented woodlands to landscape-scale disturbances caused by fire, floods, windstorms and drought. Sites known to have experienced disturbances of these types over the past 50 years all had cohorts of sapling-stage E. salmonophloia and other dominant Eucalyptus species. Sites disturbed either by fire, flood or storm during 1991-92 displayed adult tree mortality and extensive seedling establishment, although rates of establishment and survival varied between sites. No regeneration was observed at equivalent undisturbed sites. These results indicate that landscape-scale disturbances of several types are important drivers of the dynamics of these semi-arid woodlands. Lack of regeneration of fragmented woodlands in the wheatbelt is likely to be due to changed disturbance regimes coupled with altered physical and biotic conditions within remnants. We argue that it may be difficult to identify processes which are important for the long-term persistence of natural ecosystems in fragmented landscapes without reference to equivalent unfragmented areas.

Perennial grain crops: A synthesis of ecology and plant breeding

2005 ◽  
Vol 20 (1) ◽  
pp. 5-14 ◽  
Author(s):  
L.R. DeHaan ◽  
D.L. Van Tassel ◽  
T.S. Cox
Keyword(s):  
Plant Breeding ◽  
Environmental Changes ◽  
Genetic Model ◽  
Nutrient Loss ◽  
Trade Off ◽  
Grain Crops ◽  
Herbaceous Perennials ◽  
Quantitative Genetic ◽  
Quantitative Genetic Model ◽  
Perennial Grain

AbstractPerennial grain crops would address many agricultural problems, including soil erosion, nutrient loss and pesticide contamination. Doubts about the possibility of perennial grain crops rest upon two assumptions: (1) that the relationship between yield and longevity is a fixed function that cannot be influenced by selection, mutation or environmental changes; and (2) that yield and longevity trade off in a bivariate manner to the exclusion of all other traits. These assumptions are consistent with the phenotypic trade-off model, but recent research suggests that a quantitative genetic model is a more appropriate approach to trade-offs. In the quantitative genetic model, environmental and genetic changes can result in increases in two traits simultaneously even when a trade-off, or negative correlation, exists between the two traits. Empirical evidence that the trade-off between perenniality and reproductive allocation is not fixed comes from wild, herbaceous perennials that can produce more than 2000 kg seed ha−1 in the temperate zone, and herbaceous perennial crops that produce on average 8900 kg fruit ha−1 in the tropics. Ecological literature suggests that most perennials produce small amounts of seed relative to their vegetative growth not as a physiological absolute, but rather as a result of natural selection in a stable, competitive environment favoring longevity. By selecting strongly for seed yield in a population of perennial plants, the plant breeder can likely achieve that which is rare in nature—a high seed-yielding perennial plant. The same general methodologies that have allowed annual grain breeders to increase grain yield and push many combinations of negatively correlated traits to levels of expression not seen in nature are available to the perennial grain breeder. Perennial grain breeders are integrating ecological principles and traditional plant breeding methods in their efforts to develop perennial grain wheat (Triticum spp.), sorghum (Sorghum spp.), sunflower (Helianthus spp.), Illinois bundleflower (Desmanthus illinoensis) and rice (Oryza spp.).

scholarly journals Different community compositions between obligate and facultative oomycete plant parasites in a landscape-scale metabarcoding survey

2020 ◽  
Vol 57 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Anna Maria Fiore-Donno ◽  
Michael Bonkowski
Keyword(s):  
Plant Pathogens ◽  
Mineral Soil ◽  
18S Rrna Gene ◽  
Landscape Scale ◽  
Influential Factors ◽  
Rrna Gene ◽  
Natural Ecosystems ◽  
Soil C ◽  
Ecological Requirements ◽  
Edaphic Conditions

AbstractOomycetes are a ubiquitous protistan lineage including devastating crop parasites. Although their ecology in agrosystems has been widely studied, little is known of their distribution in natural and semi-natural ecosystems and how they respond to edaphic and environmental factors. We provide here a baseline of the diversity and distribution of soil oomycetes, classified by lifestyles (biotrophy, hemibiotrophy and saprotrophy), at the landscape scale in temperate grassland and forest. From 600 soil samples, we obtained 1148 operational taxonomy units representing ~ 20 million Illumina reads (region V4, 18S rRNA gene). We found a majority of hemibiotrophic plant pathogens, which are parasites spending part of their life cycle as saprotrophs after the death of the host. Overall both grassland and forest constitute an important reservoir of plant pathogens. Distance-based RDA models identified soil type and mineral soil C/N ratio as the most influential factors in shaping oomycete communities in grassland and forest. Edaphic conditions and human-induced management intensification in forest triggered opposite responses in the relative abundances of obligate biotrophs and hemibiotrophs, suggesting different ecological requirements of these two lifestyles.

scholarly journals Strategies, Advances, and Challenges in Breeding Perennial Grain Crops

2018 ◽  
Vol 10 (7) ◽  
pp. 2192 ◽  
Author(s):  
Timothy Crews ◽  
Douglas Cattani
Keyword(s):  
Grain Crops ◽  
Perennial Grain

Grain Yields of Perennial Grain Crops in Pure and Mixed Stands

2002 ◽  
Vol 188 (5) ◽  
pp. 342-349 ◽  
Author(s):  
L. Weik ◽  
H.-P. Kaul ◽  
E. Kubler ◽  
W. Aufhammer
Keyword(s):  
Mixed Stands ◽  
Grain Yields ◽  
Grain Crops ◽  
Perennial Grain

scholarly journals Review and analysis of perennial cereal crops at different maturity stages

2021 ◽  
Vol 937 (2) ◽  
pp. 022111
Author(s):  
Dmitry Rudoy ◽  
Viktor Pakhomov ◽  
Anastasiya Olshevskaya ◽  
Tatyana Maltseva ◽  
Natia Ugrekhelidze ◽  
...  
Keyword(s):  
Quality Indicators ◽  
Climatic Conditions ◽  
Comparative Characteristic ◽  
Perennial Crops ◽  
Grain Crops ◽  
Feed Production ◽  
Secale Cereale L ◽  
Perennial Grain ◽  
Positive Effect

Abstract The article presents an overview of perennial grain crops, gives a comparative characteristic of annual winter wheat and perennial grain crops such as Trititrigia (Trititrigia cziczinii Tsvelev), Thinopyrum intermedium, perennial rye (Secale cereale L) and perennial sorghum (Sorghum x derzhavinii Tzvel.). The study aims to consider the main perennial crops grown in Russia and in the world, to compare their quality indicators, sowing agrotechnical requirements, cultivation conditions, yields, and to justify the choice of perennial crops that meet the needs and climatic conditions of the Rostov region. Presented is the generalized information on the grain quality changes during maturation, ripeness phases of grain crops are considered. Based on the review, the optimal ripeness phases, at which it is advisable to harvest are presented. Literature review showed that in the phase of lactic (мoлoчнaя cпeлocть) and wax maturity (вocкoвaя cпeлocть) wheat grain contains the greatest amount of basic nutrients. It was found that perennial crops have a positive effect on the state of the soil: prevent its erosion and depletion; there is an accumulation of carbon, soil methane CH 4. Comparative characterization of perennial crops with annual crops shows increased protein content - on average 2-3% higher. Also considered are the green mass quality indicators of perennial crops as a source of nutrients in the feed-production technology.

scholarly journals Reactions of Perennial Grain Accessions to Four Major Cereal Pathogens of the Great Plains

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1235-1240 ◽  
Author(s):  
C. M. Cox ◽  
K. A. Garrett ◽  
T. S. Cox ◽  
W. W. Bockus ◽  
T. Peters
Keyword(s):  
Triticum Aestivum ◽  
Disease Management ◽  
Great Plains ◽  
Tan Spot ◽  
Yellow Dwarf ◽  
Gaeumannomyces Graminis ◽  
Grain Crops ◽  
Barley Yellow Dwarf ◽  
Perennial Grain ◽  
Take All

Methods of disease management used in annual grain crops, especially cultural practices designed to disrupt the disease cycle of a particular pathogen, will not necessarily be applicable to perennial grain crops. Resistance to multiple pathogens, therefore, will clearly be important in disease management. The objective of this research was to evaluate disease resistance in 10 perennial grain accessions (one to two accessions of each: perennial wheat (Thinopyrum sp. × Triticum aestivum), intermediate wheatgrass (Thinopyrum intermedium), perennial rye (Secale montanum), hexaploid triticale (Triticum turgidum × S. montanum), octoploid triticale (Triticum aestivum × S. montanum), tetraploid perennial rye (Secale cereale × S. montanum), and tall wheat-grass (Thinopyrum ponticum)) to tan spot (caused by Pyrenophora tritici-repentis), take-all (caused by Gaeumannomyces graminis var. tritici), wheat streak mosaic, and barley yellow dwarf, four important diseases of the Great Plains. Several of the grasses were resistant to tan spot, barley yellow dwarf, and wheat streak mosaic. Indeed, the wild grasses and perennial donors T. intermedium (including BFPMC1), T. ponticum, and S. montanum, in addition to Permontra, a tetraploid perennial rye, were highly resistant to all three diseases. Additionally, the remaining grasses tested were also more resistant to tan spot than the susceptible wheat control. However, none of the 10 grass accessions appeared highly resistant to take-all, and substantial losses in biomass were observed, although such effects may be moderated under field conditions due to the potential for take-all decline in perennial plantings.

Perennial Grain Crops: A New Option for the Future Food and Ecoagricultural Environment

2011 ◽  
Vol 361-363 ◽  
pp. 1463-1466 ◽  
Author(s):  
Yan Min Zhang ◽  
Lu Ming Jiang ◽  
Yong Peng Li ◽  
Chao Tian ◽  
Wen Jing Zhang ◽  
...  
Keyword(s):  
Food Security ◽  
Production Systems ◽  
Economic Benefits ◽  
Perennial Crop ◽  
Grain Crops ◽  
The Future ◽  
The Status ◽  
Agriculture And Environment ◽  
Below Ground ◽  
Perennial Grain

Although agriculture has traditionally been primarily the concern of the world, it now plays an increasingly important role in how we meet challenges—international food security, environmental protection, climate change, energy supply, economic sustainability, and human health. With population growth and environmental deterioration, the attention about food security and sustainable agriculture is on the increase, and the status of ecological agriculture comes into prominence. Perennial grain crops would address many agricultural problems as well as substantial ecological and economic benefits, which can provide multiple ecosystem services essential for sustainable production more effectively than production systems based on annual crops, such as protecting against soil erosion, conserving water and nutrients, storing more carbon below ground, and building better pest tolerance. This paper presents some of advantages of perennial grain crops as a new option for the food security and ecoagriculture, as well as prospects the significant utilization of perennial crop on sustainability of agriculture and environment in the future.

scholarly journals Managing for Multifunctionality in Perennial Grain Crops

BioScience ◽  
2018 ◽  
Vol 68 (4) ◽  
pp. 294-304 ◽  
Author(s):  
Matthew R Ryan ◽  
Timothy E Crews ◽  
Steven W Culman ◽  
Lee R DeHaan ◽  
Richard C Hayes ◽  
...  
Keyword(s):  
Grain Crops ◽  
Perennial Grain
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