1. What is the subject of your thesis?
2. Have you already published any articles?
3. Where and when did you publish them?
4. What are the titles of your published papers?
5. What problems do you deal with in those papers?
6. What are you going to prove in the course of your research?
7. Is there much or little material published on the subject of your research?
8. Who is the intended audience of your papers?
9. What do you give much attention to in your published papers?
10. What is of particular interest in your paper?
11. How many parts does your paper consist of?
12. What is the purpose of your paper?
13. What do you treat in your introductory part?
14. What do you say in conclusion?
15. Who do you make references to?
Text 4: Nonlegume cover crops
Commonly used nonlegume cover crops include:
Annual cereals (rye, wheat, barley, oats)
Annual or perennial forage grasses such as ryegrass
Warm-season grasses like sorghum-sudangrass
Brassicas and mustards
Nonlegume cover crops are most useful for:
Scavenging nutrients - especially N - left over from a previous crop
Reducing or preventing erosion
Producing large amounts of residue and adding organic matter to the soil
Suppressing weeds
Annual cereal grain crops have been used successfully in many different climates and cropping systems. Winter annuals usually are seeded in late summer or fall, establish and produce good root and topgrowth biomass before going dormant during the winter, then green up and produce significant biomass before maturing.
Rye, wheat, and hardy triticale all follow this pattern, with some relatively small differences that will be addressed in the section for each cover crop. There is growing interest in the use of brassica and mustard cover crops due to their biofumigation characteristics. They release biotoxic chemicals as they break down, and have been found to reduce disease, weed and nematode pressure in the subsequent crop.
Brassicas and mustards provide most of the benefits of other nonlegume cover crops, while some (forage radish, for example) are thought to alleviate soil compaction. Perennial and warm-season forage grasses also can serve well as cover crops. Forage grasses, like sod crops, are excellent for nutrient scavenging, erosion control, biomass production and weed control.
(The source: Andy Clark. Managing cover crops profitably. - 3rd ed. ‑ Sustainable Agriculture Network, 2007. ‑ 248 p.; p. 73).
Text 5: Wheat
Wheat is an important grain food crop supplying the second highest caloric intake for humans, closely behind rice. Wheat is used to produce flour for bread, pasta, couscous and other foods.
However, wheat generally consumes large amounts of nitrate and other fertilizers, so that the outcome of widespread wheat farming is often associated with extensive water pollution impacts, especially related to nitrate laden runoff.
Wheat is one of the earliest cultivated crops, and has a clear association with the emergence of sedentary agriculture around twelve millennia ago.
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Wheat is one of the most adaptable of crops, grown from the equator to near the Arctic, and from sea level to the Tibetan Plateau. Recent research demonstrates that production of the world wheat crop is likely to increase if atmospheric carbon dioxide levels rise.
To feed the burgeoning worldwide human population explosion, intensification of wheat farming has brought the by-product of increased crop diseases; such practices as intensive irrigation, lack of crop rotation and dependence on monocultures have promoted the propagation of many fungal pathogenic infections that reduce the yields of wheat and other cereal crops, and in some cases can lead to human disease via mycotoxin production.
History of cultivation
Domestication and cultivation of wheat was one of the earliest farming activities of prehistoric man, at the outset of sedentary agriculture.
A number of sites in the Levant are associated with early wheat cultivation, a site at Iraq ed-Dubb (Cave of the Bear), in present day Jordan is arguably the oldest radiocarbon dated location at 9600 BC.
Other archaeological records from: the Abu Hureyra site in the valley of the Euphrates in Syria, the Nevalı Çori site; and (in southern Turkey), from Cayonu in the Karacadag Moutains of Turkey. At each site wheat cultivation is dated to the eighth and ninth millennia BC.
Even in North Africa, where the present day climate is arid, there is evidence of Neolithic farming of emmer wheat; for example at the Volubilis archaeological site in Morocco, DNA analysis shows that the climate was mild and wet enough to support emmer production thousands of years ago. The site was eventually developed to be the regional capital of the Phoenicians and Romans as a western outpost for each of these conquering early colonial powers.
Principal species
There are several key species of wheat, chief among them being:
- Bread Wheat (Triticum aestivum), an allohexaploid species most commonly used in production of bread
- Einkorn Wheat (Triticum monococcum), a [diploid] species with 2n=14
- Wild Emmer (T. dicoccoides), a [tetraploid] hybrid formed by T. urartu and an extinct wild grass of genus Aegilops
- Emmer Wheat (T. dicoccum), a tetraploid species derived from wild emmer
- Durum Wheat (T. durum), a tetraploid species derived from wild emmer.
Fertilizer requirements
Use of nitrate fertilizers for wheat production have been common in Western nations since the mid-1800s. In China, widespread use of nitrates for wheat crops began in the 1950s subsequent to widespread famines. The concomitant outcome of massive nitrate usage is broad water pollution impacts from nitrate and other chemical fertilizer usage, driven by surface runoff. In India, for example, wheat and rice farming account for the vast majority of nitrate usage, even though other cereal grains constitute the majority of acreage planted to cereal crops.
Water requirements
Approximately one cubic meter of water is required to produce one kilogram of wheat. This value is about one half of the water needed to produce the same quantity of rice and one fifteenth that to produce one kilogram of beef. Nevertheless, world demand for water to irrigate wheat crops is extraordinarily high, owing to the massive amount of land planted to wheat.
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Particular areas where over drafting of groundwater have created ecological and agricultural disasters are the North China Plain and the Great Plains of the USA overlying the Ogallala aquifer. In both cases the aquifer has been mined at an unsustainable level over a period of decades, such that the peak agricultural yield was reached some time ago. In the case of the Ogallala aquifer, over mining of water has been occurring since the 1940s, when cheap electrical power provided by misguided federal stimulus programs led to unsustainable water extraction. In the case of the North China Plain, wheat production peaked in the 1990s as the depth to groundwater started to become prohibitive in costs for some farms.
Worldwide production
Over the past fifty years (19612011) worldwide wheat production tripled from 222 million tons to 704 million tons. During the same period the world's population doubled (2.2-fold) from 3.1 billion to 6.9 billion (a mid-year population estimates from the UN).
The dramatic increase in wheat production was not driven by an increase in land being farmed for wheat, which increased just 8% from 204 million hectares (2.04 million km2 or 788,000 miles2) to 220 million hectares (2.20 million km2 or.851,000 miles2).
The increase in wheat production is primarily related to a nearly three-fold increase in yield, from an average of just 11,000 hectograms (1.1 tons) of wheat per hectare on average to nearly 32,000 hectograms (3.2 tons) per hectare.
The increase in yield has been due to a number of factors including:
- New varieties / cultivars of wheat;
- More irrigation and more effective methods of irrigation;
- Wider use of pesticides and more effective pesticides;
- Wider use of fertilizer and more effective fertilizers; and,
- Improvements in agricultural practices and mechanization
- Changes in National Wheat Production over the Past Fifty Years
In 1961, the USSR was the world largest producer followed by the USA, China, India, and France. In those fifty years, the most dramatic increases in wheat production have occurred in China (8.2 times 1961 harvest), India (7.9 times), and Pakistan (6.6 times).
(The source: http://www.eoearth.org/view/article)
Text 6: Soil
Healthy soil is the basis of organic farming. Regular additions of organic matter in the form of cover crops, compost, or manure create a soil that is biologically active, with good structure and capacity to hold nutrients and water (note that any raw manure applications must occur at least 120 days before harvest). Decomposing plant materials will activate a diverse pool of microbes, including those that break down organic matter into plant-available nutrients as well as others that compete with plant pathogens in the soil and on the root surface.
Rotating between crop families can help prevent the buildup of diseases and nematodes that overwinter in the soil. Rotation with a grain crop, or preferably a sod that will be in place for one or more seasons, deprives many, but not all, disease-causing organisms of a host, and also contributes to a healthy soil structure that promotes vigorous plant growth.
The same practices are effective for preventing the buildup of root damaging nematodes in the soil, but keep in mind that certain grain crops are also hosts for some nematode species. Rotating between crops with late and early season planting dates can reduce the buildup of weed populations.
Organic growers must attend to the connection between soil, nutrients, pests, and weeds to succeed. Unlike cash crops, which are grown for immediate economic benefit, cover crops are grown for their valuable effect on soil properties and on subsequent cash crops.
Cover crops help maintain soil organic matter, improve soil tilth, prevent erosion and assist in nutrient management. They can also contribute to weed management, increase water infiltration, maintain or increase populations of beneficial fungi, and may help control insects and diseases.
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(Abby Seaman, ed. Production Guide for Organic Potato. New-York: Cornell University, New York State Agricultural Experiment Station, 2012).
Text 7: Environmental sustainability
The environmental sustainability of agriculture consists of three components: agricultural production, demand for agricultural products and food policy. There are several gauges of environmental sustainability including the Input and Output Rules advanced by Daly, Cobb and Goodman.
The Output Rule states that waste emissions of an action should be kept within the assimilative capacity of the local environment without unacceptable degradation of future waste absorptive capacity or the ecosystem services.
The Input Rule for renewables states that harvesting rates of renewables must be within regenerative capacity of the natural system.
The key parameters of agricultural production that impact sustainability are (a) intensiveness of fossil fuel use; (b) application of excessive chemicals to the soil; (c) overharvesting that leaves insufficient residual plant material; (d) intensive water use; and (e) excessive compaction or erosion of topsoils.
Specific sustainability practices are found in the application of polycultural cultivation; steady state fishery production; use of grazing practices that minimize erosion and are compatible with native plant survival; rotational cropping and grazing practices that allow sustaining of carbon, nitrogen and other geochemical cycles
Worldwide, more than 99.7% of human food (calories) comes from the land. Significant adverse environmental impacts, such as soil erosion, biodiversity loss, and surface water runoff carrying sediment pollution may result from all forms of terrestrial agriculture. In addition, fossil fuel-intensive agriculture causes accumulation of agricultural chemicals in soils and their discharge to surface waters.
The chief chemicals applied are nitrates and phosphates in fertilizers and a host of pesticides and herbicides, most of which have significant toxicity. When these chemicals enter the environment they alter biotic productivity cycles and can affect the metabolism of plants and animals. This metabolic change may induce stunted growth, impaired function and even mortality. As a consequence loading of extraneous chemicals into the environment is a threat to biodiversity and ecosystem function There is a critical need to assess fossil energy limits, the sustainability of agriculture, biodiversity implications and the food needs of a rapidly growing world population.
(The source: http://www.eoearth.org/view/article)
