Papers by Theodor Friedrich
... This amount is 6.41 times the food energy delivered by the system. By 1970 this ratio had inc... more ... This amount is 6.41 times the food energy delivered by the system. By 1970 this ratio had increased to approximately 7.4 (Hirst, 1973). The results of an analysis of where this primary energy was used in the food provision process in 1963 (Hirst, 1973) are given below: ...
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International Conference on Agricultural Engineering - AgEng 2010: towards environmental technologies, Clermont-Ferrand, France, 6-8 September 2010., 2010
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The impact of intensive soil tillage treatments on soil physical properties is described by means... more The impact of intensive soil tillage treatments on soil physical properties is described by means of selected data obtained through long-term, up to 18 years of investigations, interdisciplinary research. Tillage intensity of the systems considered decreases in the following sequence: Conventional plough tillage (CT), reduced tillage (RT), and no-tillage (NT). In general, bulk density in the upper layer of NT soils is increased, resulting in a decrease in the amount of coarse pores, and a lower -hydraulic conductivity when compared with the CT and RT soils. Surface cover by crop residues, higher aggregate stability, and increased infiltration rates under NT protect soil fertility by avoiding surface sealing and erosion. Lateral losses of herbicides are also reduced under NT conditions. Accumulation of organic matter and nutrients near the soil surface under NT and RT are favorable consequences of not inverting the soil and by maintaining a mulch layer on the surface. Those improvements accompany enhanced biological activities in NT and RT top soils. Increased earthworm activity in NT treatments builds up a system of continuous macropores which improves water infiltration rates and supports decomposition and incorporation of straw. Soils which have not been tilled for many years are more resistant to vehicle passage; consequently, the compaction by traffic is lower. Penetration resistance curves indicate that a uniformly stable structure has developed over the years in NT soils. Economical effects of different tillage systems are also assessed.
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Over the next few decades the production has to be doubled to respond to the food demand of a gro... more Over the next few decades the production has to be doubled to respond to the food demand of a growing population. On the other side the natural resource base for agricultural production is showing increasing signs of degradation. These problems are even more pronounced in Africa. In the past highly intensive agricultural production took a heavy toll on the environment, which was accepted as unavoidable collateral damage, while agriculture which was more respectful to the environment was less productive. The new paradigm of “sustainable production intensification” is recognizing the need for a highly productive agriculture which at the same time positively contributes to environmental services as an element of sustainability. With regard to climate change this refers to the reduction of the contributions of agricultural production to the release of green house gasses. Adequate agricultural production techniques, based on minimum disturbance of soils (no-till) and enhancement of aerobic conditions in soils can reduce these emissions and eventually even lead to the sequestration of carbon in soils reaching 0.25-2.5 bill t/year. This reduction of GHG emissions results from a better efficiency and reduced losses of production inputs and carbon and is hence not sacrificing high production levels. Sustainable production intensification, based on concepts such as Conservation Agriculture, provide also opportunities for the adaptation to climate change. With these perspectives Conservation Agriculture has a particularly high potential to address the problems of African agriculture. Harnessing the potential of conservation agriculture for carbon sequestration and reduction of GHG emissions for the payment of environmental services to farmers would provide further incentives to farmers for changing to this new way of agriculture.
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Grundlagen der Landtechnik, 1988
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Abstract. The growing world population is demanding a significant increase in global food product... more Abstract. The growing world population is demanding a significant increase in global food production and availability. While there are enough land and water resources to meet future food needs, they are increasingly degrading due to the conventional agriculture approach. At the same time, future production increases are not expected to come from area expansion but from yield and productivity increases. Yet, in many important agricultural production areas yield increases are reaching a ceiling. Additional associated challenges are environmental pollution from agriculture, increasing floods and droughts, and falling groundwater in important watersheds. Despite several decades of addressing an international agenda of sustainable development, the situation in general has not improved. Several factors are commonly addressed as causes for the problems, such as climate change, soil erosion, and overuse of agrochemicals. However, causes and consequences are often mixed up, hiding the root problem. The paper demonstrates, how and why mechanical soil tillage can be identified as such root problem, leading to loss of productivity potential, resulting in many of the above described problems and impeding an increase of global food production. Reasons are elaborated for the proposed spread of an agricultural production system, commonly known as Conservation Agriculture, based on no-tillage, a permanent soil mulch cover, and crop diversity in production as integral concepts. Global experiences with Conservation Agriculture are described as foundation for a Sustainable Intensification with a solution to produce sufficient food for coming generations while stopping the degradation of natural resources and reversing the degradation processes in already degraded agricultural landscapes.
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Springer eBooks, Dec 4, 2014
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沙漠研究 = Journal of arid land studies : 日本沙漠学会誌, Jun 1, 2012
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Field Actions Science Reports. The journal of field actions, Dec 9, 2014
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... Language, German. Notes, 3 ill.; 6 ref. Summary (En). Type, Summary. Journal Title, Entwicklu... more ... Language, German. Notes, 3 ill.; 6 ref. Summary (En). Type, Summary. Journal Title, Entwicklung und laendlicher Raum. ISSN, 0047-4002. Vol. No. v. 21(3) p. 27-29. Abstract (English), Lentils are an important crop in the arid zones in the Near East. ...
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Since achieving independence, Uzbekistan has made efforts towards developing its own market econo... more Since achieving independence, Uzbekistan has made efforts towards developing its own market economy and put a major emphasis on agricultural growth. During this transition, large and inefficient shirkat (cooperative) farms were dismantled and much smaller private farms were established. For development of this new type of farms, there are constraints associated with limited potential and abilities in crop, tillage methods, soil fertility improvement and on-farm water management. There is an urgent need to pilot changes in agricultural practices in the region in order to improve winter wheat productivity in the salt and drought-affected region of Aral Sea Basin of Uzbekistan. A four-year experiment was conducted, to identify best options of different tillage methods in winter wheat cultivation, at farmers’ field in Chimbay district, of Uzbekistan (N 42°57.091’, E 059°45.798’, 69 m above sea level). Data analysis was performed using GenStat program. The highest yield was recorded in 2...
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Aspects of applied biology, 2000
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Conservation Agriculture (CA) and the System of Rice Intensification (SRI) are both agroecologica... more Conservation Agriculture (CA) and the System of Rice Intensification (SRI) are both agroecologically-oriented production systems that support more productive, sustainable, and resource-conserving farming, with synergies arising from their respective assemblages of reinforcing agronomic methods. Application of CA principles enhances the growth, yield, and performance of the crops grown under the cropping system as well as the health and resilience of the whole ecosystem. SRI practices create more favorable conditions for the development of crop plants below- and above-ground, conditions that can be enhanced by CA management. SRI practices such as reduced plant density m-2 can elicit better phenotypic expression of the genetic potentials of crops grown with CA.. For these two agronomic systems to converge at field level, some of their respective practices for plant, soil, water, and nutrient management need to be modified or aligned. One such adaptation is to practice SRI in CA system...
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Conservation agriculture: global prospects and challenges
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Papers by Theodor Friedrich