نتایج جستجو برای: effects of different tillage systems on dispersion ratio
تعداد نتایج: 22085824 فیلتر نتایج به سال:
a major concern of farmers is deterioration of the soil and water resources. soil management is the most direct way for mankind to interfere with natural processes that may either intensify or hinder soil degradation. fractal geometry has been widely used to describe heterogeneity in a wide range of natural processes, including physical systems of soil. in this study, the effects of different m...
in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...
testing plays a vital role in any language teaching program. it allows teachers and stakeholders, including program administrators, parents, admissions officers and prospective employers to be assured that the learners are progressing according to an accepted standard (douglas, 2010). the problems currently facing language testers have both practical and theoretical implications but the first i...
A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the sh...
to investigate factors affecting the adoption of conservation tillage systems, the tillage methods utilized by wheat producers in the central darab county are categorized into conventional, reduced-tillage and no tillage systems. for this purpose, multinomial logit model approach using the stata software was applied to the data set collected by random cluster sampling method. the explanatory va...
the introduction of canola (oilseed rape; brassica napus l.) as a new source of vegetable oil production in iran prompts evaluation of the performance of this crop under different tillage systems. a field experiment was conducted to determine the impact of depth and intensity of tillage on soil physical properties, crop establishment and yield of irrigated winter canola in a loam soil (typic ha...
the skill of reading in english as a foreign language is an important and challenging one which is affected both by linguistic and extra linguistic factors. since vocabularies are part and parcel of every reading comprehension text, knowing enough vocabulary always facilitates this process. however, guessing strategy as one of the most important strategies has consistently ignored by language l...
the aim of the current study was to investigate the relationship among efl learners learning style preferences, use of language learning strategies, and autonomy. a total of 148 male and female learners, between the ages of 18 and 30, majoring in english literature and english translation at islamic azad university, central tehran were randomly selected. a package of three questionnaires was ad...
abstract nowadays, industries cannot play a crucial role in national and international competitions. the tourism industry is no exception. tourism industry development as the most important economic sector and income generation is one of the key challenges of economic development in the world. therefore, countries were successful that take advantage of the capabilities of tourism sector using ...
Soil loss due to erosion is a common problem in most parts of Iran. Reduced soil organic matter and lack of proper agricultural management have intensified the problem in recent years. Conservation tillage systems are becoming more widely used in corn production in other parts of the world because of soil losses due to wind and water erosion and energy inputs. Changes in tillage methods, howeve...
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