نتایج جستجو برای: over grazing and improper irrigation method
تعداد نتایج: 17128064 فیلتر نتایج به سال:
The purpose of this study was investigation of East Azerbaijan researchers and extension agents’ view about the role of extension services on agricultural development. The methodology was descriptive-correlation which is carried out by survey method. In this study, the sample population was 335 people including all researchers and extension agents working in the agricultural sector. To assess t...
Since the halophytes species have an important role in such ecosystem balance and they have been grazed by livestock as supplementary forage, the awareness of livestock's desire to grazing and their preference values of these species is of high priority. Regardless of the importance of halophyte species in the livestock feeding in Iran, there is less published research on the livestock grazing ...
Drylands occupy 6.15 billion hectares (Bha) or 47.2% of the world's land area. Of this, 3.5 to 4.0 Bha (57%-65%) are either desertified or prone to desertification. Despite the low soil organic carbon (SOC) concentration, total SOC pool of soils of the drylands is 241 Pg (1 Pg = petagram = 10(15)g = 1 billion metric ton) or 15.5% of the world's total of 1550 Pg to 1-meter depth. Desertification...
What is a good prior? Actual prior knowledge should be used, but for complex models this often not easily available. The can in the form of symmetry assumptions, and then choice will typically an improper prior. Also more generally, it quite common to choose priors. Motivated by we consider theoretical framework statistics that includes both priors posteriors. Knowledge represented possibly unb...
Iran with a cultivation area of 45000 ha and production of 150 ton/year is the number one saffron producer in the world. Planting of large size corms will increase flowering, but production of corms (number and size) may be affected by irrigation method or frequency. In this research which is performed in the farm of College of Agriculture, Shiraz University, the effects of method and frequency...
the rationale behind the present study is that particular learning strategies produce more effective results when applied together. the present study tried to investigate the efficiency of the semantic-context strategy alone with a technique called, keyword method. to clarify the point, the current study seeked to find answer to the following question: are the keyword and semantic-context metho...
drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...
Livestock grazing is a common human-induced activity with direct and indirect effects even on the ecosystems of protected areas. The present study analyzed the effects of different grazing management methods on species diversity and richness in the steppe rangelands of Saveh, Iran. Data were collected from sixty 2×2 m plots within the areas of three, four-years protected range management projec...
pressurized irrigation is a recent development that consumes more energy for the pressure produced. in thisstudy, energy consumption, waste and efficiency were investigated at a diesel and electrical sprinklerirrigation pumping plant in some fields in hamadan province during 2007-8. nebraska performance criteria(npc) were used to compare sprinkler irrigation pumping plant performance. the resul...
Rangelands cover approximately 85% of Kenya’s land mass and is a major resource for livestock farming with a considerable potential to mitigate climate change, yet these lands are stressed differently by various management. Our study aimed at determining the influence of grazing management systems (rotational, continuous and ungrazed) on soil organic carbon stocks in Yoani ranch located in the ...
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