نتایج جستجو برای: over grazing and improper irrigation method
تعداد نتایج: 17128064 فیلتر نتایج به سال:
one of the consequences of poor management and operation of irrigation systems, poor water delivery and distribution channels and divisions and consequently improper distribution of water level downstream. the study of simulation and performance evaluation software using hydrodynamic sobek varamin irrigation is done. in order to evaluate the network performance and compare the results of simula...
Manure application increases pasture crop production and minimizes manure storage costs. Excess N not absorbed by pasture vegetation can leach past the root zone and into ground water. A yearlong study was conducted on grazing pastures at 2 dairy farms to monitor potential nitrate (NO3) movement from the surface through the soil profile toward ground water. Precipitation, irrigation, manure app...
A long-term study of four degraded streams in the upper Owens River watershed documented the recovery of riparian habitats and significant improvement in channel morphology in response to grazing strategies, recreation management, and pre-irrigation peak flows. Increased control of livestock distribution, timing of forage use and degree of forage utilization on and near stream banks was designe...
current studies in second language (l2) learning have revealed the positive role of corrective feedback (cf) in both oral and written forms in different language features. the present study was an attempt to investigate the effect of both direct and indirect written corrective feedback (wcf) on the use of grammatical collocations in l2 writing. the study also sought to examine whether the effec...
in current study, 63 samples of bat populations collected from differ regions were used for evaluating the geographic variations. twenty cranial and dental characters for traditional morphometric and landmarks method on the ventral, dorsal skull and mandible for geometry morphometric studies were used. statistical analyses of traditional morphometric and geometry morphometric data indicated low...
Abstract Over the last fifty years, most of the semi-arid rangeland in Iran has been converted to cropland without an equivalent reduction in grazing animals. This shift has led to heavy grazing pressure on rangeland vegetation. The present study has been conducted in Sisab Research Station in the North Khorasan Province to evaluate effects of long-term grazing exclosures on biodiversity of ra...
Pathogen Transmission Routes Research Program, describing pathogen pathways from farm animals to water bodies and measures that can reduce or prevent through the deposition of faeces by grazing animals directly into waterways in New Zealand. Bridging of streams intersected by farm raceways is an appropriate mitigation measure to prevent direct deposition during herd crossings, whilst fencing st...
the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...
asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...
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...
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