نتایج جستجو برای: yield production function

تعداد نتایج: 1911023  

Journal: :پژوهش ادبیات معاصر جهان 0
سیدمحمد مرندی دانشگاه تهران، دکترا زهرا جان نثاری لادانی دانشگاه تهران، دانشجوی دکتری

stanley g. weinbaum was one of the american science fiction writers of the 1920s and 1930s who anticipated virtual reality early in the development of the genre in the united states. the machine in weinbaum’s science fiction plays a crucial role in the production of virtual space and time. not only does weinbaum’s gadgetry function within the domain of spatial alterity, but they also provide te...

2015
V. S. Dhaka Vikas Lamba

Agricultural sector area plays major role in Indian economy. This paper shows research comparison in between MLP Feed Forward Neural Network, Generalized Regression Neural Network and Radial-Basis Function Neural Network in the field of Wheat yield prediction using Z-score Normalization method. The outcome represents that GRNN present better prediction results as compared to FFNN and RBNN. Eigh...

Journal: :بوم شناسی کشاورزی 0
ابوالفضل برومند محمد حسین آق خانی حسن صدرنیا

abstract the aim of this survey is to compare utilization systems (cooperative, private and governmental) methods of energy consumption in soybean production and the evaluation of energy inputs effect in yield of soybean in moghan. for this purpose, the information were collected from 54 private farmers, 14 cooperative members farmers and 14 agro-industry units by questionnaire method. the maxi...

Water, salinity and nitrogen are the major factors affecting maize production in arid and semi-arid areas. The objectives of this study were to investigate the effects of different water, salinity and nitrogen levels on yield-water relationships, water use, water productivity (WP), water use efficiency (WUE) and water uptake reduction function by maize hybrid SC-704 in a semi-arid area and ...

Journal: :تحقیقات مهندسی کشاورزی 0
مهدی اکبری استادیار موسسه تحقیقات فنی و مهندسی کشاورزی

the greatest limitations to agricultural development and production in iran are scarcity of water resources, ineffective irrigation scheduling and wasteful water usage. avenues discussed for optimum water use include improving water productivity by improving irrigation scheduling, farm water management and water profitability. the present study evaluated current water use and ways to improve wi...

2013
Patricio Grassini Kent M. Eskridge Kenneth G. Cassman

Food security and land required for food production largely depend on rate of yield gain of major cereal crops. Previous projections of food security are often more optimistic than what historical yield trends would support. Many econometric projections of future food production assume compound rates of yield gain, which are not consistent with historical yield trends. Here we provide a framewo...

Journal: :اقتصاد و توسعه کشاورزی 0
حبیب الله سلامی مهدی نعمتی

the presence of yield systematic risk in agricultural sector is one of the main reasons for facing this sector with huge damages and is one of the restricting factors in developing agricultural insurance in iran. this study explores the presence of systematic yield risk and the extent and severity of yield spatial dependence for apple production in iran. to this end, the apple production region...

زندپارسا, شاهرخ , سلطانی, غلامرضا , سپاس‌خواه, علیرضا ,

In this study, the optimum irrigation depths for corn grain production under different conditions, i.e. maximum grain yield production and maximum benefit under limited land and water conditions, were determined under sprinkler irrigation in Bajgah (15 km. north of Shiraz). The results showed that, the optimum depth of irrigation for maximum grain yield production was 77.0 cm. Because of low pr...

Journal: :تولید گیاهان زراعی 0

a simple mechanistic model was constructed to evaluate potential dry matter of pearl millet. all needed parameters were calculated based on many field and laboratory experiments and actual data obtained from 86 fields of millet located at different regions of khorasan's provinces. the major simulated processes were crop phenology (as a function of temperature and photoperiod function curve...

2009
Richard Carew Elwin G. Smith Cynthia Grant

Production functions to explain regional wheat yields have not been studied extensively in the Canadian prairies. The objective of this study is to employ a Just-Pope production function to examine the relationship between fertilizer inputs, soil quality, biodiversity indicators, cultivars qualifying for Plant Breeders’ Rights (PBR), and climatic conditions on the mean and variance of spring wh...

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function paginate(evt) { url=/search_year_filter/ var term=document.getElementById("search_meta_data").dataset.term pg=parseInt(evt.target.text) var data={ "year":filter_year, "term":term, "pgn":pg } filtered_res=post_and_fetch(data,url) window.scrollTo(0,0); } function update_search_meta(search_meta) { meta_place=document.getElementById("search_meta_data") term=search_meta.term active_pgn=search_meta.pgn num_res=search_meta.num_res num_pages=search_meta.num_pages year=search_meta.year meta_place.dataset.term=term meta_place.dataset.page=active_pgn meta_place.dataset.num_res=num_res meta_place.dataset.num_pages=num_pages meta_place.dataset.year=year document.getElementById("num_result_place").innerHTML=num_res if (year !== "unfilter"){ document.getElementById("year_filter_label").style="display:inline;" document.getElementById("year_filter_place").innerHTML=year }else { document.getElementById("year_filter_label").style="display:none;" document.getElementById("year_filter_place").innerHTML="" } } function update_pagination() { search_meta_place=document.getElementById('search_meta_data') num_pages=search_meta_place.dataset.num_pages; active_pgn=parseInt(search_meta_place.dataset.page); document.getElementById("pgn-ul").innerHTML=""; pgn_html=""; for (i = 1; i <= num_pages; i++){ if (i===active_pgn){ actv="active" }else {actv=""} pgn_li="
  • " +i+ "
  • "; pgn_html+=pgn_li; } document.getElementById("pgn-ul").innerHTML=pgn_html var pgn_links = document.querySelectorAll('.mypgn'); pgn_links.forEach(function(pgn_link) { pgn_link.addEventListener('click', paginate) }) } function post_and_fetch(data,url) { showLoading() xhr = new XMLHttpRequest(); xhr.open('POST', url, true); xhr.setRequestHeader('Content-Type', 'application/json; charset=UTF-8'); xhr.onreadystatechange = function() { if (xhr.readyState === 4 && xhr.status === 200) { var resp = xhr.responseText; resp_json=JSON.parse(resp) resp_place = document.getElementById("search_result_div") resp_place.innerHTML = resp_json['results'] search_meta = resp_json['meta'] update_search_meta(search_meta) update_pagination() hideLoading() } }; xhr.send(JSON.stringify(data)); } function unfilter() { url=/search_year_filter/ var term=document.getElementById("search_meta_data").dataset.term var data={ "year":"unfilter", "term":term, "pgn":1 } filtered_res=post_and_fetch(data,url) } function deactivate_all_bars(){ var yrchart = document.querySelectorAll('.ct-bar'); yrchart.forEach(function(bar) { bar.dataset.active = false bar.style = "stroke:#71a3c5;" }) } year_chart.on("created", function() { var yrchart = document.querySelectorAll('.ct-bar'); yrchart.forEach(function(check) { check.addEventListener('click', checkIndex); }) }); function checkIndex(event) { var yrchart = document.querySelectorAll('.ct-bar'); var year_bar = event.target if (year_bar.dataset.active == "true") { unfilter_res = unfilter() year_bar.dataset.active = false year_bar.style = "stroke:#1d2b3699;" } else { deactivate_all_bars() year_bar.dataset.active = true year_bar.style = "stroke:#e56f6f;" filter_year = chart_data['labels'][Array.from(yrchart).indexOf(year_bar)] url=/search_year_filter/ var term=document.getElementById("search_meta_data").dataset.term var data={ "year":filter_year, "term":term, "pgn":1 } filtered_res=post_and_fetch(data,url) } } function showLoading() { document.getElementById("loading").style.display = "block"; setTimeout(hideLoading, 10000); // 10 seconds } function hideLoading() { document.getElementById("loading").style.display = "none"; } -->