نتایج جستجو برای: 400 kg n ha
تعداد نتایج: 1226864 فیلتر نتایج به سال:
The effect of nitrogen fertilization on root length (RL) distribution of winter wheat (Triticum aestivum L.) was investigated. The study was conducted in Prague-Ruzyne on clay loam Chernozemic soil in the years 1996–2003. Two (N0, N1) and three (N0, N1, N2) treatments, unfertilized (N0), fertilized with 100 kg (N1) and 200 kg N/ha (N2) were studied in 1996–2000 and 2001–2003, respectively. Nitr...
In this research, a comprehensive simulation model for water cycle and the nitrogen dynamics modeling including all the important processes involved in nitrogen transformations such as fertilizer dissolution, nitrification, denitrification, ammonium volatilization, mineralization, immobilization as well as all the important nitrogen transportation processes including nitrogen uptake by the plan...
Soil fertility degradation remains the major biophysical cause of declining per capita crop production on smallholder farms in sub-Saharan Africa. Appropriate soil fertility regimes, are therefore, critical for improved crop productivity. This study investigated the feasibility of using sole organics or their combinations with inorganic fertilisers to improve maize (Zea mays) production in the ...
Intensive management is crucial for optimizing hardwood plantation success, and nitrogen (N) nutrition management is one of the most important practices in intensive management. Because management of short-rotation woody crop plantations is a mixture of row-crop agriculture and plantation forestry, we tested the usefulness of an agronomic budget modified for deciduous perennial trees for estima...
Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in su...
Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates appli...
Biogeochemical monitoring for 45 years at the Hubbard Brook Experimental Forest in New Hampshire has revealed multiple surprises, seeming contradictions, and unresolved questions in the long-term record of ecosystem nitrogen dynamics. From 1965 to 1977, more N was accumulating in living biomass than was deposited from the atmosphere; the "missing" N source was attributed to biological fixation....
We used a seven-year urea gradient applied field experiment to investigate the effects of nitrogen (N) applications on soil N hydrolytic enzyme activity and ammonia-oxidizing microbial abundance in a typical steppe ecosystem in Inner Mongolia. The results showed that N additions inhibited the soil N-related hydrolytic enzyme activities, especially in 392 kg N ha(-1 )yr(-1) treatment. As N addit...
a two year field experiment was carried out to evaluate the competitive effects of wild mustard densities growing with rapeseed (cultivar talaye) under different nitrogen rates. treatments were wild mustard densities (0, 10, 20, 30, and 40 plant m-2) and nitrogen (n) rates (0, 50, 100, 150, and 200 kg n ha-1). the factorial set of treatments was arranged into a randomized complete block design ...
با توجه به اهمیت گندم و دانه های روغنی در ایران و کمبود منابع انرژی در جهان امروز، پژوهشی با هدف ارزیابی چگونگی مصرف انرژی در تولید گندم و کلزا در دو منطقه از شهرستان مرودشت(استان فارس) انجام گرفت.میانگین تولید گندم در مناطق سیدان و حومه به ترتیب 6813/996 و kg/ha 6046/968 و میانگین تولید کلزا نیز برای دو منطقه به ترتیب 2977/760 و kg/ha 2290/787 بود. این در حالی است که میانگین انرژی مصرفی کل در ...
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