نتایج جستجو برای: 60 kg n ha

تعداد نتایج: 1411664  

2017
Yanqiao Zhu Mingya Wang Huifang Yan Chunli Mao Peisheng Mao

A field experiment was conducted to evaluate the effects of two nitrogen levels (N: 0,100 kg ha -1 ) and four phosphorus levels (P: 0, 60, 90, 120 kg P2O5 ha -1 ) on smooth bromegrass (Bromus inermis Leyss.) seed quality by measuring germination, mean germination time (MGT), protein and phosphorus contents, acid phosphoesterase (APT) and antioxidant enzymes activities, hydrogen peroxide (H2O2) ...

2014
Teresa Dias Adelaide Clemente Maria Amélia Martins-Loução Lucy Sheppard Roland Bobbink Cristina Cruz

Enhanced nitrogen (N) availability is one of the main drivers of biodiversity loss and degradation of ecosystem functions. However, in very nutrient-poor ecosystems, enhanced N input can, in the short-term, promote diversity. Mediterranean Basin ecosystems are nutrient-limited biodiversity hotspots, but no information is available on their medium- or long-term responses to enhanced N input. Sin...

2015
Upendra M. Sainju U. M. Sainju

Little is known about the effect of management practices on net global warming potential (GWP) and greenhouse gas intensity (GHGI) that account for all sources and sinks of greenhouse gas (GHG) emissions in dryland cropping systems. The objective of this study was to compare the effect of a combination of tillage, cropping system, and N fertilization on GWP and GHGI under dryland cropping syste...

Journal: :Journal of environmental quality 2004
R D Harmel H A Torbert B E Haggard R Haney M Dozier

When improperly managed, land application of animal manures can harm the environment; however, limited watershed-scale runoff water quality data are available to research and address this issue. The water quality impacts of conversion to poultry litter fertilization on cultivated and pasture watersheds in the Texas Blackland Prairie were evaluated in this three-year study. Edge-of-field N and P...

Journal: :علوم گیاهان زراعی ایران 0
حمیدرضا علی عباسی مسعود کاوسی مسعود اصفهانی بابک ربیعی

effects of nitrogen fertilizer levels on agronomic efficiency (ea), physiological efficiency (ep), and recovery efficiency (er), in rice (oryza sativa l.) cv. khazar was investigated in a rcbd of three replications in a sandy soil in guilan province, iran in 2003. this study compared the effects of six n rates, namely: control (no n fertilizer), 40 (basal), 40+40 (basal + midtillering), 40+20+2...

2016
Xinzhang Song Honghao Gu Meng Wang Guomo Zhou Quan Li

Moso bamboo, well known for its high growth rate, is being subjected to increasing amounts of nitrogen deposition. However, how anthropogenic management practices regulate the effects of N deposition on Moso bamboo stoichiometry remains poorly understood. We observed the effects of two years of simulated N deposition (30, 60 and 90 kg N ha(-1)yr(-1)) on the foliar stoichiometry of Moso bamboo p...

2008
William H. Schlesinger John T. Gray

Assistant Professor of Botany, Duke University, Durham, N.C. 27706; and Research Assistant, Department of Biological Sciences, University of California, Santa Barbara, CA 93106 Abstract: Precipitation and dry fallout were collected over a 2-year period at a remote site in the Santa Ynez Mountains, Santa Barbara County, California, USA and analyzed for nutrient content. Mean annual depositions o...

2004
F. Nevens

On a Flemish sandy loam soil, cut and grazed swards were compared at different levels of mineral nitrogen (N) fertilization. Economically optimal N fertilization rates were 400 (or more) and 200 kg N ha yr on cut and grazed swards respectively. Considering the amounts of residual soil nitrate-N in autumn, these N rates also met the current Flemish legal provisions, i.e. no more than 90 kg ha ni...

A. KAMGAR-HAGHIGHI M. J. BAHRANI M. SHOMEILI SH. ZANDE-PARSA

Limited information is available on water and nitrogen (N) management of sugarcane (Saccharum officinarum L.) in Khuzestan, southwestern Iran, where this crop is currently and extensively grown under heavy irrigation and N fertilization. Therefore, a field experiment was conducted from September 2000 to March 2002 at the Research Department of Karoon Agro-industry in Khuzestan to determine the ...

A 3- years (2015, 2016 and 2017) field study was carried out at National Wheat Research Program, Bhirahawa, Rupandehi, Nepal to evaluate the influence of crop residues and nitrogen levels on rice. The experiment was conducted in split plot design with three replications. Main plots were two crop residue levels (with crop residues of 30 cm wheat stubble and without crop residues) and sub plots c...

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