نتایج جستجو برای: soil nutrient balance

تعداد نتایج: 374696  

2000
Anthony M. Whitbread Graeme J. Blair Rod D.B. Lefroy

Farming activities practiced on many Australian soils have resulted in substantial losses of soil organic matter (SOM), nutrient loss, soil structural degradation and declines in cereal yield and quality. Field trials, consisting of a legume or fallow phase followed by three wheat (Triticum aestivum L.) crops, were established on a degraded Ferric Luvisol (Red Earth) soil in New South Wales to ...

2015
Michael D. Cramer M. Timm Hoffman Lucas C.R. Silva

Globally, mediterranean-climate ecosystem vegetation has converged on an evergreen, sclerophyllous and shrubby growth form. The particular aspects of mediterranean-climate regions that contribute to this convergence include summer droughts and relatively nutrient-poor soils. We hypothesised that winter-precipitation implies stressful summer droughts and leaches soils due to greater water availa...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علم و صنعت ایران - دانشکده مهندسی عمران 1383

فرایند تغذیه گرایی که نتیتجه غیر مستقیم فرایندهای توسعه بر کیفیت دریاچه ها و مخازن سدهاست از جمله اثرات بسیار مضر بر کیفیت آب به شمار می رود که در وضعیت های حاد بسیاری از اهداف اقتصادی ساخت مخازن رابا مشکلات جدی روبرو می سازد و مشکلات عدیدهای را فرا روی مدیریتی کیفی مخازن قرار می دهد. مخزن سدکرخه با ظرفیت مفید بیش از 5 میلیارد متر مکعب با مصارف آبیاری و شرب از جایگاه ویژه ای برخوردار است. در ا...

2009
A. F. Bouwman A. H. W. Beusen G. Billen

[1] The Millennium Ecosystem Assessment scenarios for 2000 to 2050 describe contrasting future developments in agricultural land use under changing climate. Differences are related to the total crop and livestock production and the efficiency of nutrient use in agriculture. The scenarios with a reactive approach to environmental problems show increases in agricultural N and P soil balances in a...

2014
Simeon J. Smaill Peter W. Clinton Robert B. Allen Alan C Leckie Murray R. Davis

A recent trial found that the presence of coarse soil in fine soil increased nutrient uptake by two plant species (Smaill et al., 2014). To determine if the additional nutrient uptake was derived directly from the coarse soil, the changes in coarse soil nutrient stocks were assessed. In most cases nutrient stocks increased, despite being associated with greater plant nutrient uptake. This sugge...

Journal: :مدیریت خاک و تولید پایدار 0
عزیز مجیدی عضو هیات علمی، مرکز تحقیقات کشاورزی و منابع طبیعی آذربایجان غربی

sulfur (s) is an essential macronutrient influencing plant growth, nutrient efficiency, quality and health of agricultural crops. the purpose of this research was to study the effects of s rates and sources on growth and fruit quality of apple (malus domestica l.) trees of ‘golden delicious’ at west azerbaijan, iran. experiment was conducted during four seasons (2003-2007), using a factorial ra...

Journal: :The Science of the total environment 2016
M R Redding R Lewis T Kearton O Smith

The key to better nutrient efficiency is to simultaneously improve uptake and decrease losses. This study sought to achieve this balance using sorbent additions and manure nutrients (spent poultry litter; SL) compared with results obtained using conventional sources (Conv; urea nitrogen, N; and phosphate-phosphorus; P). Two experiments were conducted. Firstly, a phosphorus pot trial involving t...

Journal: :journal of agricultural science and technology 2011
p. zamani s. r. miraei ashtiani d. alipour m. tabatabaei h. aliarabi

some factors affecting crude protein balance (cpb), as a measure of efficiency, were studied using 2824 records of 501 lactating holstein cows. the cpb (kg d-1) was calculated as crude protein (cp) intake (kg) minus cp yield (kg). two different statistical methods including principal components (pcs) and general linear model analyses were used to study the effects of different factors. crude pr...

2016
Clive A Kirkby Alan E Richardson Len J Wade Mark Conyers John A Kirkegaard

Removing carbon dioxide (CO2) from the atmosphere and storing the carbon (C) in resistant soil organic matter (SOM) is a global priority to restore soil fertility and help mitigate climate change. Although it is widely assumed that retaining rather than removing or burning crop residues will increase SOM levels, many studies have failed to demonstrate this. We hypothesised that the microbial na...

Journal: :ecopersia 2013
reza ghazavi abbasali vali

re-vegetation of bare soil is believed to increase, or at least maintain the organic matter levels of soil. the aim of this study was to investigate the soil characteristics changes, nutrient pool sizes and their availability under mid canopy, and canopy gap positions of saltbush in an area re-vegetated with atriplex lentiformis. some of the physical and chemical soil characteristics (the parti...

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