نتایج جستجو برای: crop simulation model

تعداد نتایج: 2511500  

2012
Soren Anderson Chenguang Wang Jinhua Zhao

We propose an econometric model of crop choice in which a farmer’s profit-maximizing crop depends on physiological crop attributes interacted with local soil and climate characteristics. We estimate the model using county-level data on average crop choices for 1986–2008. We find that attributes of chosen crops correlate as expected with geographic variation in soil and climate characteristics. ...

Journal: :Journal of environmental quality 2008
Q Fang L Ma Q Yu R W Malone S A Saseendran L R Ahuja

Excessive N and water use in agriculture causes environmental degradation and can potentially jeopardize the sustainability of the system. A field study was conducted from 2000 to 2002 to study the effects of four N treatments (0, 100, 200, and 300 kg N ha(-1) per crop) on a wheat (Triticum aestivum L.) and maize (Zea mays L.) double cropping system under 70 +/- 15% field capacity in the North ...

Journal: :Remote Sensing 2013
Vikalp Mishra James F. Cruise John R. Mecikalski Christopher R. Hain Martha C. Anderson

Biophysical crop simulation models are normally forced with precipitation data recorded with either gauges or ground-based radar. However, ground-based recording networks are not available at spatial and temporal scales needed to drive the models at many critical places on earth. An alternative would be to employ satellite-based observations of either precipitation or soil moisture. Satellite o...

2003
M. Heinen

In this study, water and nutrient uptake from the substrate and responses of the crop to fertigation strategies were analysed. In an experiment and simulation study, the amount and frequency of fertigation and electrical conductivity (EC) of the fertigation water were changed for a tomato crop grown on rockwool. In a climate chamber, tomato plants were grown on rockwool while five different EC ...

Journal: :آب و خاک 0
حمید زارع ابیانه الهام فرخی مجید وظیفه دوست خلیل اژدری

abstract assessing moisture in the soil under cultivation of crops to achieve high performance and reduced water are necessary. knowledge of the moisture distribution in the root zone, time consuming and costly field tests that simulation models, a suitable alternative in answer to issues of movement and are water distribution. in this study assessment of soil moisture, to aid swap simulation m...

2010
Asha Karunaratne Neil Crout

Rainfed environments are characterised by unpredictable and highly variable seasonal rainfall and hence highly variable yields. Water use efficiency (WUE, yield per unit of water use) is commonly used for agricultural production with limited water resources. Expertise working towards the water resources need to address the multitudinous aspects in which cropping systems and amounts, timing and ...

Journal: :تحقیقات آب و خاک ایران 0
تیمور سهرابی ملایوسف استاد گروه آبیاری دانشگاه تهران عبدالمجید لیاقت استاد گروه آبیاری دانشگاه تهران حمزه علی علی زاده دانشجوی دکتری گروه آبیاری دانشگاه تهران بیژن نظری استادیار گروه آبیاری دانشگاه بین المللی امام خمینی(ره)

many factors affect wastewater management and utilization plans’ success with any change occurring in any of these factors leading to various feedbacks on other elements of wastewater use system. hence, development of a model with the capability of simulation of all factors, aspects and interactions that affect wastewater utilization indispensable. the objective followed in this study was to mo...

2007
L. Ma P. Heilman L. R. Ahuja R. S. Kanwar

Accurate simulation of agricultural management effects on N loss in tile drainage is vitally important for understanding hypoxia in the Gulf of Mexico. An experimental study was initiated in 1978 at Nashua, Iowa of the USA to study long-term effects of tillage, crop rotation, and N management practices on subsurface drainage flow and associated N losses. The Root Zone Water Quality Model (RZWQM...

E. Bougari H. Zaki dizaji M.A. Khorasani

Abstract The aim of this research is to present a simulation model for reducing economic damages of mechanized wheat harvesting in the weather conditions of Khuzestan province and similar areas. The simulated model is composed of three sub-models, for determining of the appropriate working hours, grain losses, and economic sub-model. In order to determine the appropriate working hours, a mathem...

Journal: :international journal of maritime technology 0
amin mahmoudi faculty of civil engineering, persian gulf university, bushehr, iran habib hakimzadeh faculty of civil engineering, sahand university of technology, tabriz mohammad javad ketabdari faculty of marine technology, amirkabir university of technology, tehran amir etemadshahidi griffith school of engineering, griffith university, queensland,4222, australia nick cartwright griffith school of engineering, griffith university, queensland,4222, australia hassan abyn assistant professor of naval architecture, persian gulf university, bushehr

breaking waves have ability to transport large quantities of sediment and significant impact on coastal structures morphology. hence, modeling of wave breaking is an important subject in coastal and marine engineering. in this research, the periodic wave breaking process on a plane slope is studied experimentally and numerically. laboratory experiments were conducted to record water surface ele...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید