نتایج جستجو برای: crop factor

تعداد نتایج: 908373  

Journal: :Environmental science & technology 2012
Peter Fantke Peter Wieland Ronnie Juraske Gavin Shaddick Eva Sevigné Itoiz Rainer Friedrich Olivier Jolliet

An approach for estimating human exposure to pesticides via consumption of six important food crops is presented that can be used to extend multimedia models applied in health risk and life cycle impact assessment. We first assessed the variation of model output (pesticide residues per kg applied) as a function of model input variables (substance, crop, and environmental properties) including t...

Faosiyat Olajide-Adedamola, Luqman Abiodun Akinbile

Agricultural risks constitute a fundamental challenge in Nigeria, hence the importance of agricultural insurance in managing farm risks cannot be underestimated. As the crop sub-sector contributes about 85% of the agricultural GDP in Nigeria, this study focussed on awareness and factors that can enhance the adoption of crop insurance among crop farmers in Nigeria. Data collected from 310 random...

Journal: :Entropy 2017
Sufen Wang Vijay P. Singh

The relationship between soil water content (SWC) and vegetation, topography, and climatic conditions is critical for developing effective agricultural water management practices and improving agricultural water use efficiency in arid areas. The purpose of this study was to determine how crop cover influenced spatial and temporal variation of soil water. During a study, SWC was measured under m...

I.P.S. Ahlawat N.K. Sharma R.J. Singh,

Of the several mechanisms that can bring about efficient resource use, the most widelyapplicable one is intercropping systems that can make better use of resources. The aim of thisstudy was to evaluate resource capture and resource use efficiency in transgenic cotton-peanutintercropping system and in their respective sole crops with using 25-50% substitution ofrecommended dose of nitrogen (RDN)...

2009
Martin Schönhart Erwin Schmid Uwe A. Schneider

Crop rotations are an important factor for the design and implementation of sustainable agricultural systems. Integrated agricultural land use models increasingly acknowledge the role of crop rotations by assessing economic and environmental impacts of agricultural production systems. However, insufficient data on crop rotations often challenge their implementation. In this article, we present ...

1996
Yang Hong

The study utilises survey data on 1000 households in rural China to investigate sources of disparities in factor productivities for rice, wheat and maize in different provinces. The effects of natural endowments are emphasised. It is found that for respective crops, the level of factor productivities is generally higher in their major producing areas than that in the non-major producing areas d...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت معلم تهران 1381

‏‎the purpose of the present study was to investigate the latent pattern underlying reading ability . some 272 male and female participants. english majors at the ba level , participated in the study. two valid tests were used in this study, the reading test developed exclusively for the purpose of this project and academic reading section of ielts. to investigate the possible latent underlying...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده کشاورزی 1392

یکی از چالش های موجود در بخش کشاورزی مناطق خشک ازجمله ایران افزایش دادن تولیدمحصول به ازاء واحد حجم آب مصرفی است. کم آبیاری یکی از استراتژی های افزایش کارآیی مصرف می باشد. موفقیت استراتژی کم آبیاری تا حدود زیادی بستگی به شناسایی عوامل تأثیرگذار در رشد و نمو و نحوه پاسخ گیاه هدف به این عوامل دارد. کاربرد توابع ریاضی و مدل های شبیه سازی رشد گیاهان کمک زیادی برای نیل به این هدف می کنند. در این مطا...

2000

June 23, 2000 Deciding whether a specific weed infestation is worth treating is usually based on a subjective evaluation of the potential impact of the infestation on crop yields. The two main criteria used are 1) the number of weeds present, and 2) the specific weeds present (foxtail, velvetleaf, etc.). Another factor that is just as important, if not more so, is the emergence date of the weed...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید