نتایج جستجو برای: 475 kg ha

تعداد نتایج: 242389  

2009
M. H. ULLAH S.M.I. HUQ M.D.U. ALAM M. A. RAHMAN

The experiments were carried out at the Regional Agricultural Research Station, Rahmatpur, Barisal during the rabi seasons of 2001-2002 and 2002-2003 to study the impact of different sulphur levels on bulb yield, storability and economic return of onion. Sulphur application had significant effect on yield components and bulb yield of onion. The highest bulb yields (19.75 and 19.88 t/ha) were ob...

2014
Sharif Ahmed Muhammad Salim Bhagirath S. Chauhan

Weeds are a major constraint to the success of dry-seeded rice (DSR). The main means of managing these in a DSR system is through chemical weed control using herbicides. However, the use of herbicides alone may not be sustainable in the long term. Approaches that aim for high crop competitiveness therefore need to be exploited. One such approach is the use of high rice seeding rates. Experiment...

2015
Xiujuan Ren Yanan Cheng Dafu Wu Chunhu Wang Shilin Chen

A field experiment with six treatments was conducted to study the nitrogen reserves in summer maize topsoil on the north China plain. Results showed that topdressing significantly increased topsoil nitrogen reserves. Summer corn topsoil nitrogen reserves were affected by several management measures. Shallow tillage, wheat straw no-returning and deep intertillage at the corn seedling stage signi...

Journal: :Environmental science & technology 2006
Shelie A Miller Amy E Landis Thomas L Theis

Intensive agricultural systems are largely responsible for the increase in global reactive nitrogen compounds, which are associated with significant environmental impacts. The nitrogen cycle in agricultural systems is complex and highly variable, which complicates characterization in environmental assessments. Appropriately representing nitrogen inputs into an ecosystem is essential to better u...

2005
Justin D. Derner Richard H. Hart

The efficiency of livestock production in shortgrass steppe may be increased by grazing fourwing saltbush (Atriplex canescens [Pursh] Nutt)-dominated rangeland in late fall and/or early spring, but there is a paucity of information concerning stocking rates and animal gains. The objective of this study was to compare the effects of light and moderate stocking rates on weight gains of heifers gr...

2015
Edison A. Díaz-Álvarez Roberto Lindig-Cisneros Erick de la Barrera Harpinder Sandhu

Potential ecophysiological responses to nitrogen deposition, which is considered to be one of the leading causes for global biodiversity loss, were studied for the endangered endemic Mexican epiphytic orchid, Laelia speciosa, via a shadehouse dose-response experiment (doses were 2.5, 5, 10, 20, 40, and 80 kg N ha(-1) yr(-1)) in order to assess the potential risk facing this orchid given impendi...

Journal: :Journal of environmental biology 2008
Abass Almodares Reza Taheri Ill Min Chung Majid Fathi

Sweet sorghum is tolerant to high temperature and drought and can be considered as an alternative crop to sugar beet and maize in Iran. In this study, the effects of nitrogen and potassium fertilizers on growth parameters including stem height, stem diameter, stem fresh weight, total fresh weight; carbohydrate contents including total sugar, brix value, sucrose content and purify; and juice ext...

2003
J. W. Singer K. J. Moore

Although cool-season grasses increase DM yield at high N rates, N recovery (kg plant N kg 1 N applied) Nitrogen removal by cool-season grasses may aid in capturing exgenerally declines as N rate increases. Ramage et al. cess N from animal confinement operations or phytoremediation. (1958) reported fertilizer N recovery of 0.59 and 0.59 kg Limited information exists on the N dynamics of these gr...

اطلاع از تغییرات زمانی میزان تولید رواناب و رسوب در طول فصل زراعی نه‌تنها در اتخاذ نوع و نحوه انجام کارهای حفاظتی مفید است بلکه در برآورد مدل‎های فرسایش خاک و رواناب کاربرد دارد. تحقیق حاضر با هدف بررسی تغییرات زمانی مقدار تولید رواناب و رسوب در طول فصل رشد گیاه نخود با تراکم‌های مختلف کشت تحت شرایط دیم در ایستگاه تحقیقات حفاظت خاک تیکمه‌داش در کرت­های فرسایشی اجرا شد. بدین منظور تحقیقی در قالب...

Journal: :Journal of environmental quality 2005
R J Gehl J P Schmidt L R Stone A J Schlegel G A Clark

Minimizing the risk of nitrate contamination along the waterways of the U.S. Great Plains is essential to continued irrigated corn production and quality water supplies. The objectives of this study were to quantify nitrate (NO(3)) leaching for irrigated sandy soils (Pratt loamy fine sand [sandy, mixed, mesic Lamellic Haplustalfs]) and to evaluate the effects of N fertilizer and irrigation mana...

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