نتایج جستجو برای: ecological systems indefinite weight grazing and constant yield harvesting sub supersolution method

تعداد نتایج: 17299149  

Journal: :پژوهش های حبوبات ایران 0
کامران افصحی محمد رضا مستوفی سرکاری فرید شکاری مهدی راستگو

seed loss at harvesting time is one of the factors reducing seed yield in at farms. this study was carried out within a research farm in karaj to evaluate and select a proper pinto bean line for mechanized harvesting at two moisture contents during harvesting and their effect on seed yield and yield loss among three lines of pinto bean. the experiment was split-plot based on randomized complete...

برزگر, طاهر, شیراحمدی, سیما, قهرمانی, زهرا,

In order to evaluate the effect of different training systems on growth, yield and fruit quality of greenhouse cucumber (Cucumis sativus cv. Gohar) this experiment was set out in a randomized complete block design with three replications. Treatments consisted of four training systems including twin-stem system (V-shape), modified twin-system, high-wire system and horizontal system (single-stem)...

2004
N D Barlow

’Extensive’ herbivore/vegetation models and ’intensive’ grazing models yield two conclusions for sustained-yield harvesting of populations regulated by an interaction with their resources. First, the growth curve for the population, relating growth rate to current density, and the equilibrium yield/effort curve under harvesting, are likely to be asymmetric, with peaks displaced to the right and...

Journal: :مرتع و آبخیزداری 0
نیما شاکری بروجنی دانش آموخته کارشناسی ارشد مرتع داری، دانشگاه صنعتی اصفهان، ایران حسین بشری استادیار، دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران مصطفی ترکش اصفهانی استادیار، دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران

this study sought to develop a decision support system (dss) for assisting range managers to detect range condition and make informed decisions about feridan county rangelands. all plant species frequencies were measured in 31 range sites with various grazing histories using step point method. four hundred points along four perpendiculars 30 meters transects were measured in each site and grazi...

Journal: :SIAM Journal of Applied Mathematics 2013
Jing Chen Jicai Huang Shigui Ruan Jihua Wang

In this paper we study bifurcations in predator-prey systems with seasonal prey harvesting. First, when the seasonal harvesting reduces to constant yield, it is shown that various kinds of bifurcations, including saddle-node bifurcation, degenerate Hopf bifurcation, and Bogdanov– Takens bifurcation (i.e., cusp bifurcation of codimension 2), occur in the model as parameters vary. The existence o...

Journal: :desert 2008
m. dastorani m. heshmati m. a. sadeghzadeh

this research was designed to evaluate and compare the applicability of two different types of irrigation including traditionally (surface irrigation) and simple sub-surface drip irrigation (using pricked-pipe covered with plastic cloth). two plots containing 39 pistachio trees with 720 m2 area were selected in rafsanjan, iran. both plots were irrigated using exactly the same quantity and quali...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...

2012
Gufu Oba

This article reports a rapid method for rangeland assessments in Kenya, Ethiopia and Uganda by harnessing pastoralists’ indigenous knowledge among the Orma, Afar and Karamojong pastoralists. The study developed and evaluated a methodological framework for conducting joint assessments with pastoralist range scouts. The framework has four components: selection of ecological and anthropogenic indi...

Sommart Yoosukyingsataporn Somyot Detpiratmongkol

There is little information about the effects of ethephon ripening hormone on the yield of sweet sorghum in Thailand. Therefore, this study aimed to evaluate the impact of ethephon hormone applied at different growth stages of three cultivars of sweet sorghum on its growth and yield. The experiment was conducted from December 2016 to May 2017 at a research plot of the Faculty of Agricultural Te...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید