In order to investigation the effect of row spacing and seeding rate on alfalfa (Medicago sativa L. cv. 'Mesasirsa') an experiment was carried out at the research farm of Khouzestan Agricultural Research Center from 2000 to 2004. This research was conducted in the form of a split plot design in a randomized complete block, with four replications. Main plot was three row spaces (50, 60 and 70 cm) and sub plots were five seeding rates (5, 10, 15, 20, and 25 kg seed ha -1 ). Results showed that the highest seed yield obtained in the second year. Seed yield and raceme per m 2 increased with row spacing decreased. Seeding rate did not have any significant effect on pod per raceme, seed per pod and seed weight. The interaction of year and treatments on whole of traits were not significant. It was observed that correlation among seed yield and yield components was positive and significant. It was concluded that with using 15 kg seed ha -1 obtained highest seed yield due to increase in raceme per m 2 and seed weight.

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Study of energy flow in ecosystem, especially in ecosystems that which are directly managed by human, is of great importance, because energy is flow of an ecosystem. Human could increase the efficiency of energy in agricultural products by applying management.In this survey the flow of energy in apple gardens of West Azerbaijan province ecosystem was calculated by using the statistics and information derived from agriculture (government) organization and providing of questionnaire from gardens of the province in 2009.Data's related to input and output are transferred to the rates equivalent to energy consumed and produced and then average energy was calculated (rate of output to input).The rate of applied energy is 11018330Kcal/ha and rate of produced energy is 10700 Kcal/ha, also rate of energy efficiency is 0.97. The result of this survey showed that main part of energy used in this product respectively consists of irrigation, chemical fertilizer and insecticide respectively. We Could decrease energy efficiency by using drip irrigation systems, manure, insecticide, and pesticides considering to notice reduce the incidence of pests and diseases and so pace toward sustainable agriculture and decreased environmental pollution.