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Showing 3 results for Organic Matter
Volume 4, Issue 3 (9-2015)
Abstract
Application of antagonistic agents in the rhizosphere of plants is an important approach in control of soil-borne pathogens. Establishment and persistence of biocontrol agents in the soil is a major concern in biological control. This study aimed to determine the effect of plant debris of oak forests on activity of Pseudomonas fluorescens and Trichoderma vierns against Meloidogyne javanica in tomato in green house conditions. In different treatments, both or one of the bioagents were applied to the soil inoculated with M. javanica and amended or unamended with oak plant debris. Based on the results, the growth–related factors of tomato improved in those treatments, in which plant debris were mixed with the soil. In case of nematode-related factors, the number of galls on roots decreased significantly in pots amended with plant debris. Maximum reduction in reproduction factor was observed in treatments with one or both of the biocontrol agents. In comparison to unamended treatments, the rate of reduction in root gall was 56.3% for treatments receiving T. virens and maximum increase in dry weight of root was observed in soils treated with P. fluorescens or T. virens, 68.2% and 56.1%, respectively.
Omid Shayanfar, Mehdi Ghodrati Shojaei, Siamak Behzadi,
Volume 12, Issue 2 (4-2023)
Abstract
The purpose of this research is to investigate the relative importance of Avicennia marina organic matter in the feeding of Ilisha melastoma fish in the Mangrove Biosphere Reserve; It was stable isotope approach. Three primary food sources including mangrove tree leaves, microphytobenthos and suspended organic particles were analyzed isotopically. The samples of primary food sources and fish are converted into pure and simple gases such as CO, CO2 and N2 after minimizing the size and turning into powder. Then the identified isotope ratios are compared with a measured standard and the exact amount of isotope formed in the sample is obtained. In this research, sampling was done seasonally in August in the summer season and February in the winter season of 2019 in the mangrove ecosystems of Bandar Khmer, Hormozgan province.In the summer season, the average stable carbon isotope of primary food sources fluctuated from -28.07 units per thousand for mangrove leaves to -13.58 units per thousand for microphytobenthos.This average in the winter season was obtained from -28.05 units per thousand for mangrove leaves to -13.54 units per thousand for microphytobenthos.The average stable nitrogen isotope of primary food sources in the summer season fluctuated from 1.44 units per thousand for microphytobenthos to 10.72 units per thousand for suspended organic particles.The results of this research showed that in the summer season, suspended organic particles with 63% and in the winter season, microphytobenthos with 45% play the most important role in providing the food needed by the small shemsk fish.
Volume 27, Issue 1 (12-2025)
Abstract
One of the most important environmental hazards that has created many challenges in recent years is the development of inorganic farming and the excessive use of chemical inputs in the agricultural sector. The purpose of this research was to evaluate the role of extension and educational programs in the development of Organic Farming (OF) in vegetable and summer crops in Lorestan Province, Iran. This research was quantitative in nature and applied research in terms of purpose. The population consisted of vegetable and summer crop farmers in Lorestan (N= 3,500). The sample size was determined based on Morgan table (n= 384). In order to determine the validity and reliability of the questionnaire, a panel of experts and a Ө coefficient of 0.85 were used. According to the results, the dimensions of OF were not optimal. From the ecological, health, fairness, care, social-cultural and production-economic aspects, there was a significant difference (P< 1%) between the current and the desired conditions. Farmers who participated in the programs of extension and educational class, field day, extension exhibitions, farmer field school, scientific seminars and demonstration farms had a significant difference (P< 1%) in all aspects of OF with those who did not participate. The most important factors affecting the development of OF dimensions included: (1) Development of technical knowledge and empowerment of farmers in OF, (2) Government support for OF methods and development of its dimensions, (3) Application of legal instruments for the development of OF, and (4) Changing consumers' views towards the use of organic foods.
