Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 25 1 2023 01 01 Photoacoustic Technique Applied to the Assessment of the Dosage of a NPK Fertilizer in Maize (Zea mays L.) به کار‌گیری روش فوتوآکوستیک برای ارزیابی مقدار کود NPK در ذرت (Zea mays L.)در این پژوهش، فعالیت فتوسنتزی تعدادی گیاه ذرت (.Zea mays L) که در غلظت‌های مختلف کود شیمیایی NPK رشد کرده بودند، ارزیابی و مقایسه شد تا معیاری مؤثر برای مصرف مشخص شود. گیاهان در شرایط گلخانه ای در محیط ضدعفونی‌شده کشت و رشد کردند تا از تامین کنترل شده مواد تغذیه ای اطمینان حاصل شود. تراکم روزنه (SD) و نمایه یا شاخص روزنه (SI) گیاهان از طریق تجزیه و تحلیل میکروگراف (micrograph analysis) برآورد شد. در حالی که سرعت پدید اکسی 225 238 24256 10.52547/jast.25.1.225 EN F. Gordillo-Delgado Applied Science Research Group for the Development of the Eco-Region (GICADE) assigned to Interdisciplinary Institute of Sciences, University of Quindío, Armenia – Quindío, Colombia. D. Zapata-Sarmiento Applied Science Research Group for the Development of the Eco-Region (GICADE) assigned to Interdisciplinary Institute of Sciences, University of Quindío, Armenia – Quindío, Colombia. A. Bedoya Applied Science Research Group for the Development of the Eco-Region (GICADE) assigned to Interdisciplinary Institute of Sciences, University of Quindío, Armenia – Quindío, Colombia. Journal Article <span><span><span>The photosynthetic activity of maize plants (Zea mays L.) grown at different concentrations of a synthetic NPK fertilizer was evaluated and compared to explore an effective dosage criterium. The plants were grown under greenhouse conditions in a sterile medium to ensure controlled provision of nutrients. The Stomatal Density (SD) and Stomatal Index (SI) of the plants were estimated through micrograph analysis; while the rate of oxygen evolution, the absorption spectral curves, and the thermal diffusivity of the plant leaves were measured using the Photoacoustic Technique. The results regarding photosynthetic activity and thermal diffusivity indicated an oscillatory pattern of behavior during the growth period, and the characteristics of these oscillations were affected by the application of the NPK fertilizer. The photoacoustic spectroscopy analysis served to show that the treatment with the highest dosage of NPK fertilizer caused a decrease in the absorption of the chlorophyll a and b. Based on the results, the proposed methodology and used technique could have practicality in monitoring quantifiable variables to evaluate the influence that a fertilizer has on plants such as maize, which allows the determination of appropriate dosage.</span></span></span> https://jast.modares.ac.ir/article_24256_e62f08e80dc2abefd52476b25ca29cee.pdf