نوع مقاله : مقالات پژوهشی
نویسندگان
1 دانشگاه فردوسی مشهد
2 دانشگاه آزاد اسلامی واحد کرج
چکیده
بازدارندههای نیتراتزایی ترکیباتی هستند که اکسایش زیستی آمونیوم به نیتریت را به تأخیر میاندازند و بدین ترتیب تجمع نیترات در خاک را کاهش میدهند. این پژوهش به منظور بررسی تاثیر بازدارندههای نیتراتزایی، 3 و 4-دی متیل پیرازول فسفات (DMPP)، دیسیاندیآمید (DCD) و پودر درمنه (ART)، در حضور منابع مختلف نیتروژن، بر تغییرات نیتروژن معدنی خاک، میزان نیتروژن گیاه، تجمع نیترات در برگ گیاه و برخی از خصوصیات رشدی کاهو، در قالب طرح پایه کاملا تصادفی با آرایش فاکتوریل در سه تکرار انجام شد. نتایج نشان داد که بازدارندههای نیتراتزایی در حضور منابع مختلف کود نیتروژن موجب کاهش غلظت نیتروژن نیتراتی و افزایش نیتروژن آمونیومی خاک شدند. همچنین غلظت نیتروژن در گیاه در حضور بازدارندههای نیتراتزایی افزایش یافت. کاربرد بازدارندههای نیتراتزایی موجب کاهش غلظت نیترات در برگ گیاه شد. همینطور استفاده از بازدارندههای نیتراتزایی بر خصوصیات رشدی گیاه نیز تاثیر گذاشتند. به طور کلی بهترین کارکرد بازدارندههای نیتراتزایی در حضور منبع کود اوره مشاهده شد و بازدارنده نیتراتزایی ART دارای بیشترین تاثیر و پس از آن بازدارندههای DMPP و DCD دارای بهترین کارکرد بودند.
کلیدواژهها
عنوان مقاله [English]
Effects of Artificial and Natural Nitrification Inhibitors on Plant Growth Characteristics and Nitrate Uptake by Lettuce
نویسندگان [English]
- S. Sangsefidi 1
- A. Lakzian 1
- A.R. Astaraei 1
- M. Banayan 1
- M. Mazhari 2
1 Ferdowsi University of Mashhad
2 Karaj
چکیده [English]
Introduction: Nitrification inhibitors are compounds that slow biological oxidation of ammonium to nitrite by reducing the activity of Nitrosomonas bacteria, without affecting the subsequent oxidation of nitrite to nitrate, either by inhibiting or interfering with the metabolism of nitrifying bacteria. The first step of nitrification is inhibited (i.e., the activity of Nitrosomonas bacteria) by the nitrification inhibitors, while the second step for oxidation of nitrite (NO2-) to nitrate (NO3-) is normally not influenced. In recent years, numerous compounds have been identified and used as nitrification inhibitors, particularly in agricultural soils. They are chemical compounds that slow the nitrification of ammonia, ammonium-containing, or urea-containing fertilizers, which are applied to soil as fertilizers, such as thiourea, carbon Sulfide, thioethers, ethylene, 3-amino-1,2,4-triazole, dicyandiamide (DCD), 2-amino-4-chloro-6-methyl pyrimidine, ammonium thiosulphate and 3,4-dimethylpyrazole phosphate (DMPP). These inhibitors reduce the losses of nitrogen in soil. Some nitrification inhibitors are very effective in the efficiency of the nitrogen fertilizers. Recently, a lot of attention has been paid to nitrification inhibitors from an environmental point of view. Some nitrification inhibitors are very expensive and not economically suitable for land application. Nonetheless, many farmers and researchers apply these compounds for many purposes in some specific places. On the other hand, there are many inexpensive natural nitrification inhibitors such as Artemisia powder, Karanj (Pongamia glabra), neem (Azadrachta indica) and tea (Camellia sinensis) waste which can compete with the artificial nitrification inhibitors such as 3, 4-dimethylpyrazole phosphate (DMPP), dicyandiamide (DCD) which are very common nitrification inhibitors. Applying 1.5 kg ha-1 of DMPP is sufficient to achieve optimal nitrification inhibition. 4-dimethylpyrazole phosphate (DMPP) can significantly shrink nitrate (NO3) leaching. 4-dimethylpyrazole phosphate (DMPP) may also decrease N2O emission and the use of DMPP-containing fertilizers can improve yield. The aim of this study was to compare the effect of 3, 4-dimethylpyrazole phosphate (DMPP), Dicyandiamide (DCD) and powder Artemisia (ART) at the presence of Urea, cow manure and Vermicompost.
Material and Methods: Effects of three nitrification inhibitors, (3, 4-dimethylpyrazole phosphate (DMPP), Dicyandiamide (DCD) and powder Artemisia (ART)) at the presence of three nitrogen sources (Urea, cow manure and Vermicompost) were investigated in a calcareous soil under lettuce cultivation in a greenhouse condition. The changes in the soil mineral nitrogen (nitrate and ammonium), plant nitrogen, nitrate accumulation in leaves and some of growth characteristics such as lettuce chlorophyll content, leaf area index, leaf dry weight and root dry weight were determined. The experiment was carried out in a completely randomized factorial design with three replications. Soil ammonium and nitrate concentration were measured during the experiment. The growth characteristics of lettuce were also measured at the end of experiment. Nitrogen and nitrate contents were also determined in lettuce leaves.
Results and Discussion: The results of the experiment showed that soil nitrate decreased at the presence of three nitrification inhibitors but the soil nitrogen ammonium increased significantly. Application of nitrification inhibitors also reduced the concentration of nitrate in the lettuce leaves during two harvesting times. Moreover, the nitrogen concentration in the plant increased at the presence of nitrification inhibitors. The application of nitrification inhibitors influenced the plant growth characteristics and changed the lettuce growth characteristics. Chlorophyll content increased significantly in lettuce leaves. Leaf area index, leaf and root dry weight of lettuce increased notably when 3, 4-dimethylpyrazole phosphate (DMPP) and powder Artemisia (ART) nitrification inhibitors were applied to the soil samples. These growth characteristics, however, reduced significantly when dicyandiamide nitrification inhibitors was applied to the soil samples. In addition, the symptoms of toxicity were observed in lettuce plant when dicyandiamide nitrification inhibitors were applied to the soil samples. In general, the highest efficiency of nitrification inhibitors was recorded at the presence of urea fertilizer source and the greatest efficiency was observed initially for powder Artemisia (ART) and then for 3, 4-dimethylpyrazole phosphate (DMPP) and dicyandiamide, respectively, when urea fertilizer was applied to the soil samples. There was a positive correlation between soil nitrogen content and plant nitrate in the first and second harvest. The correlation between soil ammonium and plant nitrate (in the first and second harvest) and soil nitrate was negative.
کلیدواژهها [English]
- Nitrification inhibitors
- Lettuce
- Urea
- Cow manure
- Vermicompost
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