بررسي تأثير كاربرد سطوح مختلف كود آلي و اوره بر تجمع نيترات و برخي صفات فيزيولوژيك اسفناج

The Effects of Urea and Organic Fertilizers on Nitrate Accumulation and Some Physiological Traits of Spinach (Spinacia oleraceae)

استفاده از روش‌هايي كه موجب كاهش تجمع نيترات در سبزي‌هاي برگي شود و همچنين ارزش غذايي آن‌ها را حفظ نمايد حائز اهميت مي‌باشد. به‌‌منظور بررسي تأثير سطوح مختلف (صفر، 10، 20 و 30 درصد حجمي) كودهاي آلي (دامي، ورمي‌كمپوست و مرغي) و كود اوره (102، 204 و 306 كيلوگرم در هكتار) بر تجمع نيترات و برخي خصوصيات رشدي و فيزيولوژيك اسفناج آزمايشي در قالب طرح بلوك‌هاي كامل تصادفي با سه تكرار در دانشگاه شهيد مدني آذربايجان در سال 1395 اجرا شد. نتايج نشان داد بالاترين مقادير نيترات در زمان‌هاي صبح و عصر در تيمار 306 كيلوگرم در هكتار كود اوره مشاهده شد. طول برگ تحت تأثير تيمارهاي 20 و 30 درصد كود مرغي قرار گرفت. بيشترين ميزان قند محلول و وزن ‌تر و خشك ريشه در تيمارهاي 10 و 20 درصد كود دامي مشاهده شد. تيمارهاي 20 و 30 درصد كود ورمي‌كمپوست و كود دامي و تيمار 30 درصد كود مرغي موجب افزايش وزن تر و خشك برگ شد. تمامي سطوح كودهاي ورمي‌كمپوست، دامي و مرغي موجب افزايش محتواي پتاسيم شد. بيشترين ميزان آهن، روي و محتواي فنل كل نمونه‌ها در تمامي سطوح كود دامي و ورمي‌كمپوست ملاحظه گرديد. با توجه به پاسخ مثبت گياه اسفناج به كاربرد كودهاي آلي به نظر مي‌آيد كه كاربرد اين كودها ضمن كاهش مصرف كودهاي شيميايي و كاهش اثرات سوء زيست‌محيطي آن‌ها، روش مناسبي براي توليد سالم و پايدار سبزي‌ها باشد.

Background and Objectives Management of organic fertilizers utilization is of the main components of organic crops production which can greatly affect the yield and quality of plants. Due to the short time course of leafy vegetables production, farmers commonly use nitrogenous chemical fertilizers for the nourishment of plants. The results are huge nitrate accumulation on the edible parts of the vegetables and hence the deteriorating health side effects. So, owing to the necessity of vegetables in the daily diet, resorting to the production methods to reduce the nitrate accumulation and even preserve and add up the nutritious quality of vegetables is of great interest. Materials and Methods This experiment was conducted to evaluate the effects of deferent levels of cow, vermicompost and poultry organic fertilizers (0, 10, 20 and 30% in volume) and urea (102, 204 and 306 g Kg/ha) on nitrate accumulation (morning and evening sampling time) and Fe2+, Zn2+ and potassium concentration and total phenolic content as well as on some growth characteristics of spinach as RBCD design with three replications in Azarbaijan Shahid Madani University during 2016. Results The results revealed that the highest morning nitrate accumulation (2435 mg Kg-1 Fwt) and that of evening (2052 mg Kg-1 Fwt) belonged to 306 kg/ha urea treatment. Leaf length was effected by 20% (3.6 cm) and 30% (8.8 cm) of poultry manure. The highest data for TSS and root fresh and dry weight were attained by 10 and 20% of cow manure. The treatments, 20 and 30% of vermicompost, cow manure and 30% poultry manure increased the leaves fresh and dry weight. All levels of poultry and vermicompost manure had positive effects on potassium content. The highest amounts of Fe2+, Zn2+ and total phenolic content were recorded in 10, 20 and 30% cow manure and vermicompost manure Discussion Nitrate accumulation in vegetables is dependent upon several intrinsic and extrinsic factors of which, mineral nutrition is of crucial importance. Considering the positive response of spinach to the application of organic fertilizers, it seems that using these organic fertilizers would greatly decline the chemical fertilizers input as well as reduces the environmental side effects of chemicals and virtually goes to the production of safe organic products under sustainable production systems.