تاثیر مدیریت مصرف منابع پتاسیمی بر برخی ویژگی‌های کمی و کیفی گندم پائیزه

بمنظور بررسی تاثیر مدیریت مصرف منابع پتاسیمی در زراعت گندم آبی، آزمایشی در دو مزرعه (1 و 2) به ترتیب با مقادیر پتاسیم قابل دسترس 125 و412 میلی گرم بر کیلوگرم، در قالب طرح بلوک های کامل تصادفی با پنج تیمار و چهار تکرار در سال زراعی 97-1396 در ارومیه انجام شد. تیمارهای آزمایشی شامل: (1) شاهد (مصرف عناصر پایه برمبنای آزمون خاک به جز پتاسیم)؛ (2) شاهد+ مصرف پتاسیم از منبع سولفات پتاسیم قبل از کاشت؛ (3) شاهد+ مصرف 50% پتاسیم از منبع سولفات پتاسیم قبل از کاشت و 50% باقیمانده از منبع کلرورپتاسیم؛ (4) شاهد+ مصرف 50% پتاسیم از منبع سولفات‌پتاسیم قبل از کاشت و 50% باقیمانده از منبع سولوپتاس؛(5) شاهد+ مصرف50% پتاسیم از منبع سولفات پتاسیم قبل از کاشت و 50% باقیمانده از منبع سولفات پتاسیم حاوی کلات روی بودند. نتایج نشان داد که در مکان (1) پتاسیم، اثر بخشی معنی داری بر عملکرد و پروتئین دانه گندم داشت. در این مکان، تیمار پنجم در مقایسه با سایر تیمارها، باعث افزایش بیشتر عملکرد دانه، پروتئین دانه و غلظت روی دانه گندم شد. مصرف تقسیطی پتاسیم، نسبت به مصرف قبل از کاشت، میزان کارایی کود پتاسیمی را افزایش داد. درحالی که کارایی پتاسیم در تیمار دوم برابر پنج کیلوگرم بر کیلوگرم بود، در تیمارهای سوم و چهارم به شش و در تیمار پنجم به هشت کیلوگرم بر کیلوگرم بهبود یافت. در مکان (2) مصرف کودهای حاوی این عنصر بر عوامل مذکور کم تاثیر بود. بطور کلی، چنین نتیجه گیری می شود که در مکان (1)، با اعمال مصرف بهینه کودی (تیمار 3) عملکرد هکتاری گندم 1300 کیلوگرم بر هکتار نسبت به شاهد، افزایش یافت. درحالی‌که، سولفات پتاسیم حاوی کلات روی در تیمار (5)، افزایش 11 درصدی عملکرد و 60 درصدی کارایی کود را حتی نسبت به تیمار (3) موجب شد.

Effect of Potassium Fertilizers Management on Some Quantitative and Qualitative Characteristics of Wheat

Introduction: Among growth factors, proper nutrition plays an important role in increasing yield and the quality of wheat grain.  Wheat in most human societies is a strategic product and the main supplier of protein and calories needed by communities. Among growth factors, proper nutrition plays an important role in increasing yield and the quality of wheat grain. Potassium (K) is the most abundant cation in the cytoplasm of the plant and plays an important role in plant physiological functions. Its deficiency reduces the qualitative and quantitative yield of crops. It is an essential component in the basic stages of protein biosynthesis. Its deficiency results in a decrease in wheat protein. The results showed that a small amount of potassium was needed in the establishment and wintering stages of wheat and it was highly required at the later stages of plant growth and the plant requirement reached its maximum in flowering stage. This illustrates the importance of taking potassium partition. Among the low nutrient elements, Zinc (Zn) is the most important element that is clearly deficient in calcareous soils. Zinc is essential for enzymatic activities and increases the protein, carbohydrate and gluten of wheat grains.Materials and Methods: In order to investigate the effect of different sources of potassium (K) fertilizers management on some qualitative and quantitative characteristics of wheat, two experiments were conducted in two fields with lower and higher critical level of K (Kava=125 and Kava= 412mg kg1) in a randomized complete block design with five treatments and four replications in West Azarbayjan province in 201718. Treatments were as follows: T1 = control (use of all essential nutrients based on soil test except Kfertilizer) ; T2 = T1 + whole sulfate of potassium (SOP) before planting; T3 = T1 + consumption of 50% K from (SOP) before planting and 50% from muriate of potassium (MOP) in two topdressing; T4 = T1 + consumption of 50% K from SOP before planting and 50% from soluble sulfate of potassium (SSOP) in two topdressing; T5 = T1 + consumption of 50% K from SOP before planting and 50% from SSOP + ZnEDTA in two topdressing periods during the first stem elongation and wheat heading. Basal elements based on soil analysis results were as follows: at site one, containing 250 kg ha1 potassium fertilizer, 150 kg ha1 triple superphosphate and 100 kg ha1 preplanting urea fertilizer, and at site two potassium and urea similar to site one and 75 kg ha1 triple phosphate. Topdressing 120 kg urea ha1 was used in two stages i.e. the first stem node and the emergence of cluster at both locations. The size of the plots was 4 m2 and the interval was 2 m. Mihan cultivar was planted at a density of 500 seeds m2 and 180 kg ha1 using a linear grain harvesting machine. After determination of yield parameters, soil and plant composite samples were prepared and taken to the laboratory. Physical and chemical analysis of soil was performed using conventional methods at the Soil and Water Research Institute. Statistical analysis of data for different traits at two locations was performed using SAS statistical software version 9.1. Mean comparisons were undertaken using Duncan’s multiple range test at the 5% level of probability.Results and Discussion: The results of this study revealed that in the field (1), Kfertilizers increased grain yield and protein content. In this field, T5 was the best treatment in comparison with the other treatments. Split application of SSOP+ZnEDTA was the best treatment and increased potassium fertilizer efficiency (KUE). Topdressing of SSOP+ZnEDTA compared to other Kfertilizers, due to having available K and Zn, increased the kernel, grain yield, grain protein, straw weight and Zn content. While KUE in T2 was 5 kg kg1, it became 6 kg kg1 in T3 and T4 , and increased up to 8 kg kg1 in T5. However, in the field (2) due to its higher content of available K, application of Kfertilizers had no significant effects in all treatments. In the field (1), applying the optimum amount of fertilizer (T3), increased wheat yield by 1300 kg ha1 compared to the control treatment. However, T5 increased the yield and fertilizer efficiency by 11% and 60%, respectively, even with respect to T3. Therefore, split application of Kfertilizers should be conducted based on the soil analysis result.Conclusion: Topdressing of soluble sulfate potassium +ZnEDTA compared to other Kfertilizers, due to having available K, Zn and SO4, increased grain yield, protein, straw weight and Zn content, and fertilizer efficiency.