بررسی کاربرد گوگرد و کودهای زیستی بر شاخص‌های رشدی، روند ﺟﺬب و کارایی ﻣﺼﺮف نور نخود (cicer arietinum l.)

در ﮔﯿﺎﻫﺎن زراﻋﯽ ﺷﺎﺧﺺ ﺳﻄﺢ ﺑﺮگ، روند جذب و کارایی ﻣﺼﺮف ﻧﻮر ازجمله مهم‌ترین ﺧﺼﻮﺻﯿﺎت اﮐﻮﻓﯿﺰﯾﻮﻟﻮژﯾﮑﯽ ﻣﺤﺴﻮب می‌شوند ﮐﻪ در ارزﯾﺎﺑﯽ ﻣﯿﺰان ﻧﻮر ﺟﺬب ﺷﺪه، ﺗﻮﻟﯿﺪ ﻣﺎده ﺧﺸﮏ ﻣﺆﺛﺮ است. اﯾﻦ ﭘﮋوﻫﺶ در سال زراعی 1398-1397 در مزرعه دانشکده کشاورزی دانشگاه فردوسی مشهد به‌صورت بلوک کامل تصادفی، با 10 تیمار شامل: 1 گوگرد پاستیلی (spa)، 2 گوگرد پودری (spow)، 3 spa + باکتری‌های اکسیدکننده گوگرد (sob)، 4 spa+sob + باکتری‌های آزادزی تثبیت‌کننده نیتروژن (nfb) + باکتری‌های حل‌کننده فسفات (psb) + باکتری‌های حل‌کننده پتاسیم (ksb)، 5 spow+sob، 6 spow+ssb+nfb+psb+ksb، 7 sob+nfb+psb+ksb، 8nfb+psb+ksb، 9 sob 10 شاهد در سه تکرار اجرا شد. صفات و ویژگی‌هایی از قبیل شاخص سطح برگ، ماده خشک تجمعی، مقدار نور جذب شده و کارایی مصرف نور اندازه‌گیری شد. قبل از کشت، تیمارهای گوگرد به مقدار 2500 کیلوگرم در هکتار و باکتری‌ها به مقدار پنج لیتر در هکتار در کرت‌های موردنظر به خاک اضافه شدند. نتایج نشان داد بیشترین شاخص سطح برگ در تیمار spa+ssb+nfb+psb+ksb به‌دست آمد که نسبت به شاهد 29 درصد برتری داشت. همچنین بیشترین ماده خشک تجمعی و سرعت رشد محصول در تیمار spow+ssb+nfb+psb+ksb بود که نسبت به شاهد 31 و 14 درصد افزایش داشت. حداکثر تابش جذب شده متناسب با زمان وقوع بیشترین شاخص سطح برگ نخود بود، پس از آن به‌دلیل کاهش شاخص سطح برگ تا انتهای دوره رشد کسر تابش جذب شده نور روند کاهشی در پیش گرفت. همچنین بیش‌ترین کارایی ﻣﺼﺮف ﻧﻮر در تیمار spa+ssb+nfb+psb+ksb بود (r^2=0.91**) که نسبت به شاهد 18 درصد برتری داشت. به‌طور‌کلی، نتایج نشان داد شاخص سطح برگ بالاتر سبب استفاده موثرتر از نور تابیده به کانوپی و جذب ‌شده توسط برگ‌های نخود درنتیجه افزایش کارایی مصرف نور و ماده خشک گردید.

Application of Sulfur and Biofertilizers on Growth Indices, Radiation Absorption, and Use Efficiency of Chickpea (Cicer arietinum L.)

Introduction Leaf area index, radiation absorption and radiation use efficiency are important ecophysiological characteristics, which is useful in assessing the amount of light absorbed for dry matter production. Understanding how and managing the effects of ecological factors on plant reproduction is essential for achieving sustainability in agricultural production systems. On the other hand, the use of efficient crops in utilization of resources, especially solar radiation, is one of the fundamental approaches towards achieving this goal. The purpose of this study was to investigate the effect of sulfur and biofertilizers applications on growth indices, radiation absorption and use efficiency of chickpea.Materials and Methods In order to determine the growth indices, radiation absorption, and radiation use efficiency (RUE) of chickpea, a field experiment was conducted in 2019 at the Agricultural Research Station of Ferdowsi University of Mashhad based on a completely randomized block design with ten treatments and three replications. The experimental treatments including: 1Spa, 2Spo, 3Spa+SOB, 4Spa+SOB+NFB+PSB+KSB, 5Spo+SOB 6Spo+SOB+NFB+PSB+KSB, 7SOB+NFB+PSB+KSB, 8 NFB+PSB+KSB, 9SOB and 10Control. Sampling was started 20 days after planting by taking six destructive samples. The plant was sampled two weekly intervals to determine the growth parameters of chickpea including leaf area index (LAI), dry matter accumulation (DM), crop growth rate (CGR) and radiation use efficiency (RUE). For calculations of radiation use efficiency, it was necessary to estimate daily LAI and daily absorbed, the RUE was calculated based on g MJ1 through the slope of a linear regression between total dry weight accumulations (g m2), and cumulative absorbed the total daily solar radiation.Results and Discussion The results showed that the highest leaf area index was obtained in Spa + SOB + NFB + PSB + KSB and Spo + SOB + NFB + PSB + KSB treatment which was 29 and 26 %  more than control, respectively. The application of pa + SOB and Spo + SOB treatment, which increased 12 and 7 % compared to control, respectively. In this study, sulfur was more important than other fertilizer treatments. The highest dry matter accumulation was obtained in Spo + SOB + NFB + PSB + KSB and Spa + SOB + NFB + PSB + KSB treatment which was 31 and 27% more than control. SOB and NFB + PSB + KSB treatments had the lowest amount of dry matter after control. The results showed that the highest crop growth rate observed in Spo + SOB + NFB + PSB + KSB treatment, which increased by 14% compared to control. The maximum absorbed radiation coincided with the highest leaf area index of chickpea. Then, Due to the decrease in leaf area index until the end of the growth period, the absorbed fraction of light absorbed a decreasing trend. The estimated RUE levels in different treatments were significantly different (P≤0.01). The highest radiation use efficiency was in Spa + SOB + NFB + PSB + KSB treatment (R2 = 0.91**) which was 18% more than control. Also, increasing leaf area can increase the plant’s photosynthetic potential and increase dry matter, at finally to increased RUE.Conclusion:The results showed that treatments (Spo + SOB + NFB + PSB + KSB) and (Spa + SOB + NFB + PSB + KSB) with higher leaf area index resulted in more efficient use of canopy light absorbed by chickpea leaves as a result of increased radiation and dry matter efficiency. High slope radiation use efficiency indicates the high efficiency of a plant using sunlight and converting it to dry matter. Giving attention to a more frequent application of biological fertilizers could be considered as an essential agroecological approach, which results in healthier soil and water resources.