بررسی تعاملات بین گونه‌ای بخش زیرزمینی در کشت مخلوط گیاه سویا (glycine max (l.) merrill) و دان‌سیاه (guizotia abyssinica cass.)

ارﺗﺒﺎط ﺑﯿﻦ ﮔﻮﻧﻪای ﮔﯿﺎﻫﺎن در ﺑﺨﺶ زﯾﺮزﻣﯿﻨﯽ ﯾﮏ ﻣﻮﺿﻮع ﮐﻠﯿﺪی ﺟﻬﺖ ﺷﻨﺎﺳﺎﯾﯽ ﺳﺎز و ﮐﺎر رﻗﺎﺑﺖ و ﺑﻬﺮهوری در ﮐﺸﺖ ﻣﺨﻠﻮط اﺳﺖ. ﺑﻨﺎﺑﺮاﯾﻦ، ﺑﻪ ﻣﻨﻈﻮر ارزﯾﺎﺑﯽ ﺗﻌﺎﻣﻼت ﺑﺨﺶ زﯾﺮزﻣﯿﻨﯽ در ﻧﺴﺒﺖﻫﺎی ﻣﺨﺘﻠﻒ ﮐﺸﺖ ﻣﺨﻠﻮط ﮔﯿﺎه دانﺳﯿﺎه guizotia abyssinica cass و ﺳﻮﯾﺎ glycine max l. merrill آزﻣﺎﯾﺸﯽ در دو ﺳﺎل زراﻋﯽ 97- 1396و 98- 1397 و ﺑﻪﺻﻮرت ﻃﺮح ﺑﻠﻮکﻫﺎی ﮐﺎﻣﻞ ﺗﺼﺎدﻓﯽ ﺑﺎ ﭼﻬﺎر ﺗﮑﺮار در ﻣﺰرﻋﻪ ﺗﺤﻘﯿﻘﺎﺗﯽ داﻧﺸﮕﺎه ﻋﻠﻮم ﮐﺸﺎورزی و ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ ﺳﺎری اﺟﺮا ﺷﺪ. ﺗﯿﻤﺎرﻫﺎی آزﻣﺎﯾﺶ ﺷﺎﻣﻞ ﻧﺴﺒﺖﻫﺎی ﮐﺎﺷﺖ 75:25 ،50:50 ،25:75 ،0:100 و 100:0 ﺑﻪ ﺗﺮﺗﯿﺐ دانﺳﯿﺎه- ﺳﻮﯾﺎ ﺑﻪروش ﺟﺎﯾﮕﺰﯾﻨﯽ ﺑﻮدﻧﺪ. ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ ﺑﻪدﺳﺖ آﻣﺪه، ﻧﺴﺒﺖﻫﺎی ﻣﺨﺘﻠﻒ ﮐﺎﺷﺖ اﺛﺮ ﻣﻌﻨﯽ داری ﺑﺮ درﺻﺪ ﻧﯿﺘﺮوژن ﺣﺎﺻﻞ از ﺗﺜﺒﯿﺖ ﺑﯿﻮﻟﻮژﯾﮑﯽ، ﻣﯿﺰان ﻓﻌﺎﻟﯿﺖ ﮐﻞ ﻣﯿﮑﺮوﺑﯽ ﺧﺎک، ﻓﻌﺎﻟﯿﺖ رﯾﺸﻪ و ﻣﻘﺪار ﻓﻨﻮل و ﻓﻼوﻧﻮﺋﯿﺪ ﻣﻮﺟﻮد در ﻋﺼﺎره رﯾﺸﻪ ﮔﯿﺎه دانﺳﯿﺎه داﺷﺘﻨﺪ. ﺗﻤﺎﻣﯽ ﻧﺴﺒﺖ ﻫﺎی ﻣﺨﺘﻠﻒ ﮐﺸﺖ ﻣﺨﻠﻮط در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﺗﯿﻤﺎر ﮐﺸﺖ ﺧﺎﻟﺺ دارای ﻗﺎﺑﻠﯿﺖ ﺗﺜﺒﯿﺖ ﺑﯿﻮﻟﻮژﯾﮑﯽ ﻧﯿﺘﺮوژن ﺑﯿﺸﺘﺮی ﺑﻮدﻧﺪ. ﺑﯿﺸﺘﺮﯾﻦ اﻓﺰاﯾﺶ درﺻﺪ ﻧﯿﺘﺮوژن ﺣﺎﺻﻞ از ﺗﺜﺒﯿﺖ ﺑﯿﻮﻟﻮژﯾﮑﯽ در ﻫﺮ دو ﺳﺎل زراﻋﯽ ﻣﺮﺑﻮط ﺑﻪ ﻣﺮﺣﻠﻪ 90 روز ﭘﺲ از ﮐﺎﺷﺖ ﺑﻮد. در اﯾﻦ ﻣﺮﺣﻠﻪ ﻧﺴﺒﺖ ﮐﺎﺷﺖ 50:50 ﺑﻪﺗﺮﺗﯿﺐ در ﺳﺎلﻫﺎی ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﺑﺎ ﻣﯿﺎﻧﮕﯿﻦ 85/46 و 91/58 درﺻﺪ ﺑﯿﺸﺘﺮﯾﻦ درﺻﺪ ﻧﯿﺘﺮوژن ﺣﺎﺻﻞ از ﺗﺜﺒﯿﺖ ﺑﯿﻮﻟﻮژﯾﮑﯽ را در اﺧﺘﯿﺎر داﺷﺖ. ﻋﻼوهﺑﺮ ﻣﻄﺎﻟﺐ ﻣﺬﮐﻮر ﻣﺠﻤﻮع ﻓﻌﺎﻟﯿﺖ ﮐﻞ ﻣﯿﮑﺮوﺑﯽ ﺧﺎک در ﻧﺴﺒﺖﻫﺎی ﻣﺨﺘﻠﻒ ﮐﺸﺖ ﻣﺨﻠﻮط ﺑﯿﺸﺘﺮ از ﮐﺸﺖ ﺧﺎﻟﺺ ﮔﯿﺎﻫﺎن ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﺑﻮد و در ﻣﺮﺣﻠﻪ 60 روز ﭘﺲ از ﮐﺎﺷﺖ ﻧﺴﺒﺖ ﮐﺎﺷﺖ 50:50 ﺑﺎ ﻣﯿﺎﻧﮕﯿﻦ 34/56 1-μg.fluorecsceine.g-1.h دارای ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان ﻓﻌﺎﻟﯿﺖ ﻣﯿﮑﺮوﺑﯽ ﺧﺎک ﺑﻮد. ﻫﻤﭽﻨﯿﻦ ﮔﯿﺎه دان ﺳﯿﺎه در ﻧﺴﺒﺖ ﻫﺎی ﻣﺨﺘﻠﻒ ﮐﺸﺖ ﻣﺨﻠﻮط ﺿﻤﻦ اﻓﺰاﯾﺶ ﻓﻌﺎﻟﯿﺖ رﯾﺸﻪ از ﻣﯿﺰان ﻓﻨﻞ و ﻓﻼوﻧﻮﺋﯿﺪ ﺑﯿﺸﺘﺮی ﻧﯿﺰ در ﻋﺼﺎره رﯾﺸﻪ ﺑﺮﺧﻮردار ﺑﻮد. ﻧﺴﺒﺖﻫﺎی ﻣﺨﺘﻠﻒ ﮐﺸﺖ ﻣﺨﻠﻮط ﻧﯿﺰ از ﻧﻈﺮ ﺗﻮﻟﯿﺪ ﺗﺮﮐﯿﺒﺎت ﺛﺎﻧﻮﯾﻪ ﻣﻮﻓﻖﺗﺮ از ﮐﺸﺖ ﺧﺎﻟﺺ ﮔﯿﺎه دانﺳﯿﺎه ﻋﻤﻞ ﮐﺮدﻧﺪ. در ﻧﻬﺎﯾﺖ، اﻓﺰاﯾﺶ ﻣﻌﻨ ﯽداری درﺻﺪ ﻧﯿﺘﺮوژن ﺣﺎﺻﻞ از ﺗﺜﺒﯿﺖ ﺑﯿﻮﻟﻮژﯾﮑﯽ و ﻋﻼوهﺑﺮ آن ﻓﻌﺎﻟﯿﺖ ﺑﯿﺸﺘﺮ رﯾﺸﻪ ﮔﯿﺎه دانﺳﯿﺎه ﺑﻪﻋﻨﻮان ﮔﯿﺎه ﻣﮑﻤﻞ در ﻧﺴﺒﺖﻫﺎی ﮐﺸﺖ ﻣﺨﻠﻮط ﻣﯽﺗﻮاﻧﺪ ﻧﻘﺶ ﻣﻬﻤﯽ در ﭘﻮﯾﺎﯾﯽ ﺗﻌﺎﻣﻼت ﺑﯿﻦﮔﻮﻧﻪای در ﺑﺨﺶ زﯾﺮزﻣﯿﻨﯽ در اﻟﮕﻮی ﮐﺸﺖ ﻣﺨﻠﻮط داﺷﺘﻪ ﺑﺎﺷﺪ.

investigation of below-ground interspecific interaction in the intercropping culture of soybean (glycine max (l.) merrill) and niger (guizotia abyssinica cass.)

introduction most research on intercropping cultivation in the past has focused on seed yield and yield components, and less attention has been paid to below-ground interaction processes. however, the connection of plants in the below-ground sector is a vital issue in identifying the mechanism of competition and productivity in intercropping cultivation. meanwhile, the selection of a legume plant due to the biological nitrogen fixation bnf increases the productivity in intercropping cultivation. however, the bnf by the legume component can be affected by the component crop in intercropping cultivation. therefore, creating the optimum conditions for the bnf in planting ratios plays an essential role in the dynamics of inter-species interaction. therefore, this study aimed to evaluate the interactions of the below-ground sector and the percentage of nitrogen derived from the atmosphere in different ratios of intercropping cultivation.material and methodsa field experiment was conducted for two years 2018-19 at the research farm of sari agricultural science and natural resources university, iran 33º, 36ʹ n, 53º, 03ʹ e with 43 m altitude . the experimental design was a randomized complete block with four replications. the experimental treatment was 75% soybean + 25% niger, 50% soybean + 50% niger, 25% soybean+75% niger based on the replacement method and monoculture. for example, a 25:75 combination consisted of three rows of planting a soybean and one row of niger and vice versa in the 75:25 combinations. the 50:50 also included planting two rows of each of the studied plants. this study investigated the percentage of nitrogen derived from the atmosphere, nitrogen yield, total enzymatic activity of the soil, and root activity in different planting ratios.result and discussionthe percentage of nitrogen derived from the atmosphere ndfa in all different planting ratios was higher than a single soybean crop. this trend continued until it reached 90 days after planting. at 75 and 90 days after planting, the highest ndfa has related to 50:50 and 75:25 planting ratios in both cultivation years. also, the yield of ndfa was higher than expected in planting ratios, and its value increased further as it approached the final stages of growth. in addition to the above, the total microbial activity of soil in different ratios of intercropping cultivation was higher than the monoculture of the studied plants. its amount in 50:50 planting ratio was 16.38 and 31.69% higher than monoculture soybean 0: 100 and niger 0: 100 at 60 days after planting, respectively. the most increased total microbial activity of the ground in niger and soybean plants in the middle and late stages of growth was observed at a depth of 0-20 and 10-30 cm, respectively. also, niger plant in different ratios of intercropping cultivation, while increasing root activity, have a higher number of secondary compounds in root extract. in general, the increase in root activity in the late stages of growth was accompanied by a decrease in the number of rows of niger plants, especially in the planting ratio of 75:25. also, the total phenol and flavonoids in the niger root extract increased to 105 days after planting and then decreased. thus, in general, different ratios of intercropping cultivation were more successful in producing secondary compounds than the monoculture of niger.conclusionincreasing the significance of nitrogen derived from the atmosphere and the other activity of niger root as a complementary plant in intercropping cultivation ratios can play an essential role in the dynamics of underground sector interactions intercropping cultivation patterns. in addition to the above results and based on the total microbial activity of the soil, the complementary structure of niger and soybean root in intercropping cultivation can affect the ability of interspecific competition in intercropping cultivation by distinguishing ecological niche even in a short period.