Comparison Of Yield And Nutritional Cycling Between Maize Soybean Strip Intercropping And Their Sole Cropping System Under Different K Applications

Global food security issues and the ever-growing population are continuously imposing a major challenge for agrarians to develop highly efficient cropping systems with better resource utilization.Incredibly,such challenges prompted the researchers to develop the intercropping systems in which multiple crops can be grown together.Intercropping is an intensive agricultural cropping system where two or more crops are grown simultaneously in the same area of the land.Intercropping is widely practiced for enhanced yield and nutrient acquisition advantages.In China,cereal legumes,particularly the maize-soybean intercropping system(MS_I),is a widely adopted intercropping system due to their global mean LER of 1.34.In the maize soybean intercropping system,both crops share a common-pool of resources that instigate an interspecific competition for nutrients,particularly in soybean,under large maize plants'shading stress.Under such circumstances,any variation in the ratio of macronutrients(NPK)could disturb the competitive balance between the intercropped species particularly the imbalance of potassium,which substantially affects the morphological and physiological characteristics of the soybean plant,thus reducing the final yield.Therefore,proper balanced management of potassium fertilizer could help to alleviate this problem to improve the biomass,nutrients accumulation,and crop yield of both intercropped species under MS_I.Therefore,this study was an initiative to investigate the effects of potassium treatments in maize soybean strip intercropping systems to cover the needs of balanced nutrients in maize soybean intercropping systems under the field environment.Field experiments with potassium treatments provide insights into nutrient cycling in the maize-soybean sole and intercropping system.A two-year maize-soybean intercropping field study was performed in 2018 and 2019 to assess the effects of potassium(K)fertilizer application on biomass accumulation and distribution of essential nutrients in the various plant parts(root,biomass,and seed)of sole maize(SM)and inter maize(IM),sole soybean(SS)and inter soybean(IS)under MS_I.This study employed three different treatments of K fertilizer applications:no K(T₀),inter-maize 40:sole-maize40 kg ha^-1,inter-soybean 30:sole soybean 30 kg ha^-1(T₁)and inter-maize 80:sole-maize 80 kg ha^-1,inter-soybean 60:sole soybean 60 kg ha^-1(T₂),sole-maize,and sole-soybean.The experiment was designed using the wide-narrow row planting arrangements with a row ratio of 2:2.Two rows of maize spaced 40 cm were intercropped with two rows of soybean and spaced 40 cm.The distance between the maize and soybean rows was 60 cm.The SM and SS were grown with 70-cm and 50-cm row spacing.This dissertation aims to explain the potassium effects on maize and soybean growth under MS_I and the sole cropping system.The results of the two-year study confirmed that,at V₅,R_2,and R_4,the mean PAR-transmission of soybean canopy in T₀,T₁,and T₂ have found lower than SS with mean maximum PAR-transmittance 49.81%,64.88%,and 80%while with mean lowest PAR-transmittance 35.07%,47.61%,and 65%,respectively.Our study confirmed that NPK accumulation in all maize parts by 28%,16%,and 20%grain,23%,22%,and 14%straw and 30%,17%,and 15%root,respectively,at R₆.In soybean treatments,T₂ significantly increased NPK accumulation by 23%,22%,and24%grain,16%,15%,and 12%straw and 18%,19%and 20%root,respectively.The increased accumulation of nutrient under T₂ raised the overall biomass and distribution to root,straws,and grain in maize and soybean by 11%and 18%,16%and 19%,20%,and 12%,respectively,compared to T₀.Additionally,in MS_I compared to T₀,T₂ significantly increased the mean leaf area index by 11%,stem diameter by 18%,stem breaking strength by 40%,but reduced the plant height(9%)and lodging rate by(29%)at R₄ of IS.Besides,in MS_I,the K treatments are essential to enhance the flower and pod number.The total dry matter in seed increased by 12%in T₂ compared to T₀ at R_6.Moreover,we revealed that K application also increases the rate of assimilation of CO₂,improved stomata control,and enhanced enzyme activity in soybean.On average,after two years of experiments,T₂ showed the highest yield of 1268 kg ha^-1.The T₂ intercropped maize and the soybeans showed 103%and 64%of the sole yield and attained the maximum LER of 1.66 and 1.68.Our results reveal that optimum K level application(80:60 kg ha^-1)can accelerate biomass accumulation and distribution of other essential nutrients in the plant parts of intercropped maize and soybeans.Therefore,it is immensely important to consider K application levels in developing sustainable maize-soybean intercropping systems for achieving higher productivity and land equivalent ratio(LER).Such significance interaction findings between K and intercropping can improve nitrogen fixation,nutrients uptake,total dry matter,and seed yield of maize and soybean under MS_I by employing optimum K application.I hope that the historical elements of this research enhance the need for research comparison of potassium cycling between strip intercropping and sole cropping system of maize-soybean under different K applications.