Effects Of Different Fertilizers On Growth And Development,Nitrogen Metabolism And Carbon Emissions Of Maize Peanut Intercropping Crops

Maize and peanut are important food crops and oil crops in Liaoning Province and Northeast China respectively.However,Due to long-time continuous cropping and improper fertilization,soil fertility declines and fertilizer utilization rate are low,which destroys the self-regulation ability of farmland ecosystems and threatens the safe production of grain and oil.As an emerging fertilizer,slow control fertilizer can reduce fertilizer consumption and improve fertilizer utilization rate,but the role of slow control fertilizer in intercropping has been less studied.The experiment was conducted in the Northeast Observation Experimental Station of crop physiology,ecology and farming of the Ministry of agriculture（Shenyang Agricultural University）from 2020 to 2021.Five treatments were set up:no fertilization（K0）,conventional fertilizer（K1）,slow and controlled fertilizer+peanut reduced fertilizer（K2）,monoculture Maize（SM）and monoculture peanut（SP）.The effects of different fertilizer treatments on the morphology,dry matter accumulation,nitrogen metabolism and enzyme activity of intercropping crops were studied Nitrogen absorption and utilization,greenhouse gas emissions and yield.The comprehensive effects of different fertilizer treatments on field production were analyzed to provide a theoretical basis for innovating the intercropping mode of cornflower.The main results are as follows:1.Under different fertilizer treatments,the growth and development of intercropping maize with slow and controlled fertilizer was better.The stem diameter,dry matter accumulation and maximum dry matter accumulation rate of Maize under K2 and K1treatments were significantly higher than those under monoculture and no fertilization treatments;Under different fertilizer treatments,the main stem height,lateral branch length,dry matter accumulation and maximum dry matter accumulation rate of each organ of peanut were SP>K1>K2>K0,and the middle row>side row.2.Under different fertilizer treatments,the activities of nitrogen metabolism enzymes in maize were K2>K1>K0,side row>middle row and monoculture;the activity of nitrogen metabolizing enzyme in peanut was SP>K1>K2>K0,middle row>side row.Both slow and controlled fertilizer application and intercropping increased the activity of nitrogen metabolizing enzyme in maize leaves,while intercropping and fertilizer reduction decreased the activity of nitrogen metabolizing enzyme in peanut.3.Under different fertilizer treatments,the nitrogen content of maize organs was K2>K1>K0,side row>middle row and monoculture;The nitrogen content of peanut organs showed SP>K2>K1>K0,middle row>side row.The application of slow control fertilizer and intercropping can increase the nitrogen content of maize organs and the whole plant,and the transfer of nitrogen to the ear is increased.Intercropping and fertilizer reduction reduced the nitrogen content of peanut organs and whole plant.Intercropping is beneficial for crops to absorb nitrogen in 0～40 cm soil layer.4.Maize intercropping and slow fertilizer application are beneficial to reduce greenhouse gas emissions.No fertilization increased the average emission flux and cumulative emission of CO₂ in the field.The cumulative emission of CO₂ in peanut was K0P>K1P>K2P>SP,and the cumulative emission of CO₂ in maize was K0M>SM>K1M>K2M.CH₄ showed absorption sink in intercropping system.The cumulative CH₄ emission of peanut was the lowest in K1P treatment,and that of maize was SM>K0M>K1M>K2M;The cumulative N₂O emissions of peanut are SP>K1P>K2P>K0P,and the cumulative N₂O emissions of corn are SM>K1M>K2M>K0M.5.Under different fertilizer treatments,maize intercropping can improve the fertilizer utilization rate of maize and reduce the fertilizer utilization rate of peanut.The application of slow and controlled fertilizer is beneficial to improve the nitrogen use efficiency,nitrogen partial productivity and Nitrogen Agronomic use efficiency of maize.Reducing fertilizer application increased the partial productivity of nitrogen fertilizer in intercropping peanut,and reduced the nitrogen use efficiency and Nitrogen Agronomic use efficiency.6.Maize intercropping increased the yield of compound population.Under K2 treatment,the ear length,ear diameter and grain number per ear of maize were higher than those of other treatments,and the side row of each treatment was higher than that of the middle row;Intercropping reduced the number of pods per plant,100 fruit weight and 100 kernel weight of peanut,and the middle row was higher than the side row.The land equivalent ratio of K1and K2 treatment is greater than 1,indicating that intercropping has advantages.The yield of Maize in slow and controlled fertilizer treatment was higher than that in other treatments,and the reduction of fertilizer application reduced the yield of intercropping flowers.Conclusion:the intercropping of cornflower has obvious side effect and significantly reduces the total amount of greenhouse gas emissions;The application of slow and controlled fertilizer in intercropping maize significantly increased the plant height,stem diameter,organ dry matter accumulation,organ nitrogen accumulation and yield of side row maize,and reduced greenhouse gas emissions;Intercropping peanut fertilizer intercropping significantly reduced the main stem height,lateral branch length,organ dry matter accumulation,organ nitrogen accumulation,and the total emission of CO₂ and NO₂.