Effects Of No-tillage And Irrigation Quato On Water Competition And Complementation In Maize Pea Intercropping

Intercropping has been widely used for its advantages of farmland biodiversity,full use of resources,more yield than single cropping in limited land,and biological nitrogen fixation to reduce fertilizer usage.However,limited by resource scarcity,the application of this model in arid areas is facing great challenges,and the theory and technology of intercropping water use efficiency are in urgent need of development.In view of the remarkable water-saving effect of plastic film mulching,no-tillage and limited irrigation techniques in single cropping,it is of great theoretical and practical value to apply the three techniques to intercropping and explore their water use characteristics and mechanism.In this study,corn pea intercropping was taken as the research object,and the response law of corn pea and pea to water competition and complementary utilization was studied under different tillage measures(no-tillage RT,traditional tillage CT)and different irrigation levels(local customary irrigation I2,20 % less irrigation level I1),revealing the mechanism of no-tillage and less irrigation regulating intercropping yield and water use efficiency,providing theoretical and practical basis for integrated utilization of no-tillage and limited irrigation technology in intercropping.The main findings are as follows:1.No-tillage has the advantages of weakening the competition of pea on soil water in corn belt during symbiotic period,enhancing the compensation and utilization of soil water in corn belt after pea harvest,thus obtaining the yield-increasing effect,and at the same time,irrigation reduction will reduce the competition of water among crops.Before sowing corn and during harvesting corn peas,the water transport amount of corn belt to corresponding pea belt under I2 and I1 no-tillage treatment was 83.2 mm and 52.3 mm,respectively.CT migration was 109 mm and 73.2 mm respectively.NT decreased by 13.1 %,18.9 %,25.1 % and 29.4 % compared with CT respectively.After harvesting peas,the pea belt treated by NT at I2 and I1 was transported to corn belt by 96 mm and 75.3 mm respectively.CT treatment was 78.9 mm and 63.2 mm respectively.NT was 13.6 % and 19.1 % higher than CT.2.Compared with the local irrigation level,no-tillage irrigation reduction treatment without intercropping significantly reduced the ineffective evaporation of soil by 34 mm,the water consumption in the whole growth period decreased by 111 mm,and the water consumption structure decreased by 17.8 %,which improved the water use.When the irrigation level is the same,no-tillage treatment has no significant effect on the evaporation among trees in the whole growth period of single-cropping pea and single-cropping corn.At I2 and I1 irrigation levels,the evaporation of CT monoculture peas was 5.1 % and 6.3 % higher than NT monoculture peas.The water consumption structure(E/ ET)of CT intercropping was higher than NT by 8.3 % and 2.95 % at I2 and I1 irrigation levels in intercropping mode.Compared with single cropping,CT-treated intercropping was 14.3 % and 29.2 % lower than single cropping when I2 and I1 were irrigated,and NT-treated intercropping was 10 % and 22.9 % lower than single cropping.3.No-tillage irrigation reduction is beneficial to reduce the competitiveness of peas relative to corn before harvest,and the recovery effect of no-tillage irrigation reduction after harvest is better than that of traditional tillage treatment under local irrigation level.The relative competitiveness of pea in average whole growth period was 13.8 % and 15.7 % lower than that of traditional mulching in I2 and I1,respectively.In intercropping,inter-species competitiveness can be moderately increased during crop symbiosis to improve crop yield.4.No-tillage and reduced irrigation significantly improved the water use efficiency of intercropping,and at the same time reduced water consumption,the yield of no-tillage and single cropping was equivalent to that of traditional single cropping and no-tillage at local customary water level,and was significantly higher than that of no-tillage and single cropping and traditional tillage at the same irrigation level by 7.6 % and 11.1 %.The water use efficiency of no-tillage and reduced irrigation treatment is 7 % higher than that of traditional tillage and local customary water treatment.