Effect Of Tillage And Nitrogen Application On Soil Properties And Yield Of Wheat And Jade Double Cropping System

Wheat-maize rotation was the most common cropping method in Huanghuaihai area.Tillage and nitrogen application were the main factors affecting the yield of wheat and maize.This experiment set 5 tillage treatments:CT（conventional tillage）;NT;（No-tillage tillage）;ST（deep loose tillage）;D1T（deep tillage 1）;D2T（deep tillage 2）;4 nitrogen levels for each tillage treatment:N0（no nitrogen）;N1(120 kg·hm^-2);N2(180 kg·hm^-2);N3(225kg·hm^-2).To study the effects of different tillage methods and nitrogen application interactions on soil physical and chemical properties and crop yield and quality.The research conclusions expected to provide theoretical and technical basis for optimizing fertilization system,increasing crop yield potential and improving quality.The main conclusions as follows:1 In the 0-20 cm soil layer,180 kg·hm^-2 with minimum tillage and no-tillage nitrogen application increased the total aggregate size>0.25 mm;under the condition of subsoiling,no nitrogen applied for 20-40 cm soil layer large aggregates The proportion was relatively high,and the proportion was much lower than the cultivated layer.2 The content of alkali-hydrolyzable nitrogen in the 0-60cm soil layer decreased with the increase of depth,and increased with the increase of nitrogen application rate.In the 0-20 cm soil layer,the total nitrogen and alkali-hydrolyzable nitrogen content of the minimum tillage and no-tillage soil was the highest,and the total nitrogen content of the 20-40 cm soil was higher under the subsoiling and deep tillage;the 4 nitrogen application rates under the minimum and no-tillage treatment The accumulation of ammonium nitrogen and nitrate nitrogen in the 0-100 cm soil layer were higher than other tillage treatments,and both reached the maximum at 225 kg·hm^-2 nitrogen application.3 Subsoiling could effectively increase the soil enzyme activity of 0-20 cm in the mature stage of wheat,andβX（β-1,4-xylosidase）andβG（β-1,4-glucosidase）without nitrogen application It has the highest activity with CBH（cellobiohydrolase）,NAG（β-1,4-N-acetylglucosaminidase）and LAP（leucine aminopeptidase）under the condition of 180kg·hm-2 nitrogen application The activity reaches its maximum.At the same time,subsoiling under the treatment of no nitrogen and 225 kg·hm^-2 nitrogen application can effectively increase the activities ofβX,βG and CBH in the 0-20 cm soil during the corn maturity period.4 The soil microbial biomass carbon and nitrogen of 0-20 cm wheat was the highest under the condition of subsoiling and no nitrogen,and the application of 120 kg·hm^-2 nitrogen under the condition of deep tillage 1 could significantly increase the soil microbial biomass carbon and nitrogen of 20-40 cm.Nitrogen application of 180 kg·hm^-2 under subsoiling treatment could significantly increase the soil microbial biomass carbon and nitrogen of 0-20cm corn;under the condition of deep tillage 1,180 kg·hm^-2 could significantly increase soil microbial biomass carbon of 20-40 cm.Nitrogen application of 225 kg·hm^-2 could significantly increase soil microbial biomass nitrogen by 20-40 cm.5.From the wheat season to the corn season,the microbial diversity index of the cultivated soil increased,and the population dominance and coverage decreased.Tillage had a greater impact on the level of species in the cultivated layer soil at the mature stage of wheat than on the corn cultivated layer soil.The no-tillage treatment has relatively low bacterial richness in the cultivated layer soil,and the population dominance was higher than that of rotary tillage,and was not different from subsoiling and deep tillage.Large;the diversity index of no-tillage and deep tillage 1 in the mature period of maize was higher,the dominance was lower than the rotary tillage and deep loosening.6.Wheat grain yield was highest under the condition of sub-soiling,when nitrogen application was 180 kg·hm^-2.There was a big difference between the number of ears and1000-grain weight in the interaction of tillage and nitrogen application.The number of ears of180 kg·hm^-2 in deep tillage of 30 cm was the most,and the number of ears of 225 kg·hm^-2 in other tillages was the most.Under the subsoiling treatment,the maize yield reached the maximum when the nitrogen application rate was 225 kg·hm^-2.Deep tillage 1 significantly increased the content of wheat protein,fat,gluten and sedimentation value,and performed best at 180 kg·hm^-2 nitrogen application,but reduced starch content.7.After linear multivariate analysis,the partial correlation coefficient shows that farming was the main factor affecting wheat yield,and nitrogen application was the main factor affecting corn yield.Soil nitrogen and aggregates are the main components that affect the yield of wheat and corn.Based on the results of the above indicators,180 kg·hm^-2 sub-soiling nitrogen is the most suitable for local promotion.