Effects Of Long-term Location Tillage Patterns On Soil Physicochemical Properties And Greenhouse Gas Emissions And Yield In Wheat Fields

A field experiment was conducted in Shiwang village,Xiaomeng Town,Yanzhou district,Jining city,Shandong Province during the wheat growing season from 2020 to 2021.Wheat variety Jimai 22 was selected as the experimental material.On the basis of positioning for 14years,four tillage patterns were selected:perennial plowing tillage(P),perennial rotary tillage(R),perennial minimum and no tillage(S)and minimum and no tillage with a two-year subsoiling interval(SS).The effects of tillage patterns on soil physicochemical properties,greenhouse gas emissions and yields in wheat fields were studied,and the optimal tillage patterns to balance yields and environmental benefits was explored,in order to provide theoretical basis and technical support for realizing high-yield,high-efficiency and green production of wheat.The test results are as follows:1 Effects of tillage patterns on soil physicochemical propertiesThe soil bulk density of 15?45 cm soil layers showed that SS treatment was significantly lower than other treatments;The soil porosity of SS treatment was significantly higher than that of other treatments.Meanwhile,the contents of soil organic matter,total nitrogen,the hydrolyzable nitrogen,available phosphorus and available potassium in 0?45 cm soil layers of SS treatment were significantly higher than those of other treatments before sowing.The results showed that SS treatment reduced soil bulk density,increased soil porosity,improved soil structure,and improved the supply capacity of soil water and nutrients.The activities of soil invertase,cellulase and chitinase were SS>P,S>R in 0?15 cm soil layer at jointing,and there was no significant difference between P and S treatments;In15?45 cm soil layers were SS>P>R,S,and there was no significant difference between R and S treatments.The content of soil aggregate with diameter>0.25 mm,soil organic carbon and soil microbial biomass carbon in 0?45 cm soil layers were significantly higher in SS treatment than in other treatments.The results showed that SS treatment promoted the increase of soil organic carbon components and soil enzyme activity,which was beneficial to improve soil fertility.2 Effects of tillage patterns on soil greenhouse gas emissionsThe cumulative emission fluxes of greenhouse gases and global warming potential of wheat soil were the highest in P treatment,followed by R treatment,and the lowest in S and SS treatment;The absorption of CH₄in SS treatment was significantly lower than that in P and R treatment;The greenhouse gas emission intensity of SS treatment was significantly lower than that of other treatments.The results show that SS treatment has the lowest greenhouse gas emission intensity and which is conducive to reducing the greenhouse effect brought by agricultural production while obtaining high yields.3 Effects of tillage patterns on photosynthetic characteristics of wheatAt 14,21 and 28 days after anthesis,the relative content of chlorophyll and net photosynthetic rate of flag leaves in SS treatment were significantly higher than those in P treatment,and the lowest in R and S treatment;At anthesis,7,14,21 and 28 days after anthesis,the leaf area index of each treatment was the highest in SS treatment,followed by P treatment,and the lowest in R and S treatment;21 days after anthesis,the interception amount and interception rate of total photosynthetic effective radiation in the upper,middle and canopy of wheat canopy were significantly higher than those of other treatments.The results showed that SS treatment effectively improved the photosynthetic performance of wheat and was conducive to the synthesis of photosynthetic products.4 Effects of tillage patterns on dry matter accumulation and transport of WheatThe accumulation of dry matter from jointing to maturity and the assimilation of assimilates after anthesis were the highest in SS treatment,followed by P treatment,and the lowest in R and S treatment;At maturity,the distribution and contribution rate of ¹³C assimilate and dry matter in grains of SS treatment were the highest,followed by P treatment,and the lowest in R and S treatment.The results showed that SS treatment promoted the accumulation and distribution of dry matter in grains,which was conducive to high yields.5 Effects of tillage patterns on grain filling characteristics of wheatGrain filling rate 7?28 days after anthesis and grain weight 14?35 days after anthesis of SS treatment was the highest,followed by P treatment,and R and S treatment were the lowest;Grain weight at maximum filling rate,maximum grain filling rate and average grain filling rate of SS treatment were significantly higher than those of other treatments.The results showed that SS treatment increased grain filling rate and grain weight.6 Effects of tillage patterns on grain yield and yield components of wheatThere was no significant difference in the number of grains per ear among the treatments;The number of panicles per unit area and grain weight of SS treatment were the highest,followed by P treatment,and R and S treatment were the lowest;The grain yield showed SS>P>R>S,with significant differences among treatments.The results showed that SS treatment obtained higher grain yield by increasing the number of spike number per area and1000-kernel weight of wheat.The SS pattern is the best tillage pattern considering environmental benefits and yield under the experimental conditions.