Effects Of Organic Materials Return And Nitrogen Reduction On The Grain Yield In A Wheat-Maize System In The Jianghuai Region

In order to reduce the application of nitrogen fertilizer in a wheat-maize system in Jianghuai region,organic manure pig manure and organic materials return might be adopted to replacing the reduction of chemical fertilizer;however,their effects were known.A field experiment was performed in 2015-2016 with six treatments to explore the effects of organic materials return and nitrogen reduction on grain yield and its composition,crop agronomy performance and physical and chemical properties of soil in wheat-maize system of Jianghuai region.The results show that:1.Effects of organic materials return and nitrogen fertilizer reduction on yield and its composition in wheat-maize systemIn wheat season,the effects of conventional fertilization,nitrogen reduction fertilization and straw pig manure combined application on yield and composition factors are as follows:nitrogen reduction straw treatment(T2)has the highest spike value,significantly higher than the total amount of fertilizer treatment(CK);There was no significant difference in grain number per spike among treatments.The 1000-grain weight of total straw treatment(T0)was significantly higher than that of total fertilizer treatment(CK).In terms of yield performance,nitrogen reduction straw treatment(T2)was significantly higher than nitrogen reduction straw treatment(T4)of pig manure.In the corn season,the influences of conventional fertilization,nitrogen reduction fertilization and straw pig manure combined application on the yield and composition factors are as follows:nitrogen reduction straw treatment(T2)has the highest hundred-grain weight,while total fertilization treatment(CK)has the lowest value,and there is no significant difference between treatments.The number of grain per ear was the highest in nitrogen-reducing pig manure treatment(T3),while that in nitrogen-reducing fertilizer treatment(T1)was significantly lower than that in other treatments.Nitrogen reduction manure treatment(T3)had the highest yield,while nitrogen reduction fertilization treatment(T1)had the lowest yield.In terms of overall yield,a 30%reduction in fertilization would significantly reduce the yield of corn.2.Effects of organic materials return and nitrogen fertilizer reduction on the agronomy performance of wheatReduce nitrogen,with straw,pig manure application on wheat population quality has very obvious regulation,straw returned and fertilizer,interaction effect is very obvious in the straw returned to test is in processing,number of times to take root in wheat seedling stage,tillering number,emergence rate increased,winter wheat seedling.Nitrogen reduction straw was not returned to the field(T1).The tiller per plant was significantly lower in the green returning stage than other treatments,and there was no significant difference between other treatments in the seedling stage and green returning stage.In the booting stage,nitrogen reduction straw treatment(T2)had significantly lower dry matter than other treatments.There was no significant difference in the secondary rooting among the treatments,and the relatively coordinated population structure had certain advantages compared with other treatments in comprehensive traits.3.Effects of organic materials return and nitrogen fertilizer reduction on the photosynthetic capacity of wheatThe photosynthetic capacity of wheat was affected by reducing the application of nitrogen fertilizer and combining straw and pig manure with organic fertilizer.At the jointing stage,under the condition of straw returning to the field,the photosynthetic rate of nitrogen-reducing pig manure(T4)was higher than that of other treatments.At the booting stage,there was no significant difference in photosynthetic rate between treatments.Nitrogen n reduction fertilization straw and pig manure had no significant effect on wheat photosynthesis.The application of straw and pig manure combined with the application of nitrogen fertilizer had a significant effect on the chlorophyll content of wheat.There was no significant difference in chlorophyll content SPAD between the treatments before heading,and the SPAD gradually increased from heading stage to flowering stage to grouting stage.4.Effects of organic materials return and nitrogen fertilizer reduction on the soil physical and chemical propertiesThere was no significant difference in pH value,organic matter,alkali-hydrolyzed nitrogen,total phosphorus,total potassium and content between different treatments.The total nitrogen value of nitrogen-reducing pig manure was significantly higher than that of other treatments.Nitrogen reduction pig manure treatment had the highest available phosphorus,significantly higher than other treatments.Nitrogen reduction straw pig manure has the highest available potassium,which is significantly higher than other treatments.There was no significant difference in pH value,alkali-hydrolyzed nitrogen value,total phosphorus value and total potassium value between treatments.The organic matter of nitrogen-reducing straw and pig manure was the highest,which was significantly higher than that of total fertilization.The total nitrogen value of nitrogen-reducing pig manure was the highest,significantly higher than that of other treatments.The effective phosphorus value of nitrogen-reducing pig manure treatment was significantly higher than that of total fertilization treatment.The potassium value was the highest and the total amount of straw was the lowest.Overall,our result suggest that 70%urea-N fertilizer+pig manure+without straw returned and 70%urea-N fertilizer+straw returned can be optimized management options for reducing chemical N input while improving grain yield in wheat-maize system of Jianghuai region.