The Effect Of Organic Fertilizer Amount On The Concentration Of C,N,Cu And Zn In Different Size Water-stable Aggregates Of Purple Soil

At present,the research on agricultural production shows that the application of organic fertilizer can play an active role in increasing yield and quality of the crop,but at the same time,the application of organic fertilizer also has a certain negative impact on the soil ecological environment.In this paper,the effects of organic manure on total C and total N nutrients in different water-stable aggregates and on total Cu and total Zn concentrations in heavy metals were studied.In this experiment,indoor potted plants were used to collect the Chinese cabbage cultivated at different culture time and the soil without cabbage cultivation.The water-stable aggregates of different particle sizes were separated by wet sieving.The changes of total C concentration and total N concentration And the changes of total Cu and total Zn in order to explore the law of the fluctuation of total C,total N,total Cu and total Zn in the stability of water with different grain sizes under different application rates of organic manures,Under the conditions of purple soil carbon,nitrogen,copper and zinc migration and transformation rules provide some theoretical support.The main conclusions of this thesis are as follows:1.The application of organic fertilizer on the changes of concentrations of C,N,Cu and Zn in different soil aggregates with cultivated Chinese cabbage:(1)The concentration of total C in 0.25-2mm size and >2mm size aggregates increased with the increasing of organic manure application,whereas the total Cconcentration of aggregates <0.25 mm size varied minimally with organic manure application.The harvested crop Afterwards,the soil total soil carbon concentration of water-stable aggregates with diameters of 0.25-2mm and >2mm decreased in the process of land recreation.C concentrations >2mm soil aggregates were significantly higher than 0.25-2mm particle size and <0.25 mm particle size..(2)The application of organic manure had little effect on the total N content of soil aggregates with the size of <0.25 mm.The fertilization mainly increased the N concentration of >2mm soil aggregates.After the 40 d cultivation of Chinese cabbage,the soil 0.25-2mm.The total N concentration of 0.25-2mm and >2mm water stable aggregates decreased;the N concentration of >2mm soil aggregates was significantly higher than the 0.25-2mm particle size and <0.25 mm particle size.(3)After 40 d and 120 d,with the application of organic manure,the Cu concentration of all aggregates decreased first and then increased,but with the increase of organic manure application,only Cu >2mm particle size water-stable aggregates,Cu The concentration of copper in 0.25 mm and 0.25-2mm water-stable aggregates was greater than >2mm,which indicated that the copper concentration of macro-aggregates was lower.Compared with 40 d,at 80 d and 120 d,All fertilization treatments,the three particle size Cu concentrations were significantly increased.(4)With the application of organic manure,the Zu concentration of all particle size aggregates decreased firstly and then increased with the increase of manure application rate.Compared with the 40 d,the Zn concentrations of three fertilizer treatments and three particle sizes increased significantly at 80 d and 120 d.This shows that in the process of land recreation,under the condition that precipitation will not wash away the aggregates,Zn content may decrease with the migration of water;different organic fertilizer application rates,different culture period will change the Zn concentration in >2mm,0.25-2mm,<0.25 mm distribution between the three particle sizes.(5)There was a significant positive correlation between the three particle size soil aggregate C concentrations and N concentrations,and there was a very significant positive correlation between Cu concentration and Zn concentration.2.Study on the change of concentration of C,N,Cu and Zn in different aggregates in the soil without pakchoi under organic fertilizer application amount:(1)For the agglomerates with particle sizes of 0.25-2mm and >2mm,the C concentration increased with increasing organic fertilizer application;the C concentration of >2mm soil aggregates was significantly higher than the 0.25-2mmparticle size and <0.25 mm particles Diameter;As the culture time increases,the carbon concentration of each particle size decreases.(2)For agglomerates >2mm in diameter,the concentration of agglomerate N increased with the application of organic manure;however,both the 80 d and 120 d culture significantly reduced the total particle size N concentration of >2mm soil aggregates was significantly higher than the 0.25-2mm particle size and <0.25 mm particle size.(3)The concentration of Cu in soil aggregates with three size aggregates cultured for 40 d and cultivated for >80 days and >2mm and 0.25-2mm were all increased first and then decreased with the application of organic manure.Generally speaking,<0.25 mm aggregates Cu concentration greater than >2mm and 0.25-2mm particle size;compared with the 40 d,80d and 120 d,each fertilizer treatment,three particle size Cu concentrations were significantly increased.(4)With the application of organic manure,the Zu concentrations of all aggregates with particle size decreased at first and then increased with the application of organic manure.The distribution of Zu at different particle size aggregates with different organic manure and different culture duration There are different effects;compared with40 d,at 80 d and 120 d,the fertilization treatment and the Zn concentration of the three particle sizes generally increase.(5)There was a significant positive correlation between the concentration of C and the concentration of N in the three particle sizes.However,the soil Cu concentration and Zn concentration were significantly and positively correlated only when the aggregate size was >2mm.