| In order to study the effect of biochar and chemical fertilizer on soil physical and chemical properties,wheat and corn rotation crop yield and nitrogen utilization rate,a field experiment was conducted in Dongling village,Fengyang County,Anhui Province on July 20,2018,this experiment designed two groups of experiments:biochar dosage and the proportion of biochar and different chemical fertilizer.The experiment set up blank control CK,single application of chemical fertilizer BCO,biochar dosage was 5 t·hm-2,10 t·hm-2,20 t·hm-2,30 t·hm-2,40 t·hm-2 was recorded as BC5,BC10,BC20,BC30 and BC40 respectively;the blank control CK,single application of chemical fertilizer CKO,20 t·hm-2 with biological carbon applied 60%,80%and 100%of total chemical fertilizer were recorded as BC60,BC80 and BC100 respectively.Based on the analysis of the results of soil properties,crop yield and nitrogen use efficiency of wheat and jade rotation system,the following conclusions are drawn:(1)With the increase of biochar application rate from 0 t·hm-2 to 30 t·hm-2,the soil pH of the two crops in the harvest period increased gradually.Compared with BC0,the soil pH of corn and wheat increased by 0.85 and 0.95 units respectively.The application of biochar below 20 t·hm-2 had no obvious effect on the content of soil organic matter,total nitrogen and alkali hydrolyzed nitrogen,and When the biochar application rate reached 30 t·hm-2 was over,the soil organic matter and total nitrogen would increase with the increase of the dosage.Compared with BC0,the soil organic matter of BC30 and BC40 treatments in corn season increased by 29.02%,69.26%,total nitrogen by 50.82%,56.56%,and available phosphorus by 13.81%and 17.76%respectively;the soil organic matter of BC30 and BC40 treatments in wheat season increased by 40.99%,88.98%,total nitrogen by 42.52%,52.76%,and available phosphorus by 16.59%,27.84%respectively.(2)Compared with BC0,the yield of corn increased by 6.73%-31.41%,wheat increased by 6.11%-20.51%,and the yield of wheat increased by 20%t·hm-2 biochar can make the nitrogen utilization rate of two crops and the agricultural utilization rate of chemical fertilizer nitrogen reach the maximum.Compared with BCO,the nitrogen utilization rate of corn season is increased by 47.86%,the agricultural utilization rate of chemical fertilizer nitrogen is increased by 11.36 kg·kg-1 the nitrogen utilization rate of wheat season is increased by 12.98%,and the agricultural utilization rate of chemical fertilizer nitrogen is increased by 2.46 kg·kg-1.(3)BC60,BC80,BC100 increased pH 0.29,0.32,0.37 units,soil organic matter 19.71%,18.17%23.36%,soil available K 9.55%-17.00%,soil pH 0.43,0.35,0.40 units in wheat season,compared with CK0,36.47%,34.10%,33.69%of soil organic matter and 12.11%-16.11%of soil available potassium were increased.Compared with CKO,the total nitrogen in the BC100-treated maize season increased by 56.56%,the alkali-decomposed nitrogen increased by 21.38%,the available-wheat season soil total nitrogen increased by 40.80%,and the alkali-decomposed nitrogen increased by 22.29%.(4)Compared with CKO treatment,BC100 treatment increased corn yield by 5.99%,and other combined treatments reduced crop yield.The yield of corn and wheat in BC80 treatment was the closest to CKO treatment.Compared with CKO treatment,BC60,BC80 and BC100 treatment increased nitrogen use efficiency by 8.95%-30.20%,and BC100 treatment increased nitrogen use efficiency by 13.78%.Compared with CKO treatment,biochar combined with chemical fertilizer increased the nitrogen partial productivity of chemical fertilizer.With the increase of chemical fertilizer application,the nitrogen partial productivity of corn season increased by 6.00%-59.24%.BC60 and BC80 treatment increased the nitrogen partial productivity of wheat season by 61.65%and 23.68%,respectively.BC100 treatment reduced the nitrogen partial productivity of wheat season by 2.53%.(5)It can be seen from the analysis of economic benefits that the application of biochar can improve the economic benefits of two crops.When the application amount of biochar is BC40,the economic benefits of two crops can be increased to the maximum,with an increase of 8204.78 yuan/hm2 for corn and 7218 yuan/hm2 for wheat;while the treatment of BC100 with biochar and chemical fertilizer can increase the economic benefits of corn to the maximum,with an increase of 4192.39 yuan/hm2 and BC80 for wheat The highest is 3679 yuan/hm2. |
