Effects Of Reclamation Measures On Soil Nutrients And Biological Activities In Abandoned Land

At present,the cultivated land is destroyed and the cultivated land area is gradually reduced.In order to protect the cultivated land resources,we must pay attention to the land reclamation work,in order to understand the effect of reclamation measures on soil properties,different fertilizer treatments and farming methods were studied with the combination of farming land reclamation measures on reclaimed soil nutrient content,enzyme activity and microbial biomass carbon and nitrogen,microbial entropy and the influence of the number of microorganisms,to provide scientific basis for future land reclamation work.Farming methods are divided into convention tillage(C)and no-tillage(N),fertilizer treatments include no fertilizer(CK),chemical fertilizers(X1),straw+chemical fertilizer(X2),organic fertilizer+fertilizer(X3),chemical fertilizer + organic fertilizer+straw(X4),chemical fertilizers+straw+rotten straw agent(X5),a total of 12 land reclamation measures,the main results were as follows:(1)The experimental results show that the land reclamation measures of fertilization can enhance reclamation soil nutrient content,under the ploughing and no-till farming methods,different fertilization treatment compared with the CK soil total nitrogen content were increased 0.02-0.3 g/kg,0.03-0.42 g/kg,soil alkali-hydrolysable nitrogen content increased 12.10 39.23 mg/kg,in addition to the X1 processing,the processing can improve the soil total phosphorus content,soil total phosphorus content increased 0.06-0.19 g/kg,0.08-0.26 g/kg,Soil available p content increased by 1.39-4.66mg/kg,3.28-8.11mg/kg,soil total k content increased by 0.01-2.92g/kg,0.06-3.12g/kg,soil available k content increased by 6.97-33.84mg/kg,8.35-50.88mg/kg.The nutrient contents in the reclaimed soil under straw + fertilizer and organic fertilizer + fertilizer treatment were all higher than those under fertilizer treatment.The total potassium and available potassium contents in the reclaimed soil under straw + fertilizer + ripening agent treatment were the highest,and the total nitrogen,alkali-hydrolyzed nitrogen,total phosphorus and available phosphorus contents in the soil under straw + fertilizer + organic fertilizer treatment were the highest.The average value of soil nutrient content in no-tillage treatment was higher than that in tillage treatment.(2)The soil enzyme activity in the summer's biggest land reclamation measures,winter minimum,the reclamation measures of soil urease,invertase and catalase,cellulose enzyme,neutral phosphatase activity of the average 107.7% higher than that of the summer than in winter,52.32%,27.58%,197.65%,103.95%,fertilization can increase reclamation soil enzyme activity,under the same farming,soil urease,invertase and catalase,neutral phosphatase activity sequencing for X4 > X5 > X3 > X2 > X1 > CK.The sequence of soil cellulase activity was X5 > X4 > X2 > X3 > X1 > CK.Under the same fertilization treatment,the soil enzyme activity of no-till tillage was higher than that of tillage.(3)Land reclamation measures of fertilization can increase the number of reclamation soil microorganisms,summer reclamation the maximum number of microbes in soil,compared with the CK all the fertilizer treatments in ploughing and under no-till farming reclamation soil bacteria growth between 4.11% ~ 64.78%,8.31% ~ 71.32%,the number of soil fungi growth between 22.71% ~ 85.14%,23.11% ~ 89.37%,the soil actinomycetes quantity growth between 35.46% ~ 89.08%,37.49% ~ 112.98%,The total number of soil microorganisms increased by 4.8%~65.29% and 8.92%~72.04%,respectively.The total number of bacteria,fungi and microorganisms in the reclaimed soil was ranked by X5 > X4 > X2 > X3 > X1 > CK,and the number of actinomycetes was ranked by X4 > X5 > X3 > X2 > X1 > CK.The average values of bacteria,fungi,actinomycetes and microorganisms in the cultivated soil under no-tillage treatment in summer were 8.86%,16.65%,15.29% and 9.15% higher than that under tillage treatment.(4)Fertilization can increase the microbial biomass of soil carbon and nitrogen and microbial entropy.Microbial biomass carbon and nitrogen and microbial order entropy was X4 > X5 > X3 > X2 > X1 > CK,soil microbial biomass carbon and nitrogen and microbial entropy are the biggest in the summer,ploughing,no-till farming methods under different fertilization treatment soil microbial biomass carbon than CK growth between 47.32% ~ 102.55%,3.56% ~ 58.18%,the microbial biomass nitrogen increase between 26.81% ~ 67.32%,28.58% ~ 86.35%,microbial entropy increase between 10.88% ~ 38.03% and 14% ~ 43.27%.Compared with tillage,no-tillage can improve soil microbial biomass,carbon nitrogen and microbial entropy.(5)According to the results of principal component analysis,the land reclamation measures of NX4 and NX5 were relatively high in terms of soil biological fertility,and the score of soil biological fertility was 1.55 and 1.40,ranking the first two.The comprehensive soil chemical and biological fertility is still high in NX4 and NX5 abandoned land reclamation measures,among which the comprehensive soil chemical and biological fertility score of NX4 is 1.29,ranking the first,NX4 is the most can improve the abandoned land reclamation soil fertility tillage measures.