Study On The Influence Of Nursery Soil Physicochemical Properties Of The Slurry Discharge

With the development of rural-town construction, the rapid development of biogas, biogas emissions has brought a lot of new problems. The biogas slurry which was used as an organic fertilizer for irrigation has played a good role, but continuous emission slurry also affected the security of farmland. There is a risk of long-term use in biogas farmland ecosystem, veterinary drug residues and heavy metals pollution, also has a possibility of the nutrient enrichment, and thus adversely affects the growth of crops. This experiment combines the field investigation with pot experiment, and select the same area in the wild, the same kind of soil in different soil types which were affected by the investigation biogas, pot experiment by simulating field conditions of excess slurry of rubber seedlings emissions, set three different types of fertilizer handling test which were designed to give scientific and rational references for the management of large biogas discharge. The main experiment results are the follows:1The long-term effects of biogas slurry discharge soil(0-20cm depth) bulk density is lower than control group by18.18%, soil porosity is21.74%higher than the control; pH value, organic content, total nitrogen, total phosphorus, total potassium content are higher than control group by6.19%,93.28%,91.06%,210.52%,108.59%; the density of20-40cm depth soil is lower than control group by17.93%, pH value, organic matter content, total nitrogen, total phosphorus, total potassium content were higher than the control group by3.79%,62.18%,42.68%,43.90%,103.07%. The artificial irrigation biogas soil(0--20cm depth) bulk density is lower than control group by13.98%, pH value, organic matter content, total nitrogen, total phosphorus, total potassium content were higher than control group by2.47%,35.74%,56.91%,78.95%,61.04%; the density of20-40cm depth soil is lower than control group by13.79%, pH value, organic matter content, total nitrogen, total phosphorus, total potassium content were higher than control group by2%,20.49%,18.29%,20.51%,67%. The soil which was effected by long-term discharge of biogas slurry were higher than those of artificial irrigation soil, the biogas slurry to improve the soil nutrient content has accumulation effect, the longer time discharged, the intensity is more heavier, the higher of frequency, the greater increasing for soil nutrient content, much more easy to cause the soil nutrient content is too high and lost balance easier.2Potted simulation test used biogas, biogas fertilizer formula (effective nutrient content30%, N:P:K=14:7:9), inorganic fertilizer (effective nutrient content30%, N:P: K=14:7:9) for irrigation. The results of pot experiment showed that:in0-20cm depth of soil, biogas slurry, biogas slurry fertilizer treatment with pH values were higher than control group(the treatment which was not used any fertilizers) by0.60%,5.74%, pH of inorganic value was lower than the control by3.63%; the organic content of the soil which was irrigated by biogas slurry and biogas slurry fertilizer treatment were higher than the control by204.90%,230.17%; the inorganic fertilizer treatment was lower than the control by0.29%, biogas, total nitrogen content of biogas fertilizer formula and inorganic fertilizer were higher than control by127.37%,155.79%,111.58%; total phosphorus content was8times,8.7times,7.5times of the control; the total potassium content was higher than CK by4.6times,3.9times,3.3times. The20-40cm depth of soil, biogas slurry, biogas slurry fertilizer treatments’pH values were higher than CK by0.46%,6.33%, pH of inorganic value was lower than the control by3.09%; the organic content of the soil which was irrigated by biogas slurry, biogas slurry fertilizer were higher than the control by290.82%,342.39%while the inorganic fertilizer treatment was lower than the control by3.09%, total nitrogen content reached5.25times,5.45times,4.8times of the control; the total phosphorus content was4.3times,4.8times,4.6times of the control; the total potassium content was more than the control group by2.3times,2.6times,2.1times, the excessive use of biogas slurry discharge and fertilizer can cause the nutrient content of0-20cm and20-40cm depth soil got too high, on account of excessive emissions for long-term, the soil nutrient enrichment has become more serious, and thus will have a bad effect on the crops, consistent with the results of field survey.3The soil which has a high level of nutrient content will hinder the normal growth of rubber seedlings, such as plant height, ground diameter, leaf length and width, leaf SPAD values to a slow growth trend. Biogas slurry treating rubber seedling’s leaf P content is lower than control(treatment without the use of fertilizer) by15%, the content of total potassium fertilizer treatment is lower than control by21.23%, significant difference (P<0.05); biogas slurry formula fertilizer treatment of rubber seedling leaf P content was20%lower than the control, potassium content was36.31%lower than the control, significant difference (P<0.05); inorganic compound fertilizer treatment of rubber seedling leaf nitrogen and phosphorus, potassium content were lower than control by4.31%,5%,17.88%, difference of potassium content was significant (P<0.05).