The Effect Of Sheep Dung Biochar And Composting Products On The Nutrient Improvement Of Sandy Soil

The problem of soil dissertation is of long standing.The aggravation of this problem in special areas continuous goes on,although the containment on it whole from the whole aspect.For a long time,soil dissertation in northwestern area of Sichuan province expanded constantly since the natural and anthropogenic reasons.Local soil facing the problems of fertilizer and water conservation,which has been the main reasons for local economy development.Animal husbandry in NW Sichuan province developed well,and it has been become the major income for local resident.However,the waste from animal husbandry did not treated well and become the major problem for local environment and need to be resolved immediately.Therefore,this study select sheep manure as resources for carbonization and fertilization and use polyacrylamide(PAM)as additive for soil improvement through soil column leaching experiment and pot experiment.We use carbonization furnace to carbonize the local dried and grid sheep manure as well as fertilized the sheep manure for preparation of sheep manure biochar and sheep manure fertilizer respectively.Fourier transform infrared spectrophotometer(FTIR)and scanning electron microscope(SEM)were selected for characterization of different product on their element composition,major functional group,surface structure.Biochar and compost product were added into the dissertation soil to study their potential role on the soil improvement.Soil column leaching experiment were derived into two group,with and without PAM.For the group of without PAM(H series),biochar and compost were added as only biochar(H1),biochar: compost=1:1(H2)and only compost(H3)treatments.For the treatment of with PAM(h series),PAM was added as 1% of total weight of soil.Each treatment have triplicate samples.Pot experiment have six different design: biochar:compost=3:1(C1),only PAM(C2),biochar:compost=3:1+PAM(C3),only biochar(C4),only compost(C5)and control(C6).Four replicate were conducted for each treatment.The main results showed that:(1)The pyrolysis of biochar increased with the increasing of temperature,andaromaticity increased.Some characteristic peaks disappeared.Sheep manure biochar have complicated structure and high level of specific surface area,which were benefit for the nutrients and water absorption.Moreover,surface morphology and pore structure developed also with the temperature increase.(2)The application of biochar and compost could increase the concentration of total nitrogen,available nitrogen,nitrate nitrogen,ammonium nitrogen,total phosphorus,available phosphorus,organic matter,clay content and pH value.Among them,the soil pH and organic matter content were positively correlated with the application amount of biochar,and the addition of biochar treatment significantly increased the clay content in dissertation soil.The addition of compost contribute more for the increasing of total nitrogen,nitrate nitrogen,and ammonium nitrogen content than biochar.In comparison,the application of biochar is more useful than compost for the fixation of alkaline dissolved nitrogen.(3)After adding PAM on the basis of the application of biochar and compost,the loss of nutrient content can be effectively reduced.In the upper layer(0~20 cm),almost all nutrient contents increased,but in the lower layer(20 ~ 40 cm),the total nitrogen and alkali-hydrolyzed nitrogen increased,while pH,nitrate nitrogen,and ammonium increased.This fully demonstrating that under the effect of PAM,nutrient content has been lost,but overall it has played a role in inhibiting nutrient leaching.According to the analysis of the leaching rate of total phosphorus,available phosphorus and organic matter for external aid,it can be known that most of the treatment conditions show that the leaching rate after PAM addition(h-series)is smaller than that of PAM-free treatment(H-series),and further demonstrated that PAM can effectively inhibit the leaching loss of nutrients.(4)In the pot experiment,C2 and C3 treatments had significant advantages in improving soil nitrogen status(P<0.05),total nitrogen content increased by 175.4% and173.3%,respectively;C1 and C3 treatments significantly improved soil phosphorus status.(P<0.05),the total phosphorus content increased by 35.6% and 21.3% respectively;while the treatments of C1,C3,and C4 also had significant effects on improving soil pH and organic matter content(P<0.05),and the pH increased by 2.63,2.32,and 3.39 unitsrespectively.Organic matter increased by 58.8%,52.8%,and 45.9%,respectively.Compared with other treatment methods,both biomass and dry matter content increased for C5 treatment.For the index of ADF and NDF.The crude protein content was increased by 36.5%,69.0%,and 41.6% for C2,C3,and C5 respectively.In all treatments,only the C1 treated RFV value was significantly(P<0.05)higher than the control group with an increase of 68.5%.The combination of sheep manure biomass biochar,compost and PAM can effectively improve the nutrient content and the quality of pasture in dissertation soil.Combining biochar and compost with a ratio of 3:1 had the best effect on the improvement of forage quality.Adding PAM on the basis of this ratio made the best improvement for soil quality among all of the treatments.