Study On Water And Fertilizer Conservation Effect Of Bentonite-Liquorice Residue Composite

At present,there are such phenomena as low utilization rate of fertilizer,low water retention capacity and the serious loss of nutrients of forest and fruit industry in the sandy area of Xinjiang.In addition,the high cost and low salt tolerance of polymer water retention products on the market cause soil pollution.Therefore,the natural,cheap and environmentally friendly sodium-bentonite and licorice residue were used as raw materials to prepared new eco-friendly fertilizer products.In this study used the indoor soil column simulation method to combine both bentonite and licorice residue composite materials by different proportions.First of all,pure sand was used as the control group,and the physical and chemical properties,water absorption ratio,water evaporation rate and fertilizer leakage rate were measured.The effect of water and fertilizer retention of sand matrix with different proportion of composites were analyzed.Finally,optimum ratio of composite materials were determined,and the water and fertilizer retention effect of bentonite and licorice residue composite and its application prospect was described.The main results are as follows:(1)The addition of liquorice residue can effectively adjusted the basic physical and chemical properties of bentonite,composite material of pH,EC value than bentonite has greatly reduced,let the pH is neutral,EC < 2.6 ms/cm standards,for a variety of crops are harmless,made the difference of bulk density of bentonite showed a trend of decrease,and made bentonite into a porous porous culture substrate.Therefore,the mixture of bentonite and licorice residue overcomes their respective shortcomings and achieves complementary advantages.(2)Under the condition of sufficient irrigation,the weight of composite material accounts for 20% of the sand,and the water absorption capacity of T2 treatment is relatively high,and the water retention capacity is the best.There was no significant difference betweenT1 treatment in which the weight of composite material accounted for 15%.In the case of water shortage,T2 and T3 groups,which account for 20% of the weight of composite soil,have the slowest evaporation and the best water holding capacity.(3)In the three groups of tests,in which the weight of bentonite and licorice residue composite material accounted for 10%,15% and 20% of the pure sand,the fertilizer retention effect increased with the increase of the proportion of bentonite in the composite material,which is T1> T2> T3> T4> CK.When the weight of composite material accounted for 15%of the pure sand,T1 treatment had the best effect of nitrogen and potassium protection,and the best phosphorus retention effect was achieved by T2 treatment at 20%.(4)Comprehensive consideration of bentonite-licorice slag composite material ratio of the basic physical and chemical properties,retention capacity,and cost factors.It is concluded that the treatment groups of 15%T1 and 20%T2 had the best effect on water and fertilizer conservation.It works best when the total mass of bentonite and licorice residue accounted for 15% of the pure sandy soil,the ratio of bentonite to licorice residue was 1:1 or when the total mass of bentonite and licorice residue accounted for 20% of the pure sandy soil,the ratio of bentonite to licorice residue was 1:1.5.The bentonite and licorice residue composite materials applied into the soil can absorb water quickly and reduce nutrient loss,it has the effect that prevent loss of N,P,K,it can improve nutrient utilization,reducing the consumption of water and fertilizer resources in agricultural production,protect environment,make full use of waste resources,turn waste into treasure,and provide theoretical basis for improving sandy soil by using bentonite in arid and semi-arid areas.