| From April to September 2019,annual M9T337 apple rootstock was used as test material to study the effects of different dosage of microbial fertilizer on nitrogen,phosphorus and calcium absorption of apple rootstock seedlings.The main results are as follows:1.The effects of different amounts of microbial fertilizer(0 g,200 g,400 g,600 g,800 g microbial fertilizer plus 0.8 g 15N in each pot,expressed as T1,T2,T3,T4,T5,respectively,with no bacterial fertilizer and nitrogen fertilizer as the control),the effects of different amounts of microbial fertilizer(0 g,200 g,400 g,600 g,800 g per pot,plus 0.37 g urea and0.5 g of 15N,respectively,expressed as T1,T2,T3,T4,T5,with no bacterial fertilizer and nitrogen fertilizer as the control),the effects of different amounts on the growth,soil physical and chemical properties and.The results showed that the total dry weight,root/shoot ratio,plant height,stem diameter and leaf area of Apple Rootstock Seedlings increased first and then decreased with the increase of bacterial fertilizer dosage.T3 treatment was the highest,which increased by 46.75%,46.67%,38.78%,32.85%and 52.60%compared with T1,followed by T4 treatment,which increased by 40.55%,33.33%,33.33%,31.2%and 42.31%compared with T1.The results showed that the total root length,total root surface area,total root tip number and root activity of Apple Rootstock Seedlings in different treatments were the best,and the root growth was increased by 60.50%,41.22%,42.85%and 44.50%respectively compared with T1 treatment.T3 treatment was the best,T4 was the second,T1was the lowest.Compared with T1,microbial fertilizer significantly increased 15N uptake by plants,and 15N utilization efficiency of T3 and T4 treatments increased by 43.66%and38.30%,respectively,which were significantly higher than those of other treatments;the 15N residue in T3 treatment was the highest,increased by 34.48%compared with T1,followed by T4 treatment by 29.15%;the nitrogen loss of T1 treatment was the highest,67.80%,and T3treatment was the lowest,52.68%.To sum up,the most suitable amount of microbial fertilizer and nitrogen combination for plant growth,soil physical and chemical properties and nitrogen absorption was 400g（The amount converted to square meters is 2.53kg/m2）microbial fertilizer per pot.2.The effects of different amounts of microbial fertilizer（0g,200g,400g,600g,800g microbial fertilizer plus 1.96g P2O5 in each pot,represented by A1,A2,A3,A4,A5,respectively,with no bacterial fertilizer and phosphate fertilizer as control）,the effects of microbial fertilizer on the growth of Apple Rootstock Seedlings and soil physical and chemical properties were studied.The results showed that the total dry weight,root/shoot ratio,plant height,stem diameter and leaf area of A3 treatment were the highest,which increased by 83.93%,62.5%,40.49%,37.14%and 24.99%respectively compared with A1treatment,followed by A4 treatment,which increased by 99.92%,62.5%,38.43%,34.29%and 23.74%,respectively.Compared with A1 treatment,A3 treatment had the best total root length,total root surface area,total root tip number and root activity,which increased by25.93%,55.46%,39.93%and 38.14%respectively,followed by A4 treatment,which increased by 14.53%,25.8%,18.95%and 20.86%respectively compared with A1 treatment.The number of microorganisms,soil enzyme activity,total phosphorus,available phosphorus,organic matter and pH in different treatments were the best in A3 treatment,followed by A4treatment,and the lowest in CK2 treatment.In conclusion,the most suitable amount of microbial fertilizer and phosphorus on plant growth and soil physical and chemical properties is 400g（The amount converted to square meters is 2.53kg/m2）microbial fertilizer.3.The effects of different dosages of microbial fertilizer（0 g,200 g,400 g,600 g,800 g microbial fertilizer plus 0.14 g Ca in each pot,represented by B1,B2,B3,B4,B5,respectively,with no bacterial fertilizer and calcium fertilizer as control）,the effects of microbial fertilizer on plant growth and soil physical and chemical properties were studied.The results showed that the total dry weight,root/shoot ratio,plant height,stem diameter and leaf area of B4 treatment were the highest,which were 53.76%,76.47%,28.69%,54.5%and46.05%higher than those of B1 treatment,and the increase rates of B5 treatment were49.67%,76.47%,26.5%,43.53%and 42.8%,respectively.The total root length,total root surface area,total root tip number and root activity of Apple Rootstock Seedlings in B4treatment were the best,which increased by 37.98%,70.69%,39.06%and 39.43%respectively compared with B1.The soil enzyme activity of B4 treatment was the best,followed by B5 treatment,followed by B3 treatment,while there was no significant difference between B1 and B2 treatment,and CK3 treatment was the lowest.Among the different treatments,B4 was the best,T3 and B5 had no significant difference,and CK3 was the lowest.To sum up,the most suitable amount of microbial fertilizer and calcium on apple plant growth and soil physical and chemical properties is 600g（The amount converted to square meters is3.82kg/m2）microbial fertilizer. |
